Population-based genetic study of childhood hearing impairment in the Trent region of the United Kingdom

The objective of the study was to investigate childhood hearing impairment ih a population-based sample from a genetic perspective. Participants inclu ded 82 families with hearing-impaired children (aged 4-13) previously ascer tained in the Trent Health Region. A questionnaire was mailed to all famili es, followed by a home visit and Connexin-26 35delG mutation screen. The Co nnexin-26 35delG mutation was identified in seven families (approximately 1 0 per cent of non-syndromal hearing impairment). Children of these families were significantly more likely than children with other modes of inheritan ce to have a profound hearing loss with a Rat audiogram profile. The famili es of children with a significant admission to a neonatal intensive care un it were significantly less likely to have had genetic counselling. Eight fa milies visited were found to have features suggestive of a genetic syndrome that had not been previously assigned a specific diagnosis. The study conc luded that hearing-impaired children should be investigated systematically according to an agreed-upon protocol, which should include Connexin-26 35de lG mutation analysis at least for those with severe-to-profound hearing los s.