Mutation of the Na-K-Cl Co-Transporter Gene Slc12a2 Results in Deafness in Mice

Hearing impairment is a common human condition, but we know little about the molecular basis of cochlear function. Shaker-with-syndactylism (sy)isaclassic deaf mouse mutant and we show here that a second allele, syns, is associated with abnormal production of endolymph, the fluid bathing sensory hair cells. Using a positional candidate approach, we demonstrate that mutations in the gene encoding the basolateral Na-K-Cl co-transporter Slc12a2(Nkcc1, mBSC2) cause the deafness observed in sy and syns mice. This finding provides the molecular basis of another link in the chain of K+ recycling in the cochlea, a process essential for normal cochlear function.