MOLECULAR BASES OF HEARING LOSS

Hearing loss is a frequent disorder affecting 4% of the population under the age of 45 and comprising a large spectrum of clinical manifestations. At least 60% of cases are due to genetic causes while infections, drugs, trauma, etc. can explain the remaining proportion of cases. A profound hearing loss (deafness) can make language learning and speaking difficult. The majority of genetic cases (75%-80%) are transmitted as autosomal recessive trait (NