High Incidence of Deafness from Three Frequent Connexin 26 Mutations in an Isolated Community

In a small village founded by few ancestors, three mutations in GJB2, the gene for connexin 26, are responsible for the high prevalence of deafness. A total of 15% of healthy individuals from a random sample were carriers of either 35Gdel (7.8%), W77R (2.4%), or V37I (4.8%). The three mutations appeared in the village approximately 100–150 years ago. The question of why three distinct mutations of similar age are observed at high frequency within a genetic isolate is discussed.