U.S. flag

An official website of the United States government

Format

Send to:

Choose Destination

Autosomal recessive spondylometaphyseal dysplasia, Megarbane type(SMDMDM)

MedGen UID:
413221
Concept ID:
C2750075
Disease or Syndrome
Synonym: Spondylometaphyseal dysplasia, megarbane-dagher-melki type
Modes of inheritance:
Autosomal recessive inheritance
MedGen UID:
141025
Concept ID:
C0441748
Intellectual Product
Source: Orphanet
A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele).
 
Gene (location): PAM16 (16p13.3)
 
Monarch Initiative: MONDO:0013223
OMIM®: 613320
Orphanet: ORPHA401979

Definition

Autosomal recessive spondylometaphyseal dysplasia, Mégarbané type is a rare, primary bone dysplasia characterized by intrauterine growth retardation, pre- and postnatal disproportionate short stature with short, rhizomelic limbs, facial dysmorphism, a short neck and small thorax. Hypotonia, cardiomegaly and global developmental delay have also been associated. Several radiographic findings have been reported, including ribs with cupped ends, platyspondyly, square iliac bones, horizontal and trident acetabula, hypoplastic ischia, and delayed epiphyseal ossification. [from ORDO]

Clinical features

From HPO
Micromelia
MedGen UID:
10031
Concept ID:
C0025995
Congenital Abnormality
The presence of abnormally small extremities.
Flat acetabular roof
MedGen UID:
373340
Concept ID:
C1837485
Finding
Flattening of the superior part of the acetabulum, which is a cup-shaped cavity at the base of the hipbone into which the ball-shaped head of the femur fits. The acetabular roof thereby appears horizontal rather than arched, as it normally does.
Wide distal femoral metaphysis
MedGen UID:
376560
Concept ID:
C1849309
Finding
Increased width of the distal part of the shaft (metaphysis) of the femur.
Vascular dilatation
MedGen UID:
8076
Concept ID:
C0002940
Pathologic Function
Abnormal outpouching or sac-like dilatation in the wall of an atery, vein or the heart.
Cardiomegaly
MedGen UID:
5459
Concept ID:
C0018800
Finding
Increased size of the heart, clinically defined as an increased transverse diameter of the cardiac silhouette that is greater than or equal to 50% of the transverse diameter of the chest (increased cardiothoracic ratio) on a posterior-anterior projection of a chest radiograph or a computed tomography.
Hypertensive disorder
MedGen UID:
6969
Concept ID:
C0020538
Disease or Syndrome
The presence of chronic increased pressure in the systemic arterial system.
Pulmonary arterial hypertension
MedGen UID:
425404
Concept ID:
C2973725
Disease or Syndrome
Pulmonary hypertension is defined mean pulmonary artery pressure of 25mmHg or more and pulmonary capillary wedge pressure of 15mmHg or less when measured by right heart catheterisation at rest and in a supine position.
Small for gestational age
MedGen UID:
65920
Concept ID:
C0235991
Finding
Smaller than normal size according to sex and gestational age related norms, defined as a weight below the 10th percentile for the gestational age.
Short stature
MedGen UID:
87607
Concept ID:
C0349588
Finding
A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms).
Postnatal growth retardation
MedGen UID:
395343
Concept ID:
C1859778
Finding
Slow or limited growth after birth.
Microtia
MedGen UID:
57535
Concept ID:
C0152423
Congenital Abnormality
Underdevelopment of the external ear.
Low-set ears
MedGen UID:
65980
Concept ID:
C0239234
Congenital Abnormality
Upper insertion of the ear to the scalp below an imaginary horizontal line drawn between the inner canthi of the eye and extending posteriorly to the ear.
Hypokinesia
MedGen UID:
39223
Concept ID:
C0086439
Finding
Abnormally diminished motor activity. In contrast to paralysis, hypokinesia is not characterized by a lack of motor strength, but rather by a poverty of movement. The typical habitual movements (e.g., folding the arms, crossing the legs) are reduced in frequency.
Global developmental delay
MedGen UID:
107838
Concept ID:
C0557874
Finding
A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.
Frontal bossing
MedGen UID:
67453
Concept ID:
C0221354
Congenital Abnormality
Bilateral bulging of the lateral frontal bone prominences with relative sparing of the midline.
Narrow chest
MedGen UID:
96528
Concept ID:
C0426790
Finding
Reduced width of the chest from side to side, associated with a reduced distance from the sternal notch to the tip of the shoulder.
Short ribs
MedGen UID:
98094
Concept ID:
C0426817
Finding
Reduced rib length.
Dysplastic sacrum
MedGen UID:
608984
Concept ID:
C0431414
Congenital Abnormality
