Charcot-Marie-Tooth type 1A duplication appears to arise from recombination at repeat sequences flanking the 1.5 Mb monomer unit

Nat Genet. 1992 Dec;2(4):292-300. doi: 10.1038/ng1292-292.


We have constructed a 3.1 megabase (Mb) physical map of chromosome 17p11.2-p12, which contains a submicroscopic duplication in patients with Charcot-Marie-Tooth disease type 1A (CMT1A). We find that the CMT1A duplication is a tandem repeat of 1.5 Mb of DNA. A YAC contig encompassing the CMT1A duplication and spanning the endpoints was also developed. Several low copy repeats in 17p11.2-p12 were identified including the large (> 17 kb) CMT1A-REP unit which may be part of a mosaic repeat. CMT1A-REP flanks the 1.5 Mb CMT1A monomer unit on normal chromosome 17 and is present in an additional copy on the CMT1A duplicated chromosome. We propose that the de novo CMT1A duplication arises from unequal crossing over due to misalignment at these CMT1A-REP repeat sequences during meiosis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Base Sequence
  • Charcot-Marie-Tooth Disease / classification
  • Charcot-Marie-Tooth Disease / genetics*
  • Chromosome Mapping
  • Chromosomes, Human, Pair 17
  • DNA / genetics
  • Female
  • Humans
  • Male
  • Molecular Sequence Data
  • Multigene Family*
  • Pedigree
  • Recombination, Genetic
  • Repetitive Sequences, Nucleic Acid*


  • DNA