Editor—Mutations inGJB2, the connexin 26 (Cx26) gene, are thought to account for over 50% of autosomal recessive, non-syndromic, congenital deafness, the most common form of genetic deafness1 2 and 10-30% of sporadic cases.2 3 Over 50 recessive mutations in theGJB2 gene have been reported since it was originally described4 (the connexin 26(GJB2) deafness homepage athttp://www.iro.es/cx26deaf.html). The most common mutation is a deletion of a guanosine nucleotide at position 30-35 (35delG), accounting for approximately 30-63% of mutations in white populations with a carrier frequency of 1:31 in Mediterranean populations.1 2 However, the 35delG mutation is present at a lower prevalence in different ethnic groups,5-8 with other mutations occurring at a higher prevalence, such as 167delT in the Jewish population.9-12 Both the high carrier frequency of GJB2 mutations and the prevalence of non-35delG mutations in non-white populations implies that mutations other than 35delG may be more common in non-white ethnic minorities who have settled in the UK, particularly those in which consanguinity is prevalent.

In order to examine strategies suitable for sensitive, medium throughput mutation detection in GJB2, we used denaturing high performance liquid chromatography (DHPLC) to screen for mutations in a cohort of 51 multi-ethnic patients with non-syndromic deafness who presented at our centre for genetic counselling. We found that DHPLC detected all the control mutations in the sample and that no mutations were identified by sequencing that were not detected by DHPLC. Three mutations, W24X, W77X, and Q124X, found in Indian, Pakistani, and Bangladeshi families in this study, have been previously observed in families from the Indian subcontinent, suggesting that they may be common mutations in these ethnic groups.