[PCR in the gene diagnosis of Charcot-Marie-Tooth disease]

To establish the gene diagnosis of chavcot-Marie-Tooth disease (CMT) by (PCR) polymerase chain reaction and to study the molecular genetic characteristics of the Chinese CMT.

Mutation analysis of the Cx32, MPZ and PMP22 genes were performed by PCR-RFLP, PCR-SSCP, PCR-DGGE and/or direct sequencing in 32 CMT probands of the Hans in China.

21.9% of the CMT pedigrees had mutations in the Cx32, MPZ and PMP22 genes. Ten kinds of abnormal bands were found by PCR-SSCP, including 5 kinds of polymorphism and 5 point mutations in the exons of the gene (4 of the Cx32 and 1 of the MPZ). No point mutation of the PMP22 gene was found in these patients but two families (6.3%) were diagnosed as CMT1A by the PCR-RFLP, with the tandem repeat mutation of 1.5 Mb including the PMP22 gene.

PCR-SSCP and PCR-RFLP are the first two screening methods in the gene diagnosis of CMT. PCR-DGGE is not appropriate for mutation analysis of Cx32. The point mutations must be certificated by sequencing. The mutation screening in the possible X-linkage family has to start with Cx32 gene.