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Strabismus

MedGen UID:
21337
Concept ID:
C0038379
Disease or Syndrome; Finding
Synonyms: Phoria; Phorias; Squint
SNOMED CT: Strabismus (22066006); Squint (22066006); Ocular dissociation (22066006); Disorder of binocular eye movements (22066006)
 
HPO: HP:0000486
Monarch Initiative: MONDO:0003432

Definition

A misalignment of the eyes so that the visual axes deviate from bifoveal fixation. The classification of strabismus may be based on a number of features including the relative position of the eyes, whether the deviation is latent or manifest, intermittent or constant, concomitant or otherwise and according to the age of onset and the relevance of any associated refractive error. [from HPO]

Conditions with this feature

Acrocephalosyndactyly type I
MedGen UID:
7858
Concept ID:
C0001193
Congenital Abnormality
Apert syndrome is characterized by the presence of multisuture craniosynostosis, midface retrusion, and syndactyly of the hands with fusion of the second through fourth nails. Almost all affected individuals have coronal craniosynostosis, and a majority also have involvement of the sagittal and lambdoid sutures. The midface in Apert syndrome is underdeveloped as well as retruded; a subset of affected individuals have cleft palate. The hand in Apert syndrome always includes fusion of the middle three digits; the thumb and fifth finger are sometimes also involved. Feeding issues, dental abnormalities, hearing loss, hyperhidrosis, and progressive synostosis of multiple bones (skull, hands, feet, carpus, tarsus, and cervical vertebrae) are also common. Multilevel airway obstruction may be present and can be due to narrowing of the nasal passages, tongue-based airway obstruction, and/or tracheal anomalies. Nonprogressive ventriculomegaly is present in a majority of individuals, with a small subset having true hydrocephalus. Most individuals with Apert syndrome have normal intelligence or mild intellectual disability; moderate-to-severe intellectual disability has been reported in some individuals. A minority of affected individuals have structural cardiac abnormalities, true gastrointestinal malformations, and anomalies of the genitourinary tract.
Ataxia-telangiectasia syndrome
MedGen UID:
439
Concept ID:
C0004135
Disease or Syndrome
Classic ataxia-telangiectasia (A-T) is characterized by progressive cerebellar ataxia beginning between ages one and four years, oculomotor apraxia, choreoathetosis, telangiectasias of the conjunctivae, immunodeficiency, frequent infections, and an increased risk for malignancy, particularly leukemia and lymphoma. Individuals with A-T are unusually sensitive to ionizing radiation. Non-classic forms of A-T have included adult-onset A-T and A-T with early-onset dystonia.
Gorlin syndrome
MedGen UID:
2554
Concept ID:
C0004779
Neoplastic Process
Nevoid basal cell carcinoma syndrome (NBCCS) is characterized by the development of multiple jaw keratocysts, frequently beginning in the second decade of life, and/or basal cell carcinomas (BCCs) usually from the third decade onward. Approximately 60% of individuals have a recognizable appearance with macrocephaly, frontal bossing, coarse facial features, and facial milia. Most individuals have skeletal anomalies (e.g., bifid ribs, wedge-shaped vertebrae). Ectopic calcification, particularly in the falx, is present in more than 90% of affected individuals by age 20 years. Cardiac and ovarian fibromas occur in approximately 2% and 20% of individuals respectively. Approximately 5% of all children with NBCCS develop medulloblastoma (primitive neuroectodermal tumor), generally the desmoplastic subtype. The risk of developing medulloblastoma is substantially higher in individuals with an SUFU pathogenic variant (33%) than in those with a PTCH1 pathogenic variant (<2%). Peak incidence is at age one to two years. Life expectancy in NBCCS is not significantly different from average.
Chédiak-Higashi syndrome
MedGen UID:
3347
Concept ID:
C0007965
Disease or Syndrome
Chediak-Higashi syndrome (CHS) is characterized by partial oculocutaneous albinism, immunodeficiency, and a mild bleeding tendency. Approximately 85% of affected individuals develop the accelerated phase, or hemophagocytic lymphohistiocytosis, a life-threatening, hyperinflammatory condition. All affected individuals including adolescents and adults with atypical CHS and children with classic CHS who have successfully undergone allogenic hematopoietic stem cell transplantation (HSCT) develop neurologic findings during early adulthood.
Craniofacial dysostosis
MedGen UID:
1162
Concept ID:
C0010273
Disease or Syndrome
Crouzon syndrome is an autosomal dominant disorder characterized by craniosynostosis causing secondary alterations of the facial bones and facial structure. Common features include hypertelorism, exophthalmos and external strabismus, parrot-beaked nose, short upper lip, hypoplastic maxilla, and a relative mandibular prognathism (Reardon et al., 1994; Glaser et al., 2000).
5p partial monosomy syndrome
MedGen UID:
41345
Concept ID:
C0010314
Disease or Syndrome
Cri-du-chat syndrome was first described by Lejeune et al. (1963) as a hereditary congenital syndrome associated with deletion of part of the short arm of chromosome 5. The deletions can vary in size from extremely small and involving only band 5p15.2 to the entire short arm. Although the majority of deletions arise as new mutations, approximately 12% result from unbalanced segregation of translocations or recombination involving a pericentric inversion in one of the parents.
Focal dermal hypoplasia
MedGen UID:
42055
Concept ID:
C0016395
Disease or Syndrome
Focal dermal hypoplasia is a multisystem disorder characterized primarily by involvement of the skin, skeletal system, eyes, and face. Skin manifestations present at birth include atrophic and hypoplastic areas of skin; cutis aplasia; fat nodules in the dermis manifesting as soft, yellow-pink cutaneous nodules; and pigmentary changes. Verrucoid papillomas of the skin and mucous membranes may appear later. The nails can be ridged, dysplastic, or hypoplastic; hair can be sparse or absent. Limb malformations include oligo-/syndactyly and split hand/foot. Developmental abnormalities of the eye can include anophthalmia/microphthalmia, iris and chorioretinal coloboma, and lacrimal duct abnormalities. Craniofacial findings can include facial asymmetry, notched alae nasi, cleft lip and palate, and pointed chin. Occasional findings include dental anomalies, abdominal wall defects, diaphragmatic hernia, and renal anomalies. Psychomotor development is usually normal; some individuals have cognitive impairment.
Hallermann-Streiff syndrome
MedGen UID:
5414
Concept ID:
C0018522
Disease or Syndrome
Hallermann-Streiff syndrome is characterized by a typical skull shape (brachycephaly with frontal bossing), hypotrichosis, microphthalmia, cataracts, beaked nose, micrognathia, skin atrophy, dental anomalies, and proportionate short stature (Hallermann, 1948; Streiff, 1950; Francois, 1958). Mental retardation is present in a minority of cases (Gorlin et al., 1990).
Incontinentia pigmenti syndrome
MedGen UID:
7049
Concept ID:
C0021171
Disease or Syndrome
Incontinentia pigmenti (IP) is a disorder that affects the skin, hair, teeth, nails, eyes, and central nervous system; it occurs primarily in females and on occasion in males. Characteristic skin lesions evolve through four stages: I. Blistering (birth to age ~4 months). II. Wart-like rash (for several months). III. Swirling macular hyperpigmentation (age ~6 months into adulthood). IV. Linear hypopigmentation. Alopecia, hypodontia, abnormal tooth shape, and dystrophic nails are observed. Neovascularization of the retina, present in some individuals, predisposes to retinal detachment. Neurologic findings including seizures, intellectual disability, and developmental delays are occasionally seen.
Ito hypomelanosis
MedGen UID:
5920
Concept ID:
C0022283
Congenital Abnormality
A large brown, blue, or gray hamartoma of dermal melanocytes, usually on the shoulder and upper arm that is most commonly found in Asian populations and in females. It is sometimes associated with sensory changes in the involved skin area, but very rarely becomes cancerous.
Leigh syndrome
MedGen UID:
44095
Concept ID:
C0023264
Disease or Syndrome
Leigh syndrome is a clinically and genetically heterogeneous disorder resulting from defective mitochondrial energy generation. It most commonly presents as a progressive and severe neurodegenerative disorder with onset within the first months or years of life, and may result in early death. Affected individuals usually show global developmental delay or developmental regression, hypotonia, ataxia, dystonia, and ophthalmologic abnormalities, such as nystagmus or optic atrophy. The neurologic features are associated with the classic findings of T2-weighted hyperintensities in the basal ganglia and/or brainstem on brain imaging. Leigh syndrome can also have detrimental multisystemic affects on the cardiac, hepatic, gastrointestinal, and renal organs. Biochemical studies in patients with Leigh syndrome tend to show increased lactate and abnormalities of mitochondrial oxidative phosphorylation (summary by Lake et al., 2015). Genetic Heterogeneity of Leigh Syndrome Leigh syndrome may be a clinical presentation of a primary deficiency caused by genes in any of the mitochondrial respiratory chain complexes: complex I deficiency (see 252010), complex II deficiency (see 252011), complex III deficiency (see 124000), complex IV deficiency (cytochrome c oxidase; see 220110), and complex V deficiency (see 604273) (summary by Lake et al., 2015). Mutations in mitochondrial genes have also been identified in patients with Leigh syndrome: see MTTV (590105), MTTK (590060), MTTW (590095), and MTTL1 (590050). Leigh syndrome may also be caused by mutations in components of the pyruvate dehydrogenase complex (e.g., DLD, 238331 and PDHA1, 300502). Deficiency of coenzyme Q10 (607426) can present as Leigh syndrome. Some forms of combined oxidative phosphorylation deficiency can present as Leigh syndrome (see, e.g., 617664).
Cystoid macular edema
MedGen UID:
7435
Concept ID:
C0024440
Disease or Syndrome
Dominant cystoid macular dystrophy (DCMD) is a progressive retinal dystrophy characterized primarily by early-onset cystoid fluid collections in the neuroretina (summary by Saksens et al., 2015).
Marfan syndrome
MedGen UID:
44287
Concept ID:
C0024796
Disease or Syndrome
FBN1-related Marfan syndrome (Marfan syndrome), a systemic disorder of connective tissue with a high degree of clinical variability, comprises a broad phenotypic continuum ranging from mild (features of Marfan syndrome in one or a few systems) to severe and rapidly progressive neonatal multiorgan disease. Cardinal manifestations involve the ocular, skeletal, and cardiovascular systems. Ocular findings include myopia (>50% of affected individuals); ectopia lentis (seen in approximately 60% of affected individuals); and an increased risk for retinal detachment, glaucoma, and early cataracts. Skeletal system manifestations include bone overgrowth and joint laxity; disproportionately long extremities for the size of the trunk (dolichostenomelia); overgrowth of the ribs that can push the sternum in (pectus excavatum) or out (pectus carinatum); and scoliosis that ranges from mild to severe and progressive. The major morbidity and early mortality in Marfan syndrome relate to the cardiovascular system and include dilatation of the aorta at the level of the sinuses of Valsalva (predisposing to aortic tear and rupture), mitral valve prolapse with or without regurgitation, tricuspid valve prolapse, and enlargement of the proximal pulmonary artery. Severe and prolonged regurgitation of the mitral and/or aortic valve can predispose to left ventricular dysfunction and occasionally heart failure. With proper management, the life expectancy of someone with Marfan syndrome approximates that of the general population.
Marinesco-Sjögren syndrome
MedGen UID:
6222
Concept ID:
C0024814
Disease or Syndrome
Marinesco-Sjögren syndrome (MSS) is characterized by cerebellar ataxia with cerebellar atrophy, dysarthria, nystagmus, early-onset (not necessarily congenital) cataracts, myopathy, muscle weakness, and hypotonia. Additional features may include psychomotor delay, hypergonadotropic hypogonadism, short stature, and various skeletal abnormalities. Children with MSS usually present with muscular hypotonia in early infancy; distal and proximal muscular weakness is noticed during the first decade of life. Later, cerebellar findings of truncal ataxia, dysdiadochokinesia, nystagmus, and dysarthria become apparent. Motor function worsens progressively for some years, then stabilizes at an unpredictable age and degree of severity. Cataracts can develop rapidly and typically require lens extraction in the first decade of life. Although many adults have severe disabilities, life span in MSS appears to be near normal.
Melnick-Needles syndrome
MedGen UID:
6292
Concept ID:
C0025237
Disease or Syndrome
The X-linked otopalatodigital (X-OPD) spectrum disorders, characterized primarily by skeletal dysplasia, include the following: Otopalatodigital syndrome type 1 (OPD1). Otopalatodigital syndrome type 2 (OPD2). Frontometaphyseal dysplasia type 1 (FMD1). Melnick-Needles syndrome (MNS). Terminal osseous dysplasia with pigmentary skin defects (TODPD). In OPD1, most manifestations are present at birth; females can present with severity similar to affected males, although some have only mild manifestations. In OPD2, females are less severely affected than related affected males. Most males with OPD2 die during the first year of life, usually from thoracic hypoplasia resulting in pulmonary insufficiency. Males who live beyond the first year of life are usually developmentally delayed and require respiratory support and assistance with feeding. In FMD1, females are less severely affected than related affected males. Males do not experience a progressive skeletal dysplasia but may have joint contractures and hand and foot malformations. Progressive scoliosis is observed in both affected males and females. In MNS, wide phenotypic variability is observed; some individuals are diagnosed in adulthood, while others require respiratory support and have reduced longevity. MNS in males results in perinatal lethality in all recorded cases. TODPD, seen only in females, is characterized by a skeletal dysplasia that is most prominent in the digits, pigmentary defects of the skin, and recurrent digital fibromata.
Pelger-Huët anomaly
MedGen UID:
10617
Concept ID:
C0030779
Disease or Syndrome
An autosomal dominant inherited condition caused by mutations in the lamin B receptor gene. It is characterized by defects in the neutrophil lobulation, resulting in the presence of dumbbell-shaped neutrophils with bilobed nuclei in the peripheral blood smear.
Prader-Willi syndrome
MedGen UID:
46057
Concept ID:
C0032897
Disease or Syndrome
Prader-Willi syndrome (PWS) is characterized by severe hypotonia and feeding difficulties in early infancy, followed in later infancy or early childhood by excessive eating and gradual development of morbid obesity (unless eating is externally controlled). Motor milestones and language development are delayed. All individuals have some degree of cognitive impairment. A distinctive behavioral phenotype (with temper tantrums, stubbornness, manipulative behavior, and obsessive-compulsive characteristics) is common. Hypogonadism is present in both males and females and manifests as genital hypoplasia, incomplete pubertal development, and, in most, infertility. Short stature is common (if not treated with growth hormone); characteristic facial features, strabismus, and scoliosis are often present.
Cyclical vomiting syndrome
MedGen UID:
57509
Concept ID:
C0152164
Disease or Syndrome
A condition characterized by recurrent, self-limiting episodes of vomiting associated with intense nausea, pallor, and lethargy. It is commonly a migraine precursor.
Hidrotic ectodermal dysplasia syndrome
MedGen UID:
56416
Concept ID:
C0162361
Disease or Syndrome
Hidrotic ectodermal dysplasia 2, or Clouston syndrome (referred to as HED2 throughout this GeneReview) is characterized by a triad of major clinical features including partial-to-complete alopecia, nail dystrophy, and palmoplantar hyperkeratosis. Sweating is preserved and there are usually no dental anomalies. Sparse scalp hair and dysplastic nails are seen early in life. In infancy, scalp hair is fine, sparse, and brittle. Progressive hair loss may lead to total alopecia by puberty. The nails may be milky white in early childhood; they gradually become dystrophic, thick, and distally separated from the nail bed. Palmoplantar keratoderma may develop during childhood and increases in severity with age. Associated features may include cutaneous hyperpigmentation (particularly over the joints) and finger clubbing. The clinical manifestations are highly variable even within the same family.
Angelman syndrome
MedGen UID:
58144
Concept ID:
C0162635
Disease or Syndrome
Angelman syndrome (AS) is characterized by severe developmental delay or intellectual disability, severe speech impairment, gait ataxia and/or tremulousness of the limbs, and unique behavior with an apparent happy demeanor that includes frequent laughing, smiling, and excitability. Microcephaly and seizures are also common. Developmental delays are first noted at around age six months; however, the unique clinical features of AS do not become manifest until after age one year.
Dubowitz syndrome
MedGen UID:
59797
Concept ID:
C0175691
Disease or Syndrome
Dubowitz syndrome (DS) is a rare multiple congenital syndrome characterized primarly by growth retardation, microcephaly, distinctive facial dysmorphism, cutaneous eczema, a mild to severe intellectual deficit and genital abnormalities.
Johanson-Blizzard syndrome
MedGen UID:
59798
Concept ID:
C0175692
Disease or Syndrome
Johanson-Blizzard syndrome is an autosomal recessive disorder characterized by poor growth, mental retardation, and variable dysmorphic features, including aplasia or hypoplasia of the nasal alae, abnormal hair patterns or scalp defects, and oligodontia. Other features include hypothyroidism, sensorineural hearing loss, imperforate anus, and pancreatic exocrine insufficiency (summary by Al-Dosari et al., 2008).
Smith-Lemli-Opitz syndrome
MedGen UID:
61231
Concept ID:
C0175694
Disease or Syndrome
Smith-Lemli-Opitz syndrome (SLOS) is a congenital multiple-anomaly / cognitive impairment syndrome caused by an abnormality in cholesterol metabolism resulting from deficiency of the enzyme 7-dehydrocholesterol (7-DHC) reductase. It is characterized by prenatal and postnatal growth restriction, microcephaly, moderate-to-severe intellectual disability, and multiple major and minor malformations. The malformations include distinctive facial features, cleft palate, cardiac defects, underdeveloped external genitalia in males, postaxial polydactyly, and 2-3 syndactyly of the toes. The clinical spectrum is wide; individuals with normal development and only minor malformations have been described.
Sotos syndrome
MedGen UID:
61232
Concept ID:
C0175695
Disease or Syndrome
Sotos syndrome is characterized by a distinctive facial appearance (broad and prominent forehead with a dolichocephalic head shape, sparse frontotemporal hair, downslanting palpebral fissures, malar flushing, long and narrow face, long chin); learning disability (early developmental delay, mild-to-severe intellectual impairment); and overgrowth (height and/or head circumference =2 SD above the mean). These three clinical features are considered the cardinal features of Sotos syndrome. Major features of Sotos syndrome include behavioral problems (most notably autistic spectrum disorder), advanced bone age, cardiac anomalies, cranial MRI/CT abnormalities, joint hyperlaxity with or without pes planus, maternal preeclampsia, neonatal complications, renal anomalies, scoliosis, and seizures.
Saethre-Chotzen syndrome
MedGen UID:
64221
Concept ID:
C0175699
Disease or Syndrome
Classic Saethre-Chotzen syndrome (SCS) is characterized by coronal synostosis (unilateral or bilateral), facial asymmetry (particularly in individuals with unicoronal synostosis), strabismus, ptosis, and characteristic appearance of the ear (small pinna with a prominent superior and/or inferior crus). Syndactyly of digits two and three of the hand is variably present. Cognitive development is usually normal, although those with a large genomic deletion are at an increased risk for intellectual challenges. Less common manifestations of SCS include other skeletal findings (parietal foramina, vertebral segmentation defects, radioulnar synostosis, maxillary hypoplasia, ocular hypertelorism, hallux valgus, duplicated or curved distal hallux), hypertelorism, palatal anomalies, obstructive sleep apnea, increased intracranial pressure, short stature, and congenital heart malformations.
Aarskog syndrome
MedGen UID:
61234
Concept ID:
C0175701
Disease or Syndrome
Aarskog-Scott syndrome is a genetic disorder that affects the development of many parts of the body, most commonly the head and face, the hands and feet, and the genitals and urinary system (genitourinary tract). This condition mainly affects males, although females may have mild features of the syndrome.\n\nPeople with Aarskog-Scott syndrome often have distinctive facial features, such as widely spaced eyes (hypertelorism), a small nose, a long area between the nose and mouth (philtrum), and a widow's peak hairline. They frequently have mild to moderate short stature during childhood, but their growth usually catches up with that of their peers during puberty. Hand abnormalities are common in this syndrome and include short fingers (brachydactyly), curved pinky fingers (fifth finger clinodactyly), webbing of the skin between some fingers (cutaneous syndactyly), and a single crease across the palm. Affected individuals can also have wide, flat feet with broad, rounded toes. Other abnormalities in people with Aarskog-Scott syndrome include heart defects and a split in the upper lip (cleft lip) with or without an opening in the roof of the mouth (cleft palate).\n\nMost males with Aarskog-Scott syndrome have a shawl scrotum, in which the scrotum surrounds the penis instead of hanging below. Less often, they have undescended testes (cryptorchidism) or a soft out-pouching around the belly-button (umbilical hernia) or in the lower abdomen (inguinal hernia).\n\nThe intellectual development of people with Aarskog-Scott syndrome varies widely. Most individuals with Aarskog-Scott syndrome have normal intelligence; however, some may have mild learning and behavior problems, and in rare cases, severe intellectual disability has been reported.
Williams syndrome
MedGen UID:
59799
Concept ID:
C0175702
Disease or Syndrome
Williams syndrome (WS) is characterized by cardiovascular disease (elastin arteriopathy, peripheral pulmonary stenosis, supravalvar aortic stenosis, hypertension), distinctive facies, connective tissue abnormalities, intellectual disability (usually mild), a specific cognitive profile, unique personality characteristics, growth abnormalities, and endocrine abnormalities (hypercalcemia, hypercalciuria, hypothyroidism, and early puberty). Feeding difficulties often lead to poor weight gain in infancy. Hypotonia and hyperextensible joints can result in delayed attainment of motor milestones.
Radial aplasia-thrombocytopenia syndrome
MedGen UID:
61235
Concept ID:
C0175703
Disease or Syndrome
Thrombocytopenia absent radius (TAR) syndrome is characterized by bilateral absence of the radii with the presence of both thumbs, and thrombocytopenia that is generally transient. Thrombocytopenia may be congenital or may develop within the first few weeks to months of life; in general, thrombocytopenic episodes decrease with age. Cow's milk allergy is common and can be associated with exacerbation of thrombocytopenia. Other anomalies of the skeleton (upper and lower limbs, ribs, and vertebrae), heart, and genitourinary system (renal anomalies and agenesis of uterus, cervix, and upper part of the vagina) can occur.
Pfeiffer syndrome
MedGen UID:
67390
Concept ID:
C0220658
Disease or Syndrome
Pfeiffer syndrome is an autosomal dominant craniosynostosis syndrome with characteristic anomalies of the hands and feet. Three clinical subtypes, which have important diagnostic and prognostic implications, have been identified. Type 1, the classic syndrome, is compatible with life and consists of craniosynostosis, midface deficiency, broad thumbs, broad great toes, brachydactyly, and variable syndactyly. Type 2 consists of cloverleaf skull with Pfeiffer hands and feet, together with ankylosis of the elbows. Type 3 is similar to type 2 but without cloverleaf skull. Ocular proptosis is severe, and the anterior cranial base is markedly short. Various visceral malformations have been found in association with type 3. Early demise is characteristic of types 2 and 3 (Cohen, 1993). Cohen and Barone (1994) further tabulated the findings in the 3 types of Pfeiffer syndrome.
Blepharophimosis, ptosis, and epicanthus inversus syndrome
MedGen UID:
66312
Concept ID:
C0220663
Disease or Syndrome
Blepharophimosis, ptosis, and epicanthus inversus syndrome (BPES) is defined by a complex eyelid malformation characterized by four major features, all present at birth: blepharophimosis, ptosis, epicanthus inversus, and telecanthus. BPES type I includes the four major features and primary ovarian insufficiency; BPES type II includes only the four major features. Other ophthalmic manifestations that can be associated with BPES include dysplastic eyelids, lacrimal duct anomalies, strabismus, refractive errors, and amblyopia. Other craniofacial features may include a broad nasal bridge and low-set ears.
Mucolipidosis type IV
MedGen UID:
68663
Concept ID:
C0238286
Disease or Syndrome
Mucolipidosis IV (MLIV) is an ultra-rare lysosomal storage disorder characterized by severe psychomotor delay, progressive visual impairment, and achlorhydria. Individuals with MLIV typically present by the end of the first year of life with delayed developmental milestones (due to a developmental brain abnormality) and impaired vision (resulting from a combination of corneal clouding and retinal degeneration). By adolescence, all individuals with MLIV have severe visual impairment. A neurodegenerative component of MLIV has become more widely appreciated, with the majority of individuals demonstrating progressive spastic quadriparesis and loss of psychomotor skills starting in the second decade of life. About 5% of individuals have atypical MLIV, manifesting with less severe psychomotor impairment, but still exhibiting progressive retinal degeneration and achlorhydria.
Treacher Collins syndrome
MedGen UID:
66078
Concept ID:
C0242387
Disease or Syndrome
Treacher Collins syndrome (TCS) is characterized by bilateral and symmetric downslanting palpebral fissures, malar hypoplasia, micrognathia, and external ear abnormalities. Hypoplasia of the zygomatic bones and mandible can cause significant feeding and respiratory difficulties. About 40%-50% of individuals have conductive hearing loss attributed most commonly to malformation of the ossicles and hypoplasia of the middle ear cavities. Inner ear structures tend to be normal. Other, less common abnormalities include cleft palate and unilateral or bilateral choanal stenosis or atresia. Typically intellect is normal.
DE SANCTIS-CACCHIONE SYNDROME
MedGen UID:
75550
Concept ID:
C0265201
Disease or Syndrome
A rare autosomal recessive inherited syndrome. It is characterized by xeroderma pigmentosum, mental retardation, dwarfism, hypogonadism, and neurologic abnormalities.
Weaver syndrome
MedGen UID:
120511
Concept ID:
C0265210
Disease or Syndrome
EZH2-related overgrowth includes EZH2-related Weaver syndrome at one end of the spectrum and tall stature at the other. Although most individuals diagnosed with a heterozygous EZH2 pathogenic variant have been identified because of a clinical suspicion of Weaver syndrome, a minority have been identified through molecular genetic testing of family members of probands or individuals with overgrowth who did not have a clinical diagnosis of Weaver syndrome. Thus, the extent of the phenotypic spectrum associated with a heterozygous EZH2 pathogenic variant is not yet known. Weaver syndrome is characterized by tall stature, variable intellect (ranging from normal intellect to severe intellectual disability), characteristic facial appearance, and a range of associated clinical features including advanced bone age, poor coordination, soft doughy skin, camptodactyly of the fingers and/or toes, umbilical hernia, abnormal tone, and hoarse low cry in infancy. Brain MRI has identified abnormalities in a few individuals with EZH2-related overgrowth. Neuroblastoma occurs at a slightly increased frequency in individuals with a heterozygous EZH2 pathogenic variant but data are insufficient to determine absolute risk. There is currently no evidence that additional malignancies (including hematologic malignancies) occur with increased frequency.
Freeman-Sheldon syndrome
MedGen UID:
120516
Concept ID:
C0265224
Disease or Syndrome
Freeman-Sheldon syndrome (FSS), or DA2A, is phenotypically similar to DA1. In addition to contractures of the hands and feet, FSS is characterized by oropharyngeal abnormalities, scoliosis, and a distinctive face that includes a very small oral orifice (often only a few millimeters in diameter at birth), puckered lips, and an H-shaped dimple of the chin; hence, FSS has been called 'whistling face syndrome.' The limb phenotypes of DA1 and FSS may be so similar that they can only be distinguished by the differences in facial morphology (summary by Bamshad et al., 2009). For a general phenotypic description and a discussion of genetic heterogeneity of distal arthrogryposis, see DA1 (108120).
Craniofacial microsomia
MedGen UID:
75554
Concept ID:
C0265240
Disease or Syndrome
A rare congenital malformation syndrome, most commonly presenting with hemifacial microsomia associated with ear and/or eye malformations and vertebral anomalies of variable severity. Additional malformations involving the heart, kidneys, central nervous, digestive and skeletal systems may also be associated. The phenotypic spectrum ranges from isolated mild facial asymmetry to severe bilateral craniofacial microsomia and additional multiple extracranial abnormalities. Intelligence is typically normal. The aetiology is poorly understood but is suspected to be heterogeneous and multifactorial. The gene MYT1 (20q13.33) has been implicated in a few rare cases, and chromosomal abnormalities have been associated with some of the congenital malformations associated with this condition. The condition usually occurs sporadically, but autosomal dominant inheritance has been reported.
Mietens syndrome
MedGen UID:
82695
Concept ID:
C0265249
Disease or Syndrome
Mietens syndrome is a very rare syndrome consisting of corneal opacity, nystagmus, strabismus, flexion contracture of the elbows with dislocation of the head of the radius and abnormally short ulnae and radii.
Baller-Gerold syndrome
MedGen UID:
120532
Concept ID:
C0265308
Disease or Syndrome
Baller-Gerold syndrome (BGS) can be suspected at birth in an infant with craniosynostosis and upper limb abnormality. The coronal suture is most commonly affected; the metopic, lambdoid, and sagittal sutures may also be involved alone or in combination. Upper limb abnormality can include a combination of thumb hypo- or aplasia and radial hypo- or aplasia and may be asymmetric. Malformation or absence of carpal or metacarpal bones has also been described. Skin lesions may appear anytime within the first few years after birth, typically beginning with erythema of the face and extremities and evolving into poikiloderma. Slow growth is apparent in infancy with eventual height and length typically at 4 SD below the mean.
Adenylosuccinate lyase deficiency
MedGen UID:
78641
Concept ID:
C0268126
Disease or Syndrome
Adenylosuccinase deficiency is an autosomal recessive inborn error of metabolism caused by an enzymatic defect in de novo purine synthesis (DNPS) pathway. ADSL deficiency leads to the accumulation of toxic intermediates, including succinyladenosine (S-Ado) and succinylaminoimidazole carboxamide riboside (SAICAr) in body fluids. There are 3 major phenotypic forms of the disorder that correlate with different values of the S-Ado and SAICAr concentration ratios (S-Ado/SAICAr) in the cerebrospinal fluid. These include the most severe fatal neonatal encephalopathy (S-Ado/SAICAr ratio less than 1); childhood form (type I) with severe psychomotor retardation (S-Ado/SAICAr ratio close to 1), and a milder form (type II) with psychomotor retardation or hypotonia (S-Ado/SAICAr ratio greater than 2) (summary by Baresova et al., 2012).
Deficiency of cytochrome-b5 reductase
MedGen UID:
75661
Concept ID:
C0268193
Disease or Syndrome
Methemoglobinemia due to NADH-cytochrome b5 reductase deficiency is an autosomal recessive disorder characterized clinically by decreased oxygen carrying capacity of the blood, with resultant cyanosis and hypoxia (review by Percy and Lappin, 2008). There are 2 types of methemoglobin reductase deficiency. In type I, the defect affects the soluble form of the enzyme, is restricted to red blood cells, and causes well-tolerated methemoglobinemia. In type II, the defect affects both the soluble and microsomal forms of the enzyme and is thus generalized, affecting red cells, leukocytes, and all body tissues. Type II methemoglobinemia is associated with mental deficiency and other neurologic symptoms. The neurologic symptoms may be related to the major role played by the cytochrome b5 system in the desaturation of fatty acids (Vives-Corrons et al., 1978; Kaplan et al., 1979).
Triglyceride storage disease with ichthyosis
MedGen UID:
82780
Concept ID:
C0268238
Disease or Syndrome
Chanarin-Dorfman syndrome (CDS) is a rare autosomal recessive nonlysosomal inborn error of neutral lipid metabolism. Patients present with an nonbullous erythrodermic form of ichthyosis, with variable involvement of other organs, such as liver, central nervous system, eyes, and ears. Intracellular triacylglycerol droplets are present in most tissues, and diagnosis can be confirmed by a simple blood smear, in which the characteristic lipid droplets are observed in the cytoplasm of granulocytes (summary by Lefevre et al., 2001).
Gaucher disease type II
MedGen UID:
78652
Concept ID:
C0268250
Disease or Syndrome
Gaucher disease (GD) encompasses a continuum of clinical findings from a perinatal lethal disorder to an asymptomatic type. The identification of three major clinical types (1, 2, and 3) and two other subtypes (perinatal-lethal and cardiovascular) is useful in determining prognosis and management. GD type 1 is characterized by the presence of clinical or radiographic evidence of bone disease (osteopenia, focal lytic or sclerotic lesions, and osteonecrosis), hepatosplenomegaly, anemia and thrombocytopenia, lung disease, and the absence of primary central nervous system disease. GD types 2 and 3 are characterized by the presence of primary neurologic disease; in the past, they were distinguished by age of onset and rate of disease progression, but these distinctions are not absolute. Disease with onset before age two years, limited psychomotor development, and a rapidly progressive course with death by age two to four years is classified as GD type 2. Individuals with GD type 3 may have onset before age two years, but often have a more slowly progressive course, with survival into the third or fourth decade. The perinatal-lethal form is associated with ichthyosiform or collodion skin abnormalities or with nonimmune hydrops fetalis. The cardiovascular form is characterized by calcification of the aortic and mitral valves, mild splenomegaly, corneal opacities, and supranuclear ophthalmoplegia. Cardiopulmonary complications have been described with all the clinical subtypes, although varying in frequency and severity.
Gaucher disease type III
MedGen UID:
78653
Concept ID:
C0268251
Disease or Syndrome
Gaucher disease (GD) encompasses a continuum of clinical findings from a perinatal lethal disorder to an asymptomatic type. The identification of three major clinical types (1, 2, and 3) and two other subtypes (perinatal-lethal and cardiovascular) is useful in determining prognosis and management. GD type 1 is characterized by the presence of clinical or radiographic evidence of bone disease (osteopenia, focal lytic or sclerotic lesions, and osteonecrosis), hepatosplenomegaly, anemia and thrombocytopenia, lung disease, and the absence of primary central nervous system disease. GD types 2 and 3 are characterized by the presence of primary neurologic disease; in the past, they were distinguished by age of onset and rate of disease progression, but these distinctions are not absolute. Disease with onset before age two years, limited psychomotor development, and a rapidly progressive course with death by age two to four years is classified as GD type 2. Individuals with GD type 3 may have onset before age two years, but often have a more slowly progressive course, with survival into the third or fourth decade. The perinatal-lethal form is associated with ichthyosiform or collodion skin abnormalities or with nonimmune hydrops fetalis. The cardiovascular form is characterized by calcification of the aortic and mitral valves, mild splenomegaly, corneal opacities, and supranuclear ophthalmoplegia. Cardiopulmonary complications have been described with all the clinical subtypes, although varying in frequency and severity.
Cutis laxa with osteodystrophy
MedGen UID:
82795
Concept ID:
C0268355
Disease or Syndrome
ATP6V0A2-related cutis laxa is characterized by generalized cutis laxa, findings associated with generalized connective tissue disorder, developmental delays, and a variety of neurologic findings including abnormality on brain MRI. At birth, hypotonia, overfolded skin, and distinctive facial features are present and enlarged fontanelles are often observed. During childhood, the characteristic facial features and thick or coarse hair may become quite pronounced. The skin findings decrease with age, although easy bruising and Ehlers-Danlos-like scars have been described in some. In most (not all) affected individuals, cortical and cerebellar malformations are observed on brain MRI. Nearly all affected individuals have developmental delays, seizures, and neurologic regression.
Inborn glycerol kinase deficiency
MedGen UID:
82803
Concept ID:
C0268418
Disease or Syndrome
NR0B1-related adrenal hypoplasia congenita includes both X-linked adrenal hypoplasia congenita (X-linked AHC) and Xp21 deletion (previously called complex glycerol kinase deficiency). X-linked AHC is characterized by primary adrenal insufficiency and/or hypogonadotropic hypogonadism (HH). Adrenal insufficiency is acute infantile onset (average age 3 weeks) in approximately 60% of affected males and childhood onset (ages 1-9 years) in approximately 40%. HH typically manifests in a male with adrenal insufficiency as delayed puberty (i.e., onset age >14 years) and less commonly as arrested puberty at about Tanner Stage 3. Rarely, X-linked AHC manifests initially in early adulthood as delayed-onset adrenal insufficiency, partial HH, and/or infertility. Heterozygous females very occasionally have manifestations of adrenal insufficiency or hypogonadotropic hypogonadism. Xp21 deletion includes deletion of NR0B1 (causing X-linked AHC) and GK (causing glycerol kinase deficiency), and in some cases deletion of DMD (causing Duchenne muscular dystrophy). Developmental delay has been reported in males with Xp21 deletion when the deletion extends proximally to include DMD or when larger deletions extend distally to include IL1RAPL1 and DMD.
Primary hypomagnesemia
MedGen UID:
120640
Concept ID:
C0268448
Disease or Syndrome
Familial hypomagnesemia with hypercalciuria and nephrocalcinosis is a progressive renal disorder characterized by excessive urinary Ca(2+) and Mg(2+) excretion. There is progressive loss of kidney function, and in about 50% of cases, the need for renal replacement therapy arises as early as the second decade of life (summary by Muller et al., 2006). Amelogenesis imperfecta may also be present in some patients (Bardet et al., 2016). A similar disorder with renal magnesium wasting, renal failure, and nephrocalcinosis (HOMG5; 248190) is caused by mutations in another tight-junction gene, CLDN19 (610036), and is distinguished by the association of severe ocular involvement. For a discussion of phenotypic and genetic heterogeneity of familial hypomagnesemia, see HOMG1 (602014).
Tyrosinase-positive oculocutaneous albinism
MedGen UID:
82810
Concept ID:
C0268495
Disease or Syndrome
Tyrosinase-positive oculocutaneous albinism (OCA, type II; OCA2) is an autosomal recessive disorder in which the biosynthesis of melanin pigment is reduced in skin, hair, and eyes. Although affected infants may appear at birth to have OCA type I, or complete absence of melanin pigment, most patients with OCA type II acquire small amounts of pigment with age. Individuals with OCA type II have the characteristic visual anomalies associated with albinism, including decreased acuity and nystagmus, which are usually less severe than in OCA type I (Lee et al., 1994; King et al., 2001). OCA type II has a highly variable phenotype. The hair of affected individuals may turn darker with age, and pigmented nevi or freckles may be seen. African and African American individuals may have yellow hair and blue-gray or hazel irides. One phenotypic variant, 'brown OCA,' has been described in African and African American populations and is characterized by light brown hair and skin color and gray to tan irides. The hair and irides may turn darker with time and the skin may tan with sun exposure; the ocular features of albinism are present in all variants (King et al., 2001). In addition, previous reports of so-called 'autosomal recessive ocular albinism,' (see, e.g., Witkop et al., 1978 and O'Donnell et al., 1978) with little or no obvious skin involvement, are now considered most likely to be part of the phenotypic spectrum of OCA1 or OCA2 (Lee et al., 1994; King et al., 2001).
gamma-Glutamyltransferase deficiency
MedGen UID:
82813
Concept ID:
C0268524
Disease or Syndrome
Level of glutathione in the urine above the upper limit of normal.
Infantile neuroaxonal dystrophy
MedGen UID:
82852
Concept ID:
C0270724
Disease or Syndrome
PLA2G6-associated neurodegeneration (PLAN) comprises a continuum of three phenotypes with overlapping clinical and radiologic features: Infantile neuroaxonal dystrophy (INAD). Atypical neuroaxonal dystrophy (atypical NAD). PLA2G6-related dystonia-parkinsonism. INAD usually begins between ages six months and three years with psychomotor regression or delay, hypotonia, and progressive spastic tetraparesis. Many affected children never learn to walk or lose the ability shortly after attaining it. Strabismus, nystagmus, and optic atrophy are common. Disease progression is rapid, resulting in severe spasticity, progressive cognitive decline, and visual impairment. Many affected children do not survive beyond their first decade. Atypical NAD shows more phenotypic variability than INAD. In general, onset is in early childhood but can be as late as the end of the second decade. The presenting signs may be gait instability, ataxia, or speech delay and autistic features, which are sometimes the only evidence of disease for a year or more. Strabismus, nystagmus, and optic atrophy are common. Neuropsychiatric disturbances including impulsivity, poor attention span, hyperactivity, and emotional lability are also common. The course is fairly stable during early childhood and resembles static encephalopathy but is followed by neurologic deterioration between ages seven and 12 years. PLA2G6-related dystonia-parkinsonism has a variable age of onset, but most individuals present in early adulthood with gait disturbance or neuropsychiatric changes. Affected individuals consistently develop dystonia and parkinsonism (which may be accompanied by rapid cognitive decline) in their late teens to early twenties. Dystonia is most common in the hands and feet but may be more generalized. The most common features of parkinsonism in these individuals are bradykinesia, resting tremor, rigidity, and postural instability.
Leucine-induced hypoglycemia
MedGen UID:
82888
Concept ID:
C0271714
Disease or Syndrome
Autosomal dominant optic atrophy classic form
MedGen UID:
137902
Concept ID:
C0338508
Disease or Syndrome
Optic atrophy type 1 (OPA1, or Kjer type optic atrophy) is characterized by bilateral and symmetric optic nerve pallor associated with insidious decrease in visual acuity (usually between ages 4 and 6 years), visual field defects, and color vision defects. Visual impairment is usually moderate (6/10 to 2/10), but ranges from mild or even insignificant to severe (legal blindness with acuity <1/20). The visual field defect is typically centrocecal, central, or paracentral; it is often large in those with severe disease. The color vision defect is often described as acquired blue-yellow loss (tritanopia). Other findings can include auditory neuropathy resulting in sensorineural hearing loss that ranges from severe and congenital to subclinical (i.e., identified by specific audiologic testing only). Visual evoked potentials are typically absent or delayed; pattern electroretinogram shows an abnormal N95:P50 ratio. Tritanopia is the classic feature of color vision defect, but more diffuse nonspecific dyschromatopsia is not uncommon. Ophthalmoscopic examination discloses temporal or diffuse pallor of the optic discs, sometimes associated with optic disc excavation. The neuroretinal rim shows some pallor in most cases, sometimes associated with a temporal pigmentary gray crescent.
Reis-Bucklers corneal dystrophy
MedGen UID:
83284
Concept ID:
C0339278
Disease or Syndrome
Reis-Bucklers corneal dystrophy (CDRB) is an autosomal dominant disorder of the superficial corneal stroma that manifests as recurrent corneal erosions in early childhood. Affected individuals develop corneal opacities that result in significant visual impairment. Microscopically, CDRB may be differentiated from other forms of corneal dystrophy by confluent opacities in the Bowman layer and subepithelium, which are the product of extracellular bodies that stain red with Masson trichrome stain and appear as crystalloid rod-shaped bodies on transmission electron microscopy (summary by Tanhehco et al., 2006).
Symphalangism-brachydactyly syndrome
MedGen UID:
90977
Concept ID:
C0342282
Disease or Syndrome
Multiple synostoses syndrome is characterized by multiple joint fusions, usually commencing in the hands, conductive deafness, and characteristic facial features, including a broad, tubular-shaped nose and a thin upper vermilion. Other features include brachydactyly, hypoplastic or absent middle phalanges, radial head dislocation, and pectus carinatum (summary by Takahashi et al., 2001). Genetic Heterogeneity of Multiple Synostoses Syndrome Other forms of multiple synostoses syndrome include SYNS2 (610017), caused by mutation in the GDF5 gene (601146) on chromosome 20q11; SYNS3 (612961), caused by mutation in the FGF9 gene (600921) on chromosome 13q12; and SYNS4 (617898), caused by mutation in the GDF6 gene (601147) on chromosome 8q22.
Oculocutaneous albinism type 3
MedGen UID:
87450
Concept ID:
C0342683
Disease or Syndrome
Several additional types of this disorder have been proposed, each affecting one or a few families.\n\nResearchers have identified multiple types of oculocutaneous albinism, which are distinguished by their specific skin, hair, and eye color changes and by their genetic cause. Oculocutaneous albinism type 1 is characterized by white hair, very pale skin, and light-colored irises. Type 2 is typically less severe than type 1; the skin is usually a creamy white color and hair may be light yellow, blond, or light brown. Type 3 includes a form of albinism called rufous oculocutaneous albinism, which usually affects dark-skinned people. Affected individuals have reddish-brown skin, ginger or red hair, and hazel or brown irises. Type 3 is often associated with milder vision abnormalities than the other forms of oculocutaneous albinism. Type 4 has signs and symptoms similar to those seen with type 2.\n\nOculocutaneous albinism is a group of conditions that affect coloring (pigmentation) of the skin, hair, and eyes. Affected individuals typically have very fair skin and white or light-colored hair. Long-term sun exposure greatly increases the risk of skin damage and skin cancers, including an aggressive form of skin cancer called melanoma, in people with this condition. Oculocutaneous albinism also reduces pigmentation of the colored part of the eye (the iris) and the light-sensitive tissue at the back of the eye (the retina). People with this condition usually have vision problems such as reduced sharpness; rapid, involuntary eye movements (nystagmus); and increased sensitivity to light (photophobia).
Beta-hydroxyisobutyryl-CoA deacylase deficiency
MedGen UID:
83349
Concept ID:
C0342738
Disease or Syndrome
3-Hydroxyisobutyryl-CoA hydrolase deficiency (HIBCHD) is an autosomal recessive inborn error of metabolism characterized by severely delayed psychomotor development, neurodegeneration, increased lactic acid, and brain lesions in the basal ganglia (summary by Ferdinandusse et al., 2013).
Bifunctional peroxisomal enzyme deficiency
MedGen UID:
137982
Concept ID:
C0342870
Pathologic Function
D-bifunctional protein deficiency is a disorder of peroxisomal fatty acid beta-oxidation. See also peroxisomal acyl-CoA oxidase deficiency (264470), caused by mutation in the ACOX1 gene (609751) on chromosome 17q25. The clinical manifestations of these 2 deficiencies are similar to those of disorders of peroxisomal assembly, including X-linked adrenoleukodystrophy (ALD; 300100), Zellweger cerebrohepatorenal syndrome (see 214100) and neonatal adrenoleukodystrophy (NALD; see 601539) (Watkins et al., 1995). DBP deficiency has been classified into 3 subtypes depending upon the deficient enzyme activity. Type I is a deficiency of both 2-enoyl-CoA hydratase and 3-hydroxyacyl-CoA dehydrogenase; type II is a deficiency of hydratase activity alone; and type III is a deficiency of dehydrogenase activity alone. Virtually all patients with types I, II, and III have a severe phenotype characterized by infantile-onset of hypotonia, seizures, and abnormal facial features, and most die before age 2 years. McMillan et al. (2012) proposed a type IV deficiency on the basis of less severe features; these patients have a phenotype reminiscent of Perrault syndrome (PRLTS1; 233400). Pierce et al. (2010) noted that Perrault syndrome and DBP deficiency overlap clinically and suggested that DBP deficiency may be underdiagnosed.
Aniridia 1
MedGen UID:
576337
Concept ID:
C0344542
Congenital Abnormality
PAX6-related aniridia occurs either as an isolated ocular abnormality or as part of the Wilms tumor-aniridia-genital anomalies-retardation (WAGR) syndrome. Aniridia is a pan ocular disorder affecting the cornea, iris, intraocular pressure (resulting in glaucoma), lens (cataract and lens subluxation), fovea (foveal hypoplasia), and optic nerve (optic nerve coloboma and hypoplasia). Individuals with aniridia characteristically show nystagmus and impaired visual acuity (usually 20/100 - 20/200); however, milder forms of aniridia with subtle iris architecture changes, good vision, and normal foveal structure do occur. Other ocular involvement may include strabismus and occasionally microphthalmia. Although the severity of aniridia can vary between and within families, little variability is usually observed in the two eyes of an affected individual. WAGR syndrome. The risk for Wilms tumor is 42.5%-77%; of those who develop Wilms tumor, 90% do so by age four years and 98% by age seven years. Genital anomalies in males can include cryptorchidism and hypospadias (sometimes resulting in ambiguous genitalia), urethral strictures, ureteric abnormalities, and gonadoblastoma. While females typically have normal external genitalia, they may have uterine abnormalities and streak ovaries. Intellectual disability (defined as IQ <74) is observed in 70%; behavioral abnormalities include attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder, anxiety, depression, and obsessive-compulsive disorder. Other individuals with WAGR syndrome can have normal intellect without behavioral problems.
Irido-corneo-trabecular dysgenesis
MedGen UID:
91031
Concept ID:
C0344559
Congenital Abnormality
Anterior segment dysgeneses (ASGD or ASMD) are a heterogeneous group of developmental disorders affecting the anterior segment of the eye, including the cornea, iris, lens, trabecular meshwork, and Schlemm canal. The clinical features of ASGD include iris hypoplasia, an enlarged or reduced corneal diameter, corneal vascularization and opacity, posterior embryotoxon, corectopia, polycoria, an abnormal iridocorneal angle, ectopia lentis, and anterior synechiae between the iris and posterior corneal surface (summary by Cheong et al., 2016). Anterior segment dysgenesis is sometimes divided into subtypes including aniridia (see 106210), Axenfeld and Rieger anomalies, iridogoniodysgenesis, Peters anomaly, and posterior embryotoxon (Gould and John, 2002). Patients with ASGD5 have been reported with the Peters anomaly, Axenfeld anomaly, and Rieger anomaly subtypes. Peters anomaly consists of a central corneal leukoma, absence of the posterior corneal stroma and Descemet membrane, and a variable degree of iris and lenticular attachments to the central aspect of the posterior cornea (Peters, 1906). It occurs as an isolated ocular abnormality or in association with other ocular defects. In Axenfeld anomaly, strands of iris tissue attach to the Schwalbe line; in Rieger anomaly, in addition to the attachment of iris tissue to the Schwalbe line, there is clinically evident iris stromal atrophy with hole or pseudo-hole formation and corectopia (summary by Smith and Traboulsi, 2012).
Branchiooculofacial syndrome
MedGen UID:
91261
Concept ID:
C0376524
Disease or Syndrome
The branchiooculofacial syndrome (BOFS) is characterized by: branchial (cervical or infra- or supra-auricular) skin defects that range from barely perceptible thin skin or hair patch to erythematous "hemangiomatous" lesions to large weeping erosions; ocular anomalies that can include microphthalmia, anophthalmia, coloboma, and nasolacrimal duct stenosis/atresia; and facial anomalies that can include ocular hypertelorism or telecanthus, broad nasal tip, upslanted palpebral fissures, cleft lip or prominent philtral pillars that give the appearance of a repaired cleft lip (formerly called "pseudocleft lip") with or without cleft palate, upper lip pits, and lower facial weakness (asymmetric crying face or partial 7th cranial nerve weakness). Malformed and prominent pinnae and hearing loss from inner ear and/or petrous bone anomalies are common. Intellect is usually normal.
