Genetics and Ancestry

This entry explores the influence of genetic and inherited causes of deafness on the distribution of deaf individuals and families within the population and, as a result, on social patterns, differing identities, and communication. It focuses on people born deaf or deaf from shortly after birth rather than on people who became deafened later. The latter group are less likely to have links to or affinity with Deaf communities and languages; also, aging, infection, or injury rather than genes are the more common causes of later-onset deafness.

In most of the world, there is a low proportion of deaf people within the population and they are geographically widely dispersed. There are small pockets where the incidence of deafness is higher and all residents, deaf and hearing, ...