Studying the etiology of deafness in the "deaf" schools of Alexandria.

Two hundred and twenty three children with childhood deafness were included in this study. They were collected randomly from pupils of Al-Amal schools for the deaf in Alexandria. They were subjected to complete audiological examinations. One hundred and three cases had genetically determined deafness, 12 cases were due to prenatal causes, 20 cases to perinatal causes, 45 cases to postnatal causes, and 43 cases with undefined etiology. One hundred and ninety cases had prelingual deafness, 25 cases had perilingual deafness, and only 8 cases had postlingual deafness. Consanguinity with positive family history for deafness was found to be the most important factor in the genetically determined deafness. Rubella was the most important prenatal cause, while perinatal hypoxia was the most important perinatal cause, and meningitis was the most important postnatal cause. The results were compared with another study that was conducted 25 years ago in the same schools. The comparison was done in view of the changes that occurred in the Egyptian society in the last quarter of a century.