Novel mutations in the Charcot-Marie-Tooth disease genes PMP22, MPZ, and GJB1

Charcot-Marie-Tooth disease (CMT) is a clinically and genetically heterogeneous disorder of the peripheral nervous system. CMT type 1 is most frequently caused by a 1.4 Mb tandem duplication in chromosome 17p11.2 comprising the peripheral myelin protein 22 (PMP22) gene. Furthermore sequence variations of PMP22, myelin protein zero (MPZ) and the gap junction protein b 1 gene (GJB1 or Connexin 32) may cause a variety of distinct CMT phenotypes. In this study we screened DNA from 42 unrelated patients for mutations in the PMP22, MPZ and GJB1 genes. Four novel mutations were identified. A Val65Phe amino acid exchange in PMP22 causes CMT type 1 associated with deafness, in GJB1 Tyr7_Thr8delinsSer, Pro172Ala and Ser138Asn are causes of CMTX neuropathies".