Research overview: hearing loss in white cats and the genetics of deafness

Many white cats, especially blue-eyed ones, are deaf, and this overview reviews the link between coat colour genetics and hearing. The dominant white gene can disrupt the development of pigment cells that are also essential for the inner ear sensory structures, leading to degeneration of the cochlea and congenital deafness, often correlated with blue eye colour and sometimes affecting only one ear. Researchers study the association through pigment-cell biology, hearing tests, and genetics. Why it matters: this connection between coat colour, eye colour, and deafness is a classic example of pleiotropy, where one gene affects multiple traits, and it has practical importance for breeders and owners. It also illuminates the shared developmental origins of pigment and the inner ear, linking the cat appearance to the biology of its hearing.