Assessment of the genetic causes of recessive childhood non-syndromic deafness in the UK - implications for genetic testing

• Published in: Clinical genetics Vol. 68; no. 6; pp. 506 - 512
• Main Authors: Hutchin, T, Coy, NN, Conlon, H, Telford, E, Bromelow, K, Blaydon, D, Taylor, G, Coghill, E, Brown, S, Trembath, R, Liu, XZ, Bitner-Glindzicz, M, Mueller, R
• Format: Journal Article
• Language: English
• Published: Oxford, UK; Malden, USA Blackwell Publishing Ltd/Inc 01-12-2005; Blackwell
• Subjects: Biological and medical sciences; Cadherins - genetics; Child, Preschool; Connexin 26; Connexins - genetics; deafness; Deafness - epidemiology; Deafness - genetics; DNA Mutational Analysis; Ear, auditive nerve, cochleovestibular tract, facial nerve: diseases, semeiology; European Continental Ancestry Group; Extracellular Matrix Proteins - genetics; General aspects. Genetic counseling; Genes, Recessive - genetics; Genetic Predisposition to Disease; Genetic Testing - methods; genetics; GPI-Linked Proteins; Humans; Medical genetics; Medical sciences; Membrane Glycoproteins - genetics; Membrane Proteins - genetics; Membrane Transport Proteins - genetics; Mutation - genetics; mutations; Neoplasm Proteins - genetics; Non tumoral diseases; Otorhinolaryngology. Stomatology; Polymorphism, Single-Stranded Conformational; Protein Precursors - genetics; recessive; Serine Endopeptidases - genetics; United Kingdom - epidemiology; United Kingdom; Europe; British Isles; Human; Auditory disorder; Genetic disease; Hearing loss; Genetic counseling; mutations; ENT disease; Recessive character; Genetics; Mutation; deafness; Child; recessive
• ISSN: 0009-9163; 1399-0004
• DOI: 10.1111/j.1399-0004.2005.00539.x

Approximately one in 2000 children is born with a genetic hearing impairment, mostly inherited as a non‐syndromic, autosomal recessive trait, for which more than 30 different genes have been identified. Previous studies have shown that one of these genes, connexin 26 (GJB2), accounts for 30–60% of such deafness, but the relative contribution of the many other genes is not known, especially in the outbred UK population. This lack of knowledge hampers the development of diagnostic genetic services for deafness. In an effort to determine the molecular aetiology of deafness in the population, 142 sib pairs with early‐onset, non‐syndromic hearing impairment were recruited. Those in whom deafness could not be attributed to GJB2 mutations were investigated further for other mapped genes. The genetic basis of 55 cases (38.7%) was established, 33.1% being due to mutations in the GJB2 gene and 3.5% due to mutations in SLC26A4. None of the remaining 26 loci investigated made a significant contribution to deafness in a Caucasian population. We suggest that screening the GJB2 and SLC26A4 genes should form the basis of any genetic testing programme for childhood deafness and highlight a number of important issues for consideration and future work.