Home Page
References OMIM Gene GeneReviews HGMD HGNC
GENATLAS PHENOTYPE
last update : 31-03-2016
Symbol CMT1A
Location 17p12
HGNC id 2129
Name Charcot-Marie-Tooth disease, demyelinating, type 1A
Other name(s)
  • Charcot-Marie-Tooth disease, slow nerve conduction type, unlinked to Duffy
  • Charcot-Marie-tooth neuropathy, type 1A
    • Corresponding gene PMP22
    Other symbol(s) DUP17P12, CMT1, HMSNIA, HMSN1A,
    Main clinical features
  • distal muscle weakness and amyotrophy, sensory loss, decreased or absent tendon reflexes, with decreased nerve conduction velocity
  • calf cramps are common in children with CMT1A and worsen with age; there is a link between cramp and hand tremor in children with CMT1A (PMID: 22131544))
    • Genetic determination autosomal dominant
    genomic disorder
    chromosomal
    Function/system disorder neurology
    Type disease
    Gene product
    Name peripheral myelin protein-22
    Mechanism(s)
    Gene mutationChromosome rearrangementEffectComments
      duplication   1.5 Mb duplication flanked by low copy repeats
      duplication   an identical 186-kb duplication found in seven families proximal of the PMP22 gene might lead to CMT through an unknown mechanism affecting PMP22 expression (Weterman 2010)
    Remark(s)
  • deletion of the same region cause the milder phenotype HNPP
  • triplications arose de novo from maternally transmitted duplications and caused a more severe distal symmetric polyneuropathy phenotype (PMID: 24530202))
    • Genotype/Phenotype correlations age-dependant penetrance and variable expressivity