HEARING IMPAIRMENT AMONG CHILDREN IN SAUDI-ARABIA - FAMILIAL INCIDENCE AND POTENTIAL RISK-FACTORS

A comprehensive clinical and laboratory study was carried out to eluci date the aetiology, risk factors, and familial incidence of hearing im pairment. The study involved 1072 children at risk for hearing impairm ent as well as 17 families. Evaluation of the mothers' clinical histor ies/findings suggested that the leading possible risk factors for hear ing impairment in children were frequent pregnancies, miscarriages and low birth weight. Hearing and/or speech problems in siblings, parents , or even grandparents, were noted to be of significance in hereditary transmission. Among 42 clinically-diagnosed and laboratory confirmed cases, the aetiologic agent found to occur most frequently was, unusua lly, herpes simplex virus type 1, a non-TORCH agent. Second in frequen cy of occurrence was Toxoplasma gondii. There was IgM positivity for m ultiple agents including rubella virus with cytomegalovirus. In the fa mily study, a reliable laboratory confirmation of clinically-diagnosed hearing impairment was obtained in 10-17 families (58.8%). An interes ting finding, and one which concurred with clinical histories/findings , was that the incidence of hearing impairment could be reliably corre lated with high positivities to IgG, particularly cytomegalovirus.