Familial infantile myasthenia
MedGen UID:
140751
Concept ID:
C0393929
Disease or Syndrome
Congenital myasthenic syndromes (CMS) are a group of inherited disorders affecting the neuromuscular junction (NMJ). Patients present clinically with onset of variable muscle weakness between infancy and adulthood. These disorders have been classified according to the location of the defect: presynaptic, synaptic, and postsynaptic. CMS6 is an autosomal recessive CMS resulting from a presynaptic defect; patients have onset of symptoms in infancy or early childhood and tend to have sudden apneic episodes. Treatment with acetylcholinesterase inhibitors may be beneficial (summary by Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
GAPO syndrome
MedGen UID:
98034
Concept ID:
C0406723
Disease or Syndrome
GAPO syndrome is the acronymic designation for a complex of growth retardation, alopecia, pseudoanodontia (failure of tooth eruption), and progressive optic atrophy (Tipton and Gorlin, 1984). Ilker et al. (1999) and Bayram et al. (2014) noted that optic atrophy is not a consistent feature of the disorder.
Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 4
MedGen UID:
140820
Concept ID:
C0410174
Disease or Syndrome
Fukuyama congenital muscular dystrophy (FCMD) is characterized by hypotonia, symmetric generalized muscle weakness, and CNS migration disturbances that result in changes consistent with cobblestone lissencephaly with cerebral and cerebellar cortical dysplasia. Mild, typical, and severe phenotypes are recognized. Onset typically occurs in early infancy with poor suck, weak cry, and floppiness. Affected individuals have contractures of the hips, knees, and interphalangeal joints. Later features include myopathic facial appearance, pseudohypertrophy of the calves and forearms, motor and speech delays, intellectual disability, seizures, ophthalmologic abnormalities including visual impairment and retinal dysplasia, and progressive cardiac involvement after age ten years. Swallowing disturbance occurs in individuals with severe FCMD and in individuals older than age ten years, leading to recurrent aspiration pneumonia and death.
Deletion of long arm of chromosome 18
MedGen UID:
96605
Concept ID:
C0432443
Disease or Syndrome
Monosomy 18q is a partial deletion of the long arm of chromosome 18 characterized by highly variable phenotype, most commonly including hypotonia, developmental delay, short stature, growth hormone deficiency, hearing loss and external ear anomalies, intellectual disability, palatal defects, dysmorphic facial features, skeletal anomalies (foot deformities, tapering fingers, scoliosis) and mood disorders.
Mulibrey nanism syndrome
MedGen UID:
99347
Concept ID:
C0524582
Disease or Syndrome
Mulibrey nanism (MUL) is a rare autosomal recessive growth disorder with prenatal onset, including occasional progressive cardiomyopathy, characteristic facial features, failure of sexual maturation, insulin resistance with type 2 diabetes, and an increased risk for Wilms tumor (summary by Hamalainen et al., 2006).
Costello syndrome
MedGen UID:
108454
Concept ID:
C0587248
Disease or Syndrome
While the majority of individuals with Costello syndrome share characteristic findings affecting multiple organ systems, the phenotypic spectrum is wide, ranging from a milder or attenuated phenotype to a severe phenotype with early lethal complications. Costello syndrome is typically characterized by failure to thrive in infancy as a result of severe postnatal feeding difficulties; short stature; developmental delay or intellectual disability; coarse facial features (full lips, large mouth, full nasal tip); curly or sparse, fine hair; loose, soft skin with deep palmar and plantar creases; papillomata of the face and perianal region; diffuse hypotonia and joint laxity with ulnar deviation of the wrists and fingers; tight Achilles tendons; and cardiac involvement including: cardiac hypertrophy (usually typical hypertrophic cardiomyopathy), congenital heart defect (usually valvar pulmonic stenosis), and arrhythmia (usually supraventricular tachycardia, especially chaotic atrial rhythm/multifocal atrial tachycardia or ectopic atrial tachycardia). Relative or absolute macrocephaly is typical, and postnatal cerebellar overgrowth can result in the development of a Chiari I malformation with associated anomalies including hydrocephalus or syringomyelia. Individuals with Costello syndrome have an approximately 15% lifetime risk for malignant tumors including rhabdomyosarcoma and neuroblastoma in young children and transitional cell carcinoma of the bladder in adolescents and young adults.
Floating-Harbor syndrome
MedGen UID:
152667
Concept ID:
C0729582
Disease or Syndrome
Floating-Harbor syndrome (FHS) is characterized by typical craniofacial features; low birth weight, normal head circumference, and short stature; bone age delay that normalizes between ages six and 12 years; skeletal anomalies (brachydactyly, clubbing, clinodactyly, short thumbs, prominent joints, clavicular abnormalities); severe receptive and expressive language impairment; hypernasality and high-pitched voice; and intellectual disability that is typically mild to moderate. Difficulties with temperament and behavior that are present in many children tend to improve in adulthood. Other features can include hyperopia and/or strabismus, conductive hearing loss, seizures, gastroesophageal reflux, renal anomalies (e.g., hydronephrosis / renal pelviectasis, cysts, and/or agenesis), and genital anomalies (e.g., hypospadias and/or undescended testes).
Cockayne syndrome type 2
MedGen UID:
155487
Concept ID:
C0751038
Disease or Syndrome
Cockayne syndrome (referred to as CS in this GeneReview) spans a continuous phenotypic spectrum that includes: CS type I, the "classic" or "moderate" form; CS type II, a more severe form with symptoms present at birth; this form overlaps with cerebrooculofacioskeletal (COFS) syndrome; CS type III, a milder and later-onset form; COFS syndrome, a fetal form of CS. CS type I is characterized by normal prenatal growth with the onset of growth and developmental abnormalities in the first two years. By the time the disease has become fully manifest, height, weight, and head circumference are far below the fifth percentile. Progressive impairment of vision, hearing, and central and peripheral nervous system function leads to severe disability; death typically occurs in the first or second decade. CS type II is characterized by growth failure at birth, with little or no postnatal neurologic development. Congenital cataracts or other structural anomalies of the eye may be present. Affected children have early postnatal contractures of the spine (kyphosis, scoliosis) and joints. Death usually occurs by age five years. CS type III is a phenotype in which major clinical features associated with CS only become apparent after age two years; growth and/or cognition exceeds the expectations for CS type I. COFS syndrome is characterized by very severe prenatal developmental anomalies (arthrogryposis and microphthalmia).
Cockayne syndrome type 1
MedGen UID:
155488
Concept ID:
C0751039
Disease or Syndrome
Cockayne syndrome (referred to as CS in this GeneReview) spans a continuous phenotypic spectrum that includes: CS type I, the "classic" or "moderate" form; CS type II, a more severe form with symptoms present at birth; this form overlaps with cerebrooculofacioskeletal (COFS) syndrome; CS type III, a milder and later-onset form; COFS syndrome, a fetal form of CS. CS type I is characterized by normal prenatal growth with the onset of growth and developmental abnormalities in the first two years. By the time the disease has become fully manifest, height, weight, and head circumference are far below the fifth percentile. Progressive impairment of vision, hearing, and central and peripheral nervous system function leads to severe disability; death typically occurs in the first or second decade. CS type II is characterized by growth failure at birth, with little or no postnatal neurologic development. Congenital cataracts or other structural anomalies of the eye may be present. Affected children have early postnatal contractures of the spine (kyphosis, scoliosis) and joints. Death usually occurs by age five years. CS type III is a phenotype in which major clinical features associated with CS only become apparent after age two years; growth and/or cognition exceeds the expectations for CS type I. COFS syndrome is characterized by very severe prenatal developmental anomalies (arthrogryposis and microphthalmia).
Duane retraction syndrome 2
MedGen UID:
196721
Concept ID:
C0751083
Disease or Syndrome
Duane syndrome is a strabismus condition clinically characterized by congenital non-progressive limited horizontal eye movement accompanied by globe retraction which results in narrowing of the palpebral fissure. The lateral movement anomaly results from failure of the abducens nucleus and nerve (cranial nerve VI) to fully innervate the lateral rectus muscle; globe retraction occurs as a result of abnormal innervation of the lateral rectus muscle by the oculomotor nerve (cranial nerve III). At birth, affected infants have restricted ability to move the affected eye(s) outward (abduction) and/or inward (adduction), though the limitations may not be recognized in early infancy. In addition, the globe retracts into the orbit with attempted adduction, accompanied by narrowing of the palpebral fissure. Many individuals with Duane syndrome have strabismus in primary gaze but can use a compensatory head turn to align the eyes, and thus can preserve binocular vision and avoid diplopia. Individuals with Duane syndrome who lack binocular vision are at risk for amblyopia. The majority of affected individuals with Duane syndrome have isolated Duane syndrome (i.e., they do not have other detected congenital anomalies). Other individuals with Duane syndrome fall into well-defined syndromic diagnoses. However, many individuals with Duane syndrome have non-ocular findings that do not fit a known syndrome; these individuals are included as part of the discussion of nonsyndromic Duane syndrome.
Spinocerebellar ataxia type 5
MedGen UID:
155705
Concept ID:
C0752123
Disease or Syndrome
For a general discussion of autosomal dominant spinocerebellar ataxia (SCA), see SCA1 (164400).
Recombinant 8 syndrome
MedGen UID:
167070
Concept ID:
C0795822
Disease or Syndrome
Recombinant chromosome 8 syndrome (Rec8 syndrome) is a chromosomal disorder found among individuals of Hispanic descent with ancestry from the San Luis Valley of southern Colorado and northern New Mexico. Affected individuals typically have impaired intellectual development, congenital heart defects, seizures, a characteristic facial appearance with hypertelorism, thin upper lip, anteverted nares, wide face, and abnormal hair whorl, and other manifestations (Sujansky et al., 1993, summary by Graw et al., 2000).
11q partial monosomy syndrome
MedGen UID:
162878
Concept ID:
C0795841
Disease or Syndrome
Jacobsen syndrome (JBS) is a contiguous gene deletion syndrome with major clinical features of growth retardation, psychomotor retardation, trigonocephaly, divergent intermittent strabismus, epicanthus, telecanthus, broad nasal bridge, short nose with anteverted nostrils, carp-shaped upper lip, retrognathia, low-set dysmorphic ears, bilateral camptodactyly, hammertoes, and isoimmune thrombocytopenia (Fryns et al., 1986, Epstein, 1986).
MASA syndrome
MedGen UID:
162894
Concept ID:
C0795953
Disease or Syndrome
L1 syndrome involves a phenotypic spectrum ranging from severe to mild and includes three clinical phenotypes: X-linked hydrocephalus with stenosis of the aqueduct of Sylvius (HSAS). MASA (mental retardation [intellectual disability], aphasia [delayed speech], spastic paraplegia [shuffling gait], adducted thumbs) syndrome including X-linked complicated hereditary spastic paraplegia type 1. X-linked complicated corpus callosum agenesis. Males with HSAS are born with severe hydrocephalus, adducted thumbs, and spasticity; intellectual disability is severe. In less severely affected males, hydrocephalus may be subclinically present and documented only because of developmental delay; intellectual disability ranges from mild (IQ: 50-70) to moderate (IQ: 30-50). It is important to note that all phenotypes can be observed in affected individuals within the same family.
Gomez Lopez Hernandez syndrome
MedGen UID:
163201
Concept ID:
C0795959
Disease or Syndrome
Gomez-Lopez-Hernandez syndrome (GLHS), also known as cerebellotrigeminal dermal dysplasia, is a rare neurocutaneous syndrome classically characterized by the triad of rhombencephalosynapsis, trigeminal anesthesia, often giving rise to corneal opacities, and bilateral parietal or parietooccipital alopecia. However, trigeminal anesthesia is an inconsistent finding (summary by Sukhudyan et al., 2010).
Kabuki syndrome
MedGen UID:
162897
Concept ID:
C0796004
Congenital Abnormality
Kabuki syndrome (KS) is characterized by typical facial features (long palpebral fissures with eversion of the lateral third of the lower eyelid; arched and broad eyebrows; short columella with depressed nasal tip; large, prominent, or cupped ears), minor skeletal anomalies, persistence of fetal fingertip pads, mild-to-moderate intellectual disability, and postnatal growth deficiency. Other findings may include: congenital heart defects, genitourinary anomalies, cleft lip and/or palate, gastrointestinal anomalies including anal atresia, ptosis and strabismus, and widely spaced teeth and hypodontia. Functional differences can include: increased susceptibility to infections and autoimmune disorders, seizures, endocrinologic abnormalities (including isolated premature thelarche in females), feeding problems, and hearing loss.
Marden-Walker syndrome
MedGen UID:
163206
Concept ID:
C0796033
Disease or Syndrome
Marden-Walker syndrome (MWKS) is characterized by psychomotor retardation, a mask-like face with blepharophimosis, micrognathia and a high-arched or cleft palate, low-set ears, kyphoscoliosis, and joint contractures. Other features may include Dandy-Walker malformation with hydrocephalus and vertebral abnormalities (summary by Schrander-Stumpel et al., 1993). There are 2 distal arthrogryposis syndromes with features overlapping those of Marden-Walker syndrome that are also caused by heterozygous mutation in PIEZO2: distal arthrogryposis type 3 (DA3, or Gordon syndrome; 114300) and distal arthrogryposis type 5 (DA5; 108145), which are distinguished by the presence of cleft palate and ocular abnormalities, respectively. McMillin et al. (2014) suggested that the 3 disorders may represent variable expressivity of the same condition.
Myhre syndrome
MedGen UID:
167103
Concept ID:
C0796081
Disease or Syndrome
Myhre syndrome is a connective tissue disorder with multisystem involvement, progressive and proliferative fibrosis that may occur spontaneously or following trauma or surgery, mild-to-moderate intellectual disability, and in some instances, autistic-like behaviors. Organ systems primarily involved include: cardiovascular (congenital heart defects, long- and short-segment stenosis of the aorta and peripheral arteries, pericardial effusion, constrictive pericarditis, restrictive cardiomyopathy, and hypertension); respiratory (choanal stenosis, laryngotracheal narrowing, obstructive airway disease, or restrictive pulmonary disease), gastrointestinal (pyloric stenosis, duodenal strictures, severe constipation); and skin (thickened particularly on the hands and extensor surfaces). Additional findings include distinctive craniofacial features and skeletal involvement (intrauterine growth restriction, short stature, limited joint range of motion). To date, 55 individuals with molecularly confirmed Myhre syndrome have been reported.
C syndrome
MedGen UID:
167105
Concept ID:
C0796095
Disease or Syndrome
The C syndrome, also known as Opitz trigonocephaly syndrome, is a malformation syndrome characterized by trigonocephaly, severe mental retardation, hypotonia, variable cardiac defects, redundant skin, and dysmorphic facial features, including upslanted palpebral fissures, epicanthal folds, depressed nasal bridge, and low-set, posteriorly rotated ears (summary by Kaname et al., 2007). C syndrome shows phenotypic overlap with Bohring-Opitz syndrome, or C-like syndrome (605039), a disorder with more severe features than C syndrome, caused by heterozygous mutation in the ASXL1 gene (612990) on chromosome 20q11.
Orofaciodigital syndrome VIII
MedGen UID:
208667
Concept ID:
C0796101
Disease or Syndrome
Other features occur in only one or a few types of oral-facial digital syndrome. These features help distinguish the different forms of the disorder. For example, the most common form of oral-facial-digital syndrome, type I, is associated with polycystic kidney disease. This kidney disease is characterized by the growth of fluid-filled sacs (cysts) that interfere with the kidneys' ability to filter waste products from the blood. Other forms of oral-facial-digital syndrome are characterized by neurological problems, particular changes in the structure of the brain, bone abnormalities, vision loss, and heart defects.\n\nDistinctive facial features often associated with oral-facial-digital syndrome include a split in the lip (a cleft lip); a wide nose with a broad, flat nasal bridge; and widely spaced eyes (hypertelorism).\n\nAbnormalities of the oral cavity that occur in many types of oral-facial-digital syndrome include a split (cleft) in the tongue, a tongue with an unusual lobed shape, and the growth of noncancerous tumors or nodules on the tongue. Affected individuals may also have extra, missing, or defective teeth. Another common feature is an opening in the roof of the mouth (a cleft palate). Some people with oral-facial-digital syndrome have bands of extra tissue (called hyperplastic frenula) that abnormally attach the lip to the gums.\n\nAbnormalities of the digits can affect both the fingers and the toes in people with oral-facial-digital syndrome. These abnormalities include fusion of certain fingers or toes (syndactyly), digits that are shorter than usual (brachydactyly), or digits that are unusually curved (clinodactyly). The presence of extra digits (polydactyly) is also seen in most forms of oral-facial-digital syndrome.\n\nThe signs and symptoms of oral-facial-digital syndrome vary widely. However, most forms of this disorder involve problems with development of the oral cavity, facial features, and digits. Most forms are also associated with brain abnormalities and some degree of intellectual disability.\n\nResearchers have identified at least 13 potential forms of oral-facial-digital syndrome. The different types are classified by their patterns of signs and symptoms. However, the features of the various types overlap significantly, and some types are not well defined. The classification system for oral-facial-digital syndrome continues to evolve as researchers find more affected individuals and learn more about this disorder.\n\nOral-facial-digital syndrome is actually a group of related conditions that affect the development of the oral cavity (the mouth and teeth), facial features, and digits (fingers and toes).
Orofaciodigital syndrome IX
MedGen UID:
162908
Concept ID:
C0796102
Disease or Syndrome
Syndrome with characteristics of highly arched palate with bifid tongue and bilateral supernumerary lower canines, hamartomatous tongue, multiple frenula, hypertelorism, telecanthus, strabismus, broad and/or bifid nasal tip, short stature, bifid hallux, forked metatarsal, poly and syndactyly, mild intellectual deficit and specific retinal abnormalities (bilateral optic disc coloboma and retinal dysplasia with partial detachment). Less than ten cases have been described in the literature. The causative gene has not yet been identified.
Primrose syndrome
MedGen UID:
162911
Concept ID:
C0796121
Disease or Syndrome
Primrose syndrome is characterized by macrocephaly, hypotonia, developmental delay, intellectual disability with expressive speech delay, behavioral issues, a recognizable facial phenotype, radiographic features, and altered glucose metabolism. Additional features seen in adults: sparse body hair, distal muscle wasting, and contractures. Characteristic craniofacial features include brachycephaly, high anterior hairline, deeply set eyes, ptosis, downslanted palpebral fissures, high palate with torus palatinus, broad jaw, and large ears with small or absent lobes. Radiographic features include calcification of the external ear cartilage, multiple Wormian bones, platybasia, bathrocephaly, slender bones with exaggerated metaphyseal flaring, mild epiphyseal dysplasia, and spondylar dysplasia. Additional features include hearing impairment, ocular anomalies, cryptorchidism, and nonspecific findings on brain MRI.
Corpus callosum agenesis-abnormal genitalia syndrome
MedGen UID:
163217
Concept ID:
C0796124
Disease or Syndrome
Proud syndrome is an X-linked developmental disorder characterized by agenesis of the corpus callosum, severe mental retardation, seizures, and spasticity. Males are severely affected, whereas females may be unaffected or have a milder phenotype (Proud et al., 1992). Proud syndrome is part of a phenotypic spectrum of disorders caused by mutation in the ARX gene comprising a nearly continuous series of developmental disorders ranging from lissencephaly (LISX2; 300215) to Proud syndrome to infantile spasms without brain malformations (DEE1; 308350) to syndromic (309510) and nonsyndromic (300419) mental retardation (Kato et al., 2004; Wallerstein et al., 2008).
Aicardi-Goutieres syndrome 1
MedGen UID:
162912
Concept ID:
C0796126
Disease or Syndrome
Most characteristically, Aicardi-Goutières syndrome (AGS) manifests as an early-onset encephalopathy that usually, but not always, results in severe intellectual and physical disability. A subgroup of infants with AGS present at birth with abnormal neurologic findings, hepatosplenomegaly, elevated liver enzymes, and thrombocytopenia, a picture highly suggestive of congenital infection. Otherwise, most affected infants present at variable times after the first few weeks of life, frequently after a period of apparently normal development. Typically, they demonstrate the subacute onset of a severe encephalopathy characterized by extreme irritability, intermittent sterile pyrexias, loss of skills, and slowing of head growth. Over time, as many as 40% develop chilblain skin lesions on the fingers, toes, and ears. It is becoming apparent that atypical, sometimes milder, cases of AGS exist, and thus the true extent of the phenotype associated with pathogenic variants in the AGS-related genes is not yet known.
Renpenning syndrome
MedGen UID:
208670
Concept ID:
C0796135
Disease or Syndrome
Renpenning syndrome is an X-linked mental retardation syndrome with clinically recognizable features. Affected individuals have microcephaly, short stature, small testes, and dysmorphic facies, including tall narrow face, upslanting palpebral fissures, abnormal nasal configuration, cupped ears, and short philtrum. The nose may appear long or bulbous, with overhanging columella. Less consistent manifestations include ocular colobomas, cardiac malformations, cleft palate, and anal anomalies. Stevenson et al. (2005) proposed that the various X-linked mental retardation syndromes due to PQBP1 mutations be combined under the name of Renpenning syndrome.
Microbrachycephaly-ptosis-cleft lip syndrome
MedGen UID:
162914
Concept ID:
C0796142
Disease or Syndrome
The Richieri-Costa/Guion-Almeida syndrome is characterized by mild mental retardation, short stature, microbrachycephaly, ptosis, esotropia, cleft lip/palate (Richieri-Costa and Guion-Almeida, 1992).
Acrocallosal syndrome
MedGen UID:
162915
Concept ID:
C0796147
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Spondylometaphyseal dysplasia, Golden type
MedGen UID:
208672
Concept ID:
C0796172
Disease or Syndrome
A rare primary bone dysplasia disorder with characteristics of severe short stature, coarse facies, thoracolumbar kyphoscoliosis and enlarged joints with contractures. Psychomotor delay and intellectual disability may also be associated. Radiographic features include flat vertebral bodies, lacy ossification of the metaphyses of long bones and iliac crests, and marked sclerosis of the skull base.
X-linked progressive cerebellar ataxia
MedGen UID:
163229
Concept ID:
C0796205
Disease or Syndrome
SCAX1 is an X-linked recessive neurologic disorder characterized by hypotonia at birth, delayed motor development, gait ataxia, difficulty standing, dysarthria, and slow eye movements. Brain MRI shows cerebellar ataxia (summary by Bertini et al., 2000). Genetic Heterogeneity of X-linked Spinocerebellar Ataxia X-linked recessive spinocerebellar ataxia (SCAX) is a clinically and genetically heterogeneous disorder. See also SCAX2 (302600), SCAX3 (301790), SCAX4 (301840), and SCAX5 (300703).
X-linked intellectual disability-short stature-overweight syndrome
MedGen UID:
901885
Concept ID:
C0796218
Disease or Syndrome
X-linked intellectual developmental disorder-12 (XLID12) is characterized by borderline to severe intellectual disability with variable neurologic features, short stature, and elevated body mass index (BMI) (Kumar et al., 2015).
Intellectual disability, X-linked 49
MedGen UID:
923000
Concept ID:
C0796221
Disease or Syndrome
CLCN4-related neurodevelopmental disorder (CLCN4-NDD), an X-linked disorder, is characterized in the 36 males reported to date by developmental delay or intellectual disability, behavioral/mental health issues (e.g., autism spectrum disorder, anxiety, hyperactivity, and bipolar disorder), epilepsy, and gastrointestinal dysfunction. The five heterozygous females with a de novo CLCN4 variant reported to date had findings very similar to those of affected males. Twenty-two of 25 heterozygous females identified in family studies following identification of an affected male were unaffected or had only mild specific learning difficulties and/or mental health concerns, whereas three were more severely affected.
Bohring-Opitz syndrome
MedGen UID:
208678
Concept ID:
C0796232
Disease or Syndrome
Bohring-Opitz syndrome (BOS) is characterized by distinctive facial features and posture, growth failure, variable but usually severe intellectual disability, and variable anomalies. The facial features may include microcephaly or trigonocephaly / prominent (but not fused) metopic ridge, hypotonic facies with full cheeks, synophrys, glabellar and eyelid nevus flammeus (simplex), prominent globes, widely set eyes, palate anomalies, and micrognathia. The BOS posture, which is most striking in early childhood and often becomes less apparent with age, is characterized by flexion at the elbows with ulnar deviation and flexion of the wrists and metacarpophalangeal joints. Feeding difficulties in early childhood, including cyclic vomiting, have a significant impact on overall health; feeding tends to improve with age. Seizures are common and typically responsive to standard epileptic medications. Minor cardiac anomalies and transient bradycardia and apnea may be present. Affected individuals may experience recurrent infections, which also tend to improve with age. Isolated case reports suggest that individuals with BOS are at greater risk for Wilms tumor than the general population, but large-scale epidemiologic studies have not been conducted.
3MC syndrome 2
MedGen UID:
167115
Concept ID:
C0796279
Disease or Syndrome
The term '3MC syndrome' encompasses 4 rare autosomal recessive disorders that were previously designated the Carnevale, Mingarelli, Malpuech, and Michels syndromes, respectively. The main features of these syndromes are facial dysmorphism that includes hypertelorism, blepharophimosis, blepharoptosis, and highly arched eyebrows, which are present in 70 to 95% of cases. Cleft lip and palate, postnatal growth deficiency, cognitive impairment, and hearing loss are also consistent findings, occurring in 40 to 68% of cases. Craniosynostosis, radioulnar synostosis, and genital and vesicorenal anomalies occur in 20 to 30% of cases. Rare features include anterior chamber defects, cardiac anomalies, caudal appendage, umbilical hernia (omphalocele), and diastasis recti (summary by Rooryck et al., 2011). For a discussion of genetic heterogeneity of 3MC syndrome, see 3MC1 (257920).
Elsahy-Waters syndrome
MedGen UID:
923028
Concept ID:
C0809936
Disease or Syndrome
The core phenotype of Elsahy-Waters syndrome consists of brachycephaly, facial asymmetry, marked hypertelorism, proptosis, blepharochalasis, midface hypoplasia, broad nose with concave nasal ridge, and prognathism; radicular dentin dysplasia with consequent obliterated pulp chambers, apical translucent cysts, recurrent infections, and early loss of teeth; vertebral fusions, particularly at C2-C3; and moderate mental retardation. Skin wrinkling over the glabellar region seems common, and in males, hypospadias has always been present. Inter- and intrafamilial variability has been reported regarding the presence of vertebral fusions, hearing loss, and dentigerous cysts. Midface hypoplasia, facial asymmetry, progressive dental anomalies, and impaired cognitive development become more evident in adulthood (summary by Castori et al., 2010).
Duane syndrome type 1
MedGen UID:
201329
Concept ID:
C0994516
Disease or Syndrome
Duane syndrome is a strabismus condition clinically characterized by congenital non-progressive limited horizontal eye movement accompanied by globe retraction which results in narrowing of the palpebral fissure. The lateral movement anomaly results from failure of the abducens nucleus and nerve (cranial nerve VI) to fully innervate the lateral rectus muscle; globe retraction occurs as a result of abnormal innervation of the lateral rectus muscle by the oculomotor nerve (cranial nerve III). At birth, affected infants have restricted ability to move the affected eye(s) outward (abduction) and/or inward (adduction), though the limitations may not be recognized in early infancy. In addition, the globe retracts into the orbit with attempted adduction, accompanied by narrowing of the palpebral fissure. Many individuals with Duane syndrome have strabismus in primary gaze but can use a compensatory head turn to align the eyes, and thus can preserve binocular vision and avoid diplopia. Individuals with Duane syndrome who lack binocular vision are at risk for amblyopia. The majority of affected individuals with Duane syndrome have isolated Duane syndrome (i.e., they do not have other detected congenital anomalies). Other individuals with Duane syndrome fall into well-defined syndromic diagnoses. However, many individuals with Duane syndrome have non-ocular findings that do not fit a known syndrome; these individuals are included as part of the discussion of nonsyndromic Duane syndrome.
Dyskeratosis congenita, X-linked
MedGen UID:
216941
Concept ID:
C1148551
Disease or Syndrome
Dyskeratosis congenita and related telomere biology disorders (DC/TBD) are caused by impaired telomere maintenance resulting in short or very short telomeres. The phenotypic spectrum of telomere biology disorders is broad and includes individuals with classic dyskeratosis congenita (DC) as well as those with very short telomeres and an isolated physical finding. Classic DC is characterized by a triad of dysplastic nails, lacy reticular pigmentation of the upper chest and/or neck, and oral leukoplakia, although this may not be present in all individuals. People with DC/TBD are at increased risk for progressive bone marrow failure (BMF), myelodysplastic syndrome or acute myelogenous leukemia, solid tumors (usually squamous cell carcinoma of the head/neck or anogenital cancer), and pulmonary fibrosis. Other findings can include eye abnormalities (epiphora, blepharitis, sparse eyelashes, ectropion, entropion, trichiasis), taurodontism, liver disease, gastrointestinal telangiectasias, and avascular necrosis of the hips or shoulders. Although most persons with DC/TBD have normal psychomotor development and normal neurologic function, significant developmental delay is present in both forms; additional findings include cerebellar hypoplasia (Hoyeraal Hreidarsson syndrome) and bilateral exudative retinopathy and intracranial calcifications (Revesz syndrome and Coats plus syndrome). Onset and progression of manifestations of DC/TBD vary: at the mild end of the spectrum are those who have only minimal physical findings with normal bone marrow function, and at the severe end are those who have the diagnostic triad and early-onset BMF.
Cardio-facio-cutaneous syndrome
MedGen UID:
266149
Concept ID:
C1275081
Disease or Syndrome
Cardiofaciocutaneous (CFC) syndrome is characterized by cardiac abnormalities (pulmonic stenosis and other valve dysplasias, septal defects, hypertrophic cardiomyopathy, rhythm disturbances), distinctive craniofacial appearance, and cutaneous abnormalities (including xerosis, hyperkeratosis, ichthyosis, keratosis pilaris, ulerythema ophryogenes, eczema, pigmented moles, hemangiomas, and palmoplantar hyperkeratosis). The hair is typically sparse, curly, fine or thick, woolly or brittle; eyelashes and eyebrows may be absent or sparse. Nails may be dystrophic or fast growing. Some form of neurologic and/or cognitive delay (ranging from mild to severe) is seen in all affected individuals. Neoplasia, mostly acute lymphoblastic leukemia, has been reported in some individuals.
Shprintzen-Goldberg syndrome
MedGen UID:
231160
Concept ID:
C1321551
Disease or Syndrome
Shprintzen-Goldberg syndrome (SGS) is characterized by: delayed motor and cognitive milestones and mild-to-moderate intellectual disability; craniosynostosis of the coronal, sagittal, or lambdoid sutures; distinctive craniofacial features; and musculoskeletal findings including olichostenomelia, arachnodactyly, camptodactyly, pectus excavatum or carinatum, scoliosis, joint hypermobility or contractures, pes planus, foot malposition, and C1-C2 spine malformation. Cardiovascular anomalies may include mitral valve prolapse, secundum atrial septal defect, and aortic root dilatation. Minimal subcutaneous fat, abdominal wall defects, and myopia are also characteristic findings.
Oculootoradial syndrome
MedGen UID:
233003
Concept ID:
C1327918
Disease or Syndrome
IVIC syndrome (IVIC) is an autosomal dominant disorder characterized by upper limb anomalies (radial ray defects, carpal bone fusion), extraocular motor disturbances, and congenital bilateral nonprogressive mixed hearing loss. More variable features include heart involvement, mild thrombocytopenia and leukocytosis (before age 50), shoulder girdle hypoplasia, imperforate anus, kidney malrotation, and rectovaginal fistula (summary by Paradisi and Arias, 2007).
Duane-radial ray syndrome
MedGen UID:
301647
Concept ID:
C1623209
Disease or Syndrome
SALL4-related disorders include Duane-radial ray syndrome (DRRS, Okihiro syndrome), acro-renal-ocular syndrome (AROS), and SALL4-related Holt-Oram syndrome (HOS) – three phenotypes previously thought to be distinct entities. DRRS is characterized by uni- or bilateral Duane anomaly and radial ray malformation that can include thenar hypoplasia and/or hypoplasia or aplasia of the thumbs, hypoplasia or aplasia of the radii, shortening and radial deviation of the forearms, triphalangeal thumbs, and duplication of the thumb (preaxial polydactyly). AROS is characterized by radial ray malformations, renal abnormalities (mild malrotation, ectopia, horseshoe kidney, renal hypoplasia, vesicoureteral reflux, bladder diverticula), ocular coloboma, and Duane anomaly. Rarely, pathogenic variants in SALL4 may cause clinically typical HOS (i.e., radial ray malformations and cardiac malformations without additional features).
Groenouw corneal dystrophy type I
MedGen UID:
351521
Concept ID:
C1641846
Disease or Syndrome
Groenouw type I, or granular type I, corneal dystrophy (CDGG1) is an autosomal dominant disorder characterized by irregular aggregates of hyaline material in the corneal stroma. These aggregates can cause significant visual disturbance and may require corneal transplantation for restoration of visual acuity or for relief from recurrent corneal erosions (summary by Stone et al., 1994).
Cayman type cerebellar ataxia
MedGen UID:
331319
Concept ID:
C1832585
Disease or Syndrome
Cayman cerebellar ataxia (ATCAY) is an autosomal recessive neurologic disorder characterized by hypotonia from birth, variable psychomotor retardation, and cerebellar dysfunction, including nystagmus, intention tremor, dysarthria, ataxic gait, and truncal ataxia. Although the disorder was initially believed to be restricted to an isolated region of Grand Cayman Island (summary by Nystuen et al., 1996; Bomar et al., 2003), one Pakistani family with the disorder and an ATCAY mutation has been reported, thus expanding the ethnic distribution (Manzoor et al., 2018).
ALG3-congenital disorder of glycosylation
MedGen UID:
322026
Concept ID:
C1832736
Disease or Syndrome
Congenital disorders of glycosylation (CDGs) are a genetically heterogeneous group of autosomal recessive disorders caused by enzymatic defects in the synthesis and processing of asparagine (N)-linked glycans or oligosaccharides on glycoproteins. Type I CDGs comprise defects in the assembly of the dolichol lipid-linked oligosaccharide (LLO) chain and its transfer to the nascent protein. These disorders can be identified by a characteristic abnormal isoelectric focusing profile of plasma transferrin (Leroy, 2006). CDG1D is a type I CDG that generally presents with severe neurologic involvement associated with dysmorphism and visual impairment. Liver involvement is sometimes present (summary by Marques-da-Silva et al., 2017). For a discussion of the classification of CDGs, see CDG1A (212065).
Nystagmus 2, congenital, autosomal dominant
MedGen UID:
331657
Concept ID:
C1834079
Disease or Syndrome
Classic congenital or infantile nystagmus presents as conjugate, horizontal oscillations of the eyes, in primary or eccentric gaze, often with a preferred head turn or tilt. Other associated features may include mildly decreased visual acuity, strabismus, astigmatism, and occasionally head nodding. Eye movement recordings reveal that infantile nystagmus is predominantly a horizontal jerk waveform, with a diagnostic accelerating velocity slow phase. However, pendular and triangular waveforms may also be present. The nystagmus may rarely be vertical. As these patients often have normal visual acuity, it is presumed that the nystagmus represents a primary defect in the parts of the brain responsible for ocular motor control; thus the disorder has sometimes been termed 'congenital motor nystagmus' (Tarpey et al., 2006; Shiels et al., 2007). For a discussion of genetic heterogeneity of congenital nystagmus, see NYS1 (310700).
MOMO syndrome
MedGen UID:
371897
Concept ID:
C1834759
Disease or Syndrome
A very rare genetic overgrowth/obesity syndrome with characteristics of macrocephaly, obesity, mental (intellectual) disability and ocular abnormalities. Other frequent clinical signs include macrosomia, downslanting palpebral fissures, hypertelorism, broad nasal root, high and broad forehead and delay in bone maturation, in association with normal thyroid function and karyotype.
Microphthalmia, isolated, with cataract 1
MedGen UID:
320475
Concept ID:
C1834919
Disease or Syndrome
Cone dystrophy with supernormal rod response
MedGen UID:
332081
Concept ID:
C1835897
Disease or Syndrome
Cone dystrophy with supernormal rod responses (CDSRR) is characterized by onset in the first or second decade of life of very marked photophobia, myopia, reduced color vision along the red-green axis with relatively preserved tritan discrimination, and central scotomata with peripheral widespread sensitivity loss predominating in the superior visual field. Nyctalopia is a later feature of the disorder. There is often retinal pigment epithelium disturbance at the macula with a normal retinal periphery. Autofluorescence (AF) imaging shows either a perifoveal ring or a central macular area of relative increased AF (summary by Michaelides et al., 2005).
Spinocerebellar ataxia type 27
MedGen UID:
373075
Concept ID:
C1836383
Disease or Syndrome
Disease with characteristics of early-onset tremor, dyskinesia and slowly progressive cerebellar ataxia. Fewer than 30 cases have been reported to date. This disease is caused by a mutation in the fibroblast growth factor 14 FGF14 gene (13q34). Prognosis is relatively good. Life-threatening status epilepticus and intractable seizure or severe dysphagia is rare.
Alpha-N-acetylgalactosaminidase deficiency type 1
MedGen UID:
373113
Concept ID:
C1836544
Disease or Syndrome
Alpha-N-acetylgalactosaminidase (NAGA) deficiency is a very rare lysosomal storage disorder. It is clinically heterogeneous with 3 main phenotypes: type I is an infantile-onset neuroaxonal dystrophy; type II, also known as Kanzaki disease (609242), is an adult-onset disorder characterized by angiokeratoma corporis diffusum and mild intellectual impairment; and type III is an intermediate disorder with mild to moderate neurologic manifestations (Desnick and Schindler, 2001).
MPDU1-congenital disorder of glycosylation
MedGen UID:
322968
Concept ID:
C1836669
Disease or Syndrome
Congenital disorders of glycosylation (CDGs) are metabolic deficiencies in glycoprotein biosynthesis that usually cause severe mental and psychomotor retardation. Different forms of CDGs can be recognized by altered isoelectric focusing (IEF) patterns of serum transferrin. For a general discussion of CDGs, see CDG Ia (212065) and CDG Ib (602579).
Branchiogenic deafness syndrome
MedGen UID:
322970
Concept ID:
C1836673
Disease or Syndrome
A multiple congenital anomalies syndrome, described in one family to date, with characteristics of branchial cysts or fistula, ear malformations, congenital hearing loss (conductive, sensorineural, and mixed), internal auditory canal hypoplasia, strabismus, trismus, abnormal fifth fingers, vitiliginous lesions, short stature and mild learning disability. Renal and urethral abnormalities are absent.
Emanuel syndrome
MedGen UID:
323030
Concept ID:
C1836929
Disease or Syndrome
Emanuel syndrome is characterized by pre- and postnatal growth deficiency, microcephaly, hypotonia, severe developmental delays, ear anomalies, preauricular tags or pits, cleft or high-arched palate, congenital heart defects, kidney abnormalities, and genital abnormalities in males.
Spondylometaphyseal dysplasia-cone-rod dystrophy syndrome
MedGen UID:
324684
Concept ID:
C1837073
Disease or Syndrome
Spondylometaphyseal dysplasia with cone-rod dystrophy (SMDCRD) is characterized by postnatal growth deficiency resulting in profound short stature, rhizomelia with bowing of the lower extremities, platyspondyly with anterior vertebral protrusions, progressive metaphyseal irregularity and cupping with shortened tubular bones, and early-onset progressive visual impairment associated with a pigmentary maculopathy and electroretinographic evidence of cone-rod dysfunction (summary by Hoover-Fong et al., 2014). Yamamoto et al. (2014) reviewed 16 reported cases of SMDCRD, noting that all affected individuals presented uniform skeletal findings, with rhizomelia and bowed lower limbs observed in the first year of life, whereas retinal dystrophy had a more variable age of onset. There was severe disproportionate short stature, with a final height of less than 100 cm; scoliosis was usually mild. Visual loss was progressive, with stabilization in adolescence.
Congenital myasthenic syndrome 4C
MedGen UID:
373251
Concept ID:
C1837091
Disease or Syndrome
Congenital myasthenic syndrome associated with AChR deficiency is a disorder of the postsynaptic neuromuscular junction (NMJ) clinically characterized by early-onset muscle weakness with variable severity. Electrophysiologic studies show low amplitude of the miniature endplate potential (MEPP) and current (MEPC) resulting from deficiency of AChR at the endplate. Patients with mutations in the CHRNE gene may have compensatory increased expression of the fetal subunit CHRNG (100730) and may respond to treatment with cholinergic agents, pyridostigmine, or amifampridine (summary by Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Congenital disorder of glycosylation type 1E
MedGen UID:
324784
Concept ID:
C1837396
Disease or Syndrome
Congenital disorders of glycosylation (CDGs) are metabolic deficiencies in glycoprotein biosynthesis that usually cause severe mental and psychomotor retardation. Different forms of CDGs can be recognized by altered isoelectric focusing (IEF) patterns of serum transferrin. For a general discussion of CDGs, see CDG Ia (212065) and CDG Ib (602579).
Spinocerebellar ataxia type 25
MedGen UID:
373347
Concept ID:
C1837518
Disease or Syndrome
Spinocerebellar ataxia-25 (SCA25) is an autosomal dominant neurologic disorder characterized by the onset of lower limb ataxia resulting in gait difficulties in the first few decades of life, although later onset has been reported. Affected individuals often have upper limb involvement, dysarthria, scoliosis, abnormal eye movements, and sensory neuropathy with decreased reflexes. Some patients have sensorineural hearing loss. Brain imaging shows cerebellar atrophy. There is incomplete penetrance and variable expressivity, even within families (Barbier et al., 2022). For a general discussion of autosomal dominant spinocerebellar ataxia, see SCA1 (164400).
Toriello-Lacassie-Droste syndrome
MedGen UID:
333068
Concept ID:
C1838329
Disease or Syndrome
Oculoectodermal syndrome (OES) is characterized by the association of epibulbar dermoids and aplasia cutis congenita. Affected individuals exhibit congenital scalp lesions which are atrophic, nonscarring, hairless regions that are often multiple and asymmetric in distribution, and may have associated hamartomas. Ectodermal changes include linear hyperpigmentation that may follow the lines of Blaschko and, rarely, epidermal nevus-like lesions. Epibulbar dermoids may be uni- or bilateral. Additional ocular anomalies such as skin tags of the upper eyelid and rarely optic nerve or retinal changes or microphthalmia can be present. Phenotypic expression is highly variable, and various other abnormalities have occasionally been reported, including growth failure, lymphedema, and cardiovascular defects, as well as neurodevelopmental symptoms such as developmental delay, epilepsy, learning difficulties, and behavioral abnormalities. Benign tumor-like lesions such as nonossifying fibromas of the long bones and giant cell granulomas of the jaws have repeatedly been observed and appear to be age-dependent, becoming a common manifestation in individuals aged 5 years or older (summary by Boppudi et al., 2016).
Mitochondrial complex I deficiency
MedGen UID:
374101
Concept ID:
C1838979
Disease or Syndrome
Isolated complex I deficiency is a rare inborn error of metabolism due to mutations in nuclear or mitochondrial genes encoding subunits or assembly factors of the human mitochondrial complex I (NADH: ubiquinone oxidoreductase) and is characterized by a wide range of manifestations including marked and often fatal lactic acidosis, cardiomyopathy, leukoencephalopathy, pure myopathy and hepatopathy with tubulopathy. Among the numerous clinical phenotypes observed are Leigh syndrome, Leber hereditary optic neuropathy and MELAS syndrome (see these terms).
SCARF syndrome
MedGen UID:
326461
Concept ID:
C1839321
Disease or Syndrome
Syndrome with the association of skeletal abnormalities, cutis laxa, craniostenosis, ambiguous genitalia, psychomotor retardation and facial abnormalities. So far, it has been described in two males (maternal first cousins). The mode of inheritance was suggested to be X-linked recessive.
Prieto syndrome
MedGen UID:
374294
Concept ID:
C1839730
Disease or Syndrome
Prieto syndrome (PRS) is an X-linked intellectual developmental disorder characterized by mildly to severely impaired intellectual development, developmental delay, autism spectrum disorder, or neuropsychiatric symptoms, variably accompanied by speech delay, epilepsy, microcephaly, structural brain defects, and minor facial anomalies (summary by Kury et al., 2022).
X-linked complicated corpus callosum dysgenesis
MedGen UID:
374339
Concept ID:
C1839909
Disease or Syndrome
L1 syndrome involves a phenotypic spectrum ranging from severe to mild and includes three clinical phenotypes: X-linked hydrocephalus with stenosis of the aqueduct of Sylvius (HSAS). MASA (mental retardation [intellectual disability], aphasia [delayed speech], spastic paraplegia [shuffling gait], adducted thumbs) syndrome including X-linked complicated hereditary spastic paraplegia type 1. X-linked complicated corpus callosum agenesis. Males with HSAS are born with severe hydrocephalus, adducted thumbs, and spasticity; intellectual disability is severe. In less severely affected males, hydrocephalus may be subclinically present and documented only because of developmental delay; intellectual disability ranges from mild (IQ: 50-70) to moderate (IQ: 30-50). It is important to note that all phenotypes can be observed in affected individuals within the same family.
Bencze syndrome
MedGen UID:
330655
Concept ID:
C1841640
Disease or Syndrome
A malformation syndrome involving the abnormal growth of the facial skeleton as well as its soft tissue structure and organs. The syndrome has characteristics of mild facial asymmetry with unaffected neurocranium and eyeballs, along with esotropia, amblyopia and/or convergent strabismus and occasionally submucous cleft palate. Transmission is autosomal dominant. There have been no further descriptions in the literature since 1979.
Microcephaly 6, primary, autosomal recessive
MedGen UID:
330770
Concept ID:
C1842109
Disease or Syndrome
MCPH causes intellectual disability, which is typically mild to moderate and does not become more severe with age. Most affected individuals have delayed speech and language skills. Motor skills, such as sitting, standing, and walking, may also be mildly delayed.\n\nPeople with MCPH usually have few or no other features associated with the condition. Some have a narrow, sloping forehead; mild seizures; problems with attention or behavior; or short stature compared to others in their family. The condition typically does not affect any other major organ systems or cause other health problems.\n\nInfants with MCPH have an unusually small head circumference compared to other infants of the same sex and age. Head circumference is the distance around the widest part of the head, measured by placing a measuring tape above the eyebrows and ears and around the back of the head. Affected infants' brain volume is also smaller than usual, although they usually do not have any major abnormalities in the structure of the brain. The head and brain grow throughout childhood and adolescence, but they continue to be much smaller than normal.\n\nAutosomal recessive primary microcephaly (often shortened to MCPH, which stands for "microcephaly primary hereditary") is a condition in which infants are born with a very small head and a small brain. The term "microcephaly" comes from the Greek words for "small head."
Hermansky-Pudlak syndrome 2
MedGen UID:
374912
Concept ID:
C1842362
Disease or Syndrome
Hermansky-Pudlak syndrome (HPS) is characterized by oculocutaneous albinism, a bleeding diathesis, and, in some individuals, pulmonary fibrosis, granulomatous colitis, or immunodeficiency. Ocular findings include reduced iris pigment with iris transillumination, reduced retinal pigment, foveal hypoplasia with significant reduction in visual acuity (usually in the range of 20/50 to 20/400), nystagmus, and increased crossing of the optic nerve fibers. Hair color ranges from white to brown; skin color ranges from white to olive and is usually a shade lighter than that of other family members. The bleeding diathesis can result in variable bruising, epistaxis, gingival bleeding, postpartum hemorrhage, colonic bleeding, and prolonged bleeding with menses or after tooth extraction, circumcision, and other surgeries. Pulmonary fibrosis, a restrictive lung disease, typically causes symptoms in the early thirties and can progress to death within a decade. Granulomatous colitis is severe in about 15% of affected individuals. Neutropenia and/or immune defects occur primarily in individuals with pathogenic variants in AP3B1 and AP3D1.
Gaucher disease perinatal lethal
MedGen UID:
374996
Concept ID:
C1842704
Disease or Syndrome
Gaucher disease (GD) encompasses a continuum of clinical findings from a perinatal lethal disorder to an asymptomatic type. The identification of three major clinical types (1, 2, and 3) and two other subtypes (perinatal-lethal and cardiovascular) is useful in determining prognosis and management. GD type 1 is characterized by the presence of clinical or radiographic evidence of bone disease (osteopenia, focal lytic or sclerotic lesions, and osteonecrosis), hepatosplenomegaly, anemia and thrombocytopenia, lung disease, and the absence of primary central nervous system disease. GD types 2 and 3 are characterized by the presence of primary neurologic disease; in the past, they were distinguished by age of onset and rate of disease progression, but these distinctions are not absolute. Disease with onset before age two years, limited psychomotor development, and a rapidly progressive course with death by age two to four years is classified as GD type 2. Individuals with GD type 3 may have onset before age two years, but often have a more slowly progressive course, with survival into the third or fourth decade. The perinatal-lethal form is associated with ichthyosiform or collodion skin abnormalities or with nonimmune hydrops fetalis. The cardiovascular form is characterized by calcification of the aortic and mitral valves, mild splenomegaly, corneal opacities, and supranuclear ophthalmoplegia. Cardiopulmonary complications have been described with all the clinical subtypes, although varying in frequency and severity.
Chromosome 1p36 deletion syndrome
MedGen UID:
334629
Concept ID:
C1842870
Disease or Syndrome
The constitutional deletion of chromosome 1p36 results in a syndrome with multiple congenital anomalies and mental retardation (Shapira et al., 1997). Monosomy 1p36 is the most common terminal deletion syndrome in humans, occurring in 1 in 5,000 births (Shaffer and Lupski, 2000; Heilstedt et al., 2003). See also neurodevelopmental disorder with or without anomalies of the brain, eye, or heart (NEDBEH; 616975), which shows overlapping features and is caused by heterozygous mutation in the RERE gene (605226) on proximal chromosome 1p36. See also Radio-Tartaglia syndrome (RATARS; 619312), caused by mutation in the SPEN gene (613484) on chromosome 1p36, which shows overlapping features.
Spinocerebellar ataxia type 21
MedGen UID:
375311
Concept ID:
C1843891
Disease or Syndrome
Spinocerebellar ataxia-21 (SCA21) is an autosomal dominant neurologic disorder characterized by onset in the first decades of life of slowly progressive cerebellar ataxia, which is associated with cognitive impairment in most patients (summary by Delplanque et al., 2014). For a general discussion of autosomal dominant spinocerebellar ataxia, see SCA1 (164400).
