Allele specific oligonucleotide analysis of the common deafness mutation 35delG in the connexin 26 (GJB2) gene

Abstract

Despite the large number of genes that are expected to be involved in non-syndromal, recessive deafness, only a few have been cloned. One of these genes is GJB2, which encodes connexin 26. A frameshift mutation in this gene has been reported to be common in several populations and a carrier frequency of about 1 in 30 people has been detected in Italy and Spain. Mutation 35delG is difficult to detect because it lies within a stretch of six guanines flanked by thymines, so the deletion of one G does not create or destroy a restriction site and mutagenesis primers are not useful for this mutation. We have generated an allele specific oligonucleotide method that uses 12-mer oligonucleotides and easily discriminates between the normal and 35delG alleles. The method should permit a rapid analysis of this mutation in congenital cases (recessive or sporadic), including diagnosis and carrier detection of 35delG in the population.