Mouse tales from Kresge: the deafness mouse.

Mouse models for human deafness have not only proven instrumental in the identification of genes for hereditary hearing loss, but are excellent model systems in which to examine gene function as well as the resulting pathophysiology. One mouse model for human nonsyndromic deafness is the deafness (dn) mouse, a spontaneous mutation in the curly-tail (ct) stock. The dn gene is on mouse Chromosome 19 and it was recently shown to be a novel gene called Tmc1. A mutation in Tmc1 is also found in Beethoven (Bth), which is another deaf mouse mutant. In humans, one autosomal dominant form of nonsyndromic hearing loss (DFNA36) and two autosomal recessive forms (DFNB7 and DFNB11) are associated with mutations in TMC1, the human homologue of Tmc1. The transmembrane protein encoded by this gene is required for normal cochlear hair cell function and the mouse models will facilitate the elucidation of the molecular pathway that is disrupted when mutations are present.