R75Q dominant mutation in GJB2 gene silenced by the in Cis recessive mutation c.35delG.

摘要

Hearing loss is a complex phenomenon; about 4% of individuals under 45 years of age in the general population is supposed to be affected by hearing loss. About 60% of sensorineural hearing impairments can be ascribed to genetic causes [Rehm, 2003]; the residual portion is due to several environmental factors: infections, ototoxic drugs, trauma and vascular pathologies. Hearing function deals with hundreds of genes and genetic deafness can be ascribed to a large variety of mutations in different genes (Hereditary Hearing loss Homepage, http://webh01.ua.ac.be/hhh/). About 50% of recessive sensorineural hearing losses is caused by mutations in GJB2 gene [Kelsell et al., 1997]. This gene codifies for connexin 26 protein (Cx26). One mutation, the c.35delG, is the most common variant, accounting for up to 70% of all GJB2 pathologic alleles in Caucasian patients [Gasparini et al., 2000].