Nystagmus 5, congenital, X-linked
MedGen UID:
375583
Concept ID:
C1845116
Disease or Syndrome
Classic congenital or infantile nystagmus presents as conjugate, horizontal oscillations of the eyes, in primary or eccentric gaze, often with a preferred head turn or tilt. Other associated features may include mildly decreased visual acuity, strabismus, astigmatism, and occasionally head nodding. Eye movement recordings reveal that infantile nystagmus is predominantly a horizontal jerk waveform, with a diagnostic accelerating velocity slow phase. However, pendular and triangular waveforms may also be present. The nystagmus may rarely be vertical. As these patients often have normal visual acuity, it is presumed that the nystagmus represents a primary defect in the parts of the brain responsible for ocular motor control; thus the disorder has sometimes been termed 'congenital motor nystagmus' (Tarpey et al., 2006; Shiels et al., 2007). For a discussion of genetic heterogeneity of congenital nystagmus, see NYS1 (310700).
FG syndrome 5
MedGen UID:
336854
Concept ID:
C1845119
Disease or Syndrome
Additional features seen in some people with FG syndrome include widely set eyes (hypertelorism), an upswept frontal hairline, and a large head compared to body size (relative macrocephaly). Other health problems have also been reported, including heart defects, seizures, undescended testes (cryptorchidism) in males, and a soft out-pouching in the lower abdomen (an inguinal hernia).\n\nThe physical features of FG syndrome include weak muscle tone (hypotonia), broad thumbs, and wide first (big) toes. Abnormalities of the tissue connecting the left and right halves of the brain (the corpus callosum) are also common. Most affected individuals have constipation, and many have abnormalities of the anus such as an obstruction of the anal opening (imperforate anus). People with FG syndrome also tend to have a distinctive facial appearance including small, underdeveloped ears; a tall, prominent forehead; and outside corners of the eyes that point downward (down-slanting palpebral fissures).\n\nFG syndrome affects intelligence and behavior. Almost everyone with the condition has intellectual disability, which ranges from mild to severe. Affected individuals tend to be friendly, inquisitive, and hyperactive, with a short attention span. Compared to people with other forms of intellectual disability, their socialization and daily living skills are strong, while verbal communication and language skills tend to be weaker.\n\nFG syndrome is a genetic condition that affects many parts of the body and occurs almost exclusively in males. "FG" represents the surname initials of the first family diagnosed with the disorder.
Syndromic X-linked intellectual disability Claes-Jensen type
MedGen UID:
335139
Concept ID:
C1845243
Disease or Syndrome
Claes-Jensen type of X-linked syndromic intellectual developmental disorder (MRXSCJ) is characterized by impaired intellectual development with substantial clinical heterogeneity in affected males. However, males are usually reported to have short stature, microcephaly, hyperreflexia, and aggressive behavior. In rare cases, female carriers exhibit mildly impaired intellectual development or learning difficulties (summary by Guerra et al., 2020).
X-linked intellectual disability-cerebellar hypoplasia syndrome
MedGen UID:
336920
Concept ID:
C1845366
Disease or Syndrome
X-linked intellectual deficit-cerebellar hypoplasia, also known as OPHN1 syndrome, is a rare syndromic form of cerebellar dysgenesis characterized by moderate to severe intellectual deficit and cerebellar abnormalities.
X-linked intellectual disability, Stocco dos Santos type
MedGen UID:
335202
Concept ID:
C1845530
Disease or Syndrome
X-linked intellectual disability, Stocco Dos Santos type is characterised by severe intellectual deficit with hyperactivity, language delay, congenital hip luxation, short stature, kyphosis and recurrent respiratory infections. Aggressive behaviour and frequent epileptic seizures may also be present. The syndrome has been described in four boys from the same family. Transmission is X-linked and is caused by mutations in the <i>KIAA1202</i> gene, localised to the Xp11.2 region.
Hereditary spastic paraplegia 16
MedGen UID:
375796
Concept ID:
C1846046
Disease or Syndrome
Spastic paraplegias (SPGs) are a genetically heterogeneous group of neurologic disorders characterized by progressive weakness and spasticity of the legs. Complicated SPGs are accompanied by additional neurologic symptoms such as cerebellar ataxia, sensory loss, mental retardation, nystagmus, and optic atrophy (summary by Steinmuller et al., 1997). A locus for spastic paraplegia-16 has been mapped to Xq11.2-q23 (Steinmuller et al., 1997). For a discussion of genetic heterogeneity of X-linked spastic paraplegia, see 303350.
Armfield syndrome
MedGen UID:
375800
Concept ID:
C1846057
Disease or Syndrome
MRXSA is an X-linked recessive neurodevelopmental disorder characterized by global developmental delay with impaired intellectual development, usually accompanied by walking difficulties and poor or absent speech. Affected individuals have dysmorphic features, including large head circumference, downslanting palpebral fissures, bulbous nose, high-arched palate, short stature, and small hands and feet. Ocular anomalies, including strabismus, exotropia, myopia, and keratoconus, are common. Some patients may develop seizures. Additional variable features, such as mild congenital heart defects, joint stiffness, renal anomalies, and hemangiomas, may also be present (summary by Lee et al., 2020).
MEHMO syndrome
MedGen UID:
375855
Concept ID:
C1846278
Disease or Syndrome
MEHMO syndrome is a rare intellectual disability disorder that exhibits phenotypic heterogeneity and is variably characterized by mental retardation, epileptic seizures, hypogonadism with hypogenitalism, microcephaly, and obesity. Life expectancy ranges from less than 1 year to adulthood, and the condition is associated with significant morbidity and mortality (summary by Gregory et al., 2019).
Heterotopia, periventricular, X-linked dominant
MedGen UID:
376309
Concept ID:
C1848213
Disease or Syndrome
FLNA deficiency is associated with a phenotypic spectrum that includes FLNA-related periventricular nodular heterotopia (Huttenlocher syndrome), congenital heart disease (patent ductus arteriosus, atrial and ventricular septal defects), valvular dystrophy, dilation and rupture of the thoracic aortic, pulmonary disease (pulmonary hypertension, alveolar hypoplasia, emphysema, asthma, chronic bronchitis), gastrointestinal dysmotility and obstruction, joint hypermobility, and macrothrombocytopenia.
CHIME syndrome
MedGen UID:
341214
Concept ID:
C1848392
Disease or Syndrome
CHIME syndrome, also known as Zunich neuroectodermal syndrome, is an extremely rare autosomal recessive multisystem disorder clinically characterized by colobomas, congenital heart defects, migratory ichthyosiform dermatosis, mental retardation, and ear anomalies (CHIME). Other clinical features include distinctive facial features, abnormal growth, genitourinary abnormalities, seizures, and feeding difficulties (summary by Ng et al., 2012). The disorder is caused by a defect in glycosylphosphatidylinositol (GPI) biosynthesis. For a discussion of genetic heterogeneity of GPI biosynthesis defects, see GPIBD1 (610293).
Growth delay due to insulin-like growth factor I resistance
MedGen UID:
338622
Concept ID:
C1849157
Disease or Syndrome
Patients with mutations in the receptor for insulin-like growth factor I show intrauterine growth retardation and postnatal growth failure, resulting in short stature and microcephaly. Other features may include delayed bone age, developmental delay, and dysmorphic features.
Autosomal recessive pericentral pigmentary retinopathy
MedGen UID:
340314
Concept ID:
C1849398
Disease or Syndrome
A subtype of retinitis pigmentosa in which, instead of the pathology starting in the mid-periphery like typical retinitis pigmentosa, the disease starts in the near periphery closer to the vascular arcades and tends to spare the far periphery.
Renal and mullerian duct hypoplasia
MedGen UID:
340326
Concept ID:
C1849439
Disease or Syndrome
Pyridoxine-dependent epilepsy
MedGen UID:
340341
Concept ID:
C1849508
Disease or Syndrome
Pyridoxine-dependent epilepsy – ALDH7A1 (PDE-ALDH7A1) is characterized by seizures not well controlled with anti-seizure medication that are responsive clinically and electrographically to large daily supplements of pyridoxine (vitamin B6). This is true across a phenotypic spectrum that ranges from classic to atypical PDE-ALDH7A1. Intellectual disability is common, particularly in classic PDE-ALDH7A1. Classic PDE-ALDH7A1. Untreated seizures begin within the first weeks to months of life. Dramatic presentations of prolonged seizures and recurrent episodes of status epilepticus are typical; recurrent self-limited events including partial seizures, generalized seizures, atonic seizures, myoclonic events, and infantile spasms also occur. Electrographic seizures can occur without clinical correlates. Atypical PDE-ALDH7A1. Findings in untreated individuals can include late-onset seizures beginning between late infancy and age three years, seizures that initially respond to anti-seizure medication and then become intractable, seizures during early life that do not respond to pyridoxine but are subsequently controlled with pyridoxine several months later, and prolonged seizure-free intervals (=5 months) that occur after discontinuation of pyridoxine.
Acyl-CoA oxidase deficiency
MedGen UID:
376636
Concept ID:
C1849678
Disease or Syndrome
Peroxisomal acyl-CoA oxidase deficiency is a disorder of peroxisomal fatty acid beta-oxidation. See also D-bifunctional protein deficiency (261515), caused by mutation in the HSD17B4 gene (601860) on chromosome 5q2. The clinical manifestations of these 2 deficiencies are similar to those of disorders of peroxisomal assembly, including Zellweger cerebrohepatorenal syndrome (see 214100) and neonatal adrenoleukodystrophy (see 601539) (Watkins et al., 1995).
Ophthalmoplegia totalis with ptosis and miosis
MedGen UID:
342471
Concept ID:
C1850314
Disease or Syndrome
Total ophthalmoplegia involves total paralysis of all extra- and intraocular muscles. If one or more of the external muscles, including the levator palpebrae, is not affected, the condition is known as incomplete or partial ophthalmoplegia. If only 1 nerve is affected, the palsy is named after that nerve (see, e.g., abducens palsy, 100200) (Waardenburg, 1963).
Giant axonal neuropathy 1
MedGen UID:
376775
Concept ID:
C1850386
Disease or Syndrome
GAN-related neurodegeneration comprises a phenotypic continuum ranging from severe (sometimes called classic giant axonal neuropathy) to milder pure early-onset peripheral motor and sensory neuropathies. The classic giant axonal neuropathy phenotype typically manifests as an infantile-onset neurodegenerative disorder, starting as a severe peripheral motor and sensory neuropathy and evolving into central nervous system impairment (intellectual disability, seizures, cerebellar signs, and pyramidal tract signs). Most affected individuals become wheelchair dependent in the second decade of life and eventually bedridden with severe polyneuropathy, ataxia, and dementia. Death usually occurs in the third decade. At the milder end of the spectrum are predominantly motor and sensory neuropathies (with little to no CNS involvement) that overlap with the axonal form of Charcot-Marie-Tooth neuropathies.
Keipert syndrome
MedGen UID:
338088
Concept ID:
C1850627
Disease or Syndrome
Keipert syndrome (KPTS) is characterized by craniofacial and digital abnormalities and variable learning difficulties. The distinctive facial appearance includes broad forehead, hypertelorism, prominent nose, wide mouth, and prominent upper lip with cupid bow configuration. Digital anomalies are also distinctive, with widening of all distal phalanges, particularly of the thumbs and great toes (Amor et al., 2019).
Renal coloboma syndrome
MedGen UID:
339002
Concept ID:
C1852759
Disease or Syndrome
PAX2-related disorder is an autosomal dominant disorder associated with renal and eye abnormalities. The disorder was originally referred to as renal coloboma syndrome and characterized by renal hypodysplasia and abnormalities of the optic nerve; with improved access to molecular testing, a wider range of phenotypes has been recognized in association with pathogenic variants in PAX2. Abnormal renal structure or function is noted in 92% of affected individuals and ophthalmologic abnormalities in 77% of affected individuals. Renal abnormalities can be clinically silent in rare individuals. In most individuals, clinically significant renal insufficiency / renal failure is reported. End-stage renal disease requiring renal transplant is not uncommon. Uric acid nephrolithiasis has been reported. Ophthalmologic abnormalities are typically described as optic nerve coloboma or dysplasia. Iris colobomas have not been reported in any individual with PAX2–related disorder. Ophthalmologic abnormalities may significantly impair vision in some individuals, while others have subtle changes only noted after detailed ophthalmologic examination. Additional clinical findings include high-frequency sensorineural hearing loss, soft skin, and ligamentous laxity. PAX2 pathogenic variants have been identified in multiple sporadic and familial cases of nonsyndromic renal disease including renal hypodysplasia and focal segmental glomerulosclerosis.
Autosomal recessive ataxia, Beauce type
MedGen UID:
343973
Concept ID:
C1853116
Disease or Syndrome
SYNE1 deficiency comprises a phenotypic spectrum that ranges from autosomal recessive cerebellar ataxia at the mild end to arthrogryposis multiplex congenita (AMC) at the severe end. SYNE1-deficient cerebellar ataxia, the most commonly recognized manifestation of SYNE1 deficiency to date, is a slowly progressive disorder typically beginning in adulthood (age range 6-45 years). While some individuals have a pure cerebellar syndrome (i.e., cerebellar ataxia, dysarthria, dysmetria, abnormalities in ocular saccades and smooth pursuit), many also have upper motor neuron dysfunction (spasticity, hyperreflexia, Babinski sign) and/or lower motor neuron dysfunction (amyotrophy, reduced reflexes, fasciculations). Most individuals develop features of the cerebellar cognitive and affective syndrome (i.e., significant deficits in attention, executive functioning, verbal working memory, and visuospatial/visuoconstructional skills). The two less common phenotypes are SYNE1-deficient childhood-onset multisystem disease (ataxia, upper and lower motor neuron dysfunction, muscle weakness and wasting, intellectual disability) and SYNE1-deficient arthrogryposis multiplex congenita (decreased fetal movements and severe neonatal hypotonia associated with multiple congenital joint contractures including clubfoot).
Phelan-McDermid syndrome
MedGen UID:
339994
Concept ID:
C1853490
Disease or Syndrome
Phelan-McDermid syndrome is characterized by neonatal hypotonia, absent to severely delayed speech, developmental delay, and minor dysmorphic facial features. Most affected individuals have moderate to profound intellectual disability. Other features include large fleshy hands, dysplastic toenails, and decreased perspiration that results in a tendency to overheat. Normal stature and normal head size distinguishes Phelan-McDermid syndrome from other autosomal chromosome disorders. Behavior characteristics include mouthing or chewing non-food items, decreased perception of pain, and autism spectrum disorder or autistic-like affect and behavior.
Intellectual disability, short stature, facial anomalies, and joint dislocations
MedGen UID:
342897
Concept ID:
C1853507
Disease or Syndrome
Spinocerebellar ataxia, autosomal recessive, with axonal neuropathy 2
MedGen UID:
340052
Concept ID:
C1853761
Disease or Syndrome
Ataxia with oculomotor apraxia type 2 (AOA2) is characterized by onset of ataxia between age three and 30 years after initial normal development, axonal sensorimotor neuropathy, oculomotor apraxia, cerebellar atrophy, and elevated serum concentration of alpha-fetoprotein (AFP).
Frontoocular syndrome
MedGen UID:
344278
Concept ID:
C1854405
Disease or Syndrome
Wiedemann-Steiner syndrome
MedGen UID:
340266
Concept ID:
C1854630
Disease or Syndrome
Wiedemann-Steiner syndrome (WSS) is characterized by developmental delay, intellectual disability, and characteristic facial features, with or without additional congenital anomalies. The facial features include thick eyebrows with lateral flare, vertically narrow and downslanted palpebral fissures, widely spaced eyes, long eyelashes, wide nasal bridge, broad nasal tip, thin vermilion of the upper lip, and thick scalp hair. About 60% of affected individuals have hypertrichosis cubiti ("hairy elbows"), which was once thought to be pathognomic for the syndrome, with a majority having hypertrichosis of other body parts. Other clinical features include feeding difficulties, prenatal and postnatal growth restriction, epilepsy, ophthalmologic anomalies, congenital heart defects, hand anomalies (such as brachydactyly and clinodactyly), hypotonia, vertebral anomalies (especially fusion anomalies of the cervical spine), renal and uterine anomalies, immune dysfunction, brain malformations, and dental anomalies.
Metaphyseal dysostosis-intellectual disability-conductive deafness syndrome
MedGen UID:
344437
Concept ID:
C1855175
Disease or Syndrome
Metaphyseal dysostosis-intellectual disability-conductive deafness syndrome is characterised by metaphyseal dysplasia, short-limb dwarfism, mild intellectual deficit and conductive hearing loss, associated with repeated episodes of otitis media in childhood. It has been described in three brothers born to consanguineous Sicilian parents. Variable manifestations included hyperopia and strabismus. The mode of inheritance is autosomal recessive.
Intellectual disability, autosomal recessive 1
MedGen UID:
344468
Concept ID:
C1855304
Mental or Behavioral Dysfunction
Any autosomal recessive non-syndromic intellectual disability in which the cause of the disease is a mutation in the PRSS12 gene.
Lambotte syndrome
MedGen UID:
343380
Concept ID:
C1855550
Disease or Syndrome
Oculocerebrofacial syndrome, Kaufman type
MedGen UID:
343403
Concept ID:
C1855663
Disease or Syndrome
Kaufman oculocerebrofacial syndrome (KOS) is characterized by developmental delay, severe intellectual disability, and distinctive craniofacial features. Most affected children have prenatal-onset microcephaly, hypotonia, and growth deficiency. Feeding issues, ocular abnormalities, hearing impairment, and respiratory tract abnormalities are common. Ocular abnormalities can include structural abnormalities (microcornea or microphthalmia, coloboma, optic nerve hypoplasia), refractive errors (myopia ± astigmatism, hyperopia), strabismus, and entropion. Both conductive and sensorineural hearing loss have been reported as well as mixed conductive-sensorineural hearing loss of variable severity. Breathing problems can lead to prolonged hospitalization after birth in more than half of individuals. Less common findings include ectodermal abnormalities, cardiac manifestations, urogenital abnormalities, seizures, and skeletal abnormalities.
L-2-hydroxyglutaric aciduria
MedGen UID:
341029
Concept ID:
C1855995
Disease or Syndrome
2-hydroxyglutaric aciduria is a condition that causes progressive damage to the brain. The major types of this disorder are called D-2-hydroxyglutaric aciduria (D-2-HGA), L-2-hydroxyglutaric aciduria (L-2-HGA), and combined D,L-2-hydroxyglutaric aciduria (D,L-2-HGA).\n\nThe main features of D-2-HGA are delayed development, seizures, weak muscle tone (hypotonia), and abnormalities in the largest part of the brain (the cerebrum), which controls many important functions such as muscle movement, speech, vision, thinking, emotion, and memory. Researchers have described two subtypes of D-2-HGA, type I and type II. The two subtypes are distinguished by their genetic cause and pattern of inheritance, although they also have some differences in signs and symptoms. Type II tends to begin earlier and often causes more severe health problems than type I. Type II may also be associated with a weakened and enlarged heart (cardiomyopathy), a feature that is typically not found with type I.\n\nL-2-HGA particularly affects a region of the brain called the cerebellum, which is involved in coordinating movements. As a result, many affected individuals have problems with balance and muscle coordination (ataxia). Additional features of L-2-HGA can include delayed development, seizures, speech difficulties, and an unusually large head (macrocephaly). Typically, signs and symptoms of this disorder begin during infancy or early childhood. The disorder worsens over time, usually leading to severe disability by early adulthood.\n\nCombined D,L-2-HGA causes severe brain abnormalities that become apparent in early infancy. Affected infants have severe seizures, weak muscle tone (hypotonia), and breathing and feeding problems. They usually survive only into infancy or early childhood.
Mowat-Wilson syndrome
MedGen UID:
341067
Concept ID:
C1856113
Disease or Syndrome
Mowat-Wilson syndrome (MWS) is characterized by distinctive facial features (widely spaced eyes, broad eyebrows with a medial flare, low-hanging columella, prominent or pointed chin, open-mouth expression, and uplifted earlobes with a central depression), congenital heart defects with predilection for abnormalities of the pulmonary arteries and/or valves, Hirschsprung disease or chronic constipation, genitourinary anomalies (particularly hypospadias in males), and hypogenesis or agenesis of the corpus callosum. Most affected individuals have moderate-to-severe intellectual disability. Speech is typically limited to a few words or is absent, with relative preservation of receptive language skills. Growth restriction with microcephaly and seizure disorder are also common. Most affected people have a happy demeanor and a wide-based gait that can sometimes be confused with Angelman syndrome.
Gaucher disease-ophthalmoplegia-cardiovascular calcification syndrome
MedGen UID:
341563
Concept ID:
C1856476
Disease or Syndrome
Gaucher disease (GD) encompasses a continuum of clinical findings from a perinatal lethal disorder to an asymptomatic type. The identification of three major clinical types (1, 2, and 3) and two other subtypes (perinatal-lethal and cardiovascular) is useful in determining prognosis and management. GD type 1 is characterized by the presence of clinical or radiographic evidence of bone disease (osteopenia, focal lytic or sclerotic lesions, and osteonecrosis), hepatosplenomegaly, anemia and thrombocytopenia, lung disease, and the absence of primary central nervous system disease. GD types 2 and 3 are characterized by the presence of primary neurologic disease; in the past, they were distinguished by age of onset and rate of disease progression, but these distinctions are not absolute. Disease with onset before age two years, limited psychomotor development, and a rapidly progressive course with death by age two to four years is classified as GD type 2. Individuals with GD type 3 may have onset before age two years, but often have a more slowly progressive course, with survival into the third or fourth decade. The perinatal-lethal form is associated with ichthyosiform or collodion skin abnormalities or with nonimmune hydrops fetalis. The cardiovascular form is characterized by calcification of the aortic and mitral valves, mild splenomegaly, corneal opacities, and supranuclear ophthalmoplegia. Cardiopulmonary complications have been described with all the clinical subtypes, although varying in frequency and severity.
Congenital lactic acidosis, Saguenay-Lac-Saint-Jean type
MedGen UID:
387801
Concept ID:
C1857355
Disease or Syndrome
Mitochondrial complex IV deficiency nuclear type 5 (MC4DN5) is an autosomal recessive severe metabolic multisystemic disorder with onset in infancy. Features include delayed psychomotor development, impaired intellectual development with speech delay, mild dysmorphic facial features, hypotonia, ataxia, and seizures. There is increased serum lactate and episodic hypoglycemia. Some patients may have cardiomyopathy, abnormal breathing, or liver abnormalities, reflecting systemic involvement. Brain imaging shows lesions in the brainstem and basal ganglia, consistent with a diagnosis of Leigh syndrome (see 256000). Affected individuals tend to have episodic metabolic and/or neurologic crises in early childhood, which often lead to early death (summary by Debray et al., 2011). For a discussion of genetic heterogeneity of mitochondrial complex IV (cytochrome c oxidase) deficiency, see 220110.
Cataract 9 multiple types
MedGen UID:
347693
Concept ID:
C1858679
Disease or Syndrome
Mutations in the CRYAA gene have been found to cause multiple types of cataract, which have been described as nuclear, zonular central nuclear, laminar, lamellar, anterior polar, posterior polar, cortical, embryonal, anterior subcapsular, fan-shaped, and total. Cataract associated with microcornea, sometimes called the cataract-microcornea syndrome, is also caused by mutation in the CRYAA gene. Both autosomal dominant and autosomal recessive modes of inheritance have been reported. The symbol CATC1 was formerly used for the autosomal recessive form of cataract caused by mutation in the CRYAA gene.
Infantile choroidocerebral calcification syndrome
MedGen UID:
395174
Concept ID:
C1859092
Disease or Syndrome
This syndrome has characteristics of intellectual deficit, calcification of the choroid plexus and elevated levels of cerebrospinal fluid protein. It has been described in two sibships from two unrelated families. The seven children of one of the sibships were born to consanguineous parents. Some patients also had strabismus, hyperactive deep tendon reflexes and foot deformities.
Sengers syndrome
MedGen UID:
395228
Concept ID:
C1859317
Disease or Syndrome
Sengers syndrome is an autosomal recessive mitochondrial disorder characterized by congenital cataracts, hypertrophic cardiomyopathy, skeletal myopathy, exercise intolerance, and lactic acidosis. Mental development is normal, but affected individuals may die early from cardiomyopathy (summary by Mayr et al., 2012). Skeletal muscle biopsies of 2 affected individuals showed severe mtDNA depletion (Calvo et al., 2012).
Microcephalic osteodysplastic primordial dwarfism, type 3
MedGen UID:
349167
Concept ID:
C1859439
Disease or Syndrome
Bardet-Biedl syndrome 9
MedGen UID:
347182
Concept ID:
C1859567
Disease or Syndrome
BBS9 is an autosomal recessive disorder characterized by obesity, polydactyly, renal anomalies, retinopathy, and mental retardation (Abu-Safieh et al., 2012). For a general phenotypic description and a discussion of genetic heterogeneity of Bardet-Biedl syndrome, see BBS1 (209900).
Noonan syndrome 3
MedGen UID:
349931
Concept ID:
C1860991
Disease or Syndrome
Noonan syndrome (NS) is characterized by characteristic facies, short stature, congenital heart defect, and developmental delay of variable degree. Other findings can include broad or webbed neck, unusual chest shape with superior pectus carinatum and inferior pectus excavatum, cryptorchidism, varied coagulation defects, lymphatic dysplasias, and ocular abnormalities. Although birth length is usually normal, final adult height approaches the lower limit of normal. Congenital heart disease occurs in 50%-80% of individuals. Pulmonary valve stenosis, often with dysplasia, is the most common heart defect and is found in 20%-50% of individuals. Hypertrophic cardiomyopathy, found in 20%-30% of individuals, may be present at birth or develop in infancy or childhood. Other structural defects include atrial and ventricular septal defects, branch pulmonary artery stenosis, and tetralogy of Fallot. Up to one fourth of affected individuals have mild intellectual disability, and language impairments in general are more common in NS than in the general population.
Strabismus, susceptibility to
MedGen UID:
350026
Concept ID:
C1861449
Finding
Strabismus, a misalignment of the eyes also referred to as 'squint,' is one of the most common ocular disorders in humans, affecting 1 to 4% of the population. It is frequently associated with amblyopia (uniocular visual neglect) (Parikh et al., 2003). Strabismus is also a feature of several syndromes, including congenital fibrosis of extraocular muscles (see, e.g., CFEOM1; 135700), Duane retraction syndrome (126800), and chronic progressive external ophthalmoplegia with myopathy (530000).
Brachydactyly-nystagmus-cerebellar ataxia syndrome
MedGen UID:
350589
Concept ID:
C1862099
Disease or Syndrome
A rare multiple congenital anomalies/dysmorphic syndrome characterized by brachydactyly, nystagmus, and cerebellar ataxia. Intellectual deficit and strabismus have also been reported. There have been no further descriptions in the literature since 1934.
Axenfeld-Rieger anomaly with partially absent eye muscles, distinctive face, hydrocephaly, and skeletal abnormalities
MedGen UID:
349489
Concept ID:
C1862373
Disease or Syndrome
Arthrogryposis- oculomotor limitation-electroretinal anomalies syndrome
MedGen UID:
350678
Concept ID:
C1862472
Disease or Syndrome
Distal arthrogryposis type 5 is distinguished from other forms of DA by the presence of ocular abnormalities, typically ptosis, ophthalmoplegia, and/or strabismus, in addition to contractures of the skeletal muscles. Some cases have been reported to have pulmonary hypertension as a result of restrictive lung disease (summary by Bamshad et al., 2009). There are 2 syndromes with features overlapping those of DA5 that are also caused by heterozygous mutation in PIEZO2: distal arthrogryposis type 3 (DA3, or Gordon syndrome; 114300) and Marden-Walker syndrome (MWKS; 248700), which are distinguished by the presence of cleft palate and mental retardation, respectively. McMillin et al. (2014) suggested that the 3 disorders might represent variable expressivity of the same condition. For a general phenotypic description and a discussion of genetic heterogeneity of distal arthrogryposis, see DA1A (108120). Genetic Heterogeneity of Distal Arthrogryposis 5 A subtype of DA5 due to mutation in the ECEL1 gene (605896) on chromosome 2q36 has been designated DA5D (615065). See NOMENCLATURE.
Muenke syndrome
MedGen UID:
355217
Concept ID:
C1864436
Disease or Syndrome
Muenke syndrome is defined by the presence of the specific FGFR3 pathogenic variant – c.749C>G – that results in the protein change p.Pro250Arg. Muenke syndrome is characterized by considerable phenotypic variability: features may include coronal synostosis (more often bilateral than unilateral); synostosis of other sutures, all sutures (pan synostosis), or no sutures; or macrocephaly. Bilateral coronal synostosis typically results in brachycephaly (reduced anteroposterior dimension of the skull), although turribrachycephaly (a "tower-shaped" skull) or a cloverleaf skull can be observed. Unilateral coronal synostosis results in anterior plagiocephaly (asymmetry of the skull and face). Other craniofacial findings typically include: temporal bossing; widely spaced eyes, ptosis or proptosis (usually mild); midface retrusion (usually mild); and highly arched palate or cleft lip and palate. Strabismus is common. Other findings can include: hearing loss (in 33%-100% of affected individuals); developmental delay (~33%); epilepsy; intracranial anomalies; intellectual disability; carpal bone and/or tarsal bone fusions; brachydactyly, broad toes, broad thumbs, and/or clinodactyly; and radiographic findings of thimble-like (short and broad) middle phalanges and/or cone-shaped epiphyses. Phenotypic variability is considerable even within the same family. Of note, some individuals who have the p.Pro250Arg pathogenic variant may have no signs of Muenke syndrome on physical or radiographic examination.
Rubinstein-Taybi syndrome due to 16p13.3 microdeletion
MedGen UID:
350477
Concept ID:
C1864648
Disease or Syndrome
Chromosome 16p13.3deletion syndrome is a chromosome abnormality that can affect many parts of the body. People with this condition are missing a small piece (deletion) of chromosome 16 at a location designated p13.3. Although once thought to be a severe form of Rubinstein-Taybi syndrome, it is now emerging as a unique syndrome. Signs and symptoms may include failure to thrive, hypotonia (reduced muscle tone), short stature, microcephaly (unusually small head), characteristic facial features, mild to moderate intellectual disability, organ anomalies (i.e. heart and/or kidney problems), and vulnerability to infections. Chromosome testing of both parents can provide information about whether the deletion was inherited. In most cases, parents do not have any chromosome abnormalities. However, sometimes one parent has a balanced translocation where a piece of a chromosome has broken off and attached to another one with no gain or loss of genetic material. The balanced translocation normally does not cause signs or symptoms, but it increases the risk for having a child with a chromosome abnormality like a deletion. Treatment is based on the signs and symptoms present in each person.To learn more about chromosome abnormalities in general, view our GARD fact sheet on Chromosome Disorders.
Congenital stromal corneal dystrophy
MedGen UID:
400601
Concept ID:
C1864738
Disease or Syndrome
Congenital stromal corneal dystrophy is characterized by the presence of bilateral corneal opacities that can be seen at or shortly after birth. The surface of the cornea is normal or slightly irregular; small opacities are seen throughout the stroma of the entire cornea and give the cornea a cloudy appearance. Strabismus is common. Nystagmus is uncommon. Amblyopia can develop in children.
Koolen-de Vries syndrome
MedGen UID:
355853
Concept ID:
C1864871
Disease or Syndrome
Koolen-de Vries syndrome (KdVS) is characterized by developmental delay / intellectual disability, neonatal/childhood hypotonia, dysmorphisms, congenital malformations, and behavioral features. Psychomotor developmental delay is noted in all individuals from an early age. The majority of individuals with KdVS function in the mild-to-moderate range of intellectual disability. Other findings include speech and language delay (100%), epilepsy (~33%), congenital heart defects (25%-50%), renal and urologic anomalies (25%-50%), and cryptorchidism (71% of males). Behavior in most is described as friendly, amiable, and cooperative.
Spondyloepimetaphyseal dysplasia, Genevieve type
MedGen UID:
355314
Concept ID:
C1864872
Disease or Syndrome
Spondyloepiphyseal dysplasia of the Genevieve type (SEMDG) is characterized by infantile-onset severe developmental delay and skeletal dysplasia, including short stature, premature carpal ossification, platyspondyly, longitudinal metaphyseal striations, and small epiphyses (summary by van Karnebeek et al., 2016).
Ectodermal dysplasia, sensorineural hearing loss, and distinctive facial features
MedGen UID:
355878
Concept ID:
C1864966
Disease or Syndrome
Colobomatous macrophthalmia-microcornea syndrome
MedGen UID:
400728
Concept ID:
C1865286
Disease or Syndrome
A rare genetic eye disease with characteristics of microcornea, coloboma of the iris and the optic disc, axial enlargement of the globe, staphyloma and severe myopia. Additional manifestations are mild cornea plana, iridocorneal angle abnormalities with elevation of intraocular pressure and shallow anterior chamber depth. Variable expressivity of the phenotype has been described, including unilateral or bilateral involvement or variable extent of coloboma among other features.
Desmosterolosis
MedGen UID:
400801
Concept ID:
C1865596
Disease or Syndrome
Desmosterolosis is a rare autosomal recessive disorder characterized by multiple congenital anomalies and elevated levels of the cholesterol precursor desmosterol in plasma, tissue, and cultured cells (summary by Waterham et al., 2001).
Pierpont syndrome
MedGen UID:
356049
Concept ID:
C1865644
Disease or Syndrome
Pierpont syndrome (PRPTS) is a multiple congenital anomaly syndrome associated with learning disability. Key features include distinctive facial characteristics, especially when smiling, plantar fat pads, and other limb anomalies (summary by Burkitt Wright et al., 2011).
Ehlers-Danlos syndrome, musculocontractural type
MedGen UID:
356497
Concept ID:
C1866294
Disease or Syndrome
Other types of Ehlers-Danlos syndrome have additional signs and symptoms. The cardiac-valvular type causes severe problems with the valves that control the movement of blood through the heart. People with the kyphoscoliotic type experience severe curvature of the spine that worsens over time and can interfere with breathing by restricting lung expansion. A type of Ehlers-Danlos syndrome called brittle cornea syndrome is characterized by thinness of the clear covering of the eye (the cornea) and other eye abnormalities. The spondylodysplastic type features short stature and skeletal abnormalities such as abnormally curved (bowed) limbs. Abnormalities of muscles, including hypotonia and permanently bent joints (contractures), are among the characteristic signs of the musculocontractural and myopathic forms of Ehlers-Danlos syndrome. The periodontal type causes abnormalities of the teeth and gums.\n\nBleeding problems are common in the vascular type of Ehlers-Danlos syndrome and are caused by unpredictable tearing (rupture) of blood vessels and organs. These complications can lead to easy bruising, internal bleeding, a hole in the wall of the intestine (intestinal perforation), or stroke. During pregnancy, women with vascular Ehlers-Danlos syndrome may experience rupture of the uterus. Additional forms of Ehlers-Danlos syndrome that involve rupture of the blood vessels include the kyphoscoliotic, classical, and classical-like types.\n\nMany people with the Ehlers-Danlos syndromes have soft, velvety skin that is highly stretchy (elastic) and fragile. Affected individuals tend to bruise easily, and some types of the condition also cause abnormal scarring. People with the classical form of Ehlers-Danlos syndrome experience wounds that split open with little bleeding and leave scars that widen over time to create characteristic "cigarette paper" scars. The dermatosparaxis type of the disorder is characterized by loose skin that sags and wrinkles, and extra (redundant) folds of skin may be present.\n\nAn unusually large range of joint movement (hypermobility) occurs in most forms of Ehlers-Danlos syndrome, and it is a hallmark feature of the hypermobile type. Infants and children with hypermobility often have weak muscle tone (hypotonia), which can delay the development of motor skills such as sitting, standing, and walking. The loose joints are unstable and prone to dislocation and chronic pain. In the arthrochalasia type of Ehlers-Danlos syndrome, infants have hypermobility and dislocations of both hips at birth.\n\nThe various forms of Ehlers-Danlos syndrome have been classified in several different ways. Originally, 11 forms of Ehlers-Danlos syndrome were named using Roman numerals to indicate the types (type I, type II, and so on). In 1997, researchers proposed a simpler classification (the Villefranche nomenclature) that reduced the number of types to six and gave them descriptive names based on their major features. In 2017, the classification was updated to include rare forms of Ehlers-Danlos syndrome that were identified more recently. The 2017 classification describes 13 types of Ehlers-Danlos syndrome.\n\nEhlers-Danlos syndrome is a group of disorders that affect connective tissues supporting the skin, bones, blood vessels, and many other organs and tissues. Defects in connective tissues cause the signs and symptoms of these conditions, which range from mildly loose joints to life-threatening complications.
Trichothiodystrophy 1, photosensitive
MedGen UID:
355730
Concept ID:
C1866504
Disease or Syndrome
Trichothiodystrophy is also associated with recurrent infections, particularly respiratory infections, which can be life-threatening. People with trichothiodystrophy may have abnormal red blood cells, including red blood cells that are smaller than normal. They may also have elevated levels of a type of hemoglobin called A2, which is a protein found in red blood cells. Other features of trichothiodystrophy can include dry, scaly skin (ichthyosis); abnormalities of the fingernails and toenails; clouding of the lens in both eyes from birth (congenital cataracts); poor coordination; and skeletal abnormalities including degeneration of both hips at an early age.\n\nAbout half of all people with trichothiodystrophy have a photosensitive form of the disorder, which causes them to be extremely sensitive to ultraviolet (UV) rays from sunlight. They develop a severe sunburn after spending just a few minutes in the sun. However, for reasons that are unclear, they do not develop other sun-related problems such as excessive freckling of the skin or an increased risk of skin cancer. Many people with trichothiodystrophy report that they do not sweat.\n\nIntellectual disability and delayed development are common in people with trichothiodystrophy, although most affected individuals are highly social with an outgoing and engaging personality. Some people with trichothiodystrophy have brain abnormalities that can be seen with imaging tests. A common neurological feature of this disorder is impaired myelin production (dysmyelination). Myelin is a fatty substance that insulates nerve cells and promotes the rapid transmission of nerve impulses.\n\nMothers of children with trichothiodystrophy may experience problems during pregnancy including pregnancy-induced high blood pressure (preeclampsia) and a related condition called HELLP syndrome that can damage the liver. Babies with trichothiodystrophy are at increased risk of premature birth, low birth weight, and slow growth. Most children with trichothiodystrophy have short stature compared to others their age. \n\nThe signs and symptoms of trichothiodystrophy vary widely. Mild cases may involve only the hair. More severe cases also cause delayed development, significant intellectual disability, and recurrent infections; severely affected individuals may survive only into infancy or early childhood.\n\nIn people with trichothiodystrophy, tests show that the hair is lacking sulfur-containing proteins that normally gives hair its strength. A cross section of a cut hair shows alternating light and dark banding that has been described as a "tiger tail."\n\nTrichothiodystrophy, commonly called TTD, is a rare inherited condition that affects many parts of the body. The hallmark of this condition is hair that is sparse and easily broken. 
Karsch-Neugebauer syndrome
MedGen UID:
401072
Concept ID:
C1866740
Disease or Syndrome
A rare syndrome with characteristics of split-hand and split-foot deformity and ocular abnormalities mainly a congenital nystagmus. Ten cases from four families have been reported in the literature. In some cases the hands are monodactylous. The affected patients have normal mental development. The condition seems to be autosomal dominant with a relatively high proportion of gonadal mosaicism.
Delayed speech-facial asymmetry-strabismus-ear lobe creases syndrome
MedGen UID:
355803
Concept ID:
C1866802
Disease or Syndrome
This syndrome is extremely rare and is characterized by delayed speech development, mild facial asymmetry, strabismus and transverse ear lobe creases.
Robinow-Sorauf syndrome
MedGen UID:
356703
Concept ID:
C1867146
Disease or Syndrome
The signs and symptoms of Saethre-Chotzen syndrome vary widely, even among affected individuals in the same family. This condition can cause mild changes in the hands and feet, such as partial fusion of the skin between the second and third fingers on each hand and a broad or duplicated first (big) toe. Delayed development and learning difficulties have been reported, although most people with this condition are of normal intelligence. Less common signs and symptoms of Saethre-Chotzen syndrome include short stature, abnormalities of the bones of the spine (the vertebra), hearing loss, and heart defects.\n\nMost people with Saethre-Chotzen syndrome have prematurely fused skull bones along the coronal suture, the growth line that goes over the head from ear to ear. Other parts of the skull may be malformed as well. These changes can result in an abnormally shaped head, a high forehead, a low frontal hairline, droopy eyelids (ptosis), widely spaced eyes, and a broad nasal bridge. One side of the face may appear noticeably different from the other (facial asymmetry). Most people with Saethre-Chotzen syndrome also have small, rounded ears.\n\nSaethre-Chotzen syndrome is a genetic condition characterized by the premature fusion of certain skull bones (craniosynostosis). This early fusion prevents the skull from growing normally and affects the shape of the head and face.\n\nRobinow-Sorauf syndrome is a condition with features similar to those of Saethre-Chotzen syndrome, including craniosynostosis and broad or duplicated great toes. It was once considered a separate disorder, but was found to result from mutations in the same gene and is now thought to be a variant of Saethre-Chotzen syndrome.
Ptosis-strabismus-ectopic pupils syndrome
MedGen UID:
356778
Concept ID:
C1867437
Disease or Syndrome
A rare disorder characterized by the association of ptosis, strabismus and ectopic pupils. It has been described in one family (in a mother and three of her children). Transmission is autosomal dominant.
Char syndrome
MedGen UID:
358356
Concept ID:
C1868570
Disease or Syndrome
Char syndrome is characterized by the triad of typical facial features, patent ductus arteriosus, and aplasia or hypoplasia of the middle phalanges of the fifth fingers. Typical facial features are depressed nasal bridge and broad flat nasal tip, widely spaced eyes, downslanted palpebral fissures, mild ptosis, short philtrum with prominent philtral ridges with an upward pointing vermilion border resulting in a triangular mouth, and thickened (patulous) everted lips. Less common findings include other types of congenital heart defects, other hand and foot anomalies, hypodontia, hearing loss, myopia and/or strabismus, polythelia, parasomnia, craniosynostosis (involving either the metopic or sagittal suture), and short stature.
4p partial monosomy syndrome
MedGen UID:
408255
Concept ID:
C1956097
Disease or Syndrome
Wolf-Hirschhorn syndrome is a congenital malformation syndrome characterized by pre- and postnatal growth deficiency, developmental disability of variable degree, characteristic craniofacial features ('Greek warrior helmet' appearance of the nose, high forehead, prominent glabella, hypertelorism, high-arched eyebrows, protruding eyes, epicanthal folds, short philtrum, distinct mouth with downturned corners, and micrognathia), and a seizure disorder (Battaglia et al., 2008).
Alagille syndrome due to a JAG1 point mutation
MedGen UID:
365434
Concept ID:
C1956125
Disease or Syndrome
Alagille syndrome (ALGS) is a multisystem disorder with a wide spectrum of clinical variability; this variability is seen even among individuals from the same family. The major clinical manifestations of ALGS are bile duct paucity on liver biopsy, cholestasis, congenital cardiac defects (primarily involving the pulmonary arteries), butterfly vertebrae, ophthalmologic abnormalities (most commonly posterior embryotoxon), and characteristic facial features. Renal abnormalities, growth failure, developmental delays, splenomegaly, and vascular abnormalities may also occur.
Intellectual disability, autosomal recessive 5
MedGen UID:
370849
Concept ID:
C1970199
Mental or Behavioral Dysfunction
Any autosomal recessive non-syndromic intellectual disability in which the cause of the disease is a mutation in the NSUN2 gene.
Polyhydramnios, megalencephaly, and symptomatic epilepsy
MedGen UID:
370203
Concept ID:
C1970203
Disease or Syndrome
A rare genetic neurological disorder with characteristics of pregnancy complicated by polyhydramnios, severe intractable epilepsy presenting in infancy, severe hypotonia, decreased muscle mass, global developmental delay, craniofacial dysmorphism (long face, large forehead, peaked eyebrows, broad nasal bridge, hypertelorism, large mouth with thick lips), and macrocephaly due to megalencephaly and hydrocephalus in most patients. Additional features that have been reported include cardiac anomalies like atrial septal defects, diabetes insipidus and nephrocalcinosis among others.
Pitt-Hopkins syndrome
MedGen UID:
370910
Concept ID:
C1970431
Disease or Syndrome
Pitt-Hopkins syndrome (PTHS) is characterized by significant developmental delays with moderate-to-severe intellectual disability and behavioral differences, characteristic facial features, and episodic hyperventilation and/or breath-holding while awake. Speech is significantly delayed and most individuals are nonverbal with receptive language often stronger than expressive language. Other common findings are autism spectrum disorder symptoms, sleep disturbance, stereotypic hand movements, seizures, constipation, and severe myopia.
Phosphoribosylpyrophosphate synthetase superactivity
MedGen UID:
370358
Concept ID:
C1970827
Disease or Syndrome
Phosphoribosylpyrophosphate synthetase (PRS) superactivity comprises two phenotypes, both characterized by hyperuricemia and hyperuricosuria. The mild phenotype (~75% of affected males) with onset in the second or third decade of life is typically limited to these biochemical findings, whereas the severe phenotype (~25% of affected males) with onset in the first decade of life has in addition to these biochemical findings variable combinations of developmental delay (DD) / intellectual disability (ID), sensorineural hearing loss, hypotonia, and ataxia. In the mild phenotype, uric acid crystalluria or a urinary stone is commonly the first clinical finding, followed later by gouty arthritis if serum urate concentration is not controlled.
Distal 10q deletion syndrome
MedGen UID:
436306
Concept ID:
C2674937
Disease or Syndrome
10q26 deletion syndrome is a condition that results from the loss (deletion) of a small piece of chromosome 10 in each cell. The deletion occurs on the long (q) arm of the chromosome at a position designated 10q26.\n\nThe signs and symptoms of 10q26 deletion syndrome vary widely, even among affected members of the same family. Among the more common features associated with this chromosomal change are distinctive facial features, mild to moderate intellectual disability, growth problems, and developmental delay. People with 10q26 deletion syndrome often have delayed development of speech and of motor skills such as sitting, crawling, and walking. Some have limited speech throughout life. Affected individuals may experience seizures, attention-deficit/hyperactivity disorder (ADHD), poor impulse control (impulsivity), or exhibit autistic behaviors that affect communication and social interaction.\n\nA range of facial features is seen in people with 10q26 deletion syndrome, but not all affected individuals have these features. Facial features of people with 10q26 deletion syndrome may include a prominent or beaked nose, a broad nasal bridge, a small jaw (micrognathia), malformed ears that are low set, a thin upper lip, and an unusually small head size (microcephaly). Many affected individuals have widely spaced eyes (hypertelorism) that do not look in the same direction (strabismus). Some people with this condition have a short neck with extra folds of skin (webbed neck).\n\nLess common signs and symptoms can occur in 10q26 deletion syndrome. Skeletal problems include a spine that curves to the side (scoliosis), limited movement in the elbows or other joints, or curved fifth fingers and toes (clinodactyly). Slow growth before and after birth can also occur in affected individuals. Males with this condition may have genital abnormalities, such as a small penis (micropenis), undescended testes (cryptorchidism), or the urethra opening on the underside of the penis (hypospadias). Some people with 10q26 deletion syndrome have kidney abnormalities, heart defects, breathing problems, recurrent infections, or hearing or vision problems.
Chromosome 15q26-qter deletion syndrome
MedGen UID:
390804
Concept ID:
C2675463
Disease or Syndrome
Distal monosomy 15q is a rare chromosomal anomaly syndrome characterized by pre- and postnatal growth restriction, developmental delay, variable degrees of intellectual disability, hand and foot anomalies (e.g. brachy-/clinodactyly, talipes equinovarus, nail hypoplasia, proximally placed digits) and mild craniofacial dysmorphism (incl. microcephaly, triangular face, broad nasal bridge, micrognathia). Neonatal lymphedema, heart malformations, aplasia cutis congenita, aortic root dilatation, and autistic spectrum disorder have also been reported.
Intellectual disability, autosomal dominant 5
MedGen UID:
382611
Concept ID:
C2675473
Mental or Behavioral Dysfunction
SYNGAP1-related intellectual disability (SYNGAP1-ID) is characterized by developmental delay (DD) or intellectual disability (ID) (100% of affected individuals), generalized epilepsy (~84%), and autism spectrum disorder (ASD) and other behavioral abnormalities (=50%). To date more than 50 individuals with SYNGAP1-ID have been reported. In the majority DD/ID was moderate to severe; in some it was mild. The epilepsy is generalized; a subset of individuals with epilepsy have myoclonic astatic epilepsy (Doose syndrome) or epilepsy with myoclonic absences. Behavioral abnormalities can include stereotypic behaviors (e.g., hand flapping, obsessions with certain objects) as well as poor social development. Feeding difficulties can be significant in some.
Chromosome 6pter-p24 deletion syndrome
MedGen UID:
393396
Concept ID:
C2675486
Disease or Syndrome
Distal monosomy 6p is responsible for a distinct chromosome deletion syndrome with a recognizable clinical picture including intellectual deficit, ocular abnormalities, hearing loss, and facial dysmorphism.
Chromosome 2p16.1-p15 deletion syndrome
MedGen UID:
390902
Concept ID:
C2675875
Disease or Syndrome
Chromosome 2p16.1-p15 deletion syndrome is a neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability, and variable but distinctive dysmorphic features, including microcephaly, bitemporal narrowing, smooth and long philtrum, hypertelorism, downslanting palpebral fissures, broad nasal root, thin upper lip, and high palate. Many patients have behavioral disorders, including autistic features, as well as structural brain abnormalities, such as pachygyria or hypoplastic corpus callosum. Those with deletions including the BCL11A gene (606557) also have persistence of fetal hemoglobin (HbF), which is asymptomatic and does not affected hematologic parameters or susceptibility to infection (summary by Funnell et al., 2015). Point mutation in the BCL11A gene causes intellectual developmental disorder with persistence of fetal hemoglobin (617101), which shows overlapping features. See also fetal hemoglobin quantitative trait locus-5 (HBFQTL5; 142335).
