Genetic screening for hearing loss.

The recent discovery that mutations in GJB2, the gene that encodes connexin 26 (Cx26), are responsible for up to half the cases of autosomal recessive non-syndromic hearing loss and a significant proportion of sporadic hearing loss has had immense implications for medical evaluation and genetic screening. It is now possible to couple mutational analysis of GJB2 with universal screening and provide an unequivocal diagnosis of inherited hearing loss in up to 50% of babies with severe to profound non-syndromic hearing loss. Currently, other genetic tests should be performed on the basis of specific clinical features. Current potential candidates for screening include SLC26A4, in the presence of specific temporal bone anomalies, and WFS1, in the presence of a low-frequency hearing loss.