Genetic deafness of central origin.

The autosomal recessive gene quivering in the mouse causes deafness. The cochlea in mutant animals is histologically normal, and the thresholds for compound action potentials at the round window are also normal. But the thresholds for potentials in the inferior colliculus are significantly higher in mutant animals than in normal ones, showing that the cause of deafness is retrocochlear. This mutant is believed to be the first proven instance of genetic deafness of central origin.