Thomsen or Becker myotonia? A novel autosomal recessive nonsense mutation in the CLCN1 gene associated with a mild phenotype

Muscle Nerve. 2012 Feb;45(2):279-83. doi: 10.1002/mus.22252.

Abstract

We describe a large Brazilian consanguineous kindred with 3 clinically affected patients with a Thomsen myotonia phenotype. They carry a novel homozygous nonsense mutation in the CLCN1 gene (K248X). None of the 6 heterozygote carriers show any sign of myotonia on clinical evaluation or electromyography. These findings confirm the autosomal recessive inheritance of the novel mutation in this family, as well as the occurrence of phenotypic variability in the autosomal recessive forms of myotonia.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / metabolism
  • Adolescent
  • Brazil
  • Child
  • Chloride Channels / genetics*
  • Codon, Nonsense / genetics*
  • Consanguinity
  • Echocardiography
  • Exons / genetics
  • Family Health
  • Female
  • Humans
  • Male
  • Muscle, Skeletal / pathology
  • Muscle, Skeletal / physiopathology
  • Myotonia / genetics*
  • Myotonia / pathology
  • Myotonia / physiopathology
  • Myotonia Congenita / genetics*
  • Myotonia Congenita / pathology
  • Myotonia Congenita / physiopathology
  • Neural Conduction / genetics
  • Phenotype

Substances

  • CLC-1 channel
  • Chloride Channels
  • Codon, Nonsense
  • Adenosine Triphosphatases