Chromosome 1q21.1 deletion syndrome
MedGen UID:
393913
Concept ID:
C2675897
Congenital Abnormality
The 1q21.1 recurrent microdeletion itself does not appear to lead to a clinically recognizable syndrome as some persons with the deletion have no obvious clinical findings and others have variable findings that most commonly include microcephaly (50%), mild intellectual disability (30%), mildly dysmorphic facial features, and eye abnormalities (26%). Other findings can include cardiac defects, genitourinary anomalies, skeletal malformations, and seizures (~15%). Psychiatric and behavioral abnormalities can include autism spectrum disorders, attention deficit hyperactivity disorder, autistic features, and sleep disturbances.
Diamond-Blackfan anemia 1
MedGen UID:
390966
Concept ID:
C2676137
Disease or Syndrome
Diamond-Blackfan anemia (DBA) is characterized by a profound normochromic and usually macrocytic anemia with normal leukocytes and platelets, congenital malformations in up to 50%, and growth deficiency in 30% of affected individuals. The hematologic complications occur in 90% of affected individuals during the first year of life. The phenotypic spectrum ranges from a mild form (e.g., mild anemia or no anemia with only subtle erythroid abnormalities, physical malformations without anemia) to a severe form of fetal anemia resulting in nonimmune hydrops fetalis. DBA is associated with an increased risk for acute myelogenous leukemia (AML), myelodysplastic syndrome (MDS), and solid tumors including osteogenic sarcoma.
Skeletal defects, genital hypoplasia, and intellectual disability
MedGen UID:
382795
Concept ID:
C2676231
Disease or Syndrome
Hypomyelinating leukodystrophy 4
MedGen UID:
383026
Concept ID:
C2677109
Disease or Syndrome
Any leukodystrophy in which the cause of the disease is a mutation in the HSPD1 gene.
Autosomal recessive ataxia due to ubiquinone deficiency
MedGen UID:
436985
Concept ID:
C2677589
Disease or Syndrome
Primary coenzyme Q10 (CoQ10) deficiency is usually associated with multisystem involvement, including neurologic manifestations such as fatal neonatal encephalopathy with hypotonia; a late-onset slowly progressive multiple-system atrophy-like phenotype (neurodegeneration with autonomic failure and various combinations of parkinsonism and cerebellar ataxia, and pyramidal dysfunction); and dystonia, spasticity, seizures, and intellectual disability. Steroid-resistant nephrotic syndrome (SRNS), the hallmark renal manifestation, is often the initial manifestation either as isolated renal involvement that progresses to end-stage renal disease (ESRD), or associated with encephalopathy (seizures, stroke-like episodes, severe neurologic impairment) resulting in early death. Hypertrophic cardiomyopathy (HCM), retinopathy or optic atrophy, and sensorineural hearing loss can also be seen.
Chromosome 15q13.3 microdeletion syndrome
MedGen UID:
393784
Concept ID:
C2677613
Congenital Abnormality
Individuals with the 15q13.3 recurrent deletion may have a wide range of clinical manifestations. The deletion itself may not lead to a clinically recognizable syndrome and a subset of persons with the recurrent deletion have no obvious clinical findings, implying that penetrance for the deletion is incomplete. A little over half of individuals diagnosed with this recurrent deletion have intellectual disability or developmental delay, mainly in the areas of speech acquisition and cognitive function. In the majority of individuals, cognitive impairment is mild. Other features reported in diagnosed individuals include epilepsy (in ~30%), mild hypotonia, and neuropsychiatric disorders (including autism spectrum disorder, attention-deficit/hyperactivity disorder, mood disorder, schizophrenia, and aggressive or self-injurious behavior). Congenital malformations are uncommon.
Syndromic X-linked intellectual disability Najm type
MedGen UID:
437070
Concept ID:
C2677903
Disease or Syndrome
CASK disorders include a spectrum of phenotypes in both females and males. Two main types of clinical presentation are seen: Microcephaly with pontine and cerebellar hypoplasia (MICPCH), generally associated with pathogenic loss-of-function variants in CASK. X-linked intellectual disability (XLID) with or without nystagmus, generally associated with hypomorphic CASK pathogenic variants. MICPCH is typically seen in females with moderate-to-severe intellectual disability, progressive microcephaly with or without ophthalmologic anomalies, and sensorineural hearing loss. Most are able to sit independently; 20%-25% attain the ability to walk; language is nearly absent in most. Neurologic features may include axial hypotonia, hypertonia/spasticity of the extremities, and dystonia or other movement disorders. Nearly 40% have seizures by age ten years. Behaviors may include sleep disturbances, hand stereotypies, and self biting. MICPCH in males may occur with or without severe epileptic encephalopathy in addition to severe-to-profound developmental delay. When seizures are present they occur early and may be intractable. In individuals and families with milder (i.e., hypomorphic) pathogenic variants, the clinical phenotype is usually that of XLID with or without nystagmus and additional clinical features. Males have mild-to-severe intellectual disability, with or without nystagmus and other ocular features. Females typically have normal intelligence with some displaying mild-to-severe intellectual disability with or without ocular features.
Intellectual disability, X-linked syndromic, Turner type
MedGen UID:
394425
Concept ID:
C2678046
Disease or Syndrome
Turner-type X-linked syndromic intellectual developmental disorder (MRXST) is a neurodevelopmental disorder with a highly variable phenotype. Some affected families show X-linked recessive inheritance, with only males being affected and carrier females having no abnormal findings. In other affected families, males are severely affected, and female mutation carriers show milder cognitive abnormalities or dysmorphic features. In addition, there are female patients with de novo mutations who show the full phenotype, despite skewed X-chromosome inactivation. Affected individuals show global developmental delay from infancy, with variably impaired intellectual development and poor or absent speech, often with delayed walking. Dysmorphic features are common and can include macrocephaly, microcephaly, deep-set eyes, hypotelorism, small palpebral fissures, dysplastic, large, or low-set ears, long face, bitemporal narrowing, high-arched palate, thin upper lip, and scoliosis or mild distal skeletal anomalies, such as brachydactyly or tapered fingers. Males tend to have cryptorchidism. Other features, such as hypotonia, seizures, and delayed bone age, are more variable (summary by Moortgat et al., 2018).
Christianson syndrome
MedGen UID:
394455
Concept ID:
C2678194
Disease or Syndrome
Christianson syndrome (referred to as CS in this GeneReview), an X-linked disorder, is characterized in males by cognitive dysfunction, behavioral disorder, and neurologic findings (e.g., seizures, ataxia, postnatal microcephaly, and eye movement abnormalities). Males with CS typically present with developmental delay, later meeting criteria for severe intellectual disability (ID). Behaviorally, autism spectrum disorder and hyperactivity are common, and may resemble the behaviors observed in Angelman syndrome. Hypotonia and oropharyngeal dysphagia in infancy may result in failure to thrive. Seizures, typically beginning before age three years, can include infantile spasms and tonic, tonic-clonic, myoclonic, and atonic seizures. Subsequently, regression (e.g., loss of ambulation and ability to feed independently) may occur. Manifestations in heterozygous females range from asymptomatic to mild ID and/or behavioral issues.
Mitochondrial DNA depletion syndrome, encephalomyopathic form with methylmalonic aciduria
MedGen UID:
413170
Concept ID:
C2749864
Disease or Syndrome
SUCLA2-related mitochondrial DNA (mtDNA) depletion syndrome, encephalomyopathic form with methylmalonic aciduria is characterized by onset of the following features in infancy or childhood (median age of onset 2 months; range of onset birth to 6 years): psychomotor retardation, hypotonia, dystonia, muscular atrophy, sensorineural hearing impairment, postnatal growth retardation, and feeding difficulties. Other less frequent features include distinctive facial features, contractures, kyphoscoliosis, gastroesophageal reflux, ptosis, choreoathetosis, ophthalmoplegia, and epilepsy (infantile spasms or generalized convulsions). The median survival is 20 years; approximately 30% of affected individuals succumb during childhood. Affected individuals may have hyperintensities in the basal ganglia, cerebral atrophy, and leukoencephalopathy on head MRI. Elevation of methylmalonic acid (MMA) in the urine and plasma is found in a vast majority of affected individuals, although at levels that are far below those typically seen in individuals with classic methylmalonic aciduria.
Hereditary spastic paraplegia 18
MedGen UID:
442343
Concept ID:
C2749936
Disease or Syndrome
Spastic paraplegia-18B (SPG18B) is a severe autosomal recessive neurologic disorder characterized by onset in early childhood of progressive spastic paraplegia resulting in motor disability. Most affected individuals have severe psychomotor retardation. Some may develop significant joint contractures (summary by Alazami et al., 2011 and Yildirim et al., 2011).
Cerebellar ataxia, intellectual disability, and dysequilibrium syndrome 2
MedGen UID:
412914
Concept ID:
C2750234
Disease or Syndrome
Cerebellar ataxia, impaired intellectual development, and dysequilibrium syndrome (CAMRQ) is a genetically heterogeneous disorder characterized by congenital cerebellar ataxia and intellectual disability (summary by Gulsuner et al., 2011). For a discussion of genetic heterogeneity of CAMRQ, see CAMRQ1 (224050).
Cerebellar ataxia, intellectual disability, and dysequilibrium syndrome 3
MedGen UID:
442496
Concept ID:
C2750509
Disease or Syndrome
Cerebellar ataxia, impaired intellectual development, and dysequilibrium syndrome (CAMRQ) is a genetically heterogeneous disorder characterized by congenital cerebellar ataxia and mental retardation (summary by Gulsuner et al., 2011). For a discussion of genetic heterogeneity of CAMRQ, see CAMRQ1 (224050).
Congenital stationary night blindness 1C
MedGen UID:
416373
Concept ID:
C2750747
Disease or Syndrome
The vision problems associated with this condition are congenital, which means they are present from birth. They tend to remain stable (stationary) over time.\n\nAutosomal recessive congenital stationary night blindness is a disorder of the retina, which is the specialized tissue at the back of the eye that detects light and color. People with this condition typically have difficulty seeing and distinguishing objects in low light (night blindness). For example, they may not be able to identify road signs at night or see stars in the night sky. They also often have other vision problems, including loss of sharpness (reduced acuity), nearsightedness (myopia), involuntary movements of the eyes (nystagmus), and eyes that do not look in the same direction (strabismus).
Hereditary spastic paraplegia 44
MedGen UID:
413042
Concept ID:
C2750784
Disease or Syndrome
A very rare, complex form of hereditary spastic paraplegia characterised by a late-onset, slowly progressive spastic paraplegia associated with mild ataxia and dysarthria, upper extremity involvement (i.e. loss of finger dexterity, dysmetria), and mild cognitive impairment, without the presence of nystagmus. A hypomyelinating leucodystrophy and thin corpus callosum is observed in all cases and psychomotor development is normal or near normal. Caused by mutations in the GJC2 gene (1q41-q42) encoding the gap junction gamma-2 protein.
Chromosome 5p13 duplication syndrome
MedGen UID:
416385
Concept ID:
C2750805
Disease or Syndrome
A rare partial autosomal trisomy/tetrasomy characterized by global developmental delay, intellectual disability, autistic behavior, muscular hypotonia, macrocephaly and facial dysmorphism (frontal bossing, short palpebral fissures, low set, dysplastic ears, short or shallow philtrum, high arched or narrow palate, micrognathia). Other associated clinical features include sleep disturbances, seizures, aplasia/hypoplasia of the corpus callosum, skeletal abnormalities (large hands and feet, long fingers and toes, talipes).
Autosomal recessive optic atrophy, OPA7 type
MedGen UID:
414112
Concept ID:
C2751812
Disease or Syndrome
A rare, syndromic, hereditary optic neuropathy disorder characterized by early-onset, severe, progressive visual impairment, optic disc pallor and central scotoma, variably associated with dyschromatopsia, auditory neuropathy (e.g. mild progressive sensorineural hearing loss), sensorimotor axonal neuropathy and, occasionally, moderate hypertrophic cardiomyopathy.
Microcephaly-facio-cardio-skeletal syndrome, Hadziselimovic type
MedGen UID:
414129
Concept ID:
C2751878
Disease or Syndrome
A rare syndrome with characteristics of pre-natal onset growth retardation (low birth weight and short stature), hypotonia, developmental delay and intellectual disability associated with microcephaly and craniofacial (low anterior hairline, hypotelorism, thick lips with carp-shaped mouth, high-arched palate, low-set ears), cardiac (conotruncal heart malformations such as tetralogy of Fallot) and skeletal (hypoplastic thumbs and first metacarpals) abnormalities.
Hereditary spastic paraplegia 50
MedGen UID:
442869
Concept ID:
C2752008
Disease or Syndrome
AP-4-associated hereditary spastic paraplegia (HSP), also known as AP-4 deficiency syndrome, is a group of neurodegenerative disorders characterized by a progressive, complex spastic paraplegia with onset typically in infancy or early childhood. Early-onset hypotonia evolves into progressive lower-extremity spasticity. The majority of children become nonambulatory and usually wheelchair bound. Over time spasticity progresses to involve the upper extremities, resulting in a spastic tetraplegia. Associated complications include dysphagia, contractures, foot deformities, dysregulation of bladder and bowel function, and a pseudobulbar affect. About 50% of affected individuals have seizures. Postnatal microcephaly (usually in the -2SD to -3SD range) is common. All have developmental delay. Speech development is significantly impaired and many affected individuals remain nonverbal. Intellectual disability in older children is usually moderate to severe.
ALG6-congenital disorder of glycosylation 1C
MedGen UID:
443952
Concept ID:
C2930997
Disease or Syndrome
Congenital disorders of glycosylation, previously called carbohydrate-deficient glycoprotein syndromes (CDGSs), are caused by defects in mannose addition during N-linked oligosaccharide assembly. CDGs can be divided into 2 types, depending on whether they impair lipid-linked oligosaccharide (LLO) assembly and transfer (CDG I), or affect trimming of the protein-bound oligosaccharide or the addition of sugars to it (CDG II) (Orlean, 2000). CDG Ic is characterized by psychomotor retardation with delayed walking and speech, hypotonia, seizures, and sometimes protein-losing enteropathy. It is the second largest subtype of CDG (summary by Sun et al., 2005). For a discussion of the classification of CDGs, see CDG1A (212065). Freeze and Aebi (1999) reviewed CDG Ib (602579) and CDG Ic.
Clark-Baraitser syndrome
MedGen UID:
443983
Concept ID:
C2931130
Disease or Syndrome
A rare genetic multiple congenital anomalies/dysmorphic syndrome characterized by intellectual disability, obesity, macrocephaly, behavioral abnormalities (such as aggressive tantrums and autistic-like behavior), and delayed speech development. Dysmorphic facial features include large, square forehead, prominent supraorbital ridges, broad nasal tip, large ears, prominent lower lip, and minor dental anomalies such as small upper lateral incisors and central incisor gap.
Cardiospondylocarpofacial syndrome
MedGen UID:
444060
Concept ID:
C2931461
Disease or Syndrome
Cardiospondylocarpofacial syndrome (CSCF) is characterized by growth retardation, dysmorphic facial features, brachydactyly with carpal-tarsal fusion, extensive posterior cervical vertebral synostosis, cardiac septal defects with valve dysplasia, and deafness with inner ear malformations (summary by Le Goff et al., 2016).
Intellectual disability, X-linked 1
MedGen UID:
444070
Concept ID:
C2931498
Mental or Behavioral Dysfunction
An X-linked dominant condition caused by mutation(s) in the IQSEC2 gene, encoding IQ motif and SEC7 domain-containing protein 2. It is characterized by substantially impaired intellectual functioning and behavioral abnormalities.
Familial hypertryptophanemia
MedGen UID:
419177
Concept ID:
C2931837
Disease or Syndrome
Congenital hypertryptophanemia, which is accompanied by hyperserotonemia, does not appear to have significant clinical consequences (Ferreira et al., 2017).
Bardet-Biedl syndrome 1
MedGen UID:
422452
Concept ID:
C2936862
Disease or Syndrome
Bardet-Biedl syndrome is an autosomal recessive and genetically heterogeneous ciliopathy characterized by retinitis pigmentosa, obesity, kidney dysfunction, polydactyly, behavioral dysfunction, and hypogonadism (summary by Beales et al., 1999). Eight proteins implicated in the disorder assemble to form the BBSome, a stable complex involved in signaling receptor trafficking to and from cilia (summary by Scheidecker et al., 2014). Genetic Heterogeneity of Bardet-Biedl Syndrome BBS2 (615981) is caused by mutation in a gene on 16q13 (606151); BBS3 (600151), by mutation in the ARL6 gene on 3q11 (608845); BBS4 (615982), by mutation in a gene on 15q22 (600374); BBS5 (615983), by mutation in a gene on 2q31 (603650); BBS6 (605231), by mutation in the MKKS gene on 20p12 (604896); BBS7 (615984), by mutation in a gene on 4q27 (607590); BBS8 (615985), by mutation in the TTC8 gene on 14q32 (608132); BBS9 (615986), by mutation in a gene on 7p14 (607968); BBS10 (615987), by mutation in a gene on 12q21 (610148); BBS11 (615988), by mutation in the TRIM32 gene on 9q33 (602290); BBS12 (615989), by mutation in a gene on 4q27 (610683); BBS13 (615990), by mutation in the MKS1 gene (609883) on 17q23; BBS14 (615991), by mutation in the CEP290 gene (610142) on 12q21, BBS15 (615992), by mutation in the WDPCP gene (613580) on 2p15; BBS16 (615993), by mutation in the SDCCAG8 gene (613524) on 1q43; BBS17 (615994), by mutation in the LZTFL1 gene (606568) on 3p21; BBS18 (615995), by mutation in the BBIP1 gene (613605) on 10q25; BBS19 (615996), by mutation in the IFT27 gene (615870) on 22q12; BBS20 (619471), by mutation in the IFT172 gene (607386) on 9p21; BBS21 (617406), by mutation in the CFAP418 gene (614477) on 8q22; and BBS22 (617119), by mutation in the IFT74 gene (608040) on 9p21. The CCDC28B gene (610162) modifies the expression of BBS phenotypes in patients who have mutations in other genes. Mutations in MKS1, MKS3 (TMEM67; 609884), and C2ORF86 also modify the expression of BBS phenotypes in patients who have mutations in other genes. Although BBS had originally been thought to be a recessive disorder, Katsanis et al. (2001) demonstrated that clinical manifestation of some forms of Bardet-Biedl syndrome requires recessive mutations in 1 of the 6 loci plus an additional mutation in a second locus. While Katsanis et al. (2001) called this 'triallelic inheritance,' Burghes et al. (2001) suggested the term 'recessive inheritance with a modifier of penetrance.' Mykytyn et al. (2002) found no evidence of involvement of the common BBS1 mutation in triallelic inheritance. However, Fan et al. (2004) found heterozygosity in a mutation of the BBS3 gene (608845.0002) as an apparent modifier of the expression of homozygosity of the met390-to-arg mutation in the BBS1 gene (209901.0001). Allelic disorders include nonsyndromic forms of retinitis pigmentosa: RP51 (613464), caused by TTC8 mutation, and RP55 (613575), caused by ARL6 mutation.
Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B3
MedGen UID:
461762
Concept ID:
C3150412
Disease or Syndrome
MDDGB3 is an autosomal recessive congenital muscular dystrophy with impaired intellectual development and mild brain abnormalities (Clement et al., 2008). It is part of a group of similar disorders resulting from defective glycosylation of alpha-dystroglycan (DAG1; 128239), collectively known as 'dystroglycanopathies' (Mercuri et al., 2009). For a discussion of genetic heterogeneity of congenital muscular dystrophy-dystroglycanopathy type B, see MDDGB1 (613155).
Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B2
MedGen UID:
461766
Concept ID:
C3150416
Disease or Syndrome
MDDGB2 is an autosomal recessive congenital muscular dystrophy associated with impaired intellectual development and mild structural brain abnormalities (Yanagisawa et al., 2007). It is part of a group of similar disorders, collectively known as 'dystroglycanopathies,' resulting from defective glycosylation of alpha-dystroglycan (DAG1; 128239) (Godfrey et al., 2007). For a discussion of genetic heterogeneity of congenital muscular dystrophy-dystroglycanopathy type B, see MDDGB1 (613155).
Frontonasal dysplasia with alopecia and genital anomaly
MedGen UID:
462053
Concept ID:
C3150703
Disease or Syndrome
Frontonasal dysplasia-2 (FND2) is an autosomal recessive disorder characterized by variable degrees of alopecia, skull defects, hypertelorism, depressed nasal bridge and ridge with notched alae nasi, and abnormal central nervous system findings (summary by Kariminejad et al., 2014).
Nephronophthisis 11
MedGen UID:
462146
Concept ID:
C3150796
Disease or Syndrome
The nephronophthisis (NPH) phenotype is characterized by reduced renal concentrating ability, chronic tubulointerstitial nephritis, cystic renal disease, and progression to end-stage renal disease (ESRD) before age 30 years. Three age-based clinical subtypes are recognized: infantile, juvenile, and adolescent/adult. Infantile NPH can present in utero with oligohydramnios sequence (limb contractures, pulmonary hypoplasia, and facial dysmorphisms) or postnatally with renal manifestations that progress to ESRD before age 3 years. Juvenile NPH, the most prevalent subtype, typically presents with polydipsia and polyuria, growth retardation, chronic iron-resistant anemia, or other findings related to chronic kidney disease (CKD). Hypertension is typically absent due to salt wasting. ESRD develops at a median age of 13 years. Ultrasound findings are increased echogenicity, reduced corticomedullary differentiation, and renal cysts (in 50% of affected individuals). Histologic findings include tubulointerstitial fibrosis, thickened and disrupted tubular basement membrane, sporadic corticomedullary cysts, and normal or reduced kidney size. Adolescent/adult NPH is clinically similar to juvenile NPH, but ESRD develops at a median age of 19 years. Within a subtype, inter- and intrafamilial variability in rate of progression to ESRD is considerable. Approximately 80%-90% of individuals with the NPH phenotype have no extrarenal features (i.e., they have isolated NPH); ~10%-20% have extrarenal manifestations that constitute a recognizable syndrome (e.g., Joubert syndrome, Bardet-Biedl syndrome, Jeune syndrome and related skeletal disorders, Meckel-Gruber syndrome, Senior-Løken syndrome, Leber congenital amaurosis, COACH syndrome, and oculomotor apraxia, Cogan type).
Combined oxidative phosphorylation defect type 7
MedGen UID:
462151
Concept ID:
C3150801
Disease or Syndrome
A rare mitochondrial disease due to a defect in mitochondrial protein synthesis with a variable phenotype that includes onset in infancy or early childhood of failure to thrive and psychomotor regression (after initial normal development), as well as ocular manifestations (such as ptosis, nystagmus, optic atrophy, ophthalmoplegia and reduced vision). Additional manifestations include bulbar paresis with facial weakness, hypotonia, difficulty chewing, dysphagia, mild dysarthria, ataxia, global muscle atrophy, and areflexia. It has a relatively slow disease progression with patients often living into the third decade of life.
Myopathy, lactic acidosis, and sideroblastic anemia 2
MedGen UID:
462152
Concept ID:
C3150802
Disease or Syndrome
Myopathy, lactic acidosis, and sideroblastic anemia-2 is an autosomal recessive disorder of the mitochondrial respiratory chain. The disorder shows marked phenotypic variability: some patients have a severe multisystem disorder from infancy, including cardiomyopathy and respiratory insufficiency resulting in early death, whereas others present in the second or third decade of life with sideroblastic anemia and mild muscle weakness (summary by Riley et al., 2013). For a discussion of genetic heterogeneity of MLASA, see MLASA1 (600462).
Cranioectodermal dysplasia 2
MedGen UID:
462224
Concept ID:
C3150874
Disease or Syndrome
Cranioectodermal dysplasia (CED) is a ciliopathy with skeletal involvement (narrow thorax, shortened proximal limbs, syndactyly, polydactyly, brachydactyly), ectodermal features (widely spaced hypoplastic teeth, hypodontia, sparse hair, skin laxity, abnormal nails), joint laxity, growth deficiency, and characteristic facial features (frontal bossing, low-set simple ears, high forehead, telecanthus, epicanthal folds, full cheeks, everted lower lip). Most affected children develop nephronophthisis that often leads to end-stage kidney disease in infancy or childhood, a major cause of morbidity and mortality. Hepatic fibrosis and retinal dystrophy are also observed. Dolichocephaly, often secondary to sagittal craniosynostosis, is a primary manifestation that distinguishes CED from most other ciliopathies. Brain malformations and developmental delay may also occur.
Chromosome 19p13.13 deletion syndrome
MedGen UID:
462244
Concept ID:
C3150894
Disease or Syndrome
19p13.13 deletion syndrome is a condition that results from a chromosomal change in which a small piece of chromosome 19 is deleted in each cell. The deletion occurs on the short (p) arm of the chromosome at a position designated p13.13.\n\nFeatures commonly associated with this chromosomal change include an unusually large head size (macrocephaly), tall stature, and intellectual disability that is usually moderate in severity. Many affected individuals have significantly delayed development, including speech, and children may speak few or no words. Weak muscle tone (hypotonia) and problems with coordinating muscle movement (ataxia) contribute to delays in gross motor skills (such as sitting and walking) and fine motor skills (such as holding a pencil).\n\nOther signs and symptoms that can occur with 19p13.13 deletion syndrome include seizures, abnormalities of brain structure, and mild differences in facial features (such as a prominent forehead). Many affected individuals have problems with feeding and digestion, including constipation, diarrhea, vomiting, and abdominal pain. Eye problems that can impair vision are also common. These include eyes that do not point in the same direction (strabismus) and underdevelopment of the optic nerves, which carry visual information from the eyes to the brain.\n\nThe signs and symptoms of 19p13.13 deletion syndrome vary among affected individuals. In part, this variation occurs because the size of the deletion, and the number of genes it affects, varies from person to person.
ALG11-congenital disorder of glycosylation
MedGen UID:
462263
Concept ID:
C3150913
Disease or Syndrome
A form of congenital disorders of N-linked glycosylation with characteristics of facial dysmorphism (microcephaly, high forehead, low posterior hairline, strabismus), hypotonia, failure to thrive, intractable seizures, developmental delay, persistent vomiting and gastric bleeding. Additional features that may be observed include fat pads anomalies, inverted nipples, and body temperature oscillation. The disease is caused by mutations in the gene ALG11 (13q14.3).
Intellectual disability, anterior maxillary protrusion, and strabismus
MedGen UID:
462274
Concept ID:
C3150924
Disease or Syndrome
A rare genetic multiple congenital anomalies/dysmorphic syndrome with the association of severe intellectual disability, strabismus and anterior maxillary protrusion with vertical maxillary excess, open bite and prominent crowded teeth. Mild cochlear hearing loss has been reported in addition.
Rubinstein-Taybi syndrome due to EP300 haploinsufficiency
MedGen UID:
462291
Concept ID:
C3150941
Disease or Syndrome
Rubinstein-Taybi syndrome (RSTS) is characterized by distinctive facial features, broad and often angulated thumbs and halluces, short stature, and moderate-to-severe intellectual disability. The characteristic craniofacial features are downslanted palpebral fissures, low-hanging columella, high palate, grimacing smile, and talon cusps. Prenatal growth is often normal, then height, weight, and head circumference percentiles rapidly drop in the first few months of life. Short stature is typical in adulthood. Obesity may develop in childhood or adolescence. Average IQ ranges between 35 and 50; however, developmental outcome varies considerably. Some individuals with EP300-RSTS have normal intellect. Additional features include ocular abnormalities, hearing loss, respiratory difficulties, congenital heart defects, renal abnormalities, cryptorchidism, feeding problems, recurrent infections, and severe constipation.
Noonan syndrome 7
MedGen UID:
462320
Concept ID:
C3150970
Disease or Syndrome
Noonan syndrome (NS) is characterized by characteristic facies, short stature, congenital heart defect, and developmental delay of variable degree. Other findings can include broad or webbed neck, unusual chest shape with superior pectus carinatum and inferior pectus excavatum, cryptorchidism, varied coagulation defects, lymphatic dysplasias, and ocular abnormalities. Although birth length is usually normal, final adult height approaches the lower limit of normal. Congenital heart disease occurs in 50%-80% of individuals. Pulmonary valve stenosis, often with dysplasia, is the most common heart defect and is found in 20%-50% of individuals. Hypertrophic cardiomyopathy, found in 20%-30% of individuals, may be present at birth or develop in infancy or childhood. Other structural defects include atrial and ventricular septal defects, branch pulmonary artery stenosis, and tetralogy of Fallot. Up to one fourth of affected individuals have mild intellectual disability, and language impairments in general are more common in NS than in the general population.
Chromosome 17p13.1 deletion syndrome
MedGen UID:
462419
Concept ID:
C3151069
Disease or Syndrome
Seckel syndrome 5
MedGen UID:
462537
Concept ID:
C3151187
Disease or Syndrome
Seckel syndrome is an autosomal recessive disorder characterized by proportionate short stature, severe microcephaly, mental retardation, and a typical 'bird-head' facial appearance (summary by Kalay et al., 2011). For a general phenotypic description and a discussion of genetic heterogeneity of Seckel syndrome, see 210600.
Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A3
MedGen UID:
462869
Concept ID:
C3151519
Disease or Syndrome
An autosomal recessive muscular dystrophy caused by mutations in the POMGNT1 gene. It is associated with characteristic brain and eye malformations, profound mental retardation, and death usually in the first years of life.
CK syndrome
MedGen UID:
463131
Concept ID:
C3151781
Disease or Syndrome
The NSDHL-related disorders include: CHILD (congenital hemidysplasia with ichthyosiform nevus and limb defects) syndrome, an X-linked condition that is usually male lethal during gestation and thus predominantly affects females; and CK syndrome, an X-linked disorder that affects males. CHILD syndrome is characterized by unilateral distribution of ichthyosiform (yellow scaly) skin lesions and ipsilateral limb defects that range from shortening of the metacarpals and phalanges to absence of the entire limb. Intellect is usually normal. The ichthyosiform skin lesions are usually present at birth or in the first weeks of life; new lesions can develop in later life. Nail changes are also common. The heart, lung, and kidneys can also be involved. CK syndrome (named for the initials of the original proband) is characterized by mild to severe cognitive impairment and behavior problems (aggression, attention deficit hyperactivity disorder, and irritability). All affected males reported have developed seizures in infancy and have cerebral cortical malformations and microcephaly. All have distinctive facial features, a thin habitus, and relatively long, thin fingers and toes. Some have scoliosis and kyphosis. Strabismus is common. Optic atrophy is also reported.
Fanconi anemia complementation group D2
MedGen UID:
463627
Concept ID:
C3160738
Disease or Syndrome
Fanconi anemia (FA) is characterized by physical abnormalities, bone marrow failure, and increased risk for malignancy. Physical abnormalities, present in approximately 75% of affected individuals, include one or more of the following: short stature, abnormal skin pigmentation, skeletal malformations of the upper and/or lower limbs, microcephaly, and ophthalmic and genitourinary tract anomalies. Progressive bone marrow failure with pancytopenia typically presents in the first decade, often initially with thrombocytopenia or leukopenia. The incidence of acute myeloid leukemia is 13% by age 50 years. Solid tumors – particularly of the head and neck, skin, and genitourinary tract – are more common in individuals with FA.
Fanconi anemia complementation group E
MedGen UID:
463628
Concept ID:
C3160739
Disease or Syndrome
Fanconi anemia (FA) is characterized by physical abnormalities, bone marrow failure, and increased risk for malignancy. Physical abnormalities, present in approximately 75% of affected individuals, include one or more of the following: short stature, abnormal skin pigmentation, skeletal malformations of the upper and/or lower limbs, microcephaly, and ophthalmic and genitourinary tract anomalies. Progressive bone marrow failure with pancytopenia typically presents in the first decade, often initially with thrombocytopenia or leukopenia. The incidence of acute myeloid leukemia is 13% by age 50 years. Solid tumors – particularly of the head and neck, skin, and genitourinary tract – are more common in individuals with FA.
Chromosome 15q11.2 deletion syndrome
MedGen UID:
467404
Concept ID:
C3180937
Disease or Syndrome
A heterozygous deletion of chromosome 15q11.2 may increase the susceptibility to neuropsychiatric or neurodevelopmental problems, including delayed psychomotor development, speech delay, autism spectrum disorder, attention deficit-hyperactivity disorder, obsessive-compulsive disorder, and possibly seizures (summary by Doornbos et al., 2009 and Burnside et al., 2011). See also chromosome 15q11.2 duplication syndrome (608636).
Syndromic X-linked intellectual disability Raymond type
MedGen UID:
477037
Concept ID:
C3275406
Disease or Syndrome
Raymond-type X-linked syndromic intellectual developmental disorder (MRXSR) is characterized by mildly to severely impaired intellectual development with speech and language difficulties associated with variable additional features, including marfanoid habitus, epilepsy, facial dysmorphism, hypotonia, and behavioral problems (summary by Baker et al., 2015 and Schirwani et al., 2018).
Intellectual disability, X-linked 90
MedGen UID:
477074
Concept ID:
C3275443
Mental or Behavioral Dysfunction
Any non-syndromic X-linked intellectual disability in which the cause of the disease is a mutation in the DLG3 gene.
Kabuki syndrome 2
MedGen UID:
477126
Concept ID:
C3275495
Disease or Syndrome
Kabuki syndrome (KS) is characterized by typical facial features (long palpebral fissures with eversion of the lateral third of the lower eyelid; arched and broad eyebrows; short columella with depressed nasal tip; large, prominent, or cupped ears), minor skeletal anomalies, persistence of fetal fingertip pads, mild-to-moderate intellectual disability, and postnatal growth deficiency. Other findings may include: congenital heart defects, genitourinary anomalies, cleft lip and/or palate, gastrointestinal anomalies including anal atresia, ptosis and strabismus, and widely spaced teeth and hypodontia. Functional differences can include: increased susceptibility to infections and autoimmune disorders, seizures, endocrinologic abnormalities (including isolated premature thelarche in females), feeding problems, and hearing loss.
Acrodysostosis 1 with or without hormone resistance
MedGen UID:
477858
Concept ID:
C3276228
Disease or Syndrome
Acrodysostosis-1 (ACRDYS1) is a form of skeletal dysplasia characterized by short stature, severe brachydactyly, facial dysostosis, and nasal hypoplasia. Affected individuals often have advanced bone age and obesity. Laboratory studies show resistance to multiple hormones, including parathyroid, thyrotropin, calcitonin, growth hormone-releasing hormone, and gonadotropin (summary by Linglart et al., 2011). However, not all patients show endocrine abnormalities (Lee et al., 2012). Genetic Heterogeneity of Acrodysostosis See also ACRDYS2 (614613), caused by mutation in the PDE4D gene (600129) on chromosome 5q12.
Optic atrophy with or without deafness, ophthalmoplegia, myopathy, ataxia, and neuropathy
MedGen UID:
478179
Concept ID:
C3276549
Disease or Syndrome
Syndromic optic atrophy, also known as DOA+ syndrome, is a neurologic disorder characterized most commonly by an insidious onset of visual loss and sensorineural hearing loss in childhood with variable presentation of other clinical manifestations including progressive external ophthalmoplegia (PEO), muscle cramps, hyperreflexia, and ataxia. There appears to be a wide range of intermediate phenotypes (Yu-Wai-Man et al., 2010).
Leber congenital amaurosis 16
MedGen UID:
481692
Concept ID:
C3280062
Disease or Syndrome
Leber congenital amaurosis, also known as LCA, is an eye disorder that is present from birth (congenital). This condition primarily affects the retina, which is the specialized tissue at the back of the eye that detects light and color. People with this disorder typically have severe visual impairment beginning at birth or shortly afterward. The visual impairment tends to be severe and may worsen over time.\n\nLeber congenital amaurosis is also associated with other vision problems, including an increased sensitivity to light (photophobia), involuntary movements of the eyes (nystagmus), and extreme farsightedness (hyperopia). The pupils, which usually expand and contract in response to the amount of light entering the eye, do not react normally to light. Instead, they expand and contract more slowly than normal, or they may not respond to light at all.\n\nA specific behavior called Franceschetti's oculo-digital sign is characteristic of Leber congenital amaurosis. This sign consists of affected individuals poking, pressing, and rubbing their eyes with a knuckle or finger. Poking their eyes often results in the sensation of flashes of light called phosphenes. Researchers suspect that this behavior may contribute to deep-set eyes in affected children.\n\nIn very rare cases, delayed development and intellectual disability have been reported in people with the features of Leber congenital amaurosis. Because of the visual loss, affected children may become isolated. Providing children with opportunities to play, hear, touch, understand and other early educational interventions may prevent developmental delays in children with Leber congenital amaurosis.\n\nAt least 20 genetic types of Leber congenital amaurosis have been described. The types are distinguished by their genetic cause, patterns of vision loss, and related eye abnormalities.
LAMB2-related infantile-onset nephrotic syndrome
MedGen UID:
481743
Concept ID:
C3280113
Disease or Syndrome
Nephrotic syndrome type 5 (NPHS5) is an autosomal recessive disorder characterized by very early onset of progressive renal failure manifest as proteinuria with consecutive edema starting in utero or within the first 3 months of life. A subset of patients may develop mild ocular anomalies, such as myopia, nystagmus, and strabismus (summary by Hasselbacher et al., 2006). Mutation in the LAMB2 gene can also cause Pierson syndrome (609049), which is characterized by nephrotic syndrome, distinct ocular anomalies, namely microcoria, and neurodevelopmental delay. For a general phenotypic description and a discussion of genetic heterogeneity of nephrotic syndrome, see NPHS1 (256300).
Rafiq syndrome
MedGen UID:
481757
Concept ID:
C3280127
Disease or Syndrome
Rafiq syndrome (RAFQS) is an autosomal recessive disorder characterized by variably impaired intellectual and motor development, a characteristic facial dysmorphism, truncal obesity, and hypotonia. The facial dysmorphism comprises prominent eyebrows with lateral thinning, downward-slanting palpebral fissures, bulbous tip of the nose, large ears, and a thin upper lip. Behavioral problems, including overeating, verbal and physical aggression, have been reported in some cases. Serum transferrin isoelectric focusing shows a type 2 pattern (summary by Balasubramanian et al., 2019).
Hyperphosphatasia with intellectual disability syndrome 3
MedGen UID:
481783
Concept ID:
C3280153
Disease or Syndrome
Hyperphosphatasia with impaired intellectual development syndrome-3 (HPMRS3) is an autosomal recessive disorder characterized by severe intellectual disability, hypotonia with poor motor development, poor speech, and increased serum alkaline phosphatase (summary by Hansen et al., 2013). However, the severity of the disorder can also vary to include more mild intellectual impairment (Krawitz et al., 2013). The disorder is caused by a defect in glycosylphosphatidylinositol (GPI) biosynthesis. For a discussion of genetic heterogeneity of HPMRS, see HPMRS1 (239300). For a discussion of genetic heterogeneity of GPI biosynthesis defects, see GPIBD1 (610293).
Adams-Oliver syndrome 2
MedGen UID:
481812
Concept ID:
C3280182
Disease or Syndrome
Adams-Oliver syndrome (AOS) is characterized by aplasia cutis congenita (ACC) of the scalp and terminal transverse limb defects (TTLD). ACC lesions usually occur in the midline of the parietal or occipital regions, but can also occur on the abdomen or limbs. At birth, an ACC lesion may already have the appearance of a healed scar. ACC lesions less than 5 cm often involve only the skin and almost always heal over a period of months; larger lesions are more likely to involve the skull and possibly the dura, and are at greater risk for complications, which can include infection, hemorrhage, or thrombosis, and can result in death. The limb defects range from mild (unilateral or bilateral short distal phalanges) to severe (complete absence of all toes or fingers, feet or hands, or more, often resembling an amputation). The lower extremities are almost always more severely affected than the upper extremities. Additional major features frequently include cardiovascular malformations/dysfunction (23%), brain anomalies, and less frequently renal, liver, and eye anomalies.
Chromosome 8q21.11 deletion syndrome
MedGen UID:
481861
Concept ID:
C3280231
Disease or Syndrome
The chromosome 8q21.11 deletion syndrome is characterized by impaired intellectual development and common facial dysmorphic features (summary by Palomares et al., 2011).
Cognitive impairment with or without cerebellar ataxia
MedGen UID:
482045
Concept ID:
C3280415
Disease or Syndrome
SCN8A-related epilepsy with encephalopathy is characterized by developmental delay, seizure onset in the first 18 months of life (mean 4 months), and intractable epilepsy characterized by multiple seizure types (generalized tonic-clonic seizures, infantile spasms, and absence and focal seizures). Epilepsy syndromes can include Lennox-Gastaut syndrome, West syndrome, and epileptic encephalopathies (e.g., Dravet syndrome). Hypotonia and movement disorders including dystonia, ataxia, and choreoathetosis are common. Psychomotor development varies from normal prior to seizure onset (with subsequent slowing or regression after seizure onset) to abnormal from birth. Intellectual disability, present in all, ranges from mild to severe (in ~50% of affected individuals). Autistic features are noted in some. Sudden unexpected death in epilepsy (SUDEP) of unknown cause has been reported in approximately 10% of published cases. To date SCN8A-related epilepsy with encephalopathy has been reported in the literature in about 50 individuals.
Pitt-Hopkins-like syndrome 2
MedGen UID:
482109
Concept ID:
C3280479
Disease or Syndrome
Any Pitt-Hopkins-like syndrome in which the cause of the disease is a mutation in the NRXN1 gene.
Encephalopathy, lethal, due to defective mitochondrial peroxisomal fission 1
MedGen UID:
482290
Concept ID:
C3280660
Disease or Syndrome
Encephalopathy due to defective mitochondrial and peroxisomal fission-1 (EMPF1) is characterized by delayed psychomotor development and hypotonia that may lead to death in childhood. Many patients develop refractory seizures, consistent with an epileptic encephalopathy, and thereafter show neurologic decline. The age at onset, features, and severity are variable, and some patients may not have clinical evidence of mitochondrial or peroxisomal dysfunction (summary by Sheffer et al., 2016; Fahrner et al., 2016). Genetic Heterogeneity of Encephalopathy Due to Defective Mitochondrial And Peroxisomal Fission See also EMPF2 (617086), caused by mutation in the MFF gene (614785) on chromosome 2q36.
Joubert syndrome 14
MedGen UID:
482396
Concept ID:
C3280766
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Psychomotor retardation, epilepsy, and craniofacial dysmorphism
MedGen UID:
482685
Concept ID:
C3281055
Disease or Syndrome
Neurodevelopmental disorder with hypotonia, craniofacial abnormalities, and seizures (NEDHCS) is an autosomal recessive syndrome characterized primarily by hypotonia and poor feeding apparent in early infancy. Affected individuals have severe global developmental delay, early-onset intractable seizures, and recognizable craniofacial dysmorphism with skull abnormalities. The disorder is believed to be unique to the Amish population, where it exhibits a founder effect (summary by Ammous et al., 2021).
Congenital disorder of glycosylation type Ir
MedGen UID:
482714
Concept ID:
C3281084
Disease or Syndrome
Congenital disorder of glycosylation type Ir (CDG1R) is an autosomal recessive disorder characterized by developmental delay, failure to thrive, feeding difficulties, hypotonia, and strabismus. Transferrin analysis demonstrates underglycosylation (summary by Pi et al., 2022). For a discussion of the classification of CDGs, see CDG1A (212065).
Infantile cerebellar-retinal degeneration
MedGen UID:
482822
Concept ID:
C3281192
Disease or Syndrome
Infantile cerebellar-retinal degeneration (ICRD) is a severe autosomal recessive neurodegenerative disorder characterized by onset between ages 2 and 6 months of truncal hypotonia, athetosis, seizures, and ophthalmologic abnormalities, particularly optic atrophy and retinal degeneration. Affected individuals show profound psychomotor retardation, with only some achieving rolling, sitting, or recognition of family. Brain MRI shows progressive cerebral and cerebellar degeneration (summary by Spiegel et al., 2012). A subset of patients may have a milder phenotype with variable features, including ataxia, developmental delay, and behavioral abnormalities (Blackburn et al., 2020). Mutation in the ACO2 gene also causes isolated optic atrophy (OPA9; 616289).
Coffin-Siris syndrome 1
MedGen UID:
482831
Concept ID:
C3281201
Disease or Syndrome
Coffin-Siris syndrome (CSS) is classically characterized by aplasia or hypoplasia of the distal phalanx or nail of the fifth and additional digits, developmental or cognitive delay of varying degree, distinctive facial features, hypotonia, hirsutism/hypertrichosis, and sparse scalp hair. Congenital anomalies can include malformations of the cardiac, gastrointestinal, genitourinary, and/or central nervous systems. Other findings commonly include feeding difficulties, slow growth, ophthalmologic abnormalities, and hearing impairment.
Congenital stationary night blindness 1E
MedGen UID:
482845
Concept ID:
C3281215
Disease or Syndrome
Complete congenital stationary night blindness (cCSNB) is a clinically and genetically heterogeneous group of retinal disorders characterized by nonprogressive impairment of night vision, absence of the electroretinogram (ERG) b-wave, and variable degrees of involvement of other visual functions. Individuals with cCSNB and animal models of the disorder have an ERG waveform that lacks the b-wave because of failure to transmit the photoreceptor signal through the retinal depolarizing bipolar cells (summary by Peachey et al., 2012). For a general phenotypic description and a discussion of genetic heterogeneity of congenital stationary night blindness, see CSNB1A (310500).
Fanconi anemia complementation group C
MedGen UID:
483324
Concept ID:
C3468041
Disease or Syndrome
Fanconi anemia (FA) is characterized by physical abnormalities, bone marrow failure, and increased risk for malignancy. Physical abnormalities, present in approximately 75% of affected individuals, include one or more of the following: short stature, abnormal skin pigmentation, skeletal malformations of the upper and/or lower limbs, microcephaly, and ophthalmic and genitourinary tract anomalies. Progressive bone marrow failure with pancytopenia typically presents in the first decade, often initially with thrombocytopenia or leukopenia. The incidence of acute myeloid leukemia is 13% by age 50 years. Solid tumors – particularly of the head and neck, skin, and genitourinary tract – are more common in individuals with FA.
Fanconi anemia complementation group A
MedGen UID:
483333
Concept ID:
C3469521
Disease or Syndrome
Fanconi anemia (FA) is characterized by physical abnormalities, bone marrow failure, and increased risk for malignancy. Physical abnormalities, present in approximately 75% of affected individuals, include one or more of the following: short stature, abnormal skin pigmentation, skeletal malformations of the upper and/or lower limbs, microcephaly, and ophthalmic and genitourinary tract anomalies. Progressive bone marrow failure with pancytopenia typically presents in the first decade, often initially with thrombocytopenia or leukopenia. The incidence of acute myeloid leukemia is 13% by age 50 years. Solid tumors – particularly of the head and neck, skin, and genitourinary tract – are more common in individuals with FA.
Hereditary spastic paraplegia 35
MedGen UID:
501249
Concept ID:
C3496228
Disease or Syndrome
Fatty acid hydroxylase-associated neurodegeneration (FAHN) is characterized early in the disease course by central nervous system involvement including corticospinal tract involvement (spasticity), mixed movement disorder (ataxia/dystonia), and eye findings (optic atrophy, oculomotor abnormalities), and later in the disease course by progressive intellectual impairment and seizures. With disease progression, dystonia and spasticity compromise the ability to ambulate, leading to wheelchair dependence. Life expectancy is variable. FAHN is considered to be a subtype of neurodegeneration with brain iron accumulation (NBIA).
Hereditary spastic paraplegia 54
MedGen UID:
761341
Concept ID:
C3539495
Disease or Syndrome
Spastic paraplegia-54 (SPG54) is a complicated form of spastic paraplegia, a neurodegenerative disorder affecting fibers of the corticospinal tract. Affected individuals have delayed psychomotor development, intellectual disability, and early-onset spasticity of the lower limbs. Brain MRI shows a thin corpus callosum and periventricular white matter lesions. Brain magnetic resonance spectroscopy shows an abnormal lipid peak (summary by Schuurs-Hoeijmakers et al., 2012). For a general phenotypic description and a discussion of genetic heterogeneity of autosomal recessive spastic paraplegia, see 270800.
Hereditary spastic paraplegia 55
MedGen UID:
761342
Concept ID:
C3539506
Disease or Syndrome
A rare complex type of hereditary spastic paraplegia with characteristics of childhood onset of progressive spastic paraplegia associated with optic atrophy (with reduced visual acuity and central scotoma), ophthalmoplegia, reduced upper-extremity strength and dexterity, muscular atrophy in the lower extremities and sensorimotor neuropathy. Caused by mutations in the C12ORF65 gene (12q24.31) encoding probable peptide chain release factor C12ORF65, mitochondrial.
Short stature-optic atrophy-Pelger-HuC+t anomaly syndrome
MedGen UID:
762020
Concept ID:
C3541319
Disease or Syndrome
Among the Yakuts, an Asian population isolate that is located in the northeastern part of Siberia, Maksimova et al. (2010) ascertained an autosomal recessive short stature syndrome involving postnatal growth failure, small hands and feet, loss of visual acuity with abnormalities of color vision, abnormal nuclear shape in neutrophil granulocytes (Pelger-Huet anomaly; see 169400), and normal intelligence.
Pontine tegmental cap dysplasia
MedGen UID:
762040
Concept ID:
C3541340
Disease or Syndrome
Pontine tegmental cap dysplasia (PTCD) refers to a neurologic condition characterized by a distinct pattern of hindbrain malformations apparent on brain imaging. The abnormalities affect the pons, medulla, and cerebellum. In neuroradiologic studies, the ventral side of the pons is flattened, whereas there is vaulting ('capping') of the dorsal pontine border into the fourth ventricle. Affected individuals show a variety of neurologic deficits, most commonly sensorineural deafness, impaired cranial nerve function, and variable psychomotor retardation (summary by Barth et al., 2007).
Intellectual disability, autosomal dominant 14
MedGen UID:
766161
Concept ID:
C3553247
Disease or Syndrome
Coffin-Siris syndrome is a congenital malformation syndrome characterized by developmental delay, intellectual disability, coarse facial features, feeding difficulties, and hypoplastic or absent fifth fingernails and fifth distal phalanges. Other more variable features may also occur. Patients with ARID1A mutations have a wide spectrum of manifestations, from severe intellectual disability and serious internal complications that could result in early death to mild intellectual disability (summary by Kosho et al., 2014). For a general phenotypic description and a discussion of genetic heterogeneity of Coffin-Siris syndrome, see CSS1 (135900). The chromosome 1p36.11 duplication syndrome, in which the ARID1A gene is duplicated, is characterized by impaired intellectual development, microcephaly, dysmorphic facial features, and hand and foot anomalies.
