[Marriage of blood relatives and congenital deafness].

Audiological and genealogical examination of 658 patients with congenital deafness. All of them were citizens of the Republic of Azerbaijan. It was found that 236 (35.8%) probands had a family history of blood relatives marriage with a high inbreeding coefficient (F=0.0105). Marriages between cousin sibs by a parallel type prevailed. Marriages between blood relatives promote a rise in homozygosis of the pathological recessive genes increasing the risk of beath of handicapped babies.