Charcot-Marie-Tooth phenotype produced by a duplicated PMP22 gene as part of a 17p trisomy-translocation to the X chromosome.

Academic Article


  • The Charcot-Marie-Tooth disease type 1A (CMT1A) phenotype is most often associated with a 1.5 megabase (mb), tandem duplication of chromosome 17 band p12 (17p12). The prevailing hypothesis is that the demyelinating neuropathy results from a dosage effect of the peripheral myelin protein gene PMP22 which is included within this duplication. We present a patient with clinical and electrophysiological features of CMT1A in whom an extra PMP22 gene resulted from a rare unbalanced translocation of 17p to the X chromosome. This finding further supports the hypothesis of gene dosage as the basis for CMT1A. Moreover, this case highlights the importance of fluorescence in situ hybridization (FISH) as an alternative molecular technique in the diagnosis of CMT1A.
  • Authors


  • Adult, Charcot-Marie-Tooth Disease, Chromosomes, Human, Pair 17, Gene Duplication, Humans, Myelin Proteins, Neural Conduction, Phenotype, Translocation, Genetic, Trisomy, X Chromosome
  • Digital Object Identifier (doi)

    Pubmed Id

  • 2628522
  • Author List

  • King PH; Waldrop R; Lupski JR; Shaffer LG
  • Start Page

  • 413
  • End Page

  • 416
  • Volume

  • 54
  • Issue

  • 5