Pontocerebellar hypoplasia type 1B
MedGen UID:
766363
Concept ID:
C3553449
Disease or Syndrome
EXOSC3 pontocerebellar hypoplasia (EXOSC3-PCH) is characterized by abnormalities in the posterior fossa and degeneration of the anterior horn cells. At birth, skeletal muscle weakness manifests as hypotonia (sometimes with congenital joint contractures) and poor feeding. In persons with prolonged survival, spasticity, dystonia, and seizures become evident. Within the first year of life respiratory insufficiency and swallowing difficulties are common. Intellectual disability is severe. Life expectancy ranges from a few weeks to adolescence. To date, 82 individuals (from 58 families) with EXOSC3-PCH have been described.
Malan overgrowth syndrome
MedGen UID:
766574
Concept ID:
C3553660
Disease or Syndrome
Malan syndrome (MALNS) is clinically characterized by overgrowth, advanced bone age, macrocephaly, and dysmorphic facial features. Patients develop marfanoid habitus, with long and slender body, very low body mass, long narrow face, and arachnodactyly, with age. Impaired intellectual development and behavior anomalies are present (summary by Martinez et al., 2015).
Cerebellar dysfunction with variable cognitive and behavioral abnormalities
MedGen UID:
766575
Concept ID:
C3553661
Disease or Syndrome
Cerebellar dysfunction with variable cognitive and behavioral abnormalities (CECBA) is an autosomal dominant neurologic disorder with significant phenotypic heterogeneity, even within families. The disorder is most often diagnosed through genetic analysis with retrospective clinical phenotyping. Symptom onset is usually in early childhood, although later onset, even in adulthood, has been reported. Most affected individuals show global developmental delay from early childhood, particularly of motor and language skills. Many have mild intellectual disability; behavioral and psychiatric abnormalities such as autism and obsessive-compulsive disorder are also often observed. The movement disorder is prominent and may include cerebellar signs such as ataxia, tremor, dysmetria, poor coordination, and dysarthria. Other abnormal movements including spasticity, myoclonus, and dystonia have been reported, thus widening the phenotypic spectrum. Brain imaging is usually normal, but may show cerebellar atrophy or nonspecific white matter lesions. Variable dysmorphic facial features may also be present (summary by Thevenon et al., 2012; Jacobs et al., 2021; Wijnen et al., 2020).
Autosomal recessive spinocerebellar ataxia 13
MedGen UID:
766730
Concept ID:
C3553816
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-13 (SCAR13) is an autosomal recessive neurologic disorder characterized by delayed psychomotor development beginning in infancy. Affected individuals show mildly to profoundly impaired intellectual development with poor or absent speech as well as gait and stance ataxia and hyperreflexia. Most individuals also have eye movement abnormalities. Brain MRI shows cerebellar atrophy and ventriculomegaly (Guergueltcheva et al., 2012).
Peroxisome biogenesis disorder 14B
MedGen UID:
766969
Concept ID:
C3554055
Disease or Syndrome
PBD14B is an autosomal recessive peroxisome biogenesis disorder characterized clinically by mild intellectual disability, congenital cataracts, progressive hearing loss, and polyneuropathy (Ebberink et al., 2012), all of which had been observed in patients with mild peroxisomal biogenesis disorders (e.g., Kelley et al., 1986; Poll-The et al., 1987). Additionally, recurrent migraine-like episodes following mental stress or physical exertion, not a common feature in peroxisome disorders, was reported. Thoms and Gartner (2012) classified the disorder described by Ebberink et al. (2012) in their patient as a mild 'Zellweger syndrome (214100) spectrum' (ZSS) disorder. See PBD1B (601539) for a phenotypic description and discussion of genetic heterogeneity of less severe phenotypes on the Zellweger syndrome spectrum. See PBD9B (614879) for another atypical peroxisome biogenesis disorder.
Schuurs-Hoeijmakers syndrome
MedGen UID:
767257
Concept ID:
C3554343
Disease or Syndrome
PACS1 neurodevelopmental disorder (PACS1-NDD) is characterized by mild-to-severe neurodevelopmental delays. Language skills are more severely affected than motor skills. Hypotonia is reported in about a third of individuals and is noted to improve over time. Approximately 60% of individuals are ambulatory. Feeding difficulty is common, with 25% requiring gastrostomy tube to maintain appropriate caloric intake. Other common features include constipation, seizures, behavioral issues, congenital heart anomalies, short stature, and microcephaly. Common facial features include hypertelorism, downslanting palpebral fissures, bulbous nasal tip, low-set and simple ears, smooth philtrum, wide mouth with downturned corners, thin upper vermilion, and wide-spaced teeth. To date approximately 35 individuals with PACS1-NDD have been reported.
Congenital stationary night blindness 1F
MedGen UID:
767313
Concept ID:
C3554399
Disease or Syndrome
Autosomal recessive congenital stationary night blindness is a disorder of the retina, which is the specialized tissue at the back of the eye that detects light and color. People with this condition typically have difficulty seeing and distinguishing objects in low light (night blindness). For example, they may not be able to identify road signs at night or see stars in the night sky. They also often have other vision problems, including loss of sharpness (reduced acuity), nearsightedness (myopia), involuntary movements of the eyes (nystagmus), and eyes that do not look in the same direction (strabismus).\n\nThe vision problems associated with this condition are congenital, which means they are present from birth. They tend to remain stable (stationary) over time.
Microcephalic primordial dwarfism, Alazami type
MedGen UID:
767353
Concept ID:
C3554439
Disease or Syndrome
Alazami syndrome is an autosomal recessive disorder characterized by severe growth restriction present at birth, severely impaired intellectual development, and distinctive facial features. Some patients have been reported with skeletal and behavioral features (summary by Imbert-Bouteille et al., 2019).
Severe intellectual disability-poor language-strabismus-grimacing face-long fingers syndrome
MedGen UID:
767362
Concept ID:
C3554448
Disease or Syndrome
GAND syndrome is a neurodevelopmental syndrome characterized by global developmental delay apparent from infancy, with motor delay and moderate to severely impaired intellectual development. Most patients have poor speech acquisition, especially expressive language development, and may manifest signs of speech apraxia. Affected individuals have hypotonia and feeding difficulties in infancy, as well as common dysmorphic features, such as macrocephaly, frontal bossing, hypertelorism, deep-set eyes, posteriorly rotated ears, and elongated wide nose with prominent nasal tip. More variable features may include seizures, cardiac abnormalities, and nonspecific findings on brain imaging (summary by Shieh et al., 2020).
Severe intellectual disability-progressive spastic diplegia syndrome
MedGen UID:
767363
Concept ID:
C3554449
Disease or Syndrome
CTNNB1 neurodevelopmental disorder (CTNNB1-NDD) is characterized in all individuals by mild-to-profound cognitive impairment and in up to 39% of reported individuals by exudative vitreoretinopathy, an ophthalmologic finding consistent with familial exudative vitreoretinopathy (FEVR). Other common findings include truncal hypotonia, peripheral spasticity, dystonia, behavior problems, microcephaly, and refractive errors and strabismus. Less common features include intrauterine growth restriction, feeding difficulties, and scoliosis.
Hydrocephalus, nonsyndromic, autosomal recessive 2
MedGen UID:
767605
Concept ID:
C3554691
Disease or Syndrome
Congenital hydrocephalus-2 (HYC2) is a congenital disorder with onset in utero. Affected individuals have hydrocephalus with variably dilated ventricles and variable neurologic sequelae. Some individuals have other brain abnormalities, including lissencephaly, thinning of the corpus callosum, and neuronal heterotopia. Most patients have delayed motor development and some have delayed intellectual development and/or seizures. Additional congenital features, including cardiac septal defects, iris coloboma, and nonspecific dysmorphic features, may be observed. Some patients die in utero, in infancy, or in early childhood, whereas others have long-term survival (summary by Shaheen et al., 2017). For a discussion of genetic heterogeneity of congenital hydrocephalus, see 233600.
Congenital reticular ichthyosiform erythroderma
MedGen UID:
777141
Concept ID:
C3665704
Disease or Syndrome
Ichthyosis with confetti (IWC), also known as congenital reticular ichthyosiform erythroderma (CRIE), is a rare skin condition characterized by slowly enlarging islands of normal skin surrounded by erythematous ichthyotic patches in a reticulated pattern. The condition starts in infancy as a lamellar ichthyosis, with small islands of normal skin resembling confetti appearing in late childhood and at puberty. Histopathologic findings include band-like parakeratosis, psoriasiform acanthosis, and vacuolization of keratinocytes with binucleated cells in the upper epidermis, sometimes associated with amyloid deposition in the dermis. Ultrastructural abnormalities include perinuclear shells formed from a network of fine filaments in the upper epidermis (summary by Krunic et al., 2003).
Charcot-Marie-Tooth disease type 4B3
MedGen UID:
811329
Concept ID:
C3695063
Disease or Syndrome
A subtype of Charcot-Marie-Tooth type 4 with characteristics of childhood onset of slowly progressing, demyelinating sensorimotor neuropathy, focally folded myelin sheaths in nerve biopsy, reduced nerve conduction velocities and the typical Charcot-Marie-Tooth phenotype (i.e. distal muscle weakness and atrophy, and sensory loss). There is evidence this disease is caused by homozygous or compound heterozygous mutation in the SBF1 gene on chromosome 22q.
Blepharophimosis - intellectual disability syndrome, MKB type
MedGen UID:
785805
Concept ID:
C3698541
Disease or Syndrome
MED12-related disorders include the phenotypes of FG syndrome type 1 (FGS1), Lujan syndrome (LS), X-linked Ohdo syndrome (XLOS), Hardikar syndrome (HS), and nonspecific intellectual disability (NSID). FGS1 and LS share the clinical findings of cognitive impairment, hypotonia, and abnormalities of the corpus callosum. FGS1 is further characterized by absolute or relative macrocephaly, tall forehead, downslanted palpebral fissures, small and simple ears, constipation and/or anal anomalies, broad thumbs and halluces, and characteristic behavior. LS is further characterized by large head, tall thin body habitus, long thin face, prominent nasal bridge, high narrow palate, and short philtrum. Carrier females in families with FGS1 and LS are typically unaffected. XLOS is characterized by intellectual disability, blepharophimosis, and facial coarsening. HS has been described in females with cleft lip and/or cleft palate, biliary and liver anomalies, intestinal malrotation, pigmentary retinopathy, and coarctation of the aorta. Developmental and cognitive concerns have not been reported in females with HS. Pathogenic variants in MED12 have been reported in an increasing number of males and females with NSID, with affected individuals often having clinical features identified in other MED12-related disorders.
Axenfeld-Rieger syndrome type 1
MedGen UID:
811487
Concept ID:
C3714873
Disease or Syndrome
Axenfeld-Rieger syndrome is an autosomal dominant disorder of morphogenesis that results in abnormal development of the anterior segment of the eye, and results in blindness from glaucoma in approximately 50% of affected individuals (Fitch and Kaback, 1978). Systemic anomalies are associated, including dental hypoplasia, failure of involution of periumbilical skin, and maxillary hypoplasia (Alkemade, 1969). Genetic Heterogeneity of Axenfeld-Rieger Syndrome Linkage studies indicate that a second type of Axenfeld-Rieger syndrome maps to chromosome 13q14 (RIEG2; 601499). A third form of Axenfeld-Rieger syndrome (RIEG3; 602482) is caused by mutation in the FOXC1 gene (601090) on chromosome 6p25. See 109120 for a form of Axenfeld-Rieger syndrome associated with partially absent eye muscles, hydrocephalus, and skeletal abnormalities.
TCF12-related craniosynostosis
MedGen UID:
811568
Concept ID:
C3715051
Disease or Syndrome
Craniosynostosis (CRS) is a primary abnormality of skull growth involving premature fusion of the cranial sutures such that the growth velocity of the skull often cannot match that of the developing brain. This produces skull deformity and, in some cases, raises intracranial pressure, which must be treated promptly to avoid permanent neurodevelopmental disability (summary by Fitzpatrick, 2013). Craniosynostosis-3 (CRS3) includes coronal, sagittal, and multisuture forms (Sharma et al., 2013). For discussion of genetic heterogeneity of craniosynostosis, see CRS1 (123100).
Macrocephaly/megalencephaly syndrome, autosomal recessive
MedGen UID:
812742
Concept ID:
C3806412
Disease or Syndrome
Macrocephaly refers to an abnormally enlarged head inclusive of the scalp, cranial bones, and intracranial contents. Macrocephaly may be due to megalencephaly (true enlargement of the brain parenchyma), and the 2 terms are often used interchangeably in the genetic literature (reviews by Olney, 2007 and Williams et al., 2008). Autosomal recessive macrocephaly/megalencephaly syndrome is characterized by an enlarged cranium apparent at birth or in early childhood. Affected individuals have intellectual disability and may have dysmorphic facial features resulting from the macrocephaly (summary by Alfaiz et al., 2014).
Severe motor and intellectual disabilities-sensorineural deafness-dystonia syndrome
MedGen UID:
812964
Concept ID:
C3806634
Disease or Syndrome
Deafness, dystonia, and cerebral hypomyelination is an X-linked recessive mental retardation syndrome characterized by almost no psychomotor development, dysmorphic facial features, sensorineural deafness, dystonia, pyramidal signs, and hypomyelination on brain imaging (summary by Cacciagli et al., 2013).
X-linked intellectual disability, Cantagrel type
MedGen UID:
813060
Concept ID:
C3806730
Disease or Syndrome
X-linked intellectual developmental disorder-98 (XLID98) is a neurodevelopmental disorder characterized by delayed psychomotor development, poor speech, behavioral abnormalities, poor overall growth, dysmorphic facial features, and often early-onset seizures. Some carrier females are unaffected, whereas other females with mutations are affected; males tend to be more severely affected than females. It is believed that the phenotypic variability and disease manifestations in female carriers results from skewed X-inactivation or cellular mosaicism (summary by de Lange et al., 2016).
Foveal hypoplasia - optic nerve decussation defect - anterior segment dysgenesis syndrome
MedGen UID:
814203
Concept ID:
C3807873
Disease or Syndrome
Foveal hypoplasia is defined as the lack of foveal depression with continuity of all neurosensory retinal layers in the presumed foveal area. Foveal hypoplasia as an isolated entity is a rare phenomenon; it is usually described in association with other ocular disorders, such as aniridia (106210), microphthalmia (see 251600), albinism (see 203100), or achromatopsia (see 216900). All reported cases of foveal hypoplasia have been accompanied by decreased visual acuity and nystagmus (summary by Perez et al., 2014). For a discussion of genetic heterogeneity of foveal hypoplasia, see FVH1 (136520).
Complex cortical dysplasia with other brain malformations 1
MedGen UID:
814727
Concept ID:
C3808397
Disease or Syndrome
Complex cortical dysplasia with other brain malformations (CDCBM) is a disorder of aberrant neuronal migration and disturbed axonal guidance. Affected individuals have mild to severe mental retardation, strabismus, axial hypotonia, and spasticity. Brain imaging shows variable malformations of cortical development, including polymicrogyria, gyral disorganization, and fusion of the basal ganglia, as well as thin corpus callosum, hypoplastic brainstem, and dysplastic cerebellar vermis. Extraocular muscles are not involved (summary by Poirier et al., 2010). Genetic Heterogeneity of Complex Cortical Dysplasia with Other Brain Malformations See also CDCBM2 (615282), caused by mutation in the KIF5C gene (604593) on chromosome 2q23; CDCBM3 (615411), caused by mutation in the KIF2A gene (602591) on chromosome 5q12; CDCBM4 (615412), caused by mutation in the TUBG1 gene (191135) on chromosome 17q21; CDCBM5 (615763), caused by mutation in the TUBB2A gene (615101) on chromosome 6p25; CDCBM6 (615771), caused by mutation in the TUBB gene (191130) on chromosome 6p21; CDCBM7 (610031), caused by mutation in the TUBB2B gene (612850) on chromosome 6p25; CDCBM9 (618174), caused by mutation in the CTNNA2 gene (114025) on chromosome 2p12; CDCBM10 (618677), caused by mutation in the APC2 gene (612034) on chromosome 19p13; CDCBM11 (620156), caused by mutation in the KIF26A gene (613231) on chromosome 14q32; CDCBM12 (620316), caused by mutation in the CAMSAP1 gene (613774) on chromosome 9q34; CDCBM13 (614563), caused by mutation in the DYNC1H1 gene (600112) on chromosome 14q32; CDCBM14A (606854) and CDCBM14B (615752), caused by mutation in the ADGRG1 gene (604110) on chromosome 16q21; and CDCBM15 (618737), caused by mutation in the TUBGCP2 gene (617817) on chromosome 10q26. The designation CDCBM8 was previously used to represent a phenotype caused by mutation in the TUBA8 gene (see 605742.0001) on chromosome 22q11; the patients with this phenotype were subsequently found to have a homozygous mutation in the SNAP29 gene (604202.0002), also on chromosome 22q11, that may have been responsible for the disorder. The same mutation in SNAP29 causes a similar disorder, CEDNIK syndrome (609528). See also lissencephaly (e.g., LIS1, 607432), which shows overlapping features and may result from mutation in tubulin genes.
Cardiofaciocutaneous syndrome 4
MedGen UID:
815337
Concept ID:
C3809007
Disease or Syndrome
Cardiofaciocutaneous (CFC) syndrome is characterized by cardiac abnormalities (pulmonic stenosis and other valve dysplasias, septal defects, hypertrophic cardiomyopathy, rhythm disturbances), distinctive craniofacial appearance, and cutaneous abnormalities (including xerosis, hyperkeratosis, ichthyosis, keratosis pilaris, ulerythema ophryogenes, eczema, pigmented moles, hemangiomas, and palmoplantar hyperkeratosis). The hair is typically sparse, curly, fine or thick, woolly or brittle; eyelashes and eyebrows may be absent or sparse. Nails may be dystrophic or fast growing. Some form of neurologic and/or cognitive delay (ranging from mild to severe) is seen in all affected individuals. Neoplasia, mostly acute lymphoblastic leukemia, has been reported in some individuals.
Perrault syndrome 4
MedGen UID:
815435
Concept ID:
C3809105
Disease or Syndrome
Perrault syndrome is characterized by sensorineural hearing loss (SNHL) in males and females and ovarian dysfunction in females. SNHL is bilateral and ranges from profound with prelingual (congenital) onset to moderate with early-childhood onset. When onset is in early childhood, hearing loss can be progressive. Ovarian dysfunction ranges from gonadal dysgenesis (absent or streak gonads) manifesting as primary amenorrhea to primary ovarian insufficiency (POI) defined as cessation of menses before age 40 years. Fertility in affected males is reported as normal (although the number of reported males is limited). Neurologic features described in some individuals with Perrault syndrome include learning difficulties and developmental delay, cerebellar ataxia, and motor and sensory peripheral neuropathy.
Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B14
MedGen UID:
815551
Concept ID:
C3809221
Disease or Syndrome
MDDGB14 is an autosomal recessive congenital muscular dystrophy characterized by severe muscle weakness apparent in infancy and impaired intellectual development. Some patients may have additional features, such as microcephaly, cardiac dysfunction, seizures, or cerebellar hypoplasia. It is part of a group of similar disorders resulting from defective glycosylation of alpha-dystroglycan (DAG1; 128239), collectively known as 'dystroglycanopathies' (summary by Carss et al., 2013). For a discussion of genetic heterogeneity of congenital muscular dystrophy-dystroglycanopathy type B, see MDDGB1 (613155).
Multiple congenital anomalies-hypotonia-seizures syndrome 3
MedGen UID:
815686
Concept ID:
C3809356
Disease or Syndrome
Multiple congenital anomalies-hypotonia-seizures syndrome is an autosomal recessive disorder characterized by neonatal hypotonia, lack of psychomotor development, seizures, dysmorphic features, and variable congenital anomalies involving the cardiac, urinary, and gastrointestinal systems. Most affected individuals die before 3 years of age (summary by Maydan et al., 2011). The disorder is caused by a defect in glycosylphosphatidylinositol (GPI) biosynthesis. For a discussion of genetic heterogeneity of MCAHS, see MCAHS1 (614080). For a discussion of genetic heterogeneity of GPI biosynthesis defects, see GPIBD1 (610293).
Hypotonia, infantile, with psychomotor retardation and characteristic facies 1
MedGen UID:
815784
Concept ID:
C3809454
Disease or Syndrome
Infantile hypotonia with psychomotor retardation and characteristic facies (IHPRF) is a severe autosomal recessive neurologic disorder with onset at birth or in early infancy. Affected individuals show very poor, if any, normal cognitive development. Some patients are never learn to sit or walk independently (summary by Al-Sayed et al., 2013). Genetic Heterogeneity of Infantile Hypotonia with Psychomotor Retardation and Characteristic Facies See also IHPRF2 (616801), caused by mutation in the UNC80 gene (612636) on chromosome 2q34; and IHPRF3 (616900), caused by mutation in the TBCK gene (616899) on chromosome 4q24.
Chromosome 3q13.31 deletion syndrome
MedGen UID:
815820
Concept ID:
C3809490
Disease or Syndrome
The chromosome 3q13.31 deletion syndrome is characterized by marked developmental delay, characteristic facies with a short philtrum and protruding lips, and abnormal male genitalia (Molin et al., 2012). Patients with Primrose syndrome (PRIMS; 259050) exhibit features overlapping those of the chromosome 3q13.31 deletion syndrome but also have ossified ear cartilage, severe muscle wasting, and abnormalities of glucose metabolism resulting in insulin-resistant diabetes mellitus in adulthood. Primrose syndrome is caused by mutation in the ZBTB20 gene (606025) on chromosome 3q13.
Intellectual disability-feeding difficulties-developmental delay-microcephaly syndrome
MedGen UID:
816016
Concept ID:
C3809686
Mental or Behavioral Dysfunction
A rare, genetic, neurodevelopmental disorder characterized by global developmental delay, borderline to severe intellectual disability, feeding difficulties, behavioral anomalies, vision anomalies and mild facial dysmorphism. Other associated features may include microcephaly, short stature, urogenital or palatal anomalies (e.g. cleft palate), minor cardiac defects, recurrent infections or hearing loss.
Developmental delay with autism spectrum disorder and gait instability
MedGen UID:
816083
Concept ID:
C3809753
Disease or Syndrome
Developmental delay with autism spectrum disorder and gait instability is a rare, genetic, neurological disorder characterized by infant hypotonia and feeding difficulties, global development delay, mild to moderated intellectual disability, delayed independent ambulation, broad-based gait with arms upheld and flexed at the elbow with brisk walking or running, and limited language skills. Behavior patterns are highly variable and range from sociable and affectionate to autistic behavior.
Severe intellectual disability-short stature-behavioral abnormalities-facial dysmorphism syndrome
MedGen UID:
816183
Concept ID:
C3809853
Disease or Syndrome
Severe intellectual disability-short stature-behavioral abnormalities-facial dysmorphism syndrome is a rare, genetic, syndromic intellectual disability disorder characterized by severe intellectual disability with limited or absent speech and language, short stature, acquired microcephaly, kyphoscoliosis or scoliosis, and behavioral disturbances that include hyperactivity, stereotypy and aggressiveness. Facial dysmorphism, that typically includes sloping forehead, mild synophrys, deep-set eyes, strabismus, anteverted large ears, prominent nose and dental malposition, is also characteristic.
Periventricular nodular heterotopia 6
MedGen UID:
816202
Concept ID:
C3809872
Disease or Syndrome
Any periventricular nodular heterotopia in which the cause of the disease is a mutation in the ERMARD gene.
Joubert syndrome 21
MedGen UID:
816542
Concept ID:
C3810212
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Chromosome 5q12 deletion syndrome
MedGen UID:
816612
Concept ID:
C3810282
Disease or Syndrome
PDE4D haploinsufficiency syndrome is a rare syndromic intellectual disability characterized by developmental delay, intellectual disability, low body mass index, long arms, fingers and toes, prominent nose and small chin.
Bosch-Boonstra-Schaaf optic atrophy syndrome
MedGen UID:
816693
Concept ID:
C3810363
Disease or Syndrome
Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) is an autosomal dominant disorder characterized by delayed development, moderately impaired intellectual development, and optic atrophy. Most patients also have evidence of cerebral visual impairment. Dysmorphic facial features are variable and nonspecific (summary by Bosch et al., 2014).
Intellectual disability-facial dysmorphism syndrome due to SETD5 haploinsufficiency
MedGen UID:
816736
Concept ID:
C3810406
Mental or Behavioral Dysfunction
Intellectual disability-facial dysmorphism syndrome due to SETD5 haploinsufficiency is a rare, syndromic intellectual disability characterized by intellectual disability of various severity, hypotonia, feeding difficulties, dysmorphic features, autism and behavioral issues. Growth retardation, congenital heart anomalies, gastrointestinal and genitourinary defects have been rarely associated.
Hermansky-Pudlak syndrome 5
MedGen UID:
854711
Concept ID:
C3888004
Disease or Syndrome
Hermansky-Pudlak syndrome (HPS) is characterized by oculocutaneous albinism, a bleeding diathesis, and, in some individuals, pulmonary fibrosis, granulomatous colitis, or immunodeficiency. Ocular findings include reduced iris pigment with iris transillumination, reduced retinal pigment, foveal hypoplasia with significant reduction in visual acuity (usually in the range of 20/50 to 20/400), nystagmus, and increased crossing of the optic nerve fibers. Hair color ranges from white to brown; skin color ranges from white to olive and is usually a shade lighter than that of other family members. The bleeding diathesis can result in variable bruising, epistaxis, gingival bleeding, postpartum hemorrhage, colonic bleeding, and prolonged bleeding with menses or after tooth extraction, circumcision, and other surgeries. Pulmonary fibrosis, a restrictive lung disease, typically causes symptoms in the early thirties and can progress to death within a decade. Granulomatous colitis is severe in about 15% of affected individuals. Neutropenia and/or immune defects occur primarily in individuals with pathogenic variants in AP3B1 and AP3D1.
Hermansky-Pudlak syndrome 6
MedGen UID:
854714
Concept ID:
C3888007
Disease or Syndrome
Hermansky-Pudlak syndrome (HPS) is characterized by oculocutaneous albinism, a bleeding diathesis, and, in some individuals, pulmonary fibrosis, granulomatous colitis, or immunodeficiency. Ocular findings include reduced iris pigment with iris transillumination, reduced retinal pigment, foveal hypoplasia with significant reduction in visual acuity (usually in the range of 20/50 to 20/400), nystagmus, and increased crossing of the optic nerve fibers. Hair color ranges from white to brown; skin color ranges from white to olive and is usually a shade lighter than that of other family members. The bleeding diathesis can result in variable bruising, epistaxis, gingival bleeding, postpartum hemorrhage, colonic bleeding, and prolonged bleeding with menses or after tooth extraction, circumcision, and other surgeries. Pulmonary fibrosis, a restrictive lung disease, typically causes symptoms in the early thirties and can progress to death within a decade. Granulomatous colitis is severe in about 15% of affected individuals. Neutropenia and/or immune defects occur primarily in individuals with pathogenic variants in AP3B1 and AP3D1.
Autosomal dominant vitreoretinochoroidopathy
MedGen UID:
854768
Concept ID:
C3888099
Disease or Syndrome
Bestrophinopathies, the spectrum of ophthalmic disorders caused by pathogenic variants in BEST1, are typically characterized by retinal degeneration. The four recognized phenotypes are the three autosomal dominant disorders: Best vitelliform macular dystrophy (BVMD), BEST1 adult-onset vitelliform macular dystrophy (AVMD), and autosomal dominant vitreoretinochoroidopathy (ADVIRC); and autosomal recessive bestrophinopathy (ARB). Onset is usually in the first decade (except AVMD in which onset is age 30 to 50 years). Slow visual deterioration is the usual course. Choroidal neovascularization can occur in rare cases. ADVIRC is also associated with panophthalmic involvement including nanophthalmos, microcornea, hyperopia, and narrow anterior chamber angle with angle closure glaucoma.
Hereditary spastic paraplegia 45
MedGen UID:
854816
Concept ID:
C3888209
Disease or Syndrome
A rare pure or complex form of hereditary spastic paraplegia with characteristics of onset in infancy of progressive lower limb spasticity, abnormal gait, increased deep tendon reflexes and extensor plantar responses that may be associated with intellectual disability. Additional signs such as contractures in the lower limbs, amyotrophy, clubfoot and optic atrophy, have also been reported. Caused by homozygous mutation in the NT5C2 gene on chromosome 10q24.
Intellectual disability, X-linked 101
MedGen UID:
855517
Concept ID:
C3890168
Disease or Syndrome
Any non-syndromic X-linked intellectual disability in which the cause of the disease is a mutation in the MID2 gene.
Nephronophthisis 18
MedGen UID:
855697
Concept ID:
C3890591
Disease or Syndrome
The nephronophthisis (NPH) phenotype is characterized by reduced renal concentrating ability, chronic tubulointerstitial nephritis, cystic renal disease, and progression to end-stage renal disease (ESRD) before age 30 years. Three age-based clinical subtypes are recognized: infantile, juvenile, and adolescent/adult. Infantile NPH can present in utero with oligohydramnios sequence (limb contractures, pulmonary hypoplasia, and facial dysmorphisms) or postnatally with renal manifestations that progress to ESRD before age 3 years. Juvenile NPH, the most prevalent subtype, typically presents with polydipsia and polyuria, growth retardation, chronic iron-resistant anemia, or other findings related to chronic kidney disease (CKD). Hypertension is typically absent due to salt wasting. ESRD develops at a median age of 13 years. Ultrasound findings are increased echogenicity, reduced corticomedullary differentiation, and renal cysts (in 50% of affected individuals). Histologic findings include tubulointerstitial fibrosis, thickened and disrupted tubular basement membrane, sporadic corticomedullary cysts, and normal or reduced kidney size. Adolescent/adult NPH is clinically similar to juvenile NPH, but ESRD develops at a median age of 19 years. Within a subtype, inter- and intrafamilial variability in rate of progression to ESRD is considerable. Approximately 80%-90% of individuals with the NPH phenotype have no extrarenal features (i.e., they have isolated NPH); ~10%-20% have extrarenal manifestations that constitute a recognizable syndrome (e.g., Joubert syndrome, Bardet-Biedl syndrome, Jeune syndrome and related skeletal disorders, Meckel-Gruber syndrome, Senior-Løken syndrome, Leber congenital amaurosis, COACH syndrome, and oculomotor apraxia, Cogan type).
SSR4-congenital disorder of glycosylation
MedGen UID:
860832
Concept ID:
C4012395
Disease or Syndrome
A form of congenital disorders of N-linked glycosylation with characteristics of neurologic abnormalities (global developmental delay in language, social skills and fine and gross motor development, intellectual disability, hypotonia, microcephaly, seizures/epilepsy), facial dysmorphism (deep set eyes, large ears, hypoplastic vermillion of upper lip, large mouth with widely spaced teeth), feeding problems often due to chewing difficulties and aversion to food with certain textures, failure to thrive, gastrointestinal abnormalities (reflux or vomiting) and strabismus. The disease is caused by mutations in the gene SSR4 (Xq28).
Intellectual disability-severe speech delay-mild dysmorphism syndrome
MedGen UID:
862201
Concept ID:
C4013764
Mental or Behavioral Dysfunction
Intellectual developmental disorder with language impairment and with or without autistic features is a neurodevelopmental disorder characterized by global developmental delay with moderate to severe speech delay that particularly affects expressive speech. Most patients have articulation defects, but frank verbal dyspraxia is not observed. Common dysmorphic features include broad forehead, downslanting palpebral fissures, short nose with broad tip, relative macrocephaly, frontal hair upsweep, and prominent digit pads. Gross motor skills are also delayed. Some patients have autistic features and/or behavioral problems. All reported cases have occurred de novo (review by Le Fevre et al., 2013).
Pontocerebellar hypoplasia type 9
MedGen UID:
862791
Concept ID:
C4014354
Disease or Syndrome
Pontocerebellar hypoplasia type 9 (PCH9) is an autosomal recessive neurodevelopmental and neurodegenerative disorder characterized by severely delayed psychomotor development, progressive microcephaly, spasticity, seizures, and brain abnormalities, including brain atrophy, thin corpus callosum, and delayed myelination (summary by Akizu et al., 2013). For a general phenotypic description and a discussion of genetic heterogeneity of PCH, see PCH1 (607596).
Intellectual disability, autosomal recessive 43
MedGen UID:
862823
Concept ID:
C4014386
Mental or Behavioral Dysfunction
Autosomal recessive intellectual developmental disorder-43 (MRT43) is characterized by impaired intellectual development, poor language skills, short stature, and dysmorphic features. Some patients may have significant motor delays (summary by Gangfuss et al., 2022).
Autism spectrum disorder due to AUTS2 deficiency
MedGen UID:
862872
Concept ID:
C4014435
Mental or Behavioral Dysfunction
A rare genetic syndromic intellectual disability characterized by global developmental delay and borderline to severe intellectual disability, autism spectrum disorder with obsessive behavior, stereotypies, hyperactivity but frequently friendly and affable personality, feeding difficulties, short stature, muscular hypotonia, microcephaly, characteristic dysmorphic features (hypertelorism, high arched eyebrows, ptosis, deep and/or broad nasal bridge, broad/prominent nasal tip, short and/or upturned philtrum, narrow mouth, and micrognathia), and skeletal anomalies (kyphosis and/or scoliosis, arthrogryposis, slender habitus and extremities). Other clinical features may include hernias, congenital heart defects, cryptorchidism and seizures.
Pontocerebellar hypoplasia type 2E
MedGen UID:
862925
Concept ID:
C4014488
Disease or Syndrome
Pontocerebellar hypoplasia type 2E is an autosomal recessive neurodegenerative disorder characterized by profound mental retardation, progressive microcephaly, spasticity, and early-onset epilepsy (summary by Feinstein et al., 2014). For a general phenotypic description and a discussion of genetic heterogeneity of pontocerebellar hypoplasia type 2, see PCH2A (277470).
ADNP-related multiple congenital anomalies - intellectual disability - autism spectrum disorder
MedGen UID:
862975
Concept ID:
C4014538
Disease or Syndrome
ADNP-related disorder is characterized by hypotonia, severe speech and motor delay, mild-to-severe intellectual disability, and characteristic facial features (prominent forehead, high anterior hairline, wide and depressed nasal bridge, and short nose with full, upturned nasal tip) based on a cohort of 78 individuals. Features of autism spectrum disorder are common (stereotypic behavior, impaired social interaction). Other common findings include additional behavioral problems, sleep disturbance, brain abnormalities, seizures, feeding issues, gastrointestinal problems, visual dysfunction (hypermetropia, strabismus, cortical visual impairment), musculoskeletal anomalies, endocrine issues including short stature and hormonal deficiencies, cardiac and urinary tract anomalies, and hearing loss.
Colobomatous microphthalmia-rhizomelic dysplasia syndrome
MedGen UID:
862977
Concept ID:
C4014540
Disease or Syndrome
Colobomatous microphthalmia-rhizomelic dysplasia syndrome is a rare, genetic developmental defect during embryogenesis characterized by a range of developmental eye anomalies (including anophthalmia, microphthalmia, colobomas, microcornea, corectopia, cataract) and symmetric limb rhizomelia with short stature and contractures of large joints. Intellectual disability with autistic features, macrocephaly, dysmorphic features, urogenital anomalies (hypospadia, cryptorchidism), cutaneous syndactyly and precocious puberty may also be present.
Ataxia - intellectual disability - oculomotor apraxia - cerebellar cysts syndrome
MedGen UID:
863258
Concept ID:
C4014821
Disease or Syndrome
Poretti-Boltshauser syndrome is an autosomal recessive disorder characterized by cerebellar dysplasia, cerebellar vermis hypoplasia, cerebellar cysts in most patients, high myopia, variable retinal dystrophy, and eye movement abnormalities. Affected individuals have delayed motor development and often have speech delay. Cognitive function can range from normal to intellectually disabled (summary by Aldinger et al., 2014).
Cataract-growth hormone deficiency-sensory neuropathy-sensorineural hearing loss-skeletal dysplasia syndrome
MedGen UID:
863379
Concept ID:
C4014942
Disease or Syndrome
CAGSSS, which comprises cataracts, growth hormone deficiency, sensory neuropathy, sensorineural hearing loss, and skeletal dysplasia, is an autosomal recessive multisystemic disorder with a highly variable phenotypic spectrum. Not all of these features are always present, and almost all the features may present at different times and/or become more apparent with age. The skeletal features are consistent with spondyloepimetaphyseal dysplasia (SEMD) (summary by Vona et al., 2018). One family had a distinctive presentation with infantile-onset intractable seizures and cortical abnormalities reminiscent of Leigh syndrome (see 256000). The correlation between genotype and phenotype remains unclear, but since the IARS2 gene is involved in mitochondrial function, heterogeneous manifestations can be expected (Takezawa et al., 2018).
Intellectual disability, autosomal dominant 29
MedGen UID:
863578
Concept ID:
C4015141
Mental or Behavioral Dysfunction
SETBP1 haploinsufficiency disorder (SETBP1-HD) is characterized by hypotonia and mild motor developmental delay; intellectual abilities ranging from normal to severe disability; speech and language disorder; behavioral problems (most commonly attention/concentration deficits and hyperactivity, impulsivity), and refractive errors and strabismus. Typically children with SETBP1-HD whose intellect is in the normal or borderline range (IQ 80-90) were diagnosed following genetic testing for behavioral problems and/or severe speech and language disorders (respectively: the inability to produce sounds in words correctly, and deficits in the understanding and/or expression of words and sentences). To date, 47 individuals with SETBP1-HD have been reported.
Intellectual disability, autosomal recessive 46
MedGen UID:
863720
Concept ID:
C4015283
Mental or Behavioral Dysfunction
Any autosomal recessive non-syndromic intellectual disability in which the cause of the disease is a mutation in the NDST1 gene.
Autosomal recessive spinocerebellar ataxia 17
MedGen UID:
863738
Concept ID:
C4015301
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-17 (SCAR17) is a neurologic disorder characterized by onset of gait ataxia and cerebellar signs in early childhood. Patients also have variably impaired intellectual development (summary by Evers et al., 2016).
PURA-related severe neonatal hypotonia-seizures-encephalopathy syndrome
MedGen UID:
863794
Concept ID:
C4015357
Disease or Syndrome
PURA-related neurodevelopmental disorders include PURA syndrome, caused by a heterozygous pathogenic sequence variant in PURA, and 5q31.3 deletion syndrome, caused by a genomic 5q31.3 deletion encompassing all or part of PURA. PURA-related neurodevelopmental disorders are characterized by moderate-to-severe neurodevelopmental delay with absence of speech in most and lack of independent ambulation in many. Early-onset problems can include hypotonia, hypothermia, hypersomnolence, feeding difficulties, excessive hiccups, recurrent central and obstructive apneas, epileptic seizures, abnormal nonepileptic movements (dystonia, dyskinesia, and dysconjugate eye movements), and abnormal vision. Congenital heart defects, urogenital malformations, skeletal abnormalities, and endocrine disorders occur, but are less common.
Cerebellar-facial-dental syndrome
MedGen UID:
863932
Concept ID:
C4015495
Disease or Syndrome
Cerebellofaciodental syndrome is an autosomal recessive neurodevelopmental disorder characterized by delayed development, intellectual disability, abnormal facial and dental findings, and cerebellar hypoplasia (summary by Borck et al., 2015).
Cone-rod synaptic disorder, congenital nonprogressive
MedGen UID:
874422
Concept ID:
C4041558
Disease or Syndrome
Congenital nonprogressive cone-rod synaptic disorder (CRSD) is characterized by stable low vision, nystagmus, photophobia, a normal or near-normal fundus appearance, and no night blindness. Electroretinography shows an electronegative waveform response to scotopic bright flash, near-normal to subnormal rod function, and delayed and/or decreased to nonrecordable cone responses (Traboulsi, 2013; Khan, 2014).
Spasticity-ataxia-gait anomalies syndrome
MedGen UID:
905660
Concept ID:
C4225178
Disease or Syndrome
Childhood-onset spasticity with hyperglycinemia is an autosomal recessive disorder characterized by onset of slowly progressive spasticity that results in impaired gait in the first decade of life. Imaging of the central nervous system shows leukodystrophy and/or lesions in the upper spinal cord. More variable features include visual defects and mild learning disabilities. Serum glycine is increased, but CSF glycine is only mildly increased or normal; serum lactate is normal. The disorder represents a form of 'variant' nonketotic hyperglycinemia and is distinct from classic nonketotic hyperglycinemia (NKH, or GCE; 605899), which is characterized by significantly increased CSF glycine. Several forms of 'variant' NKH, including SPAHGC, appear to result from defects of mitochondrial lipoate biosynthesis (summary by Baker et al., 2014).
Meier-Gorlin syndrome 6
MedGen UID:
905079
Concept ID:
C4225188
Disease or Syndrome
Any Meier-Gorlin syndrome in which the cause of the disease is a mutation in the GMNN gene.
Severe intellectual disability-corpus callosum agenesis-facial dysmorphism-cerebellar ataxia syndrome
MedGen UID:
902346
Concept ID:
C4225193
Disease or Syndrome
A rare genetic neurological disorder with characteristics of congenital microcephaly, severe intellectual disability, hypertonia at birth lessening with age, ataxia and specific dysmorphic facial features including hirsutism, low anterior hairline and bitemporal narrowing arched thick and medially sparse eyebrows, long eyelashes, lateral upper eyelids swelling and a skin fold partially covering the inferior eyelids, low-set posteriorly rotated protruding ears, anteverted nares and a full lower lip. Brain imaging shows partial to almost complete agenesis of the corpus callosum and variable degrees of cerebellar hypoplasia. Caused by homozygous mutation in the FRMD4A gene on chromosome 10p13.
Severe hypotonia-psychomotor developmental delay-strabismus-cardiac septal defect syndrome
MedGen UID:
902080
Concept ID:
C4225196
Disease or Syndrome
Severe hypotonia-psychomotor developmental delay-strabismus-cardiac septal defect syndrome is a rare, genetic, non-dystrophic congenital myopathy disorder characterized by a neonatal-onset of severe generalized hypotonia associated with mild psychomotor delay, congenital strabismus with abducens nerve palsy, and atrial and/or ventricular septal defects. Cryptorchidism is commonly reported in male patients and muscle biopsy typically reveals increased variability in muscle fiber size.
Lamb-Shaffer syndrome
MedGen UID:
903542
Concept ID:
C4225202
Disease or Syndrome
Lamb-Shaffer syndrome is a neurodevelopmental disorder characterized by global developmental delay, intellectual disability, poor expressive speech, and mild dysmorphic facial features. Additional variable skeletal abnormalities may also be present (summary by Nesbitt et al., 2015).
Cardiac anomalies - developmental delay - facial dysmorphism syndrome
MedGen UID:
900924
Concept ID:
C4225208
Disease or Syndrome
Impaired intellectual development and distinctive facial features with or without cardiac defects (MRFACD) is an autosomal dominant, complex syndromic neurodevelopmental disorder characterized by delayed psychomotor development, poor speech acquisition, distinctive dysmorphic facial features, including frontal bossing, upslanting palpebral fissures, depressed nasal bridge with bulbous tip, and macrostomia. There is variable penetrance of cardiac malformations, ranging from no malformations to patent foramen ovale to septal defects and/or transposition of the great arteries (summary by Adegbola et al., 2015).
Spastic paraplegia-severe developmental delay-epilepsy syndrome
MedGen UID:
897828
Concept ID:
C4225215
Disease or Syndrome
Spastic paraplegia and psychomotor retardation with or without seizures is an autosomal recessive complex neurodevelopmental disorder with onset in infancy. Affected children show hypotonia followed by severely impaired global development and significant motor disability. Most develop seizures in childhood and have speech delay. Other features, such as ocular abnormalities, foot deformities, hypoplasia of the corpus callosum, and decreased white matter, are more variable (summary by Hollstein et al., 2015).
Skin creases, congenital symmetric circumferential, 2
MedGen UID:
902880
Concept ID:
C4225225
Congenital Abnormality
Congenital symmetric circumferential skin creases is characterized by the folding of excess skin, which leads to ringed creases, primarily of the limbs. Affected individuals also exhibit intellectual disability, cleft palate, and dysmorphic features (summary by Isrie et al., 2015). For a discussion of genetic heterogeneity of congenital symmetric circumferential skin creases, see CSCSC1 (156610).
Palatal anomalies-widely spaced teeth-facial dysmorphism-developmental delay syndrome
MedGen UID:
895943
Concept ID:
C4225229
Disease or Syndrome
Palatal anomalies-widely spaced teeth-facial dysmorphism-developmental delay syndrome is a rare, genetic multiple congenital anomalies/dysmorphic syndrome characterized by global developmental delay, axial hypotonia, palate abnormalities (including cleft palate and/or high and narrow palate), dysmorphic facial features (including prominent forehead, hypertelorism, downslanting palpebral fissures, wide nasal bridge, thin lips and widely spaced teeth), and short stature. Additional manifestations may include digital anomalies (such as brachydactyly, clinodactyly, and hypoplastic toenails), a single palmar crease, lower limb hypertonia, joint hypermobility, as well as ocular and urogenital anomalies.
SLC39A8-CDG
MedGen UID:
899837
Concept ID:
C4225234
Disease or Syndrome
Congenital disorder of glycosylation type IIn (CDG2N) is an autosomal recessive severe multisystem developmental disorder characterized by delayed psychomotor development apparent from infancy, hypotonia, and variable additional features, such as short stature, seizures, visual impairment, and cerebellar atrophy. Serum transferrin analysis shows a CDG type II pattern (summary by Boycott et al., 2015 and Park et al., 2015). For a discussion of genetic heterogeneity of CDG type II, see CDG2A (212066).
Seizures-scoliosis-macrocephaly syndrome
MedGen UID:
909039
Concept ID:
C4225248
Disease or Syndrome
Seizures, scoliosis, and macrocephaly/microcephaly syndrome (SSMS) is an autosomal recessive neurodevelopmental disorder characterized by global developmental delay apparent from early infancy, impaired intellectual development, behavioral problems, poor or absent speech, seizures, dysmorphic facial features with macro- or microcephaly, and skeletal abnormalities, including scoliosis and delayed bone age. Other features may include hypotonia, gastrointestinal problems, and exostoses (summary by Gentile et al., 2019).
PMP22-RAI1 contiguous gene duplication syndrome
MedGen UID:
894862
Concept ID:
C4225255
Disease or Syndrome
Yuan-Harel-Lupski syndrome is a complex neurodevelopmental disorder characterized by global developmental delay and early-onset peripheral neuropathy. The disorder comprises features of both demyelinating Charcot-Marie-Tooth disease type 1A (CMT1A; 118220), which results from duplication of the PMP22 gene on 17p12, and Potocki-Lupski syndrome (PTLS; 610883), which results from duplication of a slightly proximal region on 17p11.2 that includes the RAI1 gene. These 2 loci are about 2.5 Mb apart. The resultant YUHAL phenotype may be more severe in comparison to the individual contributions of each gene, with particularly early onset of peripheral neuropathy and features of both central and peripheral nervous system involvement (summary by Yuan et al., 2015).
Macrocephaly-intellectual disability-neurodevelopmental disorder-small thorax syndrome
MedGen UID:
899689
Concept ID:
C4225259
Disease or Syndrome
Smith-Kingsmore syndrome (SKS) is a rare autosomal dominant syndromic intellectual disability syndrome characterized by macrocephaly, seizures, umbilical hernia, and facial dysmorphic features including frontal bossing, midface hypoplasia, small chin, hypertelorism with downslanting palpebral fissures, depressed nasal bridge, smooth philtrum, and thin upper lip (Smith et al., 2013; Baynam et al., 2015).
Senior-Loken syndrome 9
MedGen UID:
899086
Concept ID:
C4225263
Disease or Syndrome
Senior-Loken syndrome-9 is an autosomal recessive disorder characterized by early-onset nephronophthisis and pigmentary retinopathy. Additional more variable features can include liver defects, skeletal anomalies, and obesity (summary by Bizet et al., 2015). For a phenotypic description and a discussion of genetic heterogeneity of Senior-Loken syndrome, see 266900.
Cutis laxa, autosomal dominant 3
MedGen UID:
899774
Concept ID:
C4225268
Disease or Syndrome
Autosomal dominant cutis laxa-3 is characterized by thin skin with visible veins and wrinkles, cataract or corneal clouding, clenched fingers, pre- and postnatal growth retardation, and moderate intellectual disability. In addition, patients exhibit a combination of muscular hypotonia with brisk muscle reflexes (Fischer-Zirnsak et al., 2015). For a general phenotypic description and discussion of genetic heterogeneity of autosomal dominant cutis laxa, see ARCL1 (123700).
Craniosynostosis 6
MedGen UID:
904675
Concept ID:
C4225269
Disease or Syndrome
Craniosynostosis is a primary abnormality of skull growth involving premature fusion of the cranial sutures such that the growth velocity of the skull often cannot match that of the developing brain. This produces skull deformity and, in some cases, raises intracranial pressure, which must be treated promptly to avoid permanent neurodevelopmental disability (summary by Fitzpatrick, 2013). Craniosynostosis-6 is a bicoronal form associated with bony defects in the sagittal, metopic, or lambdoid sutures (Twigg et al., 2015). For a discussion of genetic heterogeneity of craniosynostosis, see CRS1 (123100). Structural brain anomalies with impaired intellectual development and craniosynostosis (BAIDCS; 618736) is an allelic disorder.
Microcephaly-intellectual disability-sensorineural hearing loss-epilepsy-abnormal muscle tone syndrome
MedGen UID:
895574
Concept ID:
C4225276
Disease or Syndrome
Neurodevelopmental disorder with hearing loss, seizures, and brain abnormalities (NEDHSB) is an autosomal recessive disorder characterized by severe neurologic impairment including impaired intellectual development, epilepsy, microcephaly, abnormal muscle tone, and sensorineural hearing loss. Most affected individuals are nonambulatory, cannot sit unassisted, and have no speech development. More variable features include feeding difficulties, poor growth, cortical visual impairment, spasticity, scoliosis, immunodeficiency, and thrombocytopenia (Tanaka et al., 2015).
