Prenatal diagnosis of prelingual deafness: carrier testing and prenatal diagnosis of the common GJB2 35delG mutation.

Mutations in the gene encoding the gap-junction protein connexin 26 (GJB2) on chromosome 13q11 (DFNB1 locus) have been shown as a major contributor to prelingual, non-syndromic, autosomal recessive deafness in Caucasian populations. One specific mutation, 35delG, has accounted for the majority of the mutations detected in the GJB2 gene and is one of the most frequent disease mutations identified to date. We have previously reported a carrier frequency of 35delG of 3.5% in the Greek population, and the 35delG mutation has been detected in one-third of the alleles in Greek patients with sensorineural, prelingual, non-syndromic deafness. The description of this common mutation has opened the way to prenatal diagnosis of prelingual deafness, and we here describe our experience with 29 couples requesting counseling, carrier testing and prenatal diagnosis of DFNB1 deafness. Copyright 2001 John Wiley & Sons, Ltd.