Physical and Genetic-Mapping of the Cmt4a Locus and Exclusion of Pmp-2 As the Defect in Cmt4a

We have previously localized one form of the autosomal recessive Charcot-Marie-Tooth disease type 4 (CMT4A) to a 5-cM region of chromosome 8q13-q21. We now report the formation of a 7-Mb YAC contig spanning the region. This contig was used to map nine additional microsatellites and six STSs to this region, and subsequent haplotype analysis has narrowed the CMT4A flanking interval to less than 1 cM. In addition, using SSCP and our physical map, we have demonstrated that the myelin protein PMP-2, mapped by FISH to this region, is not the defect in CMT4A.