Congenital cataract-microcephaly-nevus flammeus simplex-severe intellectual disability syndrome
MedGen UID:
897292
Concept ID:
C4225323
Disease or Syndrome
Basel-Vanagaite-Smirin-Yosef syndrome is an autosomal recessive multiple congenital anomaly disorder characterized by severely delayed psychomotor development resulting in mental retardation, as well as variable eye, brain, cardiac, and palatal abnormalities (summary by Basel-Vanagaite et al., 2015).
Intellectual disability-microcephaly-strabismus-behavioral abnormalities syndrome
MedGen UID:
897984
Concept ID:
C4225351
Disease or Syndrome
White-Sutton syndrome is a neurodevelopmental disorder characterized by a wide spectrum of cognitive dysfunction, developmental delays (particularly in speech and language acquisition), hypotonia, autism spectrum disorder, and other behavioral problems. Additional features commonly reported include seizures, refractive errors and strabismus, hearing loss, sleep disturbance (particularly sleep apnea), feeding and gastrointestinal problems, mild genital abnormalities in males, and urinary tract involvement in both males and females.
Autosomal dominant intellectual disability-craniofacial anomalies-cardiac defects syndrome
MedGen UID:
903767
Concept ID:
C4225396
Disease or Syndrome
Arboleda-Tham syndrome (ARTHS) is an autosomal dominant disorder with the core features of impaired intellectual development, speech delay, microcephaly, cardiac anomalies, and gastrointestinal complications (summary by Kennedy et al., 2019).
Congenital contractures of the limbs and face, hypotonia, and developmental delay
MedGen UID:
907234
Concept ID:
C4225398
Disease or Syndrome
CLIFAHDD is a congenital disorder characterized by congenital contractures of the limbs and face, resulting in characteristic facial features, hypotonia, and variable degrees of developmental delay. All reported cases have occurred de novo (summary by Chong et al., 2015).
Congenital myasthenic syndrome 4A
MedGen UID:
908188
Concept ID:
C4225413
Disease or Syndrome
Slow-channel congenital myasthenic syndrome (SCCMS) is a disorder of the postsynaptic neuromuscular junction (NMJ) characterized by early-onset progressive muscle weakness. The disorder results from kinetic abnormalities of the acetylcholine receptor channel, specifically from prolonged opening and activity of the channel, which causes prolonged synaptic currents resulting in a depolarization block. This is associated with calcium overload, which may contribute to subsequent degeneration of the endplate and postsynaptic membrane. Treatment with quinine, quinidine, or fluoxetine may be helpful; acetylcholinesterase inhibitors and amifampridine should be avoided (summary by Engel et al., 2015). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Intellectual disability, X-linked 99, syndromic, female-restricted
MedGen UID:
899839
Concept ID:
C4225416
Disease or Syndrome
Female-restricted X-linked syndromic intellectual developmental disorder-99 (MRXS99F) is an X-linked dominant neurodevelopmental disorder characterized by delayed psychomotor development and mild to moderate intellectual disability. Affected females can have a wide range of additional congenital anomalies, including scoliosis, postaxial polydactyly, mild cardiac or urogenital anomalies, dysmorphic facial features, and mild structural brain abnormalities (summary by Reijnders et al., 2016).
Syndromic X-linked intellectual disability 34
MedGen UID:
902184
Concept ID:
C4225417
Mental or Behavioral Dysfunction
X-linked syndromic intellectual developmental disorder-34 (MRXS34) is an X-linked recessive neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability with poor speech, dysmorphic facial features, and mild structural brain abnormalities, including thickening of the corpus callosum (summary by Mircsof et al., 2015).
Intellectual disability, X-linked, syndromic 33
MedGen UID:
895979
Concept ID:
C4225418
Disease or Syndrome
X-linked syndromic intellectual developmental disorder-33 (MRXS33) is an X-linked recessive neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability, and characteristic facial features (summary by O'Rawe et al., 2015).
Linear skin defects with multiple congenital anomalies 3
MedGen UID:
906997
Concept ID:
C4225421
Disease or Syndrome
Microphthalmia with linear skin defects (MLS) syndrome is characterized by unilateral or bilateral microphthalmia and/or anophthalmia and linear skin defects, usually involving the face and neck, which are present at birth and heal with age, leaving minimal residual scarring. Other findings can include a wide variety of other ocular abnormalities (e.g., corneal anomalies, orbital cysts, cataracts), central nervous system involvement (e.g., structural anomalies, developmental delay, infantile seizures), cardiac concerns (e.g., hypertrophic or oncocytic cardiomyopathy, atrial or ventricular septal defects, arrhythmias), short stature, diaphragmatic hernia, nail dystrophy, hearing impairment, and genitourinary malformations. Inter- and intrafamilial variability is described.
Spastic paraplegia, intellectual disability, nystagmus, and obesity
MedGen UID:
924883
Concept ID:
C4284592
Disease or Syndrome
Spastic paraplegia, intellectual disability, nystagmus, and obesity (SINO) is an autosomal dominant neurologic disorder characterized by rapid growth in infancy, global developmental delay, spastic paraplegia, variable ophthalmologic defects, and dysmorphic facial features (summary by Josifova et al., 2016).
Intellectual developmental disorder with dysmorphic facies and ptosis
MedGen UID:
934584
Concept ID:
C4310617
Disease or Syndrome
Intellectual developmental disorder with dysmorphic facies and ptosis (IDDDFP) is an autosomal dominant neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability, delayed language, and dysmorphic facial features, most notably ptosis/blepharophimosis. Additional features may include poor growth, hypotonia, and seizures (summary by Mattioli et al., 2017). See also chromosome 3p deletion syndrome (613792).
Hypotonia, ataxia, and delayed development syndrome
MedGen UID:
934585
Concept ID:
C4310618
Disease or Syndrome
EBF3 neurodevelopmental disorder (EBF3-NDD) is associated with developmental delay (DD) / intellectual disability (ID), speech delay, gait or truncal ataxia, hypotonia, behavioral problems, and facial dysmorphism. Variability between individuals with EBF3-NDD is significant. Although all affected children have DD noted in early infancy, intellect generally ranges from mild to severe ID, with two individuals functioning in the low normal range. Less common issues can include genitourinary abnormalities and gastrointestinal and/or musculoskeletal involvement. To date, 42 symptomatic individuals from 39 families have been reported.
Optic atrophy 11
MedGen UID:
934595
Concept ID:
C4310628
Disease or Syndrome
Optic atrophy-11 (OPA11) is an autosomal recessive disorder characterized by delayed psychomotor development, intellectual disability, ataxia, optic atrophy, and leukoencephalopathy on brain imaging. Laboratory studies are consistent with mitochondrial dysfunction (summary by Hartmann et al., 2016). For a discussion of genetic heterogeneity of optic atrophy, see OPA1 (165500).
Dystonia 28, childhood-onset
MedGen UID:
934600
Concept ID:
C4310633
Disease or Syndrome
KMT2B-related dystonia (DYT-KMT2B) is a complex childhood-onset (mean age 7 years) movement disorder described to date in 39 individuals. It is characterized by a progressive disease course evolving commonly from lower-limb focal dystonia into generalized dystonia with prominent cervical, cranial, and laryngeal involvement. Communication difficulties, secondary to articulation difficulties and low speech volume, are common. Bulbar dysfunction leads to impaired swallowing. Intellectual disability (ID) / developmental delay (DD) are commonly reported. Additional findings can include eye movement abnormalities, skin changes, psychiatric comorbidities (attention-deficit/hyperactivity disorder, anxiety, depression, and obsessive-compulsive disorder), myoclonus, seizures, spasticity, and sensorineural hearing loss. Many affected individuals follow a similar disease course, though milder and atypical findings have been described.
Neurodevelopmental disorder with hypotonia, seizures, and absent language
MedGen UID:
934610
Concept ID:
C4310643
Disease or Syndrome
Early-onset progressive diffuse brain atrophy-microcephaly-muscle weakness-optic atrophy syndrome
MedGen UID:
934638
Concept ID:
C4310671
Disease or Syndrome
PEBAT is an autosomal recessive neurodevelopmental disorder characterized by severely delayed psychomotor development apparent soon after birth or in infancy, profound intellectual disability, poor or absent speech, and seizures. Most patients are never able to walk due to hypotonia or spasticity. Brain imaging shows cerebral and cerebellar atrophy, thin corpus callosum, and secondary hypomyelination. The disorder shows progressive features, including microcephaly, consistent with a neurodegenerative process (summary by Miyake et al., 2016; Flex et al., 2016).
Encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy, 1
MedGen UID:
934642
Concept ID:
C4310675
Disease or Syndrome
Early-onset progressive encephalopathy with brain edema and/or leukoencephalopathy-1 (PEBEL1) is an autosomal recessive severe neurometabolic disorder characterized by rapidly progressive neurologic deterioration that is usually associated with a febrile illness. Affected infants tend to show normal early development followed by acute psychomotor regression with ataxia, hypotonia, respiratory insufficiency, and seizures, resulting in coma and death in the first years of life. Brain imaging shows multiple abnormalities, including brain edema and signal abnormalities in the cortical and subcortical regions (summary by Kremer et al., 2016). Genetic Heterogeneity of PEBEL See also PEBEL2 (618321), caused by mutation in the NAXD gene (615910) on chromosome 13q34.
Short stature, rhizomelic, with microcephaly, micrognathia, and developmental delay
MedGen UID:
934653
Concept ID:
C4310686
Disease or Syndrome
The core features of short stature-micrognathia syndrome (SSMG) are intrauterine growth restriction (IUGR), postnatal short stature that is often rhizomelic, and micrognathia. Other common features include preterm birth, microcephaly, developmental delay, and genitourinary malformations in males. Transient liver dysfunction and glycosylation abnormalities during illness, giant cell hepatitis, hepatoblastoma, and cataracts have also been observed. Inter- and intrafamilial phenotypic severity varies greatly, from a relatively mild disorder to intrauterine death or stillbirth (Ritter et al., 2022).
Short stature-brachydactyly-obesity-global developmental delay syndrome
MedGen UID:
934656
Concept ID:
C4310689
Disease or Syndrome
A rare genetic, multiple congenital anomalies syndrome characterized by short stature, hand brachydactyly with hypoplastic distal phalanges, global development delay, intellectual disability, and more variably seizures, obesity, and craniofacial dysmorphism that includes microcephaly, high forehead, flat face, hypertelorism, deep set eyes, flat nasal bridge, averted nostrils, long philtrum, thin lip vermilion, and short neck.
ZTTK syndrome
MedGen UID:
934663
Concept ID:
C4310696
Disease or Syndrome
ZTTK syndrome (ZTTKS) is a severe multisystem developmental disorder characterized by delayed psychomotor development and intellectual disability. Affected individuals have characteristic dysmorphic facial features, hypotonia, poor feeding, poor overall growth, and eye or visual abnormalities. Most patients also have musculoskeletal abnormalities, and some have congenital defects of the heart and urogenital system. Brain imaging usually shows developmental abnormalities such as gyral changes, cortical and/or cerebellar atrophy, and thin corpus callosum (summary by Kim et al., 2016).
Joubert syndrome 28
MedGen UID:
934672
Concept ID:
C4310705
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Tall stature-intellectual disability-renal anomalies syndrome
MedGen UID:
934682
Concept ID:
C4310715
Disease or Syndrome
Thauvin-Robinet-Faivre syndrome is an autosomal recessive disorder characterized by generalized overgrowth, mainly of height, and mildly delayed psychomotor development with mild or severe learning difficulties. More variable features may include congenital heart defects, kidney abnormalities, and skeletal defects. Patients may have an increased risk for Wilms tumor (summary by Akawi et al., 2016).
Developmental and epileptic encephalopathy, 42
MedGen UID:
934683
Concept ID:
C4310716
Disease or Syndrome
Developmental and epileptic encephalopathy-42 (DEE42) is a neurologic disorder characterized by the onset of various types of seizures in the first hours or days of life, although rare patients may have onset in the first weeks of life. The seizures tend to be refractory and associated with EEG abnormalities, including multifocal spikes and generalized spike-wave complexes. Affected infants show global developmental delay with severely impaired intellectual development. Other features may include axial hypotonia, peripheral hypertonia with hyperreflexia, tremor, ataxia, and abnormal eye movements (summary by the Epi4K Consortium, 2016). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Meier-Gorlin syndrome 7
MedGen UID:
934705
Concept ID:
C4310738
Disease or Syndrome
Any Meier-Gorlin syndrome in which the cause of the disease is a mutation in the CDC45 gene.
Severe growth deficiency-strabismus-extensive dermal melanocytosis-intellectual disability syndrome
MedGen UID:
934712
Concept ID:
C4310745
Disease or Syndrome
Neurodevelopmental disorder with microcephaly and gray sclerae (NEDMIGS) is a severe autosomal recessive disorder characterized by impaired global development with hypotonia often precluding independent ambulation, profoundly impaired intellectual development with poor or absent language, mild microcephaly, and abnormal visual fixation. Patients also have gray sclerae and may have coarse facial features. Most affected individuals have seizures; some may have brain imaging abnormalities (summary by Shaheen et al., 2016 and Froukh et al., 2020).
Pontocerebellar hypoplasia, type 2F
MedGen UID:
934724
Concept ID:
C4310757
Disease or Syndrome
Pontocerebellar hypoplasia type 2F (PCH2F) is an autosomal recessive neurodevelopmental disorder characterized by progressive microcephaly and variable neurologic signs and symptoms, including cognitive and motor delay, poor or absent speech, seizures, and spasticity (summary by Breuss et al., 2016). For a general phenotypic description and a discussion of genetic heterogeneity of pontocerebellar hypoplasia type 2, see PCH2A (277470).
Cerebral palsy, spastic quadriplegic, 3
MedGen UID:
934734
Concept ID:
C4310767
Disease or Syndrome
Any spastic quadriplegia in which the cause of the disease is a mutation in the ADD3 gene.
Neurodevelopmental disorder with or without anomalies of the brain, eye, or heart
MedGen UID:
934739
Concept ID:
C4310772
Disease or Syndrome
RERE-related disorders are characterized by neurodevelopmental problems with or without structural anomalies of the eyes, heart, kidneys, and genitourinary tract and mild sensorineural hearing loss. Hypotonia and feeding problems are common among affected individuals. Developmental delay and intellectual disability range from mild to profound. Behavior problems may include attention-deficit/hyperactivity disorder, self-injurious behavior, and autism spectrum disorder. A variety of eye anomalies (coloboma, optic nerve anomalies, microphthalmia, and/or Peter's anomaly) and vision issues (myopia, anisometropia, astigmatism, exotropia, esotropia) have been reported. Congenital heart defects, most commonly septal defects, have also been described. Genitourinary abnormalities include vesicoureteral reflux, and cryptorchidism and hypospadias in males. Sensorineural hearing loss can be unilateral or bilateral.
Intellectual disability, autosomal dominant 42
MedGen UID:
934741
Concept ID:
C4310774
Mental or Behavioral Dysfunction
GNB1 encephalopathy (GNB1-E) is characterized by moderate-to-severe developmental delay / intellectual disability, structural brain abnormalities, and often infantile hypotonia and seizures. Other less common findings include dystonia, reduced vision, behavior issues, growth delay, gastrointestinal (GI) problems, genitourinary (GU) abnormalities in males, and cutaneous mastocytosis.
Immunodeficiency-centromeric instability-facial anomalies syndrome 3
MedGen UID:
934766
Concept ID:
C4310799
Disease or Syndrome
Immunodeficiency-centromeric instability-facial anomalies syndrome-3 is an autosomal recessive disorder characterized by recurrent infections in childhood and variable dysmorphic facial features. Laboratory studies show hypomethylation of certain chromosomal regions. Additional features, including delayed development, are variable (summary by Thijssen et al., 2015). For a discussion of genetic heterogeneity of immunodeficiency-centromeric instability-facial anomalies syndrome, see ICF1 (242860).
SIN3A-related intellectual disability syndrome due to a point mutation
MedGen UID:
934771
Concept ID:
C4310804
Disease or Syndrome
Witteveen-Kolk syndrome (WITKOS) is an autosomal dominant disorder with characteristic distinctive facial features, microcephaly, short stature, and mildly impaired intellectual development with delayed cognitive and motor development and subtle anomalies on MRI-brain imaging (summary by Balasubramanian et al., 2021).
Midface hypoplasia, hearing impairment, elliptocytosis, and nephrocalcinosis
MedGen UID:
934777
Concept ID:
C4310810
Disease or Syndrome
Midface hypoplasia, hearing impairment, elliptocytosis, and nephrocalcinosis is an X-linked recessive disorder with onset of features in early childhood. Anemia is sometimes present. Some patients may show mild early motor or speech delay, but cognition is normal (summary by Andreoletti et al., 2017).
Intellectual disability, X-linked 104
MedGen UID:
934784
Concept ID:
C4310817
Disease or Syndrome
Any non-syndromic X-linked intellectual disability in which the cause of the disease is a mutation in the FRMPD4 gene.
Dias-Logan syndrome
MedGen UID:
934800
Concept ID:
C4310833
Disease or Syndrome
BCL11A-related intellectual disability (BCL11A-ID) is characterized by developmental delay / intellectual disability of variable degree, neonatal hypotonia, microcephaly, distinctive but variable facial characteristics, behavior problems, and asymptomatic persistence of fetal hemoglobin. Growth delay, seizures, and autism spectrum disorder have also been reported in some affected individuals.
Noonan syndrome-like disorder with loose anagen hair 1
MedGen UID:
1379805
Concept ID:
C4478716
Disease or Syndrome
Noonan syndrome-like disorder with loose anagen hair is characterized by facial features similar to those observed in Noonan syndrome (163950), including hypertelorism, ptosis, downslanting palpebral fissures, low-set posteriorly angulated ears, and overfolded pinnae. In addition, patients display short stature, frequently with growth hormone (GH; see 139250) deficiency; cognitive deficits; relative macrocephaly; small posterior fossa resulting in Chiari I malformation; hypernasal voice; cardiac defects, especially dysplasia of the mitral valve and septal defects; and ectodermal abnormalities, in which the most characteristic feature is the hair anomaly, including easily pluckable, sparse, thin, slow-growing hair (summary by Bertola et al., 2017). Reviews Komatsuzaki et al. (2010) reviewed the clinical manifestations of patients with Noonan syndrome, Costello syndrome (218040), and cardiofaciocutaneous syndrome (CFC; see 115150) compared to patients with mutations in the SHOC2 gene. They noted that although there is phenotypic overlap among the disorders, loose anagen/easily pluckable hair had not been reported in mutation-positive patients with Noonan, CFC, or Costello syndrome, and appeared to be a distinctive feature of SHOC2 mutation-positive patients. Genetic Heterogeneity of Noonan Syndrome-Like Disorder with Loose Anagen Hair NSLH2 (617506) is caused by mutation in the PPP1CB gene (600590) on chromosome 2p23.
Developmental and epileptic encephalopathy, 51
MedGen UID:
1372686
Concept ID:
C4479208
Disease or Syndrome
Developmental and epileptic encephalopathy-51 (DEE51) is an autosomal recessive severe neurodevelopmental disorder characterized by onset of intractable seizures and hypotonia in the first days or weeks of life. Affected individuals have severely delayed psychomotor development and may show abnormal movements. Brain imaging shows nonspecific abnormalities, such as cerebral atrophy, cerebellar atrophy, and delayed myelination. Laboratory studies showed increased lactate, suggesting mitochondrial dysfunction (summary by Ait-El-Mkadem et al., 2017). For a discussion of genetic heterogeneity of DEE, see 308350.
Congenital heart defects, dysmorphic facial features, and intellectual developmental disorder
MedGen UID:
1385307
Concept ID:
C4479246
Disease or Syndrome
CDK13-related disorder, reported in 43 individuals to date, is characterized in all individuals by developmental delay / intellectual disability (DD/ID); nearly all individuals older than age one year display impaired verbal language skills (either absent or restricted speech). Other common findings are recognizable facial features in some individuals, behavioral problems (autism spectrum disorder or autistic traits/stereotypies, attention-deficit/hyperactivity disorder), feeding difficulties in infancy, structural cardiac defects, and seizures.
Autosomal recessive cutis laxa type 2C
MedGen UID:
1385755
Concept ID:
C4479387
Disease or Syndrome
Autosomal recessive cutis laxa type IIC (ARCL2C) is characterized by generalized skin wrinkling with sparse subcutaneous fat and dysmorphic progeroid facial features. Most patients also exhibit severe hypotonia as well as cardiovascular involvement (summary by Van Damme et al., 2017). For a general phenotypic description and a discussion of genetic heterogeneity of autosomal recessive cutis laxa, see ARCL1A (219100).
Congenital muscular dystrophy with cataracts and intellectual disability
MedGen UID:
1382291
Concept ID:
C4479410
Disease or Syndrome
MDCCAID is an autosomal recessive form of muscular dystrophy with onset of progressive muscle weakness in early childhood. Almost all patients also have early-onset cataracts, most have intellectual disability of varying severity, and some have seizures (summary by Wiessner et al., 2017 and Osborn et al., 2017).
Intellectual developmental disorder with gastrointestinal difficulties and high pain threshold
MedGen UID:
1385744
Concept ID:
C4479517
Disease or Syndrome
Jansen-de Vries syndrome (JDVS) is an autosomal dominant neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability with speech delay, and behavioral abnormalities. Most patients have variable additional features, including feeding and gastrointestinal difficulties, high pain threshold and/or hypersensitivity to sound, and dysmorphic features, including mild facial abnormalities, strabismus, and small hands and feet (summary by Jansen et al., 2017).
Arthrogryposis multiplex congenita 1, neurogenic, with myelin defect
MedGen UID:
1373185
Concept ID:
C4479539
Disease or Syndrome
AMC1 is an autosomal recessive severe neurologic disorder with onset in utero. Most affected individuals die in utero or are subject to pregnancy termination because of lack of fetal movements and prenatal evidence of contractures of virtually all joints. Those who survive have generalized contractures and hypotonia. The disorder is caused by a neurogenic defect and poor or absent myelin formation around peripheral nerves rather than by a muscular defect (summary by Xue et al., 2017). <Genetic Heterogeneity of Arthrogryposis Multiplex Congenita Also see AMC2 (208100), caused by mutation in the ERGIC1 gene (617946); AMC3 (618484), caused by mutation in the SYNE1 gene (608441); AMC4 (618776), caused by mutation in the SCYL2 gene (616365); AMC5 (618947), caused by mutation in the TOR1A gene (605204), and AMC6 (619334), caused by mutation in the NEB gene (161650)
Stankiewicz-Isidor syndrome
MedGen UID:
1375936
Concept ID:
C4479599
Disease or Syndrome
Stankiewicz-Isidor syndrome (STISS) is a neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability, behavioral disorders, mild craniofacial anomalies, and variable congenital defects of the cardiac and/or urogenital systems (summary by Kury et al., 2017).
Neurodevelopmental disorder with midbrain and hindbrain malformations
MedGen UID:
1385580
Concept ID:
C4479613
Disease or Syndrome
Neurodevelopmental disorder with midbrain and hindbrain malformations (NEDMHM) is an autosomal recessive disorder comprising impaired intellectual development, speech delay, mild microcephaly, and midbrain-hindbrain malformation (Ravindran et al., 2017).
Rahman syndrome
MedGen UID:
1388282
Concept ID:
C4479637
Disease or Syndrome
The name HIST1H1E syndrome has been proposed as a mnemonic for the characteristic features of this emerging, recognizable phenotype: hypotonia; intellectual disability with behavioral issues; skeletal; testes (undescended) and thyroid; heart anomalies (most commonly atrial septal defect); and ectodermal issues (including sparse hair, thin nails, and abnormal dentition). In the 47 affected individuals reported to date, predominant findings were intellectual disability (ranging from mild to profound) and behavioral problems (combinations of anxiety/phobias, obsessive behaviors, attention-deficit/hyperactivity disorder, and autistic spectrum disorder/traits among others). Skeletal involvement can include scoliosis and decreased bone mineral density. Other findings in some include seizures, craniosynostosis, and hearing loss. Life expectancy does not appear to be reduced in HIST1H1E syndrome.
Gabriele de Vries syndrome
MedGen UID:
1375401
Concept ID:
C4479652
Disease or Syndrome
Gabriele-de Vries syndrome is characterized by mild-to-profound developmental delay / intellectual disability (DD/ID) in all affected individuals and a wide spectrum of functional and morphologic abnormalities. Intrauterine growth restriction or low birth weight and feeding difficulties are common. Congenital brain, eye, heart, kidney, genital, and/or skeletal system anomalies have also been reported. About half of affected individuals have neurologic manifestations, including hypotonia and gait abnormalities. Behavioral issues can include attention-deficit/hyperactivity disorder, anxiety, autism or autistic behavior, and schizoaffective disorder.
Autosomal recessive limb-girdle muscular dystrophy type R18
MedGen UID:
1385598
Concept ID:
C4517996
Disease or Syndrome
Autosomal recessive limb-girdle muscular dystrophy-18 (LGMD18) is characterized by childhood-onset of proximal muscle weakness resulting in gait abnormalities and scapular winging. Serum creatine kinase is increased. A subset of patients may show a hyperkinetic movement disorder with chorea, ataxia, or dystonia and global developmental delay (summary by Bogershausen et al., 2013). Additional more variable features include alacrima, achalasia, cataracts, or hepatic steatosis (Liang et al., 2015; Koehler et al., 2017). For a discussion of genetic heterogeneity of autosomal recessive limb-girdle muscular dystrophy, see LGMDR1 (253600).
Psychomotor regression-oculomotor apraxia-movement disorder-nephropathy syndrome
MedGen UID:
1621949
Concept ID:
C4539828
Disease or Syndrome
Birk-Landau-Perez syndrome (BILAPES) is an autosomal recessive syndromic developmental disorder characterized by global developmental delay apparent from infancy or early childhood. Some patients have developmental regression with loss of speech and motor skills, whereas other patients never achieve these milestones. More variable features may include hypotonia, poor overall growth, ataxia, dystonia, abnormal eye movements, and renal insufficiency (Perez et al., 2017; Kleyner et al., 2022).
Multiple mitochondrial dysfunctions syndrome 5
MedGen UID:
1623132
Concept ID:
C4539919
Disease or Syndrome
ISCA1-related multiple mitochondrial dysfunctions syndrome (ISCA1-MMDS) is a severe neurodegenerative condition typically characterized by either no attainment of developmental milestones or very early loss of achieved milestones, seizures in early infancy, development of spasticity with exaggerated deep tendon reflexes, nystagmus, and risk for sensorineural hearing loss. Affected individuals may also demonstrate elevated blood lactate levels with an elevated lipid-lactate peak on brain MR spectroscopy. Further brain MRI findings may include extensive cerebral and cerebellar deep white matter hyperintensities, marked dilatation of the cerebral ventricles, and pachygyria. Prognosis is poor and most individuals succumb to an intercurrent illness in early childhood.
Skraban-Deardorff syndrome
MedGen UID:
1627555
Concept ID:
C4539927
Disease or Syndrome
WDR26-related intellectual disability (ID) is characterized by developmental delay / intellectual disability, characteristic facial features, hypotonia, epilepsy, and infant feeding difficulties. To date 15 individuals, ages 24 months to 34 years, have been reported. Developmental delay is present in all individuals and ranges from mild to severe. All individuals have delayed speech. Although some begin to develop speech in the second year, others have remained nonverbal. Seizures, present in all affected individuals reported to date, can be febrile or non-febrile (tonic-clonic, absence, rolandic seizures); most seizures are self limited or respond well to standard treatment. Affected individuals are generally described as happy and socially engaging; several have stereotypies / autistic features (repetitive or rocking behavior, abnormal hand movements or posturing, and at times self-stimulation).
Congenital anomalies of kidney and urinary tract syndrome with or without hearing loss, abnormal ears, or developmental delay
MedGen UID:
1612119
Concept ID:
C4539968
Disease or Syndrome
CAKUTHED is an autosomal dominant highly pleiotropic developmental disorder characterized mainly by variable congenital anomalies of the kidney and urinary tract, sometimes resulting in renal dysfunction or failure, dysmorphic facial features, and abnormalities of the outer ear, often with hearing loss. Most patients have global developmental delay (summary by Heidet et al., 2017 and Slavotinek et al., 2017).
Combined oxidative phosphorylation deficiency 32
MedGen UID:
1617600
Concept ID:
C4540029
Disease or Syndrome
Combined oxidative phosphorylation deficiency-32 is an autosomal recessive neurodegenerative disorder characterized by onset of delayed psychomotor development and developmental regression in infancy. Affected individuals have multiple variable symptoms, including poor or absent speech, inability to walk, and abnormal movements. Brain imaging shows T2-weighted abnormalities in the basal ganglia and brainstem consistent with Leigh syndrome (256000). Patient cells showed decreased activities of mitochondrial respiratory chain complexes, I, III, and IV, as well as impaired mitochondrial translation (summary by Lake et al., 2017). For a discussion of genetic heterogeneity of combined oxidative phosphorylation deficiency, see COXPD1 (609060).
Pontocerebellar hypoplasia, type 11
MedGen UID:
1627627
Concept ID:
C4540164
Congenital Abnormality
Pontocerebellar hypoplasia type 11 (PCH11) is an autosomal recessive neurodevelopmental disorder characterized by severely delayed psychomotor development with impaired intellectual development and poor speech, microcephaly, dysmorphic features, and pontocerebellar hypoplasia on brain imaging. Additional features are more variable (summary by Marin-Valencia et al., 2017). For a general phenotypic description and a discussion of genetic heterogeneity of PCH, see PCH1 (607596).
3-methylglutaconic aciduria type 9
MedGen UID:
1622927
Concept ID:
C4540171
Disease or Syndrome
3-Methylglutaconic aciduria type IX (MGCA9) is an autosomal recessive disorder characterized by early-onset seizures, severely delayed psychomotor development and intellectual disability. Patients have hypotonia or spasticity, and laboratory investigations show increased serum lactate and 3-methylglutaconic aciduria, suggestive of a mitochondrial defect (summary by Shahrour et al., 2017). For a phenotypic description and a discussion of genetic heterogeneity of 3-methylglutaconic aciduria, see MGCA type I (250950).
Neurodevelopmental disorder, mitochondrial, with abnormal movements and lactic acidosis, with or without seizures
MedGen UID:
1619876
Concept ID:
C4540192
Disease or Syndrome
NEMMLAS is an autosomal recessive multisystemic disorder characterized by delayed psychomotor development, intellectual disability, and abnormal motor function, including hypotonia, dystonia, ataxia, and spasticity. Patient tissues may show deficiencies in one or more of the mitochondrial oxidative phosphorylation (OXPHOS) enzymes, but this is not a constant finding (summary by Wortmann et al., 2017).
Galloway-Mowat syndrome 3
MedGen UID:
1627611
Concept ID:
C4540266
Disease or Syndrome
Galloway-Mowat syndrome is a renal-neurologic disease characterized by early-onset nephrotic syndrome associated with microcephaly, gyral abnormalities of the brain, and delayed psychomotor development. Most patients have dysmorphic facial features, often including hypertelorism, ear abnormalities, and micrognathia. Other features, such as arachnodactyly and visual impairment, are more variable. Most patients die in the first years of life (summary by Braun et al., 2017). For a general phenotypic description and a discussion of genetic heterogeneity of GAMOS, see GAMOS1 (251300).
Joubert syndrome 31
MedGen UID:
1618082
Concept ID:
C4540355
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Retinitis pigmentosa-hearing loss-premature aging-short stature-facial dysmorphism syndrome
MedGen UID:
1615526
Concept ID:
C4540367
Disease or Syndrome
SHRF is an autosomal recessive disorder characterized by short stature, brachydactyly, dysmorphic facial features, hearing loss, and visual impairment. Onset of the hearing and visual abnormalities, including retinitis pigmentosa, varies from birth to the second decade. Patients have mild intellectual disability and mild cerebellar atrophy with myelination defects on brain imaging (summary by Di Donato et al., 2016).
Intellectual disability, autosomal dominant 52
MedGen UID:
1615839
Concept ID:
C4540478
Mental or Behavioral Dysfunction
Intellectual disability, autosomal dominant 53
MedGen UID:
1623344
Concept ID:
C4540481
Mental or Behavioral Dysfunction
Intellectual disability, autosomal dominant 54
MedGen UID:
1614787
Concept ID:
C4540484
Mental or Behavioral Dysfunction
Neurodevelopmental disorder with severe motor impairment and absent language
MedGen UID:
1622162
Concept ID:
C4540496
Mental or Behavioral Dysfunction
NEDMIAL is a neurodevelopmental disorder characterized by delayed psychomotor development and hypotonia apparent from early infancy, resulting in feeding difficulties, ataxic gait or inability to walk, delayed or absent speech development, and impaired intellectual development, sometimes with behavioral abnormalities, such as hand-flapping. Additional common features may include sleep disorder, nonspecific dysmorphic facial features, and joint hyperlaxity (summary by Lessel et al., 2017 and Mannucci et al., 2021).
Neurodevelopmental disorder with ataxic gait, absent speech, and decreased cortical white matter
MedGen UID:
1621102
Concept ID:
C4540498
Disease or Syndrome
NDAGSCW is a neurodevelopmental disorder characterized by severely delayed psychomotor development apparent from infancy. Affected individuals have delayed and difficulty walking, intellectual disability, absent speech, and variable additional features, including hip dysplasia, tapering fingers, and seizures. Brain imaging shows decreased cortical white matter, often with decreased cerebellar white matter, thin corpus callosum, and thin brainstem (summary by Lamers et al., 2017).
Nephrotic syndrome 14
MedGen UID:
1617660
Concept ID:
C4540559
Disease or Syndrome
Sphingosine phosphate lyase insufficiency syndrome (SPLIS) is characterized by varying combinations of steroid-resistant nephrotic syndrome (ranging from nonimmune fetal hydrops to adolescent onset), primary adrenal insufficiency (with or without mineralocorticoid deficiency), testicular insufficiency, hypothyroidism, ichthyosis, lymphopenia/immunodeficiency, and neurologic abnormalities that can include developmental delay, regression / progressive neurologic involvement, cranial nerve deficits, and peripheral motor and sensory neuropathy.
Seckel syndrome 1
MedGen UID:
1637056
Concept ID:
C4551474
Disease or Syndrome
Seckel syndrome is a rare autosomal recessive disorder characterized by intrauterine growth retardation, dwarfism, microcephaly with mental retardation, and a characteristic 'bird-headed' facial appearance (Shanske et al., 1997). Genetic Heterogeneity of Seckel Syndrome Other forms of Seckel syndrome include SCKL2 (606744), caused by mutation in the RBBP8 gene (604124) on chromosome 18q11; SCKL4 (613676), caused by mutation in the CENPJ gene (609279) on chromosome 13q12; SCKL5 (613823), caused by mutation in the CEP152 gene (613529) on chromosome 15q21; SCKL6 (614728), caused by mutation in the CEP63 gene (614724) on chromosome 3q22; SCKL7 (614851), caused by mutation in the NIN gene (608684) on chromosome 14q22; SCKL8 (615807), caused by mutation in the DNA2 gene (601810) on chromosome 10q21; SCKL9 (616777), caused by mutation in the TRAIP gene (605958) on chromosome 3p21; SCKL10 (617253), caused by mutation in the NSMCE2 gene (617246) on chromosome 8q24; and SCKL11 (620767), caused by mutation in the CEP295 gene (617728) on chromosome 11q21. The report of a Seckel syndrome locus on chromosome 14q, designated SCKL3, by Kilinc et al. (2003) was found to be in error; see History section.
LEOPARD syndrome 1
MedGen UID:
1631694
Concept ID:
C4551484
Disease or Syndrome
Noonan syndrome with multiple lentigines (NSML) is a condition in which the cardinal features consist of lentigines, hypertrophic cardiomyopathy, short stature, pectus deformity, and dysmorphic facial features including widely spaced eyes and ptosis. Multiple lentigines present as dispersed flat, black-brown macules, mostly on the face, neck, and upper part of the trunk with sparing of the mucosa. In general, lentigines do not appear until age four to five years but then increase to the thousands by puberty. Some individuals with NSML do not exhibit lentigines. Approximately 85% of affected individuals have heart defects, including hypertrophic cardiomyopathy (typically appearing during infancy and sometimes progressive) and pulmonary valve stenosis. Postnatal growth restriction resulting in short stature occurs in fewer than 50% of affected persons, although most affected individuals have a height that is less than the 25th centile for age. Sensorineural hearing deficits, present in approximately 20% of affected individuals, are poorly characterized. Intellectual disability, typically mild, is observed in approximately 30% of persons with NSML.
Tyrosinase-negative oculocutaneous albinism
MedGen UID:
1643910
Concept ID:
C4551504
Disease or Syndrome
Oculocutaneous albinism is a group of conditions that affect coloring (pigmentation) of the skin, hair, and eyes. Affected individuals typically have very fair skin and white or light-colored hair. Long-term sun exposure greatly increases the risk of skin damage and skin cancers, including an aggressive form of skin cancer called melanoma, in people with this condition. Oculocutaneous albinism also reduces pigmentation of the colored part of the eye (the iris) and the light-sensitive tissue at the back of the eye (the retina). People with this condition usually have vision problems such as reduced sharpness; rapid, involuntary eye movements (nystagmus); and increased sensitivity to light (photophobia).\n\nResearchers have identified multiple types of oculocutaneous albinism, which are distinguished by their specific skin, hair, and eye color changes and by their genetic cause. Oculocutaneous albinism type 1 is characterized by white hair, very pale skin, and light-colored irises. Type 2 is typically less severe than type 1; the skin is usually a creamy white color and hair may be light yellow, blond, or light brown. Type 3 includes a form of albinism called rufous oculocutaneous albinism, which usually affects dark-skinned people. Affected individuals have reddish-brown skin, ginger or red hair, and hazel or brown irises. Type 3 is often associated with milder vision abnormalities than the other forms of oculocutaneous albinism. Type 4 has signs and symptoms similar to those seen with type 2.\n\nSeveral additional types of this disorder have been proposed, each affecting one or a few families.
Abducens nerve palsy
MedGen UID:
1645218
Concept ID:
C4551519
Disease or Syndrome
Malfunction of the abducens nerve as manifested by impairment of the ability of the affected eye to be moved outward. Patients who develop abducens nerve palsy often present with binocular horizontal diplopia, which is a double vision when looking at objects side by side. There will be a notable weakness of the ipsilateral lateral rectus muscle leading to a deficit in of eye abduction on the affected side. Some patients may present with a constant head turning movement to maintain binocular fusion and to lessen the degree of diplopia.
Cerebellar ataxia, intellectual disability, and dysequilibrium syndrome 1
MedGen UID:
1639436
Concept ID:
C4551552
Disease or Syndrome
VLDLR cerebellar hypoplasia (VLDLR-CH) is characterized by non-progressive congenital ataxia that is predominantly truncal and results in delayed ambulation, moderate-to-profound intellectual disability, dysarthria, strabismus, and seizures. Children either learn to walk very late (often after age 6 years) or never achieve independent ambulation. Brain MRI findings include hypoplasia of the inferior portion of the cerebellar vermis and hemispheres, simplified gyration of the cerebral hemispheres, and small brain stem – particularly the pons.
Joubert syndrome 1
MedGen UID:
1644883
Concept ID:
C4551568
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Galloway-Mowat syndrome 1
MedGen UID:
1634188
Concept ID:
C4551772
Disease or Syndrome
Cornelia de Lange syndrome 1
MedGen UID:
1645760
Concept ID:
C4551851
Disease or Syndrome
Cornelia de Lange syndrome (CdLS) encompasses a spectrum of findings from mild to severe. Severe (classic) CdLS is characterized by distinctive facial features, growth restriction (prenatal onset; <5th centile throughout life), hypertrichosis, and upper-limb reduction defects that range from subtle phalangeal abnormalities to oligodactyly (missing digits). Craniofacial features include synophrys, highly arched and/or thick eyebrows, long eyelashes, short nasal bridge with anteverted nares, small widely spaced teeth, and microcephaly. Individuals with a milder phenotype have less severe growth, cognitive, and limb involvement, but often have facial features consistent with CdLS. Across the CdLS spectrum IQ ranges from below 30 to 102 (mean: 53). Many individuals demonstrate autistic and self-destructive tendencies. Other frequent findings include cardiac septal defects, gastrointestinal dysfunction, hearing loss, myopia, and cryptorchidism or hypoplastic genitalia.
Rubinstein-Taybi syndrome due to CREBBP mutations
MedGen UID:
1639327
Concept ID:
C4551859
Disease or Syndrome
Rubinstein-Taybi syndrome (RSTS) is characterized by distinctive facial features, broad and often angulated thumbs and halluces, short stature, and moderate-to-severe intellectual disability. The characteristic craniofacial features are downslanted palpebral fissures, low-hanging columella, high palate, grimacing smile, and talon cusps. Prenatal growth is often normal, then height, weight, and head circumference percentiles rapidly drop in the first few months of life. Short stature is typical in adulthood. Obesity may develop in childhood or adolescence. Average IQ ranges between 35 and 50; however, developmental outcome varies considerably. Some individuals with EP300-RSTS have normal intellect. Additional features include ocular abnormalities, hearing loss, respiratory difficulties, congenital heart defects, renal abnormalities, cryptorchidism, feeding problems, recurrent infections, and severe constipation.
Meier-Gorlin syndrome 1
MedGen UID:
1641240
Concept ID:
C4552001
Disease or Syndrome
The Meier-Gorlin syndrome is a rare disorder characterized by severe intrauterine and postnatal growth retardation, microcephaly, bilateral microtia, and aplasia or hypoplasia of the patellae (summary by Shalev and Hall, 2003). While almost all cases have primordial dwarfism with substantial prenatal and postnatal growth retardation, not all cases have microcephaly, and microtia and absent/hypoplastic patella are absent in some. Despite the presence of microcephaly, intellect is usually normal (Bicknell et al., 2011). Genetic Heterogeneity of Meier-Gorlin Syndrome Most forms of Meier-Gorlin syndrome are autosomal recessive disorders, including Meier-Gorlin syndrome-1; Meier-Gorlin syndrome-2 (613800), caused by mutation in the ORC4 gene (603056) on chromosome 2q23; Meier-Gorlin syndrome-3 (613803), caused by mutation in the ORC6 gene (607213) on chromosome 16q11; Meier-Gorlin syndrome-4 (613804), caused by mutation in the CDT1 gene (605525) on chromosome 16q24; Meier-Gorlin syndrome-5 (613805), caused by mutation in the CDC6 gene (602627) on chromosome 17q21; Meier-Gorlin syndrome-7 (617063), caused by mutation in the CDC45L gene (603465) on chromosome 22q11; and Meier-Gorlin syndrome-8 (617564), caused by mutation in the MCM5 gene (602696) on chromosome 22q12. An autosomal dominant form of the disorder, Meier-Gorlin syndrome-6 (616835), is caused by mutation in the GMNN gene (602842) on chromosome 6p22.
Neurodevelopmental disorder with or without hyperkinetic movements and seizures, autosomal recessive
MedGen UID:
1646665
Concept ID:
C4693325
Disease or Syndrome
GRIN1-related neurodevelopmental disorder (GRIN1-NDD) is characterized by mild-to-profound developmental delay / intellectual disability (DD/ID) in all affected individuals. Other common manifestations are epilepsy, muscular hypotonia, movement disorders, spasticity, feeding difficulties, and behavior problems. A subset of individuals show a malformation of cortical development consisting of extensive and diffuse bilateral polymicrogyria. To date, 72 individuals with GRIN1-NDD have been reported.
Alkuraya-Kucinskas syndrome
MedGen UID:
1634304
Concept ID:
C4693347
Disease or Syndrome
ALKKUCS is an autosomal recessive severe neurodevelopmental disorder characterized by arthrogryposis, brain abnormalities associated with cerebral parenchymal underdevelopment, and global developmental delay. Most affected individuals die in utero or soon after birth. Additional abnormalities may include hypotonia, dysmorphic facial features, and involvement of other organ systems, such as cardiac or renal. The few patients who survive have variable intellectual disability and may have seizures (summary by Gueneau et al., 2018).
Neurodevelopmental disorder with microcephaly, epilepsy, and brain atrophy
MedGen UID:
1637443
Concept ID:
C4693390
Disease or Syndrome
NEDMEBA is an autosomal recessive neurodegenerative disorder characterized by global developmental delay, severe intellectual disability with poor or absent speech and autistic stereotypic behaviors, microcephaly, early-onset generalized seizures, and hypotonia (summary by Marin-Valencia et al., 2018).
Neurodevelopmental disorder with or without seizures and gait abnormalities
MedGen UID:
1645968
Concept ID:
C4693391
Disease or Syndrome
Neurodevelopmental disorder with or without seizures and gait abnormalities (NEDSGA) is an autosomal dominant disorder characterized by global developmental delay apparent from infancy or early childhood, resulting in variably impaired intellectual development that can range from profound with absent speech to mild with an ability to attend special schools. Most affected individuals show irritability, stiffness, and hypertonia early in life, which progresses to spasticity and impaired gait later. Some patients may develop seizures of variable severity early in life (summary by Martin et al., 2017).
Neurodevelopmental disorder with movement abnormalities, abnormal gait, and autistic features
MedGen UID:
1647077
Concept ID:
C4693405
Disease or Syndrome
Neurodevelopmental disorder with movement abnormalities, abnormal gait, and autistic features (NEDMAGA) is characterized by infantile-onset global developmental delay with severe to profound intellectual disability, mildly delayed walking with broad-based and unsteady gait, and absence of meaningful language. Patients have features of autism, with repetitive behaviors and poor communication, but usually are socially reactive and have a happy demeanor. More variable neurologic features include mild seizures, spasticity, and peripheral neuropathy (summary by Palmer et al., 2017).
Microcephaly 20, primary, autosomal recessive
MedGen UID:
1641618
Concept ID:
C4693572
Congenital Abnormality
Chromosome 1p35 deletion syndrome
MedGen UID:
1632676
Concept ID:
C4693669
Disease or Syndrome
Developmental and epileptic encephalopathy, 63
MedGen UID:
1646846
Concept ID:
C4693810
Disease or Syndrome
Developmental and epileptic encephalopathy-63 (DEE63) is an autosomal recessive neurologic disorder characterized by early-onset refractory infantile spasms and myoclonic seizures in the first months to years of life. Affected individuals have severe to profound developmental delay, often with hypotonia and inability to sit or speak (summary by Redler et al., 2017). For a discussion of genetic heterogeneity of DEE, see 308350.
PHIP-related behavioral problems-intellectual disability-obesity-dysmorphic features syndrome
MedGen UID:
1641154
Concept ID:
C4693860
Disease or Syndrome
Chung-Jansen syndrome (CHUJANS) is characterized by global developmental delay apparent from infancy, impaired intellectual development or learning difficulties, behavioral abnormalities, dysmorphic features, and obesity. The severity of the phenotype and additional features are variable (summary by Jansen et al., 2018).
Combined oxidative phosphorylation defect type 15
MedGen UID:
1646555
Concept ID:
C4706313
Disease or Syndrome
A rare mitochondrial disease due to a defect in mitochondrial protein synthesis with onset in infancy or early childhood of muscular hypotonia, gait ataxia, mild bilateral pyramidal tract signs, developmental delay (affecting mostly speech and coordination) and subsequent intellectual disability. Short stature, obesity, microcephaly, strabismus, nystagmus, reduced visual acuity, lactic acidosis, and a brain neuropathology consistent with Leigh syndrome are also reported. Caused by homozygous or compound heterozygous mutation in the MTFMT gene on chromosome 15q22.
3p- syndrome
MedGen UID:
1643555
Concept ID:
C4706503
Disease or Syndrome
Characteristic features of the distal 3p- syndrome include low birth weight, microcephaly, trigonocephaly, hypotonia, psychomotor and growth retardation, ptosis, telecanthus, downslanting palpebral fissures, and micrognathia. Postaxial polydactyly, renal anomalies, cleft palate, congenital heart defects (especially atrioventricular septal defects), preauricular pits, sacral dimple, and gastrointestinal anomalies are variable features. Although intellectual deficits are almost invariably associated with cytogenetically visible 3p deletions, rare patients with a 3p26-p25 deletion and normal intelligence or only mild abnormalities have been described (summary by Shuib et al., 2009).
Alacrima, achalasia, and intellectual disability syndrome
MedGen UID:
1640947
Concept ID:
C4706563
Disease or Syndrome
Alacrima, achalasia, and impaired intellectual development syndrome (AAMR) is an autosomal recessive disorder characterized by onset of these 3 main features at birth or in early infancy. More variable features include hypotonia, gait abnormalities, anisocoria, and visual or hearing deficits. The disorder shows similarity to the triple A syndrome (231550), but patients with AAMR do not have adrenal insufficiency (summary by Koehler et al., 2013). See also 300858 for a phenotypically similar disorder that shows X-linked inheritance.
Renal hypomagnesemia 5 with ocular involvement
MedGen UID:
1648449
Concept ID:
C4721891
Disease or Syndrome
HOMG5 is an autosomal recessive disorder characterized by severe renal magnesium wasting, progressive renal failure, nephrocalcinosis, and severe visual impairment (Konrad et al., 2006). Amelogenesis imperfecta may also be present in some patients (Yamaguti et al., 2017). For a discussion of genetic heterogeneity of renal hypomagnesemia, see 602014.
Coffin-Siris syndrome 7
MedGen UID:
1648281
Concept ID:
C4747954
Disease or Syndrome
Coffin-Siris syndrome (CSS) is classically characterized by aplasia or hypoplasia of the distal phalanx or nail of the fifth and additional digits, developmental or cognitive delay of varying degree, distinctive facial features, hypotonia, hirsutism/hypertrichosis, and sparse scalp hair. Congenital anomalies can include malformations of the cardiac, gastrointestinal, genitourinary, and/or central nervous systems. Other findings commonly include feeding difficulties, slow growth, ophthalmologic abnormalities, and hearing impairment.
Intellectual disability, autosomal dominant 57
MedGen UID:
1648280
Concept ID:
C4748003
Mental or Behavioral Dysfunction
MRD57 is an autosomal dominant neurodevelopmental disorder with a highly variable phenotype. Most affected individuals have delayed psychomotor development apparent in infancy or early childhood, language delay, and behavioral abnormalities. Additional features may include hypotonia, feeding problems, gastrointestinal issues, and dysmorphic facial features (summary by Reijnders et al., 2018).
