Achievements of the European Working Group on Genetics of Hearing Impairment

Three years ago an European Working Group for the study of genetics of hearing impairment was founded with the aim to standardise terminology and protocols in order to collect families with genetic hearing impairments for a European-based epidemiological, clinical and genetic analysis. Hereditary hearing impairments include a large variety of genetic causes. The occurrence of the different forms is rare, but the overall genetic aetiology is thought to account for up to 50% of newborns' hearing impairment as well as several late onset, progressive cases. In the later years, several locations associated with non-syndromal hearing impairments and different mutations for the syndromic diseases have been identified. Five subgroups have been formed: Definitions and protocols, Epidemiology, Vestibular involvement, Otological and cranial malformations, Molecular biology. Meetings were organised for discussion and establishment of common ground work. Application of the agreed documents was performed to verify protocols. Final agreements were circulated by Infoletter (1-5). Informatic working tools on the Internet have been designed. Standardised definitions, audiological and vestibular protocols have been defined. Pilot studies using experimental protocols to identify informative carriers or to help clinical differentiation between non-syndromic forms have also been performed. Two web sites related to the work have been created. A description of phenotypes of locations identified has been defined. Joining forces to standardise definitions and protocols and collaboration between clinicians and geneticists has contributed considerably to progress in this field.