A novel KCNA1 mutation causing episodic ataxia type I

Muscle Nerve. 2014 Aug;50(2):289-91. doi: 10.1002/mus.24242. Epub 2014 Jul 14.


We describe the clinical phenotype of a novel de novo KNCA1 mutation, and functional characterization of the effects of the mutation on Kv1.1 channel function. HEK293 cells were transfected transiently with either wild-type or mutant channels. Representative currents were evoked after application of a series of square voltage steps from -80 mV to +50 mV in 200-ms intervals from Vh = -80 mV. Extracellular K(+) was added to evoke tail currents. Equal amounts of wild-type and Kv1.1(I262M) mutant DNA were transfected transiently in HEK293 cells to evaluate the influence of the mutation. We found that Kv1.1(I262M) leads to a defective voltage-gated potassium channel. Coexpression studies revealed a dominant-negative effect. We describe the phenotype of a novel KCNA1 mutation causing episodic ataxia. Patch-clamp studies confirm the pathogenicity of the mutation in vitro and suggest that it is dominant with respect to wild-type.

Keywords: KCNA1; channelopathy; episodic ataxia type 1; ion channels; potassium channel.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • DNA Mutational Analysis
  • Humans
  • Kv1.1 Potassium Channel / genetics*
  • Mutation / genetics*
  • Spinocerebellar Ataxias / genetics*


  • KCNA1 protein, human
  • Kv1.1 Potassium Channel