Title: KCNQ4, a novel potassium channel expressed in sensory outer hair cells, is mutated in dominant deafness.

Authors: C Kubisch, B C Schroeder, T Friedrich, B Lütjohann, A El-Amraoui, S Marlin, C Petit, T J Jentsch

Journal, date & volume: Cell, 1999 Feb 5 , 96, 437-46

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/10025409

Abstract
Potassium channels regulate electrical signaling and the ionic composition of biological fluids. Mutations in the three known genes of the KCNQ branch of the K+ channel gene family underlie inherited cardiac arrhythmias (in some cases associated with deafness) and neonatal epilepsy. We have now cloned KCNQ4, a novel member of this branch. It maps to the DFNA2 locus for a form of nonsyndromic dominant deafness. In the cochlea, it is expressed in sensory outer hair cells. A mutation in this gene in a DFNA2 pedigree changes a residue in the KCNQ4 pore region. It abolishes the potassium currents of wild-type KCNQ4 on which it exerts a strong dominant-negative effect. Whereas mutations in KCNQ1 cause deafness by affecting endolymph secretion, the mechanism leading to KCNQ4-related hearing loss is intrinsic to outer hair cells.