Referenced in: none

Automatically associated channels: Cav2.1 , Kv1.1

Title: A novel mutation in KCNA1 causes episodic ataxia without myokymia.

Authors: Hane Lee, Hui Wang, Joanna C Jen, Chiara Sabatti, Robert W Baloh, Stanley F Nelson

Journal, date & volume: Hum. Mutat., 2004 Dec , 24, 536

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/15532032

Abstract
We describe a unique family in which several individual are affected with episodes of ataxia that best fit the phenotype of episodic ataxia type 2 (EA2). All of the affected family members had episodes typically lasting for several hours, and none of them had muscle abnormalities including myokymia. Episodic ataxia type 1 (EA1) was not considered initially as a clinical diagnosis for the affected individuals in this family. However, by linkage mapping, sequencing and polymorphism analysis, all affecteds were found to have a novel mutation in KCNA1. Numerous missense mutations have been described previously in KCNA1 that cause EA1. The mutation c.1025G>T replaces a highly conserved serine with isoleucine at position 342 (p.Ser342Ile) in the highly conserved fifth transmembrane domain of the KCNA1. This mutation leads to a distinct clinical phenotype without myokymia broadening the scope of clinical characteristics of EA1 and highlighting the heterogeneity of phenotypic effects from distinct missense mutations.