Intellectual developmental disorder with or without epilepsy or cerebellar ataxia
MedGen UID:
1648354
Concept ID:
C4748041
Disease or Syndrome
Developmental and epileptic encephalopathy, 66
MedGen UID:
1648486
Concept ID:
C4748070
Disease or Syndrome
Developmental and epileptic encephalopathy-66 (DEE66) is a neurologic disorder characterized by the onset of various types of seizures in the first days or weeks of life. Most seizures have focal origins; secondary generalization is common. Seizure control is difficult at first, but may become easier with time. Affected individuals show global developmental delay with hypotonia, behavioral abnormalities, and dysmorphic features or ophthalmologic defects. Brain imaging often shows cerebellar dysgenesis. A subset of patients have extraneurologic manifestations, including hematologic and distal limb abnormalities (summary by Olson et al., 2018). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Spinocerebellar ataxia 42, early-onset, severe, with neurodevelopmental deficits
MedGen UID:
1648308
Concept ID:
C4748120
Disease or Syndrome
Intellectual developmental disorder with dysmorphic facies and behavioral abnormalities
MedGen UID:
1648498
Concept ID:
C4748135
Disease or Syndrome
Intellectual disability, autosomal dominant 58
MedGen UID:
1648488
Concept ID:
C4748195
Disease or Syndrome
Intellectual disability, autosomal recessive 65
MedGen UID:
1648401
Concept ID:
C4748219
Mental or Behavioral Dysfunction
Peripheral neuropathy, autosomal recessive, with or without impaired intellectual development
MedGen UID:
1648480
Concept ID:
C4748283
Disease or Syndrome
Autosomal recessive peripheral neuropathy with or without impaired intellectual development is an early childhood-onset neurologic disorder characterized by slowly progressive distal motor impairment resulting in gait difficulties, often with loss of ambulation, and difficulties using the hands in most patients. Most affected individuals also have impaired intellectual development, although some have normal cognition. Electrophysiologic testing and sural nerve biopsy are most compatible with an axonal motor neuropathy; some patients may show signs of demyelination. Additional features may include eye movement abnormalities, claw hands, foot deformities, and scoliosis (summary by Ylikallio et al., 2017).
Hennekam lymphangiectasia-lymphedema syndrome 3
MedGen UID:
1648368
Concept ID:
C4748408
Disease or Syndrome
Hennekam lymphangiectasia-lymphedema syndrome-3 (HKKLLS3) is characterized by widespread congenital edema that is more severe in more dependent areas of the body. Associated features include facial dysmorphism and protein-losing enteropathy of variable severity (Brouillard et al., 2017). For a discussion of genetic heterogeneity of Hennekam lymphangiectasia-lymphedema syndrome, see HKLLS1 (235510).
Cardiac, facial, and digital anomalies with developmental delay
MedGen UID:
1648330
Concept ID:
C4748484
Disease or Syndrome
CAFDADD is a multisystemic developmental disorder with variable cardiac and digital anomalies and facial dysmorphism. Some patients may have seizures and ocular/aural abnormalities (Tokita et al., 2018).
Neurodegeneration, childhood-onset, stress-induced, with variable ataxia and seizures
MedGen UID:
1648391
Concept ID:
C4748527
Disease or Syndrome
Stress-induced childhood-onset neurodegeneration with variable ataxia and seizures (CONDSIAS) is an autosomal recessive neurodegenerative disorder with onset in the first years of life following normal early development. Patient have cyclic episodic deterioration in response to stress, such as infection or febrile illness. The severity is highly variable: some patients develop seizures early in life that are associated with loss of developmental milestones and early sudden death in childhood, whereas others present at a later age with muscle weakness, gait ataxia, impaired speech, more subtle clinical deterioration, and cognitive decline. Neurologic involvement includes gait ataxia, cerebellar signs associated with cerebellar atrophy, generalized brain atrophy, impaired intellectual development, hearing loss, and peripheral neuropathy (summary by Ghosh et al., 2018).
Snijders Blok-Campeau syndrome
MedGen UID:
1648495
Concept ID:
C4748701
Disease or Syndrome
Snijders Blok-Campeau syndrome (SNIBCPS) is an autosomal dominant neurodevelopmental disorder characterized by global developmental delay with impaired intellectual development and delayed speech acquisition. Affected individuals tend to have expressive language deficits, with speech apraxia and dysarthria. Other features include macrocephaly and characteristic facial features, such as prominent forehead and hypertelorism, hypotonia, and joint laxity. The severity of the neurologic deficits and presence of nonneurologic features is variable (summary by Snijders Blok et al., 2018).
Infantile hypotonia-oculomotor anomalies-hyperkinetic movements-developmental delay syndrome
MedGen UID:
1648431
Concept ID:
C4748715
Disease or Syndrome
Baker-Gordon syndrome (BAGOS) is a neurodevelopmental disorder characterized by infantile hypotonia, ophthalmic abnormalities, moderate to profound global developmental delay, poor or absent speech, behavioral abnormalities, hyperkinetic movements, and EEG abnormalities in the absence of overt seizures (summary by Baker et al., 2018).
Mitochondrial complex 1 deficiency, nuclear type 4
MedGen UID:
1648324
Concept ID:
C4748753
Disease or Syndrome
Mitochondrial complex 1 deficiency, nuclear type 5
MedGen UID:
1648292
Concept ID:
C4748754
Disease or Syndrome
Mitochondrial complex 1 deficiency, nuclear type 21
MedGen UID:
1648383
Concept ID:
C4748792
Disease or Syndrome
Neurodegeneration, childhood-onset, with cerebellar atrophy
MedGen UID:
1648286
Concept ID:
C4748934
Disease or Syndrome
Childhood-onset neurodegeneration with cerebellar atrophy (CONDCA) is a severe autosomal recessive neurodevelopmental disorder affecting the central and peripheral nervous system. Patients present in the first year of life with global developmental delay, impaired intellectual development, poor or absent speech, and motor abnormalities. Brain imaging shows cerebellar atrophy. The severity is variable, but death in childhood may occur (Shashi et al., 2018).
Fibrosis, neurodegeneration, and cerebral angiomatosis
MedGen UID:
1648312
Concept ID:
C4748939
Disease or Syndrome
Fibrosis, neurodegeneration, and cerebral angiomatosis (FINCA) is characterized by severe progressive cerebropulmonary symptoms, resulting in death in infancy from respiratory failure. Features include malabsorption, progressive growth failure, recurrent infections, chronic hemolytic anemia, and transient liver dysfunction. Neuropathology shows increased angiomatosis-like leptomeningeal, cortical, and superficial white matter vascularization and congestion, vacuolar degeneration and myelin loss in white matter, as well as neuronal degeneration. Interstitial fibrosis and granuloma-like lesions are seen in the lungs, and there is hepatomegaly with steatosis and collagen accumulation (Uusimaa et al., 2018).
Intellectual developmental disorder, autosomal recessive 67
MedGen UID:
1648350
Concept ID:
C4749019
Disease or Syndrome
Severe feeding difficulties-failure to thrive-microcephaly due to ASXL3 deficiency syndrome
MedGen UID:
1656239
Concept ID:
C4750837
Disease or Syndrome
ASXL3-related disorder is characterized by developmental delay or intellectual disability, typically in the moderate to severe range, with speech and language delay and/or absent speech. Affected individuals may also display autistic features. There may be issues with feeding. While dysmorphic facial features have been described, they are typically nonspecific. Affected individuals may also have hypotonia that can transition to spasticity resulting in unusual posture with flexion contractions of the elbows, wrists, and fingers. Other findings may include poor postnatal growth, strabismus, seizures, sleep disturbance, and dental anomalies.
Intellectual disability-strabismus syndrome
MedGen UID:
1665943
Concept ID:
C4750838
Disease or Syndrome
Neurodevelopmental disorder with brain abnormalities, poor growth, and dysmorphic facies (NEDBGF) is an autosomal recessive disorder characterized by global developmental delay with delayed walking, impaired intellectual development, and speech delay apparent from infancy or early childhood. Most patients have dysmorphic facial features, often with microcephaly and strabismus, and white matter abnormalities on brain imaging. More variable features may include teeth anomalies, distal joint contractures, spasticity, peripheral neuropathy, and behavioral problems (summary by Sharkia et al., 2019).
Pontocerebellar hypoplasia type 10
MedGen UID:
1676575
Concept ID:
C5190575
Disease or Syndrome
Pontocerebellar hypoplasia type 10 is an autosomal recessive neurodevelopmental and neurodegenerative disorder characterized by severely delayed psychomotor development, progressive microcephaly, spasticity, seizures, and brain abnormalities, including brain atrophy and delayed myelination. Some patients have dysmorphic features and an axonal sensorimotor neuropathy (summary by Karaca et al., 2014 and Schaffer et al., 2014). For a general phenotypic description and a discussion of genetic heterogeneity of PCH, see PCH1 (607596).
Congenital muscular dystrophy with intellectual disability and severe epilepsy
MedGen UID:
1682844
Concept ID:
C5190603
Disease or Syndrome
A rare fatal inborn error of metabolism disorder with characteristics of respiratory distress and severe hypotonia at birth, severe global developmental delay, early-onset intractable seizures, myopathic facies with craniofacial dysmorphism (trigonocephaly/progressive microcephaly, low anterior hairline, arched eyebrows, hypotelorism, strabismus, small nose, prominent philtrum, thin upper lip, high-arched palate, micrognathia, malocclusion), severe, congenital flexion joint contractures and elevated serum creatine kinase levels. Scoliosis, optic atrophy, mild hepatomegaly, and hypoplastic genitalia may also be associated. There is evidence the disease is caused by homozygous or compound heterozygous mutation in the DPM2 gene on chromosome 9q34.
Intellectual developmental disorder, X-linked 108
MedGen UID:
1680544
Concept ID:
C5193009
Disease or Syndrome
X-linked intellectual developmental disorder-108 (MRX108) is characterized by early hypotonia, global developmental delay, and moderately to severely impaired intellectual development. Brisk tendon reflexes, variable facial dysmorphism, and fifth finger clinodactyly may be present (Khayat et al., 2019).
Intellectual developmental disorder with cardiac defects and dysmorphic facies
MedGen UID:
1675627
Concept ID:
C5193024
Disease or Syndrome
IDDCDF is an autosomal recessive syndromic neurodevelopmental disorder characterized by globally impaired development with intellectual disability and speech delay, congenital cardiac malformations, and dysmorphic facial features. Additional features, such as distal skeletal anomalies, may also be observed (Stephen et al., 2018).
Myasthenic syndrome, congenital, 25, presynaptic
MedGen UID:
1683288
Concept ID:
C5193027
Disease or Syndrome
Congenital myasthenic syndrome-25 (CMS25) is an autosomal recessive neuromuscular disorder characterized by hypotonia and generalized muscle weakness apparent from birth. Affected individuals have feeding difficulties and delayed motor development, usually never achieving independent ambulation. Additional variable features include eye movement abnormalities, joint contractures, and rigid spine. Pyridostigmine treatment may be partially effective (summary by Shen et al., 2017). For a discussion of genetic heterogeneity of CMS, see CMS1A (601462).
Congenital disorder of glycosylation with defective fucosylation 2
MedGen UID:
1676187
Concept ID:
C5193028
Disease or Syndrome
Lissencephaly 9 with complex brainstem malformation
MedGen UID:
1681109
Concept ID:
C5193029
Disease or Syndrome
Lissencephaly-9 with complex brainstem malformation (LIS9) is an autosomal dominant neurologic disorder characterized by global developmental delay apparent since infancy, impaired intellectual development with poor or absent speech, and sometimes abnormal or involuntary movements associated with abnormal brain imaging that typically shows pachygyria, lissencephaly, and malformation of the brainstem consistent with a neuronal migration defect (summary by Dobyns et al., 2018). For a general description and a discussion of genetic heterogeneity of lissencephaly, see LIS1 (607432).
Menke-Hennekam syndrome 1
MedGen UID:
1675629
Concept ID:
C5193034
Disease or Syndrome
Menke-Hennekam syndrome-1 (MKHK1) is a congenital disorder characterized by variable impairment of intellectual development and facial dysmorphisms. Feeding difficulties, autistic behavior, recurrent upper airway infections, hearing impairment, short stature, and microcephaly are also frequently seen. Although mutations in the same gene cause Rubinstein-Taybi syndrome-1 (RSTS1; 180849), patients with MKHK1 do not resemble the striking phenotype of RSTS1. Genetic Heterogeneity of Menke-Hennekam Syndrome Menke-Hennekam syndrome-2 (MKHK2; 618333) is caused by heterozygous mutation in exons 30 or 31 of the EP300 gene (602700). Mutation elsewhere in that gene results in RSTS2 (613684).
Menke-Hennekam syndrome 2
MedGen UID:
1676668
Concept ID:
C5193035
Disease or Syndrome
Menke-Hennekam syndrome-2 (MKHK2) is a congenital disorder characterized by variable impairment of intellectual development and facial dysmorphisms. Feeding difficulties, autistic behavior, recurrent upper airway infections, and hearing impairment are also frequently seen. Although mutations in the same gene cause Rubinstein-Taybi syndrome-2 (RSTS2; 613684), patients with MKHK1 do not resemble the striking phenotype of RSTS2. For a discussion of genetic heterogeneity of Menke-Hennekam syndrome, see MKHK1 (618332).
Galloway-Mowat syndrome 8
MedGen UID:
1675829
Concept ID:
C5193045
Disease or Syndrome
Galloway-Mowat syndrome-8 is an autosomal recessive disorder characterized by impaired psychomotor development, poor overall growth with microcephaly, and early-onset progressive nephrotic syndrome associated with focal segmental glomerulosclerosis on renal biopsy. Some patients may have seizures, and some may die in childhood (summary by Fujita et al., 2018). For a general phenotypic description and a discussion of genetic heterogeneity of GAMOS, see GAMOS1 (251300).
Developmental delay with variable intellectual impairment and behavioral abnormalities
MedGen UID:
1676192
Concept ID:
C5193092
Disease or Syndrome
Developmental delay with variable intellectual impairment and behavioral abnormalities (DDVIBA) is an autosomal dominant neurodevelopmental disorder. Most patients have impaired intellectual development with speech difficulties, and many have behavioral abnormalities, most commonly autism spectrum disorder (ASD), defects in attention, and/or hyperactivity. Many patients have dysmorphic features, although there is not a consistent gestalt. Additional more variable features may include hypotonia, somatic overgrowth with macrocephaly, mild distal skeletal anomalies, sleep disturbances, movement disorders, and gastrointestinal issues, such as constipation. The phenotype is highly variable (summary by Vetrini et al., 2019 and Torti et al., 2019).
Neurodevelopmental disorder with or without variable brain abnormalities; NEDBA
MedGen UID:
1675664
Concept ID:
C5193102
Disease or Syndrome
Neurodevelopmental disorder with or without variable brain abnormalities (NEDBA) is characterized by global developmental delay apparent from infancy or early childhood, resulting in mildly delayed walking, variably impaired intellectual development, and poor or absent speech. Additional features may include hypotonia, spasticity, or ataxia. About half of patients have abnormal findings on brain imaging, including cerebral or cerebellar atrophy, loss of white matter volume, thin corpus callosum, and perisylvian polymicrogyria. Seizures are not a prominent finding, and although some patients may have nonspecific dysmorphic facial features, there is no common or consistent gestalt (summary by Platzer et al., 2019).
Khan-Khan-Katsanis syndrome
MedGen UID:
1682553
Concept ID:
C5193110
Disease or Syndrome
Khan-Khan-Katsanis syndrome (3KS) is an autosomal recessive neurodevelopmental disorder with variable involvement of the ocular, renal, skeletal, and sometimes cardiac systems. Affected individuals present at birth with multiple congenital anomalies, defects in urogenital and limb morphogenesis, poor overall growth with microcephaly, and global developmental delay (summary by Khan et al., 2019).
Cerebellar, ocular, craniofacial, and genital syndrome
MedGen UID:
1680057
Concept ID:
C5193118
Disease or Syndrome
Cerebellar, ocular, craniofacial, and genital syndrome (COFG) is characterized by moderate to severe developmental delay and impaired intellectual development, severe cerebellar hypoplasia, a noticeably short forehead, medially sparse/flared and laterally extended eyebrows, corneal dystrophy, underdeveloped labioscrotal folds, and tufts of hair extruding from the lactiferous ducts with breast and nipple underdevelopment. Additional features such as pontine involvement, retinal degeneration, anteverted nares, and low-set ears have been variably observed (Rad et al., 2019).
Arthrogryposis multiplex congenita 3, myogenic type
MedGen UID:
1680655
Concept ID:
C5193121
Disease or Syndrome
Myogenic-type arthrogryposis multiplex congenita-3 (AMC3) is an autosomal recessive disorder characterized by decreased fetal movements, hypotonia, variable skeletal defects, including clubfoot and scoliosis, and delayed motor milestones with difficulty walking (summary by Baumann et al., 2017).
Hypotonia, hypoventilation, impaired intellectual development, dysautonomia, epilepsy, and eye abnormalities
MedGen UID:
1672905
Concept ID:
C5193124
Disease or Syndrome
Hypotonia, hypoventilation, impaired intellectual development, dysautonomia, epilepsy, and eye abnormalities (HIDEA) is an autosomal recessive neurodevelopmental syndrome characterized by global developmental delay, poor or absent speech, hypotonia, variable ocular movement and visual abnormalities, and respiratory difficulties, including hypoventilation, and sleep apnea. Patients may have significant breathing problems during respiratory infections that may lead to early death (summary by Rahikkala et al., 2019).
Neurodevelopmental disorder with seizures and nonepileptic hyperkinetic movements
MedGen UID:
1678038
Concept ID:
C5193128
Disease or Syndrome
Neurodevelopmental disorder with seizures and nonepileptic hyperkinetic movements (NEDNEH) is an autosomal recessive severe neurologic disorder characterized by delayed psychomotor development with inability to walk or speak, early-onset refractory seizures, and nonepileptic hyperkinetic movement disorders, including myoclonus dystonia and dyskinesias. Patients require tube feeding and may die of respiratory failure in childhood or in the second decade (summary by Gorman et al., 2019).
Cerebellar atrophy with seizures and variable developmental delay
MedGen UID:
1683734
Concept ID:
C5193132
Disease or Syndrome
Cerebellar atrophy with seizures and variable developmental delay (CASVDD) is an autosomal recessive neurologic disorder characterized by cerebellar ataxia associated with atrophy of the cerebellar vermis on brain imaging. Most patients also have onset of severe refractory seizures in the first year of life and show global developmental delay, compatible with epileptic encephalopathy (summary by Edvardson et al., 2013). However, at least 1 patient with normal cognitive development and only 1 febrile seizure has been reported (Valence et al., 2019), suggesting significant clinical variability of this disorder.
Neurodevelopmental disorder with coarse facies and mild distal skeletal abnormalities
MedGen UID:
1682403
Concept ID:
C5193134
Disease or Syndrome
Stolerman neurodevelopmental syndrome (NEDSST) is a highly variable disorder characterized by developmental delay, often with motor and speech delay, mildly impaired intellectual development (in most patients), learning difficulties, and behavioral abnormalities, including autism spectrum disorder. Psychosis is observed in a small percentage of individuals over the age of 12 years. Most individuals have nonspecific and mild dysmorphic facial features without a common gestalt. A subset of patients may have involvement of other organ systems, including gastrointestinal with poor early feeding or gastroesophageal reflux, distal skeletal anomalies, and congenital heart defects. Most mutations occur de novo, but rare autosomal dominant inheritance with incomplete penetrance has been observed (Stolerman et al., 2019; Rots et al., 2023).
Shukla-Vernon syndrome
MedGen UID:
1674076
Concept ID:
C5193146
Disease or Syndrome
Shukla-Vernon syndrome (SHUVER) is an X-linked recessive neurodevelopmental disorder characterized by global developmental delay, variably impaired intellectual development, and behavioral abnormalities, including autism spectrum disorder and ADHD. Dysmorphic features are common and may include tall forehead, downslanting palpebral fissures, and tapering fingers. Some patients may have seizures and/or cerebellar atrophy on brain imaging. Carrier mothers may have mild manifestations, including learning disabilities (summary by Shukla et al., 2019).
Intellectual developmental disorder 59
MedGen UID:
1678593
Concept ID:
C5193190
Disease or Syndrome
Rothmund-Thomson syndrome type 2
MedGen UID:
1684753
Concept ID:
C5203410
Disease or Syndrome
Rothmund-Thomson syndrome (RTS) is characterized by a rash that progresses to poikiloderma; sparse hair, eyelashes, and/or eyebrows; small size; skeletal and dental abnormalities; juvenile cataracts; and an increased risk for cancer, especially osteosarcoma. A variety of benign and malignant hematologic abnormalities have been reported in affected individuals. The rash of RTS typically develops between ages three and six months (occasionally as late as age two years) as erythema, swelling, and blistering on the face, subsequently spreading to the buttocks and extremities. The rash evolves over months to years into the chronic pattern of reticulated hypo- and hyperpigmentation, telangiectasias, and punctate atrophy (collectively known as poikiloderma) that persist throughout life. Hyperkeratotic lesions occur in approximately one third of individuals. Skeletal abnormalities can include radial ray defects, ulnar defects, absent or hypoplastic patella, and osteopenia.
Neurodevelopmental disorder with visual defects and brain anomalies
MedGen UID:
1684774
Concept ID:
C5231404
Disease or Syndrome
Neurodevelopmental disorder with visual defects and brain anomalies (NEDVIBA) is characterized by global developmental delay with impaired intellectual development and speech delay, variable visual defects, including retinitis pigmentosa and optic atrophy, hypotonia or hypertonia, and variable structural brain abnormalities. Other nonspecific features may be found (summary by Okur et al., 2019).
Neurodevelopmental disorder with cataracts, poor growth, and dysmorphic facies
MedGen UID:
1684661
Concept ID:
C5231414
Disease or Syndrome
Glycosylphosphatidylinositol biosynthesis defect 21
MedGen UID:
1684749
Concept ID:
C5231419
Disease or Syndrome
Neurodevelopmental disorder with brain anomalies, seizures, and scoliosis (NEDBSS) is an autosomal recessive disorder characterized by severely impaired psychomotor development, hypotonia, seizures, and structural brain anomalies, including thin corpus callosum and cerebellar atrophy. Other features include scoliosis, dysmorphic facies, and visual impairment. Affected individuals are usually unable to walk or speak and may require tube feeding in severe cases. The disorder is caused by a defect in glycosylphosphatidylinositol (GPI) biosynthesis (summary by Knaus et al., 2019). For a discussion of genetic heterogeneity of GPI biosynthesis defects, see GPIBD1 (610293).
Neurodevelopmental disorder with hypotonia and variable intellectual and behavioral abnormalities
MedGen UID:
1684818
Concept ID:
C5231423
Disease or Syndrome
Neurodevelopmental disorder with hypotonia and variable intellectual and behavioral abnormalities (NEDHIB) is characterized by early-onset hypotonia, delayed walking, poor speech, and impaired intellectual development. Additional features may include feeding difficulties, dysmorphic features, and visual defects. Brain imaging tends to show delayed myelination, thin corpus callosum, and/or enlarged ventricles. The severity of the disorder is highly variable; initial evidence suggests that the severity may depend on the type of mutation (summary by Haijes et al., 2019).
Pontocerebellar hypoplasia, type 13
MedGen UID:
1684708
Concept ID:
C5231425
Disease or Syndrome
Pontocerebellar hypoplasia type 13 (PCH13) is an autosomal recessive disorder characterized by global developmental delay, impaired intellectual development with absent speech, microcephaly, and progressive atrophy of the cerebellar vermis and brainstem. Additional features, including seizures and visual impairment, are variable (summary by Uwineza et al., 2019). For a general phenotypic description and a discussion of genetic heterogeneity of PCH, see PCH1A (607596).
Noonan syndrome 12
MedGen UID:
1684730
Concept ID:
C5231432
Disease or Syndrome
Noonan syndrome (NS) is characterized by characteristic facies, short stature, congenital heart defect, and developmental delay of variable degree. Other findings can include broad or webbed neck, unusual chest shape with superior pectus carinatum and inferior pectus excavatum, cryptorchidism, varied coagulation defects, lymphatic dysplasias, and ocular abnormalities. Although birth length is usually normal, final adult height approaches the lower limit of normal. Congenital heart disease occurs in 50%-80% of individuals. Pulmonary valve stenosis, often with dysplasia, is the most common heart defect and is found in 20%-50% of individuals. Hypertrophic cardiomyopathy, found in 20%-30% of individuals, may be present at birth or develop in infancy or childhood. Other structural defects include atrial and ventricular septal defects, branch pulmonary artery stenosis, and tetralogy of Fallot. Up to one fourth of affected individuals have mild intellectual disability, and language impairments in general are more common in NS than in the general population.
Intellectual developmental disorder with impaired language and dysmorphic facies
MedGen UID:
1684804
Concept ID:
C5231444
Disease or Syndrome
Intellectual developmental disorder with impaired language and dysmorphic facies (IDDILF) is an autosomal dominant disorder characterized by global developmental delay apparent from infancy, impaired language development, and dysmorphic facial features, including hypertelorism, epicanthal folds, and abnormal palpebral fissures. Some patients may have additional findings, including feeding difficulties, mild cardiac or genitourinary defects, and distal skeletal anomalies (summary by Balak et al., 2019).
Intellectual developmental disorder, autosomal recessive 72
MedGen UID:
1684805
Concept ID:
C5231452
Disease or Syndrome
Intellectual developmental disorder with speech delay, autism, and dysmorphic facies
MedGen UID:
1684848
Concept ID:
C5231456
Disease or Syndrome
Neurodevelopmental disorder with absent language and variable seizures
MedGen UID:
1684803
Concept ID:
C5231469
Disease or Syndrome
Heyn-Sproul-Jackson syndrome
MedGen UID:
1684743
Concept ID:
C5231475
Disease or Syndrome
Heyn-Sproul-Jackson syndrome (HESJAS) is characterized by microcephalic dwarfism and global developmental delay (Heyn et al., 2019).
Ectodermal dysplasia with facial dysmorphism and acral, ocular, and brain anomalies
MedGen UID:
1684719
Concept ID:
C5231477
Disease or Syndrome
EDFAOB is characterized by linear hypopigmentation and craniofacial asymmetry in association with ocular, dental, and acral anomalies. Brain imaging has revealed some abnormalities, including diffuse cystic leukoencephalopathy and mildly enlarged lateral ventricles, but patients show no intellectual or neurologic impairment (Vabres et al., 2019).
Liang-Wang syndrome
MedGen UID:
1684847
Concept ID:
C5231479
Disease or Syndrome
Liang-Wang syndrome (LIWAS) is a polymalformation syndrome apparent from birth that shows large phenotypic variability and severity. However, all patients have some degree of neurologic dysfunction. The most severely affected individuals have severe global developmental delay with impaired intellectual development and poor or absent speech, marked craniofacial dysmorphism, and visceral and connective tissue abnormalities affecting the bones and vessels. The least severely affected individuals lack seizures, significant dysmorphism, and visceral involvement; they come to attention for neurologic signs and symptoms, including developmental delay with speech delay, strabismus, and/or ataxia. About half of patients have brain imaging anomalies, notably cerebral and cerebellar atrophy and thin corpus callosum, whereas the other half have normal brain imaging (summary by Liang et al., 2019).
Neurodevelopmental disorder with brain anomalies and with or without vertebral or cardiac anomalies
MedGen UID:
1684772
Concept ID:
C5231481
Disease or Syndrome
Structural brain anomalies with impaired intellectual development and craniosynostosis
MedGen UID:
1684861
Concept ID:
C5231485
Disease or Syndrome
Patients with BAIDCS have small head circumference with abnormalities in brain anatomy including variable deficiency of the corpus callosum (including agenesis), abnormal conformation of the ventricles and posterior fossa, hypoplasia of both cerebellar hemispheres, colpocephaly, and partial rhombencephalosynapsis (absence of the cerebellar vermis with fusion of the cerebellar hemispheres). Intellectual development is moderately to severely impaired. Bicoronal synostosis, scoliosis, and tethered cord may be present (Twigg et al., 2015; Vandervore et al., 2018). Craniosynostosis-6 (CRS6; 616602) is an allelic disorder.
Intellectual developmental disorder with hypotonia and behavioral abnormalities
MedGen UID:
1684709
Concept ID:
C5231489
Disease or Syndrome
Intellectual developmental disorder with hypotonia and behavioral abnormalities (IDDHBA) is a neurodevelopmental disorder characterized by onset of hypotonia and variably impaired global developmental delay in infancy. Affected individuals tend to have learning disability, usually requiring special schooling, as well as behavioral abnormalities, such as autistic features and attention deficit-hyperactivity disorder (ADHD). Additional more variable features may include nonspecific dysmorphic facial features, congenital heart defects, visual or ocular movement anomalies, and poor feeding and/or gastroesophageal reflux (summary by Calpena et al., 2019).
Catifa syndrome
MedGen UID:
1684686
Concept ID:
C5231492
Disease or Syndrome
CATIFA syndrome is characterized by global developmental delay and impaired intellectual development ranging from mild to severe, with most patients exhibiting attention-deficit hyperactivity disorder (ADHD). Patients show an elongated face with long philtrum and small ears. Ocular anomalies include congenital cataracts, strabismus, and amblyopia, which may be associated with reduced vision; other anomalies include cleft lip and/or palate and misaligned teeth with extensive caries (Unlu et al., 2020).
Joubert syndrome 36
MedGen UID:
1684786
Concept ID:
C5231493
Disease or Syndrome
Joubert syndrome-36 (JBTS36) is an autosomal recessive ciliopathy characterized by global developmental delay, ocular movement abnormalities, and mesoaxial polydactyly. Brain imaging may be normal or show the classic 'molar tooth sign.' There is some phenotypic similarity to and overlap with orofaciodigital syndrome VI (OFD6; 277170) (summary by Shaheen et al., 2019). For a discussion of genetic heterogeneity of Joubert syndrome, see JBTS1 (213300).
ALDH18A1-related de Barsy syndrome
MedGen UID:
1720006
Concept ID:
C5234852
Disease or Syndrome
De Barsy syndrome, or autosomal recessive cutis laxa type III (ARCL3), is characterized by cutis laxa, a progeria-like appearance, and ophthalmologic abnormalities (summary by Kivuva et al., 2008). For a phenotypic description and a discussion of genetic heterogeneity of autosomal recessive cutis laxa, see 219100. Genetic Heterogeneity of de Barsy Syndrome Also see ARCL3B (614438), caused by mutation in the PYCR1 gene (179035) on chromosome 17q25.
Intellectual disability, X-linked 102
MedGen UID:
1715418
Concept ID:
C5393299
Disease or Syndrome
DDX3X-related neurodevelopmental disorder (DDX3X-NDD) typically occurs in females and very rarely in males. All affected individuals reported to date have developmental delay / intellectual disability (ID) ranging from mild to severe; about 50% of affected girls remain nonverbal after age five years. Hypotonia, a common finding, can be associated with feeding difficulty in infancy. Behavioral issues can include autism spectrum disorder, attention-deficit/hyperactivity disorder and hyperactivity, self-injurious behavior, poor impulse control, and aggression. Other findings can include seizures, movement disorders (dyskinesia, spasticity, abnormal gait), vision and hearing impairment, congenital heart defects, respiratory difficulties, joint laxity, and scoliosis. Neuroblastoma has been observed in three individuals.
Hao-Fountain syndrome
MedGen UID:
1719035
Concept ID:
C5393908
Disease or Syndrome
Hao-Fountain syndrome (HAFOUS) is a neurodevelopmental disorder characterized by global developmental delay, variably impaired intellectual development with significant speech delay, behavioral abnormalities, such as autism, and mild dysmorphic facies. Additional features are variable, but may include hypotonia, feeding problems, delayed walking with unsteady gait, hypogonadism in males, and ocular anomalies, such as strabismus. Some patients develop seizures and some have mild white matter abnormalities on brain imaging (summary by Fountain et al., 2019).
CEBALID syndrome
MedGen UID:
1710973
Concept ID:
C5394044
Disease or Syndrome
Individuals with MN1 C-terminal truncation (MCTT) syndrome have mild-to-moderate intellectual disability, severe expressive language delay, dysmorphic facial features (midface hypoplasia, downslanting palpebral fissures, hypertelorism, exophthalmia, short upturned nose, and small low-set ears), and distinctive findings on brain imaging (including perisylvian polymicrogyria and atypical rhombencephalosynapsis). Mild-to-moderate prelingual hearing loss (usually bilateral, conductive, and/or sensorineural) is common. Generalized seizures (observed in the minority of individuals) are responsive to anti-seizure medication. There is an increased risk for craniosynostosis and, thus, increased intracranial pressure. To date, 25 individuals with MCTT syndrome have been identified.
Intellectual developmental disorder 62
MedGen UID:
1712636
Concept ID:
C5394083
Disease or Syndrome
DLG4-related synaptopathy is a condition that affects neurological development. This condition is characterized by delayed development and mild to moderate intellectual disabilities that typically becomes evident before age 2. Over time, many individuals with DLG4-related synaptopathy lose skills that they have learned, such as speech or motor skills. About 20 percent of people with this condition cannot speak. Affected individuals often have neurodevelopmental disorders, such as autism spectrum disorder or attention-deficit/hyperactivity disorder. About half of individuals with this condition have recurrent seizures (epilepsy) that typically begin in childhood. Brain changes can also occur. These include brain tissue loss (atrophy) and abnormalities of the tissue connecting the left and right halves of the brain (corpus callosum) or the  hippocampus, which is a region of the brain that is involved in learning and memory.\n\nIndividuals with DLG4-related synaptopathy can also have weak muscle tone (hyptonia), loose joints (joint laxity), or a spine that curves to the side (scoliosis). Movement problems, including impaired muscle coordination (ataxia), involuntary muscle coordination (dystonia), or rhythmic shaking (tremor) are common in people with this condition. Other problems can include migraine, sleep problems, or anxiety. Some people with DLG4-related synaptopathy have a distinctive body type that includes a long face, slim body, and long fingers.\n\nLess commonly, DLG4-related synaptopathy can affect a person's vision. Affected individuals can have eyes that do not point in the same direction (strabismus), farsightedness (hyperopia), or involuntary movements of the eyes (nystagmus). Some affected individuals have blindness because the area of the brain responsible for processing vision is impaired. \n\nDLG4-related synaptopathy can also cause gastrointestinal difficulties that make it difficult to eat. These can include a backflow of stomach acids into the esophagus (gastroesophageal reflux disease or GERD).\n\n
Beck-Fahrner syndrome
MedGen UID:
1711894
Concept ID:
C5394097
Disease or Syndrome
Beck-Fahrner syndrome (BEFAHRS) is a developmental disorder characterized by global developmental delay with variably impaired intellectual development. Affected individuals often have behavioral abnormalities, such as autistic features or attention deficit-hyperactivity disorder (ADHD), as well as learning disabilities. Most patients have hypotonia and dysmorphic facies. Some may have growth abnormalities, including overgrowth or poor growth, poor feeding, and rarely, seizures. Although both monoallelic and biallelic mutations have been reported, some heterozygous carriers in autosomal recessive families may have milder symptoms; thus, both groups are included in this entry (summary by Beck et al., 2020).
Spinocerebellar ataxia, autosomal recessive 28
MedGen UID:
1712568
Concept ID:
C5394101
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-28 (SCAR28) is a neurologic disorder characterized by onset in early childhood of mildly delayed motor development, gait ataxia, incoordination of fine motor movements, and dysarthria. Affected individuals may have features of spasticity and may show mildly impaired cognitive function. Brain imaging shows cerebellar vermis hypoplasia (summary by Walker et al., 2019).
Genitourinary and/or brain malformation syndrome
MedGen UID:
1720440
Concept ID:
C5394158
Disease or Syndrome
Individuals with PPP1R12A-related urogenital and/or brain malformation syndrome (UBMS) usually present with multiple congenital anomalies, commonly including brain and/or urogenital malformations. The brain abnormalities are variable, with the most severe belonging to the holoprosencephaly spectrum and associated with moderate-to-profound intellectual disability, seizures, and feeding difficulties. In individuals without brain involvement, variable degrees of developmental delay and/or intellectual disability may be present, although normal intelligence has been seen in a minority of affected individuals. Eye abnormalities and skeletal issues (kyphoscoliosis, joint contractures) can also be present in individuals of either sex. Regardless of the presence of a brain malformation, affected individuals with a 46,XY chromosome complement may have a disorder of sex development (DSD) with gonadal abnormalities (dysgenetic gonads or streak gonads). Individuals with a 46,XX chromosome complement may have varying degrees of virilization (clitoral hypertrophy, posterior labial fusion, urogenital sinus).
Neurodevelopmental disorder with relative macrocephaly and with or without cardiac or endocrine anomalies
MedGen UID:
1714169
Concept ID:
C5394221
Disease or Syndrome
Nabais Sa-de Vries syndrome type 2 (NSDVS2) is characterized by global developmental delay apparent from birth and distinctive dysmorphic facial features. Most patients have additional anomalies, including congenital heart defects, sleep disturbances, hypotonia, and variable endocrine abnormalities, such as hypothyroidism (summary by Nabais Sa et al., 2020).
Neurodegeneration, childhood-onset, with ataxia, tremor, optic atrophy, and cognitive decline
MedGen UID:
1715031
Concept ID:
C5394335
Disease or Syndrome
Childhood-onset neurodegeneration with ataxia, tremor, optic atrophy, and cognitive decline (CONATOC) is an autosomal recessive progressive disorder with onset of symptoms in the first decade. Brain imaging may show variable features, including leukoencephalopathy and cerebellar atrophy (summary by Fagerberg et al., 2020).
Nizon-Isidor syndrome
MedGen UID:
1715748
Concept ID:
C5394350
Disease or Syndrome
Nizon-Isidor syndrome (NIZIDS) is a neurodevelopmental disorder characterized by global developmental delay, mildly delayed walking, poor speech and language, variably impaired intellectual development, and behavioral abnormalities, such as autistic features or attention deficit-hyperactivity disorder (ADHD). Some patients may have additional features, including nonspecific facial dysmorphism, gastrointestinal difficulties, distal hand anomalies, and thin corpus callosum on brain imaging (summary by Nizon et al., 2019).
Neurodevelopmental, jaw, eye, and digital syndrome
MedGen UID:
1712714
Concept ID:
C5394477
Disease or Syndrome
Neurodevelopmental, jaw, eye, and digital syndrome (NEDJED) is characterized by phenotypic diversity, with patients exhibiting a range of overlapping phenotypes. Most patients show developmental delay ranging from mild to severe, and often have behavioral disorders as well. Brain imaging shows hypoplasia of the corpus callosum, prominence of lateral ventricles, and/or white matter abnormalities. Many patients have retro- or micrognathia, but mild prognathism has also been observed. Ocular anomalies are variably present, and may be severe and complex; however, some patients show only mild myopia. Abnormalities of fingers and toes include brachydactyly, clinodactyly, syndactyly, and contractures; polydactyly is rarely seen (Holt et al., 2019).
Agenesis of corpus callosum, cardiac, ocular, and genital syndrome
MedGen UID:
1718475
Concept ID:
C5394523
Disease or Syndrome
Agenesis of corpus callosum, cardiac, ocular, and genital syndrome (ACOGS) is a syndromic neurodevelopmental disorder characterized by global developmental delay and/or intellectual disability, corpus callosum agenesis or hypoplasia, craniofacial dysmorphisms, and ocular, cardiac, and genital anomalies (Accogli et al., 2019).
FG syndrome 1
MedGen UID:
1768809
Concept ID:
C5399762
Disease or Syndrome
MED12-related disorders include the phenotypes of FG syndrome type 1 (FGS1), Lujan syndrome (LS), X-linked Ohdo syndrome (XLOS), Hardikar syndrome (HS), and nonspecific intellectual disability (NSID). FGS1 and LS share the clinical findings of cognitive impairment, hypotonia, and abnormalities of the corpus callosum. FGS1 is further characterized by absolute or relative macrocephaly, tall forehead, downslanted palpebral fissures, small and simple ears, constipation and/or anal anomalies, broad thumbs and halluces, and characteristic behavior. LS is further characterized by large head, tall thin body habitus, long thin face, prominent nasal bridge, high narrow palate, and short philtrum. Carrier females in families with FGS1 and LS are typically unaffected. XLOS is characterized by intellectual disability, blepharophimosis, and facial coarsening. HS has been described in females with cleft lip and/or cleft palate, biliary and liver anomalies, intestinal malrotation, pigmentary retinopathy, and coarctation of the aorta. Developmental and cognitive concerns have not been reported in females with HS. Pathogenic variants in MED12 have been reported in an increasing number of males and females with NSID, with affected individuals often having clinical features identified in other MED12-related disorders.
Chromosome 17q11.2 deletion syndrome, 1.4Mb
MedGen UID:
1726802
Concept ID:
C5401456
Disease or Syndrome
Approximately 5 to 20% of all patients with neurofibromatosis type I (162200) carry a heterozygous deletion of approximately 1.4 Mb involving the NF1 gene and contiguous genes lying in its flanking regions (Riva et al., 2000; Jenne et al., 2001), which is caused by nonallelic homologous recombination of NF1 repeats A and C (Dorschner et al., 2000). The 'NF1 microdeletion syndrome' is often characterized by a more severe phenotype than that observed in the majority of NF1 patients. In particular, patients with NF1 microdeletion often show variable facial dysmorphism, mental retardation, developmental delay, an excessive number of early-onset neurofibromas (Venturin et al., 2004), and an increased risk for malignant peripheral nerve sheath tumors (De Raedt et al., 2003).
Arthrogryposis multiplex congenita 5
MedGen UID:
1731112
Concept ID:
C5436453
Disease or Syndrome
Arthrogryposis multiplex congenita-5 (AMC5) is an autosomal recessive disorder characterized by severe joint contractures apparent at birth. Affected individuals usually have hypertonia and abnormal movements suggestive of dystonia, as well as feeding and/or breathing difficulties. More variable features may include poor overall growth, strabismus, dysmorphic facies, and global developmental delay with impaired speech (summary by Kariminejad et al., 2017).
Suleiman-El-Hattab syndrome
MedGen UID:
1738652
Concept ID:
C5436458
Disease or Syndrome
Suleiman-El-Hattab syndrome (SULEHS) is an autosomal recessive multisystem developmental disorder characterized by hypotonia and feeding difficulties soon after birth, global developmental delay with impaired intellectual development and poor expressive speech, and a general happy demeanor. There is a distinctive facial appearance with microcephaly, thick arched eyebrows with synophrys, hypertelorism, epicanthal folds, low-set ears, broad nasal bridge, and thin upper lip. Additional more variable features include recurrent respiratory infections, cardiovascular malformations, cryptorchidism, seizures, and distal anomalies of the hands and feet (summary by Suleiman et al., 2019).
Deeah syndrome
MedGen UID:
1756624
Concept ID:
C5436579
Disease or Syndrome
DEEAH syndrome is an autosomal recessive multisystemic disorder with onset in early infancy. Affected individuals usually present in the perinatal period with respiratory insufficiency, apneic episodes, and generalized hypotonia. The patients have failure to thrive and severely impaired global development with poor acquisition of motor, cognitive, and language skills. Other common features include endocrine, pancreatic exocrine, and autonomic dysfunction, as well as hematologic disturbances, mainly low hemoglobin. Patients also have dysmorphic and myopathic facial features. Additional more variable features include seizures, undescended testes, and distal skeletal anomalies. Death in early childhood may occur (summary by Schneeberger et al., 2020).
Retinitis pigmentosa 90
MedGen UID:
1733837
Concept ID:
C5436588
Disease or Syndrome
Retinitis pigmentosa-90 (RP90) is characterized by early-onset night blindness, within the first decade of life. Patients exhibit other typical features of RP, including retinal vessel attenuation, optic disc pallor, and retinal pigment epithelium (RPE) atrophy and pigmentation abnormalities. Macular pseudocoloboma and cystoid macular edema have also been observed (Pierrache et al., 2017). For a discussion of genetic heterogeneity of RP, see 268000.
IFAP syndrome 2
MedGen UID:
1763502
Concept ID:
C5436607
Disease or Syndrome
Follicular ichthyosis, atrichia, and photophobia syndrome-2 (IFAP2) is characterized by ichthyosis follicularis or follicular hyperkeratosis, sparse to no body hair, and photophobia with corneal lesions. Ultrastructural hair analysis shows trichorrhexis nodosa (Wang et al., 2020). For a discussion of genetic heterogeneity of IFAP syndrome, see IFAP1 (308205).
Cleft palate, proliferative retinopathy, and developmental delay
MedGen UID:
1765503
Concept ID:
C5436739
Disease or Syndrome
Cleft palate, proliferative retinopathy, and developmental delay (CPPRDD) is characterized by motor and speech delay, with intellectual disability ranging from mild to severe. Brain imaging shows ventriculomegaly as well as other malformations (Harel et al., 2019).
Neurodevelopmental disorder with dysmorphic facies, sleep disturbance, and brain abnormalities
MedGen UID:
1777442
Concept ID:
C5436821
Disease or Syndrome
Neurodevelopmental disorder with dysmorphic facies, sleep disturbance, and brain abnormalities (NEDFASB) is a syndromic disorder with multisystemic involvement. Affected individuals have severe global developmental delay with severely impaired intellectual development, poor or absent language, behavioral abnormalities, seizures, and sleep disturbances. Craniofacial dysmorphisms, while variable, include round face, prognathism, depressed nasal bridge, and cleft or high-arched palate. Brain imaging shows dysgenesis of the corpus callosum and progressive cerebellar atrophy. Additional features may include genitourinary tract anomalies, hearing loss, and mild distal skeletal defects (summary by Humbert et al., 2020).
COACH syndrome 2
MedGen UID:
1752166
Concept ID:
C5436837
Disease or Syndrome
COACH syndrome is classically defined as Cerebellar vermis hypoplasia, Oligophrenia, Ataxia, Colobomas, and Hepatic fibrosis (Verloes and Lambotte, 1989). Brain MRI demonstrates the molar tooth sign, which is a feature of Joubert syndrome. The disorder has been described as a Joubert syndrome-related disorder with liver disease (summary by Doherty et al., 2010). For a general phenotypic description and a discussion of genetic heterogeneity of COACH syndrome, see 216360.
COACH syndrome 3
MedGen UID:
1755565
Concept ID:
C5436841
Disease or Syndrome
COACH syndrome is classically defined as Cerebellar vermis hypoplasia, Oligophrenia, Ataxia, Colobomas, and Hepatic fibrosis (Verloes and Lambotte, 1989). Brain MRI demonstrates the molar tooth sign, which is a feature of Joubert syndrome. The disorder has been described as a Joubert syndrome-related disorder with liver disease (summary by Doherty et al., 2010). For a general phenotypic description and a discussion of genetic heterogeneity of COACH syndrome, see 216360.
Neurodevelopmental disorder with cardiomyopathy, spasticity, and brain abnormalities
MedGen UID:
1750805
Concept ID:
C5436848
Disease or Syndrome
Neurodevelopmental disorder with cardiomyopathy, spasticity, and brain abnormalities (NEDCASB) is an autosomal recessive multisystemic disorder characterized by global neurodevelopmental delay, severely impaired intellectual development, poor overall growth, and spasticity of the lower limbs resulting in gait difficulties. Most affected individuals also develop progressive hypertrophic cardiomyopathy in childhood or have cardiac developmental anomalies. Additional more variable features include dysmorphic facies and axonal sensory peripheral neuropathy. Brain imaging tends to show thin corpus callosum and polymicrogyria (summary by Garcia-Cazorla et al., 2020).
Chromosome 13q33-q34 deletion syndrome
MedGen UID:
1744234
Concept ID:
C5436890
Disease or Syndrome
Chromosome 13q33-q34 deletion syndrome is associated with developmental delay and/or impaired intellectual development, facial dysmorphism, and an increased risk for epilepsy, cardiac defects and additional anatomic anomalies (summary by Sagi-Dain et al., 2019).
Lessel-Kreienkamp syndrome
MedGen UID:
1762595
Concept ID:
C5436892
Disease or Syndrome
Lessel-Kreienkamp syndrome (LESKRES) is a neurodevelopmental disorder characterized by global developmental delay with intellectual disability and speech and language delay apparent from infancy or early childhood. The severity of the disorder is highly variable: some patients have mildly delayed walking and mild cognitive deficits, whereas others are nonambulatory and nonverbal. Most have behavioral disorders. Additional features, including seizures, hypotonia, gait abnormalities, visual defects, cardiac defects, and nonspecific dysmorphic facial features, may also be present (summary by Lessel et al., 2020).
Hermansky-Pudlak syndrome 11
MedGen UID:
1727728
Concept ID:
C5436936
Disease or Syndrome
Hermansky-Pudlak syndrome (HPS) is characterized by oculocutaneous albinism, a bleeding diathesis, and, in some individuals, pulmonary fibrosis, granulomatous colitis, or immunodeficiency. Ocular findings include reduced iris pigment with iris transillumination, reduced retinal pigment, foveal hypoplasia with significant reduction in visual acuity (usually in the range of 20/50 to 20/400), nystagmus, and increased crossing of the optic nerve fibers. Hair color ranges from white to brown; skin color ranges from white to olive and is usually a shade lighter than that of other family members. The bleeding diathesis can result in variable bruising, epistaxis, gingival bleeding, postpartum hemorrhage, colonic bleeding, and prolonged bleeding with menses or after tooth extraction, circumcision, and other surgeries. Pulmonary fibrosis, a restrictive lung disease, typically causes symptoms in the early thirties and can progress to death within a decade. Granulomatous colitis is severe in about 15% of affected individuals. Neutropenia and/or immune defects occur primarily in individuals with pathogenic variants in AP3B1 and AP3D1.
Coffin-Siris syndrome 12
MedGen UID:
1782096
Concept ID:
C5444111
Disease or Syndrome
Coffin-Siris syndrome-12 (CSS12) is a neurodevelopmental disorder characterized by global developmental delay with variably impaired intellectual development, speech and language delay, and behavioral abnormalities, such as autism or hyperactivity. Affected individuals may have hypotonia and poor feeding in infancy. There are variable dysmorphic facial features, although most patients do not have the classic hypoplastic fifth digit/nail abnormalities that are often observed in other forms of CSS (Barish et al., 2020). For a general phenotypic description and a discussion of genetic heterogeneity of Coffin-Siris syndrome, see CSS1 (135900).
