Mutation analysis of the GJB2 (Connexin 26) gene by DGGE in Greek patientswith sensorineural deafness

The GJB2 (connexin 26) gene, one of the major genes responsible for autosom al recessive deafness, has been investigated previously by a variety of tec hniques, including PCR-SSCP and sequencing of the entire gene for screening of unknown mutations, and allele-specific PCR, ASO, and PCR-mediated site- directed mutagenesis for the detection of the common mutation 35delG, Here, we present the development of a DGGE method for the characterization of th e full spectrum of mutations in the GJB2 gene. The GJB2 cDNA and flanking s equences were amplified in three overlapping segments. We screened 26 Greek patients with prelingual, sensorineural deafness, where syndromic forms an d environmental causes of deafness had been excluded. The 35delG mutation w as detected in 28 chromosomes (53.8%), while another three sequence variati ons accounted for 7.6% of the alleles. The sequence variation R127H, previo usly described in a few Spanish and Balkan patients, was detected in two pa tients as the sole mutation. A novel sequence variation, K224Q, was identif ied as the sole mutation in one patient. Use of this approach may contribut e to the full description of mutations in this important deafness gene. Hum Mutat 16:7-12, 2000. (C) 2000 Wiley-Liss, Inc.