Consanguinity among parents of hearing-impaired children in relation to ethnic groups in the Jewish population of Jerusalem.

A longitudinal study was performed on Jewish children with moderately-severe to profound hearing impairment born in Jerusalem during a period of 15 years (1967-1982), and the data on consanguineous matings among their parents were analyzed. These data were estimated in relation to the records obtained in an earlier survey performed on Jewish deaf children during the years 1955-1964. The rate of consanguinity among the parents of hearing-impaired children was much lower in the present survey than in the earlier one in both the Ashkenazi (Central and Eastern European origin) and the non-Ashkenazi (Asian-African origin) group. It is assumed that there is a better understanding of the genetic risk in consanguineous unions, especially when a disability such as hereditary deafness is involved.