Hearing lossGene: GJB1
Created: 9 Feb 2016, 10:06 a.m.
Inheritance:X-linked dominant Inheritance:X-linked dominant
Created: 7 Feb 2016, 8:57 a.m.
Mode of inheritance
#302800:Charcot-Marie-Tooth neuropathy, X-linked dominant, 1[Sensorineural hearing loss (uncommon); Nystagmus (in some patients); Achilles tendon contractures; Pes cavus; Muscle biopsy showed neurogenic changesFiber size variationType 1 fiber predominanceDistal muscle atrophy; Central nervous system involvement (in some patients)Delayed motor developmentTransient, reversible neurologic deficitsParaparesisMonoparesisNumbnessMotor aphasiaDysarthriaDysphagiaTremorSpinocerebellar ataxia (in some patients)Limb incoordination (in some patients)Dysmetria (in some patients)Pyramidal signs (in some patients)Hyperreflexia in the lower limbs (in some patients)Extensor plantar responses (in some patients)Cerebellar atrophy (in some patients)White matter abnormalities seen on MRI which resolve over time; Distal limb muscle weakness due to peripheral neuropathyDistal limb muscle atrophy due to peripheral neuropathyGait disturbanceToe-walkingDifficulty walking on heelsHyporeflexiaDistal sensory impairmentReduced motor nerve conduction velocity (NCV) (range less than 38 m/s to normal)Normal NCVLoss of myelinated fibers seen on nerve biopsyAxonal degenerationRegenerative nerve sproutingThin myelin sheathsOnion bulb formations]
GJB1 was added to Congenital hearing impairment (Profound/Severe)panel. Sources: Expert