Research overview: congenital deafness in white cats

Deafness is strongly associated with the dominant white coat gene in cats, particularly in blue-eyed white individuals, and this overview surveys the phenomenon and its biology. It examines how the white gene affects the migration and survival of pigment cells, which are also essential for the function of the inner ear, so that the same developmental pathway underlies both white coat and degeneration of the cochlea. The survey discusses the elevated rates of deafness in white cats, the higher risk in blue-eyed and odd-eyed animals, the possibility of unilateral deafness detectable only by specialized hearing tests, and the welfare and breeding implications. It connects this to the wider link between pigmentation genes and sensory development across mammals, presenting white-cat deafness as a classic example of pleiotropy where a coat-colour gene affects hearing.