Reporting the presence of three different diseases causing GJB2 mutations in a consanguineous deaf family

This paper reports a consanguineous deaf family with three different mutations in the GJB2 gene.

Four members of an Iranian deaf family were recruited in this study. The GJB2 coding region and exon-intron boundaries were investigated using direct sequencing.

The proposita was a 12-year-old girl with congenital non-syndromic hearing loss. She was born to consanguineous parents. The proposita, her parents and deaf maternal uncle were screened for GJB2 mutations.

Sequencing demonstrated the presence of the c.176_191del and c.327_328delGGinsA mutations in the proposita, the c.176_191del mutation in her father, and the c.35delG and c.327_328delGGinsA mutations in trans in her apparently unaffected mother as well as in her congenitally deaf uncle. Follow-up pure-tone audiometry revealed moderate to severe mid- and high-frequency hearing loss in the mother.

This study shows the complexity of genetic testing and counseling for hearing loss.