Aetiology of bilateral sensorineural hearing impairment in children: a 10 year study.

The study was carried out on children born over a 10 year period from 1981 to 1990 in a defined area known as Greater Manchester and referred to the Centre for Audiology or the Manchester Royal Infirmary for specialist audiological assessment. The children were investigated for possible congenital or intrauterine infection. Perinatal assessment was carried out in conjunction with paediatricians for adverse aetiological factors. Full medical histories were obtained with detailed family history relevant to hearing impairment and any associated condition or syndrome. Parents and siblings were examined and hearing assessed. A total of 339 cases was studied. Children with positive family history of deafness in parents or siblings, or both, constituted 23.3% of the cases (genetic group). Other aetiological groups showed the following distribution: cause unknown 33.9%; perinatal group 12.8%; congenital infections 8.2%; bacterial meningitis 6.5%; chromosomal anomalies 5.3%; syndromal group 5.3%; and miscellaneous group 4.7%. The high incidence of genetic causes indicates that steps should be taken to facilitate genetic counselling and conceivably to reduce the numbers affected.