CMTX: X-linked dominant Charcot-Marie-Tooth disease with connexin 32 (Cx32) muta

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Clin Genet. 2011 Feb

X-linked dominant Charcot-Marie-Tooth disease with connexin 32 (Cx32) mutations

of Koreans.

Kim Y, Choi KG, Park KD, Lee GS, Chung KW, Choi BO.

Department of Neurology and Ewha Medical Research Center, 911-1 Mok-dong,

Yangchun-Gu, Seoul, 158-710, South Korea Department of Biological Science,

Kongju National University, 182 Sinkwan-dong, Kongju, Chungnam 314-701, South

Korea.

Abstract

X-linked dominant Charcot-Marie-Tooth disease (CMTX) is an inherited peripheral

neuropathy, caused mainly by a mutation of connexin 32 (Cx32) gene.

We performed a mutation analysis of Cx32 by direct sequencing of the coding

sequence, then identified 23 mutations from 28 Korean CMTX families. Nine

mutations were not reported previously: Gly5Ser, Ser26fs, Val37Leu, Thr86Ile,

Val152fs, Phe153Cys, Asp178X, Ala197Val, and Ile214Asn.

The extracellular domain 2 (EC2) of Cx32 protein was the hot spot mutation

domain in 44% of Koreans. Transmembrane domain 4 (TM4) was rarely affected in

Koreans (4%), compared with 14% of Europeans.

The EC1 and intracellular domain (IC) was not affected in Koreans, although they

were frequently affected in Europeans.

This study revealed that the frequencies of CMTX with Cx32 mutations are

different ethnic group specifically. The frequency of CMTX (5.3%) caused by Cx32

mutation in Koreans is similar to those in Asians, but lower than those in

Europeans.

This study suggests differences between CMTX patients with Cx32 mutations and

ethnic background.