Compound heterozygosity of the novel c.292C>T (p.R98W) and the c.35delG GJB2 mutations in postlingual, non-syndromic, sensorineural deafness

Abstract

Objectives: Connexins (Cxs) are membrane-spanning proteins that co-assemble into intercellular gap junction channels. Gap junction channels mediate electrical and biochemical communication between adjacent cells and play vital roles as mediators of intercellular molecular signaling. Cx-linked deafness highlights the key role of gap junctions in the physiological processes of hearing. Co-localization of Cxs with the gap junction system in the inner ear suggests a role in cochlear electrolyte homeostasis. During auditory transduction, they are proposed to maintain membrane potentials by regulating the flow of potassium ions between the sensory epithelia of the inner ear.

Methods: Clinical and molecular genetic methods were employed in a Greek proband presenting with bilateral, postlingual, non-syndromic, sensorineural deafness.

Results: We detected a novel c.292C>T (p.R98W) mutation in compound heterozygosity with the c.35delG mutation in the GJB2 gene.

Conclusion: Although mutations in the GJB2 gene usually cause prelingual, severe to profound deafness, compound heterozygosity of the novel c.292C>T (p.R98W) and the c.35delG GJB2 mutations appears to be the cause of postlingual, moderate, sensorineural deafness in our proband.