Martsolf syndrome 1
MedGen UID:
1778114
Concept ID:
C5542298
Disease or Syndrome
RAB18 deficiency is the molecular deficit underlying both Warburg micro syndrome (characterized by eye, nervous system, and endocrine abnormalities) and Martsolf syndrome (characterized by similar – but milder – findings). To date Warburg micro syndrome comprises >96% of reported individuals with genetically defined RAB18 deficiency. The hallmark ophthalmologic findings are bilateral congenital cataracts, usually accompanied by microphthalmia, microcornea (diameter <10), and small atonic pupils. Poor vision despite early cataract surgery likely results from progressive optic atrophy and cortical visual impairment. Individuals with Warburg micro syndrome have severe to profound intellectual disability (ID); those with Martsolf syndrome have mild to moderate ID. Some individuals with RAB18 deficiency also have epilepsy. In Warburg micro syndrome, a progressive ascending spastic paraplegia typically begins with spastic diplegia and contractures during the first year, followed by upper-limb involvement leading to spastic quadriplegia after about age five years, often eventually causing breathing difficulties. In Martsolf syndrome infantile hypotonia is followed primarily by slowly progressive lower-limb spasticity. Hypogonadism – when present – manifests in both syndromes, in males as micropenis and/or cryptorchidism and in females as hypoplastic labia minora, clitoral hypoplasia, and small introitus.
Multiple congenital anomalies-neurodevelopmental syndrome, X-linked
MedGen UID:
1788942
Concept ID:
C5542341
Disease or Syndrome
X-linked multiple congenital anomalies-neurodevelopmental syndrome (MCAND) is an X-linked recessive congenital multisystemic disorder characterized by poor growth, global developmental delay with impaired intellectual development, and variable abnormalities of the cardiac, skeletal, and genitourinary systems. Most affected individuals also have hypotonia and dysmorphic craniofacial features. Brain imaging typically shows enlarged ventricles and thin corpus callosum; some have microcephaly, whereas others have hydrocephalus. The severity of the disorder is highly variable, ranging from death in early infancy to survival into the second or third decade. Pathogenetically, the disorder results from disrupted gene expression and signaling during embryogenesis, thus affecting multiple systems (summary by Tripolszki et al., 2021 and Beck et al., 2021). Beck et al. (2021) referred to the disorder as LINKED syndrome (LINKage-specific deubiquitylation deficiency-induced Embryonic Defects).
Short stature, facial dysmorphism, and skeletal anomalies with or without cardiac anomalies 2
MedGen UID:
1782253
Concept ID:
C5543057
Disease or Syndrome
Short stature, facial dysmorphism, and skeletal anomalies with or without cardiac anomalies-2 (SSFSC2) is characterized by thin and short long bones, distinctive facial dysmorphism, and dental and skeletal abnormalities, in the absence of developmental delay or intellectual disability. Cardiac anomalies have been reported in some patients (Lin et al., 2021). For a discussion of genetic heterogeneity of SSFSC, see SSFSC1 (617877).
Intellectual developmental disorder, autosomal dominant 64
MedGen UID:
1784554
Concept ID:
C5543067
Disease or Syndrome
Autosomal dominant intellectual developmental disorder-64 (MRD64) is characterized by mildly to severely impaired intellectual development (ID) with speech delays. Most patients also have autism spectrum disorder (ASD). Additional features are highly variable but may include motor delay, attention deficit-hyperactivity disorder (ADHD), and nonspecific dysmorphic features (summary by Mirzaa et al., 2020).
Alzahrani-Kuwahara syndrome
MedGen UID:
1782127
Concept ID:
C5543274
Disease or Syndrome
Alzahrani-Kuwahara syndrome (ALKUS) is an autosomal recessive neurodevelopmental syndrome characterized by global developmental delay with severely impaired intellectual function and poor or absent speech. Patients have poor overall growth and dysmorphic facial features. More variable findings include early-onset cataracts, hypotonia, congenital heart defects, lower limb spasticity, and hypospadias (summary by Alzahrani et al., 2020).
KINSSHIP syndrome
MedGen UID:
1779339
Concept ID:
C5543317
Disease or Syndrome
KINSSHIP syndrome (KINS) is an autosomal dominant disorder characterized by a recognizable pattern of anomalies including developmental delay, impaired intellectual development, seizures, mesomelic dysplasia, dysmorphic facial features, horseshoe or hypoplastic kidney, and failure to thrive (summary by Voisin et al., 2021).
Pontocerebellar hypoplasia, type 1F
MedGen UID:
1785905
Concept ID:
C5543331
Disease or Syndrome
Pontocerebellar hypoplasia type 1F (PCH1F) is an autosomal recessive neurologic disorder characterized by hypotonia, global developmental delay, poor overall growth, and dysmorphic facial features. Brain imaging shows pontocerebellar hypoplasia, thin corpus callosum, cerebral atrophy, and delayed myelination (summary by Somashekar et al., 2021). For a phenotypic description and a discussion of genetic heterogeneity of PCH, see PCH1A (607596).
Buratti-Harel syndrome
MedGen UID:
1788293
Concept ID:
C5543351
Disease or Syndrome
Buratti-Harel syndrome (BURHAS) is a neurodevelopmental disorder characterized by infantile hypotonia, global developmental delay, mild motor and speech delay, and mild to moderately impaired intellectual development. Some patients are able to attend special schools and show learning difficulties, whereas others are more severely affected. Patients have prominent dysmorphic facial features, including hypertelorism, downslanting palpebral fissures, strabismus, and small low-set ears. Additional features may include laryngomalacia with feeding difficulties and distal skeletal anomalies (summary by Buratti et al., 2021).
Leukodystrophy, hypomyelinating, 22
MedGen UID:
1787833
Concept ID:
C5543406
Disease or Syndrome
Hypomyelinating leukodystrophy-22 (HLD22) is a neurologic disorder characterized by global developmental delay with mildly impaired intellectual development and marked motor impairment with limited or no ability to walk and dysarthria. Affected individuals have limb spasticity with pyramidal signs, as well as nystagmus, hypermetropia, and astigmatism. Brain imaging shows hypomyelination and a delay in myelination, although serial imaging shows some progress in both the central and peripheral white matter regions (Riedhammer et al., 2021). For a general phenotypic description and a discussion of genetic heterogeneity of HLD, see 312080.
Deafness, cataract, impaired intellectual development, and polyneuropathy
MedGen UID:
1781637
Concept ID:
C5543482
Disease or Syndrome
Deafness, cataract, impaired intellectual development, and polyneuropathy (DCIDP) is characterized by early-onset of deafness, cataract, severe developmental delay, and severely impaired intellectual development. Patients later develop polyneuropathy of the lower extremities, associated with depigmentation of the hair in that area (Kroll-Hermi et al., 2020).
Spinocerebellar ataxia, autosomal recessive 31
MedGen UID:
1786855
Concept ID:
C5543627
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-31 (SCAR31) is a complex neurodevelopmental disorder characterized by global developmental delay with hypotonia and variably impaired intellectual and language development. Affected individuals have an ataxic gait, tremor, and dysarthria; more severely affected patients also have spasticity with inability to walk. Most have optic atrophy. Brain imaging shows cerebellar hypoplasia, enlarged ventricles, and atrophy of the posterior corpus callosum. Additional features may include retinitis pigmentosa, sensorineural deafness, dysmorphic facial features, and possibly endocrine dysfunction (summary by Collier et al., 2021).
Neurodevelopmental disorder with dysmorphic facies and thin corpus callosum
MedGen UID:
1790413
Concept ID:
C5551361
Disease or Syndrome
Neurodevelopmental disorder with dysmorphic facies and thin corpus callosum (NEDDFAC) is characterized by global developmental delay, impaired intellectual development with poor or absent speech and language, and dysmorphic facial features. Brain imaging tends to show thin corpus callosum and decreased white matter volume. Additional features such as seizures, cardiac defects, and behavioral abnormalities may also occur. The phenotype is variable (summary by Bina et al., 2020).
Intellectual disability, X-linked 21
MedGen UID:
1790509
Concept ID:
C5551510
Disease or Syndrome
NR0B1-related adrenal hypoplasia congenita includes both X-linked adrenal hypoplasia congenita (X-linked AHC) and Xp21 deletion (previously called complex glycerol kinase deficiency). X-linked AHC is characterized by primary adrenal insufficiency and/or hypogonadotropic hypogonadism (HH). Adrenal insufficiency is acute infantile onset (average age 3 weeks) in approximately 60% of affected males and childhood onset (ages 1-9 years) in approximately 40%. HH typically manifests in a male with adrenal insufficiency as delayed puberty (i.e., onset age >14 years) and less commonly as arrested puberty at about Tanner Stage 3. Rarely, X-linked AHC manifests initially in early adulthood as delayed-onset adrenal insufficiency, partial HH, and/or infertility. Heterozygous females very occasionally have manifestations of adrenal insufficiency or hypogonadotropic hypogonadism. Xp21 deletion includes deletion of NR0B1 (causing X-linked AHC) and GK (causing glycerol kinase deficiency), and in some cases deletion of DMD (causing Duchenne muscular dystrophy). Developmental delay has been reported in males with Xp21 deletion when the deletion extends proximally to include DMD or when larger deletions extend distally to include IL1RAPL1 and DMD.
Intellectual developmental disorder, X-linked, syndromic, with pigmentary mosaicism and coarse facies
MedGen UID:
1794140
Concept ID:
C5561930
Disease or Syndrome
X-linked syndromic intellectual developmental disorder with pigmentary mosaicism and coarse facies (MRXSPF) is characterized by a phenotypic triad of severe developmental delay, coarse facial dysmorphisms, and Blaschkoid pigmentary mosaicism. Additional clinical features may include epilepsy, orthopedic abnormalities, hypotonia, and growth abnormalities. The disorder affects both males and females (Villegas et al., 2019; Diaz et al., 2020).
Ritscher-Schinzel syndrome 4
MedGen UID:
1794149
Concept ID:
C5561939
Disease or Syndrome
Ritscher-Schinzel syndrome-4 (RTSC4) is characterized by a constellation of congenital anomalies, including dysmorphic craniofacial features and structural brain anomalies, such as Dandy-Walker malformation (220200), hindbrain malformations, or agenesis of the corpus callosum, associated with global developmental delay and impaired intellectual development. Congenital cardiac defects have been reported in 1 family (summary by Ritscher et al., 1987 and Jeanne et al., 2021). For a discussion of genetic heterogeneity of Ritscher-Schinzel syndrome, see RTSC1 (220210).
Luo-Schoch-Yamamoto syndrome
MedGen UID:
1794156
Concept ID:
C5561946
Disease or Syndrome
Luo-Schoch-Yamamoto syndrome (LUSYAM) is a neurodevelopmental disorder characterized by global developmental delay and impaired intellectual development apparent from infancy. Affected individuals have delayed walking, early-onset seizures, hypotonia, dysmorphic facial features, and white matter abnormalities on brain imaging (Luo et al., 2021).
Usmani-Riazuddin syndrome, autosomal dominant
MedGen UID:
1794162
Concept ID:
C5561952
Disease or Syndrome
Autosomal dominant Usmani-Riazzudin syndrome (USRISD) is a neurodevelopmental disorder characterized by global developmental delay with impaired intellectual development and speech delay, hypotonia, and behavioral abnormalities, most commonly aggressive behavior. More variable additional features may include seizures and distal limb anomalies (summary by Usmani et al., 2021).
Neurodevelopmental disorder with motor and speech delay and behavioral abnormalities
MedGen UID:
1794164
Concept ID:
C5561954
Disease or Syndrome
Neurodevelopmental disorder with motor and speech delay and behavioral abnormalities (NEDMOSBA) is an autosomal recessive disorder characterized by global developmental delay apparent from early childhood. There is significant phenotypic variability: some patients achieve walking and talking after a few years, whereas others develop spastic tetraplegia with inability to walk independently and never gain proper speech. Affected individuals may have variable additional features, including poor overall growth, hypotonia, tremor, ocular anomalies, seizures, and nonspecific dysmorphic facial features (summary by Polla et al., 2021).
Developmental delay, impaired speech, and behavioral abnormalities
MedGen UID:
1794167
Concept ID:
C5561957
Disease or Syndrome
Developmental delay, impaired speech, and behavioral abnormalities (DDISBA) is characterized by global developmental delay apparent from early childhood. Intellectual disability can range from mild to severe. Additional variable features may include dysmorphic facial features, seizures, hypotonia, motor abnormalities such as Tourette syndrome or dystonia, and hearing loss (summary by Cousin et al., 2021).
Joubert syndrome 38
MedGen UID:
1794168
Concept ID:
C5561958
Disease or Syndrome
Joubert syndrome-38 (JBTS38) is characterized by hypotonia, global developmental delay, oculomotor apraxia, and breathing abnormalities, with a 'molar tooth sign' on brain MRI. Patients also exhibit pituitary abnormalities with growth hormone deficiency (Stephen et al., 2017). For a general phenotypic description and discussion of genetic heterogeneity of Joubert syndrome, see JBTS1 (213300).
Central hypoventilation syndrome, congenital, 2, and autonomic dysfunction
MedGen UID:
1794173
Concept ID:
C5561963
Disease or Syndrome
Congenital central hypoventilation syndrome-2 and autonomic dysfunction (CCHS2) is an autosomal recessive disorder characterized by shallow breathing and apneic spells apparent in the neonatal period. Affected infants require mechanical ventilation due to impaired ventilatory response to hypercapnia, as well as tube feeding due to poor swallowing, aspiration, and gastrointestinal dysmotility. Some patients have other features of autonomic dysfunction, including bladder dysfunction, sinus bradycardia, and temperature dysregulation. Although mild global developmental delay with learning difficulties and seizures were present in the single family reported, it was unclear if these features were related to the hypoventilation phenotype (Spielmann et al., 2017). For a discussion of genetic heterogeneity of CCHS, see CCHS1 (209880).
Congenital disorder of glycosylation, type 2v
MedGen UID:
1794181
Concept ID:
C5561971
Disease or Syndrome
Congenital disorder of glycosylation type 2v (CDG2V) is an autosomal recessive disorder characterized by neurodevelopmental delay and variable facial dysmorphisms (Polla et al., 2021).
Chopra-Amiel-Gordon syndrome
MedGen UID:
1794185
Concept ID:
C5561975
Disease or Syndrome
Chopra-Amiel-Gordon syndrome (CAGS) is an autosomal dominant disorder characterized by developmental delay and/or impaired intellectual development, speech delay, facial dysmorphism, and variable other features, including recurrent bacterial infections, ophthalmologic abnormalities, and nonspecific brain abnormalities (Chopra et al., 2021).
Neurodevelopmental disorder with hypotonia and brain abnormalities
MedGen UID:
1794187
Concept ID:
C5561977
Disease or Syndrome
Neurodevelopmental disorder with hypotonia and brain abnormalities (NEDHYBA) is characterized by impaired development of motor skills, cognitive function, and speech acquisition beginning in infancy or early childhood. Some affected individuals may have feeding difficulties, seizures, behavioral abnormalities, and nonspecific dysmorphic facial features. Brain imaging shows variable abnormalities, including corpus callosum defects, cerebellar defects, and decreased white matter volume. There is significant phenotypic variability (summary by Duncan et al., 2021).
Congenital disorder of glycosylation, type IIw
MedGen UID:
1794196
Concept ID:
C5561986
Disease or Syndrome
Congenital disorder of glycosylation type IIw (CDG2W) is an autosomal dominant metabolic disorder characterized by liver dysfunction, coagulation deficiencies, and profound abnormalities in N-glycosylation of serum specific proteins. All reported patients carry the same mutation (602671.0017) (summary by Ng et al., 2021). For an overview of congenital disorders of glycosylation, see CDG1A (212065) and CDG2A (212066).
Intellectual developmental disorder with hypotonia, impaired speech, and dysmorphic facies
MedGen UID:
1794207
Concept ID:
C5561997
Disease or Syndrome
Intellectual developmental disorder with hypotonia, impaired speech, and dysmorphic facies (IDDHISD) is characterized by global developmental delay with impaired intellectual development and poor or absent speech, hypotonia, ophthalmologic abnormalities, and nonspecific dysmorphic features. Some affected individuals have seizures, and a few have involvement of other organ systems (Goodman et al., 2021).
Short stature, impaired intellectual development, microcephaly, hypotonia, and ocular anomalies
MedGen UID:
1794208
Concept ID:
C5561998
Disease or Syndrome
SIMHA syndrome is characterized by short stature, impaired intellectual development, microcephaly, hypotonia, and ocular anomalies. Inter- and intrafamilial phenotypic variability has been observed (Kambouris et al., 2014; Zahra et al., 2020).
Developmental delay with or without intellectual impairment or behavioral abnormalities
MedGen UID:
1794214
Concept ID:
C5562004
Disease or Syndrome
Developmental delay with or without intellectual impairment or behavioral abnormalities (DDIB) is an autosomal dominant disorder with a nonspecific phenotype of developmental delay. Additional features may include neonatal feeding problems, hypotonia, and dysmorphic facial features (Dulovic-Mahlow et al., 2019; van Woerden et al., 2021).
Cerebellar ataxia, brain abnormalities, and cardiac conduction defects
MedGen UID:
1794215
Concept ID:
C5562005
Disease or Syndrome
Cerebellar ataxia, brain abnormalities, and cardiac conduction defects (CABAC) is an autosomal recessive primarily neurologic disorder with variable manifestations. Common features included infantile-onset hypotonia, poor motor development, poor feeding and overall growth, and ataxic gait due to cerebellar ataxia. Other features include dysarthria, nystagmus, variable ocular anomalies, spasticity, hyperreflexia, and nonspecific dysmorphic features. Most, but not all, patients have global developmental delay with impaired intellectual development and speech delay. Brain imaging shows cerebellar hypoplasia, often with brainstem hypoplasia, enlarged ventricles, delayed myelination, and thin corpus callosum. A significant number of patients develop cardiac conduction defects in childhood or adolescence, often requiring pacemaker placement (summary by Slavotinek et al., 2020).
Neurodevelopmental disorder with impaired language and ataxia and with or without seizures
MedGen UID:
1794216
Concept ID:
C5562006
Disease or Syndrome
Neurodevelopmental disorder with impaired language and ataxia and with or without seizures (NEDLAS) is characterized by axial hypotonia and global developmental delay apparent in early infancy. Affected individuals have delayed walking with gait ataxia and poor language development. Behavioral abnormalities also commonly occur. The severity is highly variable: a subset of patients have a more severe phenotype with early-onset seizures resembling epileptic encephalopathy, inability to walk or speak, and hypomyelination on brain imaging (summary by Stolz et al., 2021).
Developmental delay, hypotonia, musculoskeletal defects, and behavioral abnormalities
MedGen UID:
1794222
Concept ID:
C5562012
Disease or Syndrome
Developmental delay, hypotonia, musculoskeletal defects, and behavioral abnormalities (DEHMBA) is an early-onset neurodevelopmental disorder characterized by these features. Affected individuals also have nonspecific and variable dysmorphic facial features that do not constitute a recognizable gestalt. Although the disorder is caused by truncating mutations in the SRCAP gene as is FLHS, the DEHMBA phenotype is clinically distinguishable from FLHS by the lack of short stature, brachydactyly, and delayed bone age, as well as absence of a specific facial appearance. There are some overlapping features between the 2 disorders, mainly impaired intellectual development and speech delay (summary by Rots et al., 2021).
Hengel-Maroofian-Schols syndrome
MedGen UID:
1794242
Concept ID:
C5562032
Disease or Syndrome
Hengel-Maroofian-Schols syndrome (HEMARS) is an autosomal recessive neurodevelopmental disorder characterized by severe global developmental delay apparent from infancy or early childhood. Affected individuals have delayed walking or inability to walk, impaired intellectual development with poor or absent speech, pyramidal signs manifest as lower limb spasticity, poor overall growth often with short stature and microcephaly, and dysmorphic facial features. Some patients develop seizures. Brain imaging shows thinning of the posterior part of the corpus callosum, delayed myelination, and cerebral and cerebellar atrophy (Hengel et al., 2021).
Brunet-Wagner neurodevelopmental syndrome
MedGen UID:
1794266
Concept ID:
C5562056
Disease or Syndrome
Brunet-Wagner neurodevelopmental syndrome (BRUWAG) is an autosomal recessive disorder characterized by infantile hypotonia and severely impaired development affecting both motor and cognitive skills. Affected individuals either do not achieve independent ambulation or walk with an unsteady gait; those who walk may lose the ability due to spasticity of the lower limbs. They have absent language, poor or absent social skills, and behavioral abnormalities. Most have variable ocular findings, including nystagmus, strabismus, optic atrophy, myopia, or hypermetropia (summary by Brunet et al., 2020 and Samra et al., 2021).
Ferguson-Bonni neurodevelopmental syndrome
MedGen UID:
1794275
Concept ID:
C5562065
Disease or Syndrome
Ferguson-Bonni neurodevelopmental syndrome (FERBON) is an autosomal recessive disorder characterized by global developmental delay, impaired intellectual development, and hypotonia with early motor delay. Additional features may include dysmorphic facies, mild skeletal abnormalities, and hearing loss (summary by Ferguson et al., 2022).
Congenital disorder of glycosylation, type Iw, autosomal dominant
MedGen UID:
1794278
Concept ID:
C5562068
Disease or Syndrome
Autosomal dominant congenital disorder of glycosylation type Iw (CDG1WAD) is characterized by variable skeletal anomalies, short stature, macrocephaly, and dysmorphic features; about half of patients have impaired intellectual development. Additional features include increased muscle tone and muscle cramps (Wilson et al., 2021).
Progressive spondyloepimetaphyseal dysplasia-short stature-short fourth metatarsals-intellectual disability syndrome
MedGen UID:
1800305
Concept ID:
C5568882
Disease or Syndrome
A rare genetic multiple congenital anomalies/dysmorphic syndrome with characteristics of global developmental delay and intellectual disability, progressive spondyloepimetaphyseal dysplasia, short stature, short fourth metatarsals and dysmorphic craniofacial features (including microcephaly, hypertelorism, epicanthal folds, mild ptosis, strabismus, malar hypoplasia, short nose, depressed nasal bridge, full lips, small, low-set ears and short neck). Craniosynostosis, generalized hypotonia, as well as asymmetry of the cerebral hemispheres and mild thinning of the corpus callosum on brain imaging have also been described.
Craniotubular dysplasia, Ikegawa type
MedGen UID:
1806238
Concept ID:
C5575335
Disease or Syndrome
Craniotubular dysplasia, Ikegawa type (CTDI) is characterized by childhood-onset short stature in association with macrocephaly, dolichocephaly, or prominent forehead. Radiography shows hyperostosis of the calvaria and skull base, with metadiaphyseal undermodeling of the long tubular bones and mild shortening and diaphyseal broadening of the short tubular bones. Affected individuals experience progressive vision loss in the first decade of life due to optic nerve compression, and deafness may develop in the second decade of life (Guo et al., 2021).
Intellectual disability, autosomal dominant 40
MedGen UID:
1810363
Concept ID:
C5676894
Disease or Syndrome
Neurodevelopmental disorder with hypotonia, impaired language, and dysmorphic features (NEDHILD) is a rare neurodevelopmental disorder associated with impaired intellectual development, speech and language impairment, microcephaly, seizures, hypotonia, ophthalmologic issues, constipation/gastroesophageal reflux, and behavioral problems, including autism and sleep disturbances (summary by Garrity et al., 2021).
Bryant-Li-Bhoj neurodevelopmental syndrome 1
MedGen UID:
1801103
Concept ID:
C5676905
Disease or Syndrome
Bryant-Li-Bhoj neurodevelopmental syndrome-1 (BRYLIB1) is a highly variable phenotype characterized predominantly by moderate to severe global developmental delay with impaired intellectual development, poor or absent speech, and delayed motor milestones. Most patients have hypotonia, although some have peripheral hypertonia. Common features include abnormal head shape, variable dysmorphic facial features, oculomotor abnormalities, feeding problems, and nonspecific brain imaging abnormalities. Additional features may include hearing loss, seizures, short stature, and mild skeletal defects (summary by Bryant et al., 2020). Genetic Heterogeneity of Bryant-Li-Bhoj Neurodevelopmental Syndrome See also BRYLIB2 (619721), caused by heterozygous mutation in the H3F3B gene (601058).
Combined oxidative phosphorylation deficiency 55
MedGen UID:
1806598
Concept ID:
C5676915
Disease or Syndrome
Combined oxidative phosphorylation deficiency-55 (COXPD55) is characterized by global developmental delay, hypotonia, short stature, and impaired intellectual development with speech disabilities in childhood. Indolent progressive external ophthalmoplegia phenotype has been described in 1 patient (summary by Olahova et al., 2021). For a discussion of genetic heterogeneity of combined oxidative phosphorylation deficiency, see COXPD1 (609060).
Tessadori-van Haaften neurodevelopmental syndrome 1
MedGen UID:
1810348
Concept ID:
C5676922
Disease or Syndrome
Tessadori-Bicknell-van Haaften neurodevelopmental syndrome-1 (TEBIVANED1) is characterized by poor overall growth with short stature, microcephaly, hypotonia, profound global developmental delay often with poor or absent speech, and characteristic dysmorphic facial features, including hypertelorism and abnormal nose. Other variable neurologic and systemic features may also occur (Tessadori et al., 2017). Genetic Heterogeneity of Tessadori-van Haaften Neurodevelopmental Syndrome See also TEBIVANED2 (619759), caused by mutation in the H4C11 gene (602826); TEBIVANED3 (619950), caused by mutation in the H4C5 gene (602830); and TEBIVANED4 (619951), caused by mutation in the H4C9 gene (602833).
Cerebellar dysfunction, impaired intellectual development, and hypogonadotropic hypogonadism
MedGen UID:
1808634
Concept ID:
C5676924
Disease or Syndrome
Cerebellar dysfunction, impaired intellectual development, and hypogonadotropic hypogonadism (CDIDHH) is characterized by delayed motor development, ataxia, severe progressive scoliosis, moderate to severe intellectual disability, and delayed sexual development. Cerebellar hypoplasia has been observed in some patients (Whittaker et al., 2021).
Kury-Isidor syndrome
MedGen UID:
1807460
Concept ID:
C5676925
Disease or Syndrome
Kury-Isidor syndrome (KURIS) is a neurodevelopmental disorder with a highly variable phenotype. It is characterized mainly by mild global developmental delay apparent from infancy or early childhood with walking delayed by a few years and speech delay, often with language deficits. Intellectual development may be mildly delayed, borderline, or even normal; most patients have behavioral problems, including autism. Additional variable systemic features may include poor overall growth, hypotonia, distal skeletal anomalies, seizures, and nonspecific dysmorphic facial features (summary by Kury et al., 2022).
Developmental and epileptic encephalopathy 100
MedGen UID:
1809351
Concept ID:
C5676932
Disease or Syndrome
Developmental and epileptic encephalopathy-100 (DEE100) is a severe neurologic disorder characterized by global developmental delay and onset of variable types of seizures in the first months or years of life. Most patients have refractory seizures and show developmental regression after seizure onset. Affected individuals have ataxic gait or inability to walk and severe to profoundly impaired intellectual development, often with absent speech. Additional more variable features may include axial hypotonia, hyperkinetic movements, dysmorphic facial features, and brain imaging abnormalities (summary by Schneider et al., 2021). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Spinocerebellar ataxia 49
MedGen UID:
1805601
Concept ID:
C5676950
Disease or Syndrome
Spinocerebellar ataxia-49 (SCA49) is an autosomal dominant neurologic disorder characterized initially by gait abnormalities, gaze-evoked nystagmus, and hyperreflexia. The age at onset is highly variable, ranging from the second to seventh decades, even within the same family. The disorder is slowly progressive, and later features may include dysarthria, dysmetria, diplopia, pyramidal signs, and axonal peripheral neuropathy. Brain imaging shows cerebellar atrophy and myelination defects (Corral-Juan et al., 2022).
Neurodevelopmental disorder with neuromuscular and skeletal abnormalities
MedGen UID:
1803456
Concept ID:
C5676965
Disease or Syndrome
Neurodevelopmental disorder with neuromuscular and skeletal abnormalities (NEDNMS) is an autosomal recessive disorder characterized by global developmental delay apparent from infancy or early childhood. The severity of the disorder is highly variable. Affected individuals show impaired intellectual development and motor delay associated with either severe hypotonia or hypertonia and spasticity. Most affected individuals have skeletal defects and dysmorphic facial features. Some may have ocular or auditory problems, peripheral neuropathy, behavioral abnormalities, and nonspecific findings on brain imaging (Kurolap et al., 2022).
Neurodevelopmental disorder with microcephaly, hypotonia, nystagmus, and seizures
MedGen UID:
1810140
Concept ID:
C5676986
Disease or Syndrome
Neurodevelopmental disorder with microcephaly, hypotonia, nystagmus, and seizures (NEDMHS) is an autosomal recessive disorder characterized by global developmental delay and impaired intellectual development apparent from infancy. Affected individuals have hypotonia with poor or absent motor skills, feeding difficulties with poor overall growth, microcephaly, mild dysmorphic features, and early-onset seizures. Additional variable features, such as nystagmus, cortical blindness, and spasticity, may also occur. Patients with this disorder tend to have recurrent respiratory infections, likely due to aspiration, that may lead to death in childhood (Arnadottir et al., 2022).
Neurodevelopmental disorder with poor growth and skeletal anomalies
MedGen UID:
1804653
Concept ID:
C5676990
Disease or Syndrome
Neurodevelopmental disorder with poor growth and skeletal anomalies (NEDGS) is an autosomal recessive disorder characterized by global developmental delay and impaired intellectual development apparent from infancy. Affected individuals have hypotonia, delayed walking, poor or absent speech, and variable skeletal anomalies. More variable features include seizures, nonspecific dysmorphic facial features, oculomotor apraxia, and nonspecific brain imaging abnormalities (Iqbal et al., 2021).
Intellectual developmental disorder, autosomal dominant 68
MedGen UID:
1802176
Concept ID:
C5677008
Mental or Behavioral Dysfunction
Autosomal dominant intellectual developmental disorder-68 (MRD68) is characterized by developmental delay/intellectual disability, microcephaly, poor growth, feeding difficulties, and dysmorphic features. Some patients may have autism spectrum disorder or attention deficit-hyperactivity disorder (ADHD) (Cif et al., 2020).
Tessadori-Van Haaften neurodevelopmental syndrome 4
MedGen UID:
1804234
Concept ID:
C5677016
Disease or Syndrome
Tessadori-Bicknell-van Haaften neurodevelopmental syndrome-4 (TEBIVANED4) is characterized by global developmental delay with poor overall growth, variably impaired intellectual development, learning difficulties, distal skeletal anomalies, and dysmorphic facies. Some patients have visual or hearing deficits. The severity and manifestations of the disorder are highly variable (Tessadori et al., 2022). For a discussion of genetic heterogeneity of TEBIVANED, see TEBIVANED1 (619758).
Dworschak-Punetha neurodevelopmental syndrome
MedGen UID:
1800957
Concept ID:
C5677017
Disease or Syndrome
Dworschak-Punetha neurodevelopmental syndrome (DWOPNED) is an autosomal recessive disorder characterized mainly by global developmental delay and mildly impaired intellectual development (IQ range 77 to 85), often with behavioral abnormalities, including autism spectrum disorder and hyperactivity. Some affected individuals may have only speech delay or behavioral manifestations. More variable additional features include optic disc hypoplasia, ptosis, hypo- or hyperpigmented skin lesions, nonspecific dysmorphic facial features, and brain imaging abnormalities of the ventricles or corpus callosum. Of note, not all patients exhibit all features, and there is significant inter- and intrafamilial phenotypic variability (Dworschak et al., 2021).
ACCES syndrome
MedGen UID:
1804308
Concept ID:
C5677019
Disease or Syndrome
Aplasia cutis congenita and ectrodactyly skeletal syndrome (ACCES) is characterized by highly variable expressivity, even within the same family. Most patients exhibit scalp defects, whereas ectrodactyly is less common; however, more variable and less obvious digital and skeletal anomalies are often present. Early growth deficiency and neurodevelopmental delay are also commonly seen (Schnur et al., 2021).
Craniofacial dysmorphism, skeletal anomalies, and impaired intellectual development 1
MedGen UID:
1808104
Concept ID:
C5677021
Disease or Syndrome
Craniofacial dysmorphism, skeletal anomalies, and impaired intellectual development syndrome-1 (CFSMR1) is characterized by cranial involvement with macrocrania at birth, brachycephaly, anomalies of middle fossa structures including hypoplasia of corpus callosum, enlargement of septum pellucidum, and dilated lateral ventricles, as well as cortical atrophy and hypodensity of the gray matter. Facial dysmorphisms include flat face, hypertelorism, epicanthal folds, synophrys, broad nasal bridge, cleft lip and cleft palate, and low-set posteriorly rotated ears. Patients also exhibit short neck and multiple costal and vertebral anomalies. The face is rather characteristic, and various authors have consistently reported affable/friendly personality, despite intellectual delay (summary by Alanay et al., 2014). Genetic Heterogeneity of Craniofacial Dysmorphism, Skeletal Anomalies, and Impaired Intellectual Development Syndrome CFSMR2 (616994) is caused by mutation in the RAB5IF gene (619960) on chromosome 20q11.
Chilton-Okur-Chung neurodevelopmental syndrome
MedGen UID:
1803276
Concept ID:
C5677022
Disease or Syndrome
Chilton-Okur-Chung neurodevelopmental syndrome (CHOCNS) is characterized mainly by global developmental delay with variably impaired intellectual development and occasional speech delay. Most patients have behavioral abnormalities, including autism spectrum disorder, ADHD, and aggression. About half of patients have dysmorphic facial features, and about half have nonspecific brain abnormalities, including thin corpus callosum. Rare involvement of other organ systems may be present. At least 1 child with normal development at age 2.5 years has been reported (Chilton et al., 2020).
DeSanto-Shinawi syndrome due to WAC point mutation
MedGen UID:
1841517
Concept ID:
C5681129
Disease or Syndrome
WAC-related intellectual disability (ID) is typically characterized by variable degrees of developmental delay and/or intellectual disability. Behavioral abnormalities including anxiety, attention-deficit/hyperactivity disorder, and/or autism spectrum disorder are observed in the majority of older children and adults. Most affected infants have significant but nonspecific features at birth such as neonatal hypotonia and feeding problems. Some affected individuals come to medical attention with respiratory or vision problems. Facial features may be mildly dysmorphic, but are nonspecific. To date, 18 individuals have been identified with WAC-related ID.
Transketolase deficiency
MedGen UID:
1814561
Concept ID:
C5700245
Disease or Syndrome
A rare disorder of pentose phosphate metabolism with characteristics of developmental delay and intellectual disability, delayed or absent speech, short stature and congenital heart defects (such as ventricular septal defect, atrial septal defect and patent foramen ovale). Additional reported features include hypotonia, hyperactivity, stereotypic behaviour, ophthalmologic abnormalities (bilateral cataract, uveitis, strabismus), hearing impairment and variable facial dysmorphism among others. Laboratory analysis shows elevated plasma and urinary polyols (erythritol, arabitol and ribitol) and urinary sugar-phosphates (ribose-5-phosphate and xylulose/ribulose-5-phosphate).
Neurodevelopmental disorder with gait disturbance, dysmorphic facies, and behavioral abnormalities, X-linked
MedGen UID:
1823953
Concept ID:
C5774179
Disease or Syndrome
Hijazi-Reis syndrome (HIJRS) is an X-linked dominant disorder characterized by global developmental delay with hypotonia, motor delay, impaired intellectual development, and speech and language delay. Affected individuals also have dysmorphic facial features, gastrointestinal issues, and ocular anomalies. Rare patients have seizures (Hijazi et al., 2022).
Spastic paraplegia 87, autosomal recessive
MedGen UID:
1813069
Concept ID:
C5774182
Disease or Syndrome
Autosomal recessive spastic paraplegia-87 (SPG87) is a neurologic disorder characterized by the onset of lower limb spasticity in infancy or early childhood. Affected individuals have mildly delayed walking, spastic gait, and hyperreflexia; the upper limbs and bulbar regions are not affected. Some patients may also have mild intellectual disability or speech problems. Thus, SPG87 can manifest as either a pure or a complex disorder (Tabara et al., 2022). For a discussion of genetic heterogeneity of autosomal recessive SPG, see SPG5A (270800).
Developmental and epileptic encephalopathy 105 with hypopituitarism
MedGen UID:
1823963
Concept ID:
C5774190
Disease or Syndrome
Developmental and epileptic encephalopathy-105 with hypopituitarism (DEE105) is an autosomal recessive disorder characterized by the onset of seizures and pituitary insufficiency in the first weeks or months of life. Affected individuals have profoundly impaired development with almost no acquisition of skills. They are hypotonic, unable to sit or speak, and have poor or absent visual fixation. Endocrine workup shows central pituitary dysfunction with low hormone levels. Brain imaging shows cerebral atrophy, thin corpus callosum, and small pituitary gland (Schanzer et al., 2021). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Neurodevelopmental disorder with intention tremor, pyramidal signs, dyspraxia, and ocular anomalies
MedGen UID:
1823969
Concept ID:
C5774196
Disease or Syndrome
Neurodevelopmental disorder with intention tremor, pyramidal signs, dyspraxia, and ocular anomalies (NEDITPO) is an autosomal recessive multiple congenital anomaly syndrome characterized by mild to moderate intellectual disability, dysmorphic facial features, intention tremor, dyspraxia, and vertical strabismus (Rahikkala et al., 2022).
Developmental delay, hypotonia, and impaired language
MedGen UID:
1823975
Concept ID:
C5774202
Disease or Syndrome
Developmental delay, hypotonia, and impaired language (DEDHIL) is a neurodevelopmental disorder characterized by variably impaired intellectual development usually with hypotonia, mild motor delay, and language difficulties. Affected individuals may also have nonspecific dysmorphic facial features, gastrointestinal problems, and abnormalities on brain imaging (Stephenson et al., 2022).
Microcephaly 29, primary, autosomal recessive
MedGen UID:
1823993
Concept ID:
C5774220
Disease or Syndrome
Autosomal recessive primary microcephaly-29 (MCPH29) is characterized by small head circumference apparent at birth and associated with global developmental delay, impaired intellectual development, speech delay, and behavioral abnormalities. Affected individuals also have poor overall growth with short stature, mild dysmorphic facial features, and seizures (Khan et al., 2020). For a discussion of genetic heterogeneity of primary microcephaly, see MCPH1 (251200).
Neurodevelopmental disorder with microcephaly, cerebral atrophy, and visual impairment
MedGen UID:
1823998
Concept ID:
C5774225
Disease or Syndrome
Neurodevelopmental disorder with microcephaly, cerebral atrophy, and visual impairment (NEDMVIC) is an autosomal recessive disorder characterized by global developmental delay, impaired intellectual development, facial dysmorphism, and microcephaly (Ziegler et al., 2022).
Neurodevelopmental disorder with dysmorphic facies and skeletal and brain abnormalities
MedGen UID:
1824004
Concept ID:
C5774231
Disease or Syndrome
Neurodevelopmental disorder with dysmorphic facies and skeletal and brain abnormalities (NEDDFSB) is a multisystemic developmental disorder characterized by feeding difficulties, poor overall growth, and global developmental delay with moderate to severely impaired intellectual development and poor or absent speech. Affected individuals have dysmorphic facial features and skeletal defects, mainly affecting the distal extremities. More variable additional findings include hypotonia, seizures, and ocular defects. Brain imaging tends to show structural defects of the corpus callosum and cerebellar hypoplasia (Duijkers et al., 2019).
Neurodevelopmental disorder with craniofacial dysmorphism and skeletal defects
MedGen UID:
1824008
Concept ID:
C5774235
Disease or Syndrome
Neurodevelopmental disorder with craniofacial dysmorphism and skeletal defects (NEDCDS) is characterized by global developmental delay, severely impaired intellectual development with poor or absent speech, characteristic facial features, and variable skeletal abnormalities. Additional features include feeding difficulties, inability to walk or walking with an abnormal gait, and cerebellar or other abnormalities on brain imaging (Reichert et al., 2020).
Neurodevelopmental disorder with eye movement abnormalities and ataxia
MedGen UID:
1824014
Concept ID:
C5774241
Disease or Syndrome
Neurodevelopmental disorder with eye movement abnormalities and ataxia (NEDEMA) is characterized by global developmental delay apparent from infancy. Affected individuals show delayed walking with an unsteady gait, variably impaired intellectual development, learning disabilities, and speech difficulties. Abnormal eye movements, which are often noted in early childhood, include opsoclonus, nystagmus, and strabismus. Some patients have seizures, which may be refractory (Lu et al., 2022).
Orofaciodigital syndrome 19
MedGen UID:
1824021
Concept ID:
C5774248
Disease or Syndrome
Orofaciodigital syndrome XIX (OFD19) is an autosomal recessive ciliopathy characterized by tongue nodules; dental anomalies including congenital absence or abnormal shape of incisors; narrow, high-arched or cleft palate; retrognathia; and digital anomalies. Some patients have notching of the upper or lower lip (Iturrate et al., 2022).
Developmental delay, language impairment, and ocular abnormalities
MedGen UID:
1824035
Concept ID:
C5774262
Disease or Syndrome
Developmental delay, language impairment, and ocular abnormalities (DEVLO) is characterized by delayed acquisition of skills particularly affecting speech and language development, although many patients show mild motor delay. Most affected individuals also have a small head circumference (down to -3 SD) and may have mild dysmorphic features. Variable ocular anomalies include strabismus, cataracts, and cortical visual impairment. Older patients require special schooling and often demonstrate behavioral abnormalities (Laboy Cintron et al., 2022).
Tessadori-Van Haaften neurodevelopmental syndrome 3
MedGen UID:
1824083
Concept ID:
C5774310
Disease or Syndrome
Tessadori-Bicknell-van Haaften neurodevelopmental syndrome-3 (TEBIVANED3) is characterized by global developmental delay with poor overall growth, impaired intellectual development, and speech difficulties. More variable features include hypotonia, microcephaly, and dysmorphic facies. The severity and manifestations of the disorder are highly variable (Tessadori et al., 2022). For a discussion of genetic heterogeneity of Tessadori-Bicknell-van Haaften neurodevelopmental disorder, see TEBIVANED1 (619758).
Intellectual disability-macrocephaly-hypotonia-behavioral abnormalities syndrome
MedGen UID:
1830493
Concept ID:
C5779996
Disease or Syndrome
PPP2R5D-related neurodevelopmental disorder is characterized by mild to severe neurodevelopmental delay. Pronounced hypotonia with delay in gross motor skills is common. Onset of independent walking varies widely and ataxia is reported. All reported individuals have speech impairment, with a wide range of abilities. Autism spectrum disorder is reported in six individuals. Macrocephaly is common. Seizures and ophthalmologic abnormalities are reported in fewer than half of individuals. Additional anomalies include skeletal, endocrine, and cardiac malformations, each reported in a few individuals. To date, 23 individuals with PPP2R5D-related neurodevelopmental disorder have been reported.
Neurodevelopmental disorder with hypotonia, dysmorphic facies, and skeletal anomalies, with or without seizures
MedGen UID:
1840880
Concept ID:
C5830244
Disease or Syndrome
Neurodevelopmental disorder with hypotonia, dysmorphic facies, and skeletal anomalies, with or without seizures (NEDFSS), is characterized by these features and global developmental delay with delayed or absent walking, moderate to severely impaired intellectual development, and poor or absent speech acquisition. Affected individuals may also have behavioral abnormalities. About half of patients develop various types of seizures that are usually well-controlled with medication. Rare patients are noted to have heat intolerance or insensitivity to pain (Lines et al., 2022).
Intellectual developmental disorder, autosomal recessive 78
MedGen UID:
1840905
Concept ID:
C5830269
Mental or Behavioral Dysfunction
Autosomal recessive intellectual developmental disorder-78 (MRT78) is a neurodevelopmental disorder characterized by impaired intellectual development that is usually mild, but shows variable severity. Affected individuals have microcephaly and mild short stature. Additional features may include ocular abnormalities and mild skeletal defects (Haag et al., 2021).
Developmental delay with hypotonia, myopathy, and brain abnormalities
MedGen UID:
1840906
Concept ID:
C5830270
Disease or Syndrome
Developmental delay with hypotonia, myopathy, and brain abnormalities (DEDHMB) is an autosomal recessive disorder characterized by global developmental delay and muscle weakness apparent in infancy. Affected individuals show severe motor delay and may not achieve independent walking due to central hypotonia and skeletal muscle myopathy. Some have poor overall growth with microcephaly, subtle dysmorphic features, and delayed language acquisition. Brain imaging shows cerebral atrophy, thinning of the corpus callosum, and delayed myelination (Shamseldin et al., 2016; Kotecha et al., 2021).
Neurodevelopmental disorder with poor growth and behavioral abnormalities
MedGen UID:
1840909
Concept ID:
C5830273
Disease or Syndrome
Neurodevelopmental disorder with poor growth and behavioral abnormalities (NEDGBA) is an autosomal recessive disorder characterized by global developmental delay, moderately to severely impaired intellectual development, often with absent speech, and behavioral abnormalities, including hyperactivity, short attention span, and ADHD. Affected individuals show failure to thrive with poor overall growth; some have microcephaly. Additional features may include nonspecific facial dysmorphism, hypotonia, and feeding difficulties (Vogt et al., 2022; Meng et al., 2023).
Neurodevelopmental disorder with language delay and behavioral abnormalities, with or without seizures
MedGen UID:
1841001
Concept ID:
C5830365
Disease or Syndrome
Neurodevelopmental disorder with language delay and behavioral abnormalities, with or without seizures (NEDLBAS), is characterized by global developmental delay with variably impaired intellectual development apparent from infancy or early childhood. Affected individuals have significant speech delay, and most demonstrate behavioral abnormalities, including autistic features. About half of patients develop seizures, which may be controlled or refractory. More variable features include hypotonia, feeding difficulties, and subtle facial dysmorphism (Schalk et al., 2022).
Pituitary hormone deficiency, combined or isolated, 8
MedGen UID:
1841011
Concept ID:
C5830375
Disease or Syndrome
Combined pituitary hormone deficiency-8 (CPHD8) is an autosomal dominant disorder characterized by deficiency of one or more of the pituitary hormones. Affected individuals have short stature due to growth hormone (GH; 139250) deficiency with variable deficiencies of other pituitary hormones, including TSH (see 188540), ACTH, and LH/FSH (see 118850). Posterior pituitary deficiency leading to central diabetes insipidus is rare (Bashamboo et al., 2017). Many patients are diagnosed with 'pituitary stalk interruption syndrome' (PSIS), which is characterized by a thin or absent pituitary stalk, absent or ectopic posterior pituitary, and hypoplasia of the anterior pituitary demonstrated on brain imaging, although this classic triad may be incomplete. Brauner et al. (2020) noted the complex phenotypic and genetic heterogeneity of PSIS, and concluded that it is a feature of genetic disorders or syndromes rather than a specific clinical entity. For a discussion of genetic heterogeneity of combined pituitary hormone deficiency, see CPHD1 (613038).
Neurooculorenal syndrome
MedGen UID:
1841013
Concept ID:
C5830377
Disease or Syndrome
Neurooculorenal syndrome (NORS) is an autosomal recessive developmental disorder with highly variable clinical manifestations involving several organ systems. Some affected individuals present in utero with renal agenesis and structural brain abnormalities incompatible with life, whereas others present in infancy with a neurodevelopmental disorder characterized by global developmental delay and dysmorphic facial features that may be associated with congenital anomalies of the kidney and urinary tract (CAKUT). Additional more variable features may include ocular anomalies, most commonly strabismus, congenital heart defects, and pituitary hormone deficiency. Brain imaging usually shows structural midline defects, including dysgenesis of the corpus callosum and hindbrain. There is variation in the severity, manifestations, and expressivity of the phenotype, even within families (Rasmussen et al., 2018; Munch et al., 2022).
Neurodegeneration with developmental delay, early respiratory failure, myoclonic seizures, and brain abnormalities
MedGen UID:
1841069
Concept ID:
C5830433
Disease or Syndrome
Neurodegeneration with developmental delay, early respiratory failure, myoclonic seizures, and brain abnormalities (NDDRSB) is a severe autosomal recessive disorder characterized by onset of these features in infancy. Affected individuals present with respiratory failure requiring intubation soon after birth; some die due to cardiorespiratory insufficiency. Those that survive show severe global developmental delay, refractory myoclonic seizures, hyperkinetic movements with exaggerated startle response, and microcephaly with dysmorphic features. Additional findings may include sensorineural hearing loss and ocular defects. Brain imaging shows variable abnormalities consistent with progressive neurodegeneration (Cali et al., 2022).
Intellectual developmental disorder, autosomal dominant 72
MedGen UID:
1841248
Concept ID:
C5830612
Mental or Behavioral Dysfunction
Autosomal dominant intellectual developmental disorder-72 (MRD72) is characterized by developmental delay, predominant speech delay, autistic or attention-deficit/hyperactivity disorder features, overfriendliness, generalized hypotonia, overweight/obesity, and dysmorphic features (Cuinat et al., 2022).
Neurodevelopmental disorder with microcephaly and movement abnormalities
MedGen UID:
1841260
Concept ID:
C5830624
Disease or Syndrome
Neurodevelopmental disorder with microcephaly and movement abnormalities (NEDMIM) is an autosomal recessive disorder characterized by global developmental delay, impaired intellectual development with poor or absent speech, and delayed walking with an abnormal gait. Affected individuals may show hypotonia or hypertonia with spasticity, ataxia, and choreoathetoid movements. Most patients have microcephaly and short stature. Ophthalmic features, behavioral abnormalities, and nonspecific dysmorphic features are commonly observed. Additional more variable features include seizures, brain imaging abnormalities, and skeletal defects (Serey-Gaut et al., 2023).
Congenital disorder of deglycosylation 1
MedGen UID:
989503
Concept ID:
CN306977
Disease or Syndrome
Individuals with NGLY1-related congenital disorder of deglycosylation (NGLY1-CDDG) typically display a clinical tetrad of developmental delay / intellectual disability in the mild to profound range, hypo- or alacrima, elevated liver transaminases that may spontaneously resolve in childhood, and a complex hyperkinetic movement disorder that can include choreiform, athetoid, dystonic, myoclonic, action tremor, and dysmetric movements. About half of affected individuals will develop clinical seizures. Other findings may include obstructive and/or central sleep apnea, oral motor defects that affect feeding ability, auditory neuropathy, constipation, scoliosis, and peripheral neuropathy.