A developmental defect of the sacrum characterized by partial or disordered development of the sacrum in which portions of the sacrum, which normally is formed by fusion of five sacral vertebrae S1-S5, fail to form or fail to form normally.
Large fontanelles
MedGen UID:
105329
Concept ID:
C0456132
Finding
In newborns, the two frontal bones, two parietal bones, and one occipital bone are joined by fibrous sutures, which form a small posterior fontanelle, and a larger, diamond-shaped anterior fontanelle. These regions allow for the skull to pass the birth canal and for later growth. The fontanelles gradually ossify, whereby the posterior fontanelle usually closes by eight weeks and the anterior fontanelle by the 9th to 16th month of age. Large fontanelles are diagnosed if the fontanelles are larger than age-dependent norms.
Delayed skeletal maturation
MedGen UID:
108148
Concept ID:
C0541764
Finding
A decreased rate of skeletal maturation. Delayed skeletal maturation can be diagnosed on the basis of an estimation of the bone age from radiographs of specific bones in the human body.
Metaphyseal cupping
MedGen UID:
323062
Concept ID:
C1837082
Finding
Metaphyseal cupping refers to an inward bulging of the metaphyseal profile giving the metaphysis a cup-like appearance.
Squared iliac bones
MedGen UID:
324963
Concept ID:
C1838186
Finding
A shift from the normally round (convex) appearance of the iliac wing towards a square-like appearance.
Severe platyspondyly
MedGen UID:
338014
Concept ID:
C1850293
Finding
Axial hypotonia
MedGen UID:
342959
Concept ID:
C1853743
Finding
Muscular hypotonia (abnormally low muscle tone) affecting the musculature of the trunk.
Short long bone
MedGen UID:
344385
Concept ID:
C1854912
Finding
One or more abnormally short long bone.
Iliac crest serration
MedGen UID:
387761
Concept ID:
C1857186
Finding
Irregularities of the iliac crest that produce the appearance of a lace border around it.
Hypoplastic ischia
MedGen UID:
347146
Concept ID:
C1859447
Finding
Underdevelopment of the ischium, which forms the lower and back part of the hip bone.
Bell-shaped thorax
MedGen UID:
351320
Concept ID:
C1865186
Finding
The rib cage has the shape of a wide mouthed bell. That is, the superior portion of the rib cage is constricted, followed by a convex region, and the inferior portion of the rib cage expands again to have a large diameter.
Delayed epiphyseal ossification
MedGen UID:
351324
Concept ID:
C1865200
Finding
Wormian bones
MedGen UID:
766814
Concept ID:
C3553900
Congenital Abnormality
The presence of extra bones within a cranial suture. Wormian bones are irregular isolated bones which appear in addition to the usual centers of ossification of the cranium.
Spondylometaphyseal dysplasia
MedGen UID:
1674850
Concept ID:
C4759767
Disease or Syndrome
A heterogeneous group of disorders associated with walking and growth disturbances that become evident during the second year of life. Characteristics are platyspondyly (flattened vertebrae) and marked hip and knee metaphyseal lesions. The different forms of spondylometaphyseal dysplasia are distinguished by the localisation and severity of involvement of the affected metaphyses.
Tachypnea
MedGen UID:
66669
Concept ID:
C0231835
Finding
Very rapid breathing.
Round face
MedGen UID:
116087
Concept ID:
C0239479
Finding
The facial appearance is more circular than usual as viewed from the front.
Wide nose
MedGen UID:
140869
Concept ID:
C0426421
Finding
Interalar distance more than two standard deviations above the mean for age, i.e., an apparently increased width of the nasal base and alae.
Short neck
MedGen UID:
99267
Concept ID:
C0521525
Finding
Diminished length of the neck.
Depressed nasal bridge
MedGen UID:
373112
Concept ID:
C1836542
Finding
Posterior positioning of the nasal root in relation to the overall facial profile for age.
Prominent forehead
MedGen UID:
373291
Concept ID:
C1837260
Finding
Forward prominence of the entire forehead, due to protrusion of the frontal bone.
Deep philtrum
MedGen UID:
374311
Concept ID:
C1839797
Finding
Accentuated, prominent philtral ridges giving rise to an exaggerated groove in the midline between the nasal base and upper vermillion border.
Anteverted nares
MedGen UID:
326648
Concept ID:
C1840077
Finding
Anteriorly-facing nostrils viewed with the head in the Frankfurt horizontal and the eyes of the observer level with the eyes of the subject. This gives the appearance of an upturned nose (upturned nasal tip).
Short nose
MedGen UID:
343052
Concept ID:
C1854114
Finding
Distance from nasion to subnasale more than two standard deviations below the mean, or alternatively, an apparently decreased length from the nasal root to the nasal tip.

Supplemental Content

Recent activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...