Absence of deafness-associated connexin-26 (GJB2) gene mutations in the Omani population.

We have investigated the prevalence of mutations in the connexin 26 (GJB2) gene in Omani population using both PCR-RFLP and direct DNA sequencing methods. Two common GJB2 gene mutations (35delG and 167delT) were screened in 280 healthy controls and 95 deaf patients using two different PCR-RFLP methods. To investigate other GJB2 mutations, we have amplified and sequenced DNA from 51 unrelated deaf patients and 17 control subjects. None of the samples studied, either by RFLP or sequencing, revealed any deafness-associated mutations in the coding region of the GJB2 gene. These findings disagree with many reports on the GJB2 gene, describing various mutations as the cause of congenital recessive deafness. Although, an amino acid substitution (S86T) was identified by sequencing, we conclude that this change could not be associated with deafness since it was present in all the control and patient samples sequenced.