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Lichtenstein-Knorr syndrome(SCAR19; LIKNS)

MedGen UID:
898996
Concept ID:
C4225383
Disease or Syndrome
Synonym: SPINOCEREBELLAR ATAXIA, AUTOSOMAL RECESSIVE 19
SNOMED CT: Lichtenstein Knorr syndrome (1237413006); SCAR19 - spinocerebellar ataxia, autosomal recessive 19 (1237413006); Progressive autosomal recessive cerebellar ataxia, sensorineural hearing loss syndrome (1237413006); Progressive autosomal recessive ataxia, deafness syndrome (1237413006)
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): SLC9A1 (1p36.11)
 
Monarch Initiative: MONDO:0014572
OMIM®: 616291
Orphanet: ORPHA448251

Definition

Lichtenstein-Knorr syndrome is an autosomal recessive neurologic disorder characterized by postnatal onset of severe progressive sensorineural hearing loss and progressive cerebellar ataxia. Features usually develop in childhood or young adulthood (summary by Guissart et al., 2015). Some patients with SLC9A1 mutations may not have deafness (Iwama et al., 2018) [from OMIM]

Clinical features

From HPO
Areflexia of lower limbs
MedGen UID:
347285
Concept ID:
C1856694
Finding
Inability to elicit tendon reflexes in the lower limbs.
Areflexia of upper limbs
MedGen UID:
388832
Concept ID:
C2674177
Finding
Inability to elicit tendon reflexes in the upper limbs.
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).
Sensorineural hearing loss disorder
MedGen UID:
9164
Concept ID:
C0018784
Disease or Syndrome
A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve.
Vestibular hyporeflexia
MedGen UID:
336378
Concept ID:
C1848606
Finding
A general descriptive term that describes impaired functioning of the vestibular apparatus that leads to manifestations such as dizziness or postural imbalance
Cerebellar ataxia
MedGen UID:
849
Concept ID:
C0007758
Disease or Syndrome
Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly).
Dysarthria
MedGen UID:
8510
Concept ID:
C0013362
Mental or Behavioral Dysfunction
Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed.
Dysmetria
MedGen UID:
68583
Concept ID:
C0234162
Finding
A type of ataxia characterized by the inability to carry out movements with the correct range and motion across the plane of more than one joint related to incorrect estimation of the distances required for targeted movements.
Action tremor
MedGen UID:
65875
Concept ID:
C0234376
Sign or Symptom
A tremor present when the limbs are active, either when outstretched in a certain position or throughout a voluntary movement.
Dysdiadochokinesis
MedGen UID:
115975
Concept ID:
C0234979
Sign or Symptom
A type of ataxia characterized by the impairment of the ability to perform rapidly alternating movements, such as pronating and supinating his or her hand on the dorsum of the other hand as rapidly as possible.
Delayed ability to walk
MedGen UID:
66034
Concept ID:
C0241726
Finding
A failure to achieve the ability to walk at an appropriate developmental stage. Most children learn to walk in a series of stages, and learn to walk short distances independently between 12 and 15 months.
Cerebellar atrophy
MedGen UID:
196624
Concept ID:
C0740279
Disease or Syndrome
Cerebellar atrophy is defined as a cerebellum with initially normal structures, in a posterior fossa with normal size, which displays enlarged fissures (interfolial spaces) in comparison to the foliae secondary to loss of tissue. Cerebellar atrophy implies irreversible loss of tissue and result from an ongoing progressive disease until a final stage is reached or a single injury, e.g. an intoxication or infectious event.
Cerebellar vermis atrophy
MedGen UID:
149271
Concept ID:
C0742028
Disease or Syndrome
Wasting (atrophy) of the vermis of cerebellum.
Limb ataxia
MedGen UID:
196692
Concept ID:
C0750937
Finding
A kind of ataxia that affects movements of the extremities.
Gait ataxia
MedGen UID:
155642
Concept ID:
C0751837
Sign or Symptom
A type of ataxia characterized by the impairment of the ability to coordinate the movements required for normal walking. Gait ataxia is characteirzed by a wide-based staggering gait with a tendency to fall.
Motor delay
MedGen UID:
381392
Concept ID:
C1854301
Finding
A type of Developmental delay characterized by a delay in acquiring motor skills.
Cafe-au-lait spot
MedGen UID:
113157
Concept ID:
C0221263
Finding
Cafe-au-lait spots are hyperpigmented lesions that can vary in color from light brown to dark brown with smooth borders and having a size of 1.5 cm or more in adults and 0.5 cm or more in children.
Nystagmus
MedGen UID:
45166
Concept ID:
C0028738
Disease or Syndrome
Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVLichtenstein-Knorr syndrome

Recent clinical studies

Therapy

Iwama K, Osaka H, Ikeda T, Mitsuhashi S, Miyatake S, Takata A, Miyake N, Ito S, Mizuguchi T, Matsumoto N
J Hum Genet 2018 Oct;63(10):1049-1054. Epub 2018 Jul 17 doi: 10.1038/s10038-018-0488-x. PMID: 30018422

Supplemental Content

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