Original Synthetic Report: Carrier frequencies of the common <i>GJB2</i> (connexin-26) 35delG mutation in the Greek-Turkish area: predominance of the mutation in Crete

Abstract

Abstract – Mutation 35delG in the connexin-26 gene is the main cause of recessive deafness in Europe. The aim of this study is to determine the percentage of carriers of this mutation in seven regions of the Greek-Turkish area; previous studies indicated that the prevalence of the mutation was relatively elevated in Greece. This study has been carried out on the genomic DNAs of a total of 1038 healthy subjects originating from Albania, Bulgaria, Athens (Greece) and Crete, and within Turkish origin from Ankara, Istanbul and Cyprus. Genotyping were performed using an allele-specific PCR protocol. The most elevated value of carrier frequency (5.36%) obtained concerns the Cretan population. Carrier frequencies are = 3.66% in Athens, = 1.34% in Istanbul and = 0.40% in Ankara. No carrier of the mutation was found in individuals with Turkish origin from Cyprus, Albania and Bulgaria. These results were compared to those already obtained in other published populations in the same area. A 35delG-allelic map in this area was constructed, which confirms that Crete corresponds to the most elevated value obtained. We discuss the historico-geographical and genetic arguments explaining this 35delG focus of elevated frequency in Crete.

Key words: Connexin-26; GJB2 gene; 35delG mutation; Greek-Turkish area; Crete.