FAMILIAL HEREDITARY PROGRESSIVE SENSORINEURAL HEARING-LOSS AMONG SAUDI POPULATION

Clinical and audiological studies of 234 Saudi patients from the centr al area of Saudi Arabia with progressive sensorineural hearing loss we re carried out in Riyadh. One hundred and sixty-four came from 38 fami lies, i.e. 70% of the total and 30% were sporadic cases. Consanguinity was found in 80.8%. Their hearing loss was characterized as being bil ateral sensorineural, starting at 1 kHz frequency and gradually slopin g the pure tone audiogram to severe and profound hearing loss at 8 kHz . Special tests for recruitment indicate hair cell lesions. Caloric te sts were normal in 56 patients tested. No abnormal internal ears were found in a C.T. scan done for 84 cases. Serology for TORCH and non-TOR CH agents were done for (124) selected cases. Syphilis was negative, h owever, positive immunoglobulins for cytomegalovirus, herpes simplex t ype 1 and 2, and toxoplasmosis were seen in 52 cases. All patients cam e from one area called Qassim where old customs and the tradition of c onsanguineous marriage were still practiced. Some of these families ar e now under molecular and cytogenetic study.