Dominantly inherited myotonia congenita resulting from a mutation that increases open probability of the muscle chloride channel CLC-1.

ABSTRACT: Myotonia congenita-inducing mutations in the muscle chloride channel CLC-1 normally result in reduced open probability (P (o)) of this channel. One well-accepted mechanism of the dominant inheritance of this disease involves a dominant-negative effect of the mutation on the function of the common-gate of this homodimeric, double-barreled molecule. We report here a family with myotonia congenita characterized by muscle stiffness and clinical and electrophysiologic myotonic phenomena transmitted in an autosomal dominant pattern. DNA sequencing of DMPK and ZNF9 genes for myotonic muscular dystrophy types I and II was normal, whereas sequencing of CLC-1 encoding gene, CLCN1, identified a single heterozygous missense mutation, G233S. Patch-clamp analyses of this mutant CLC-1 channel in Xenopus

SUBMITTER: Richman DP 

PROVIDER: S-EPMC3508202 | biostudies-literature | 2012 Dec

REPOSITORIES: biostudies-literature