CONNEXIN MUTATIONS IN X-LINKED CHARCOT-MARIE-TOOTH DISEASE

X-linked Charcot-Marie-Tooth disease (CMTX) is a form of hereditary ne uropathy with demyelination. Recently, this disorder was mapped to chr omosome Xq13.1. The gene for the gap junction protein connexin32 is lo cated in the same chromosomal segment, which led to its consideration as a candidate gene for CMTX. With the use of Northern (RNA) blot and immunohistochemistry technique, it was found that connexin32 is normal ly expressed in myelinated peripheral nerve. Direct sequencing of the connexin32 gene showed seven different mutations in affected persons f rom eight CMTX families. These findings, a demonstration of inherited defects in a gap junction protein, suggest that connexin32 plays an im portant role in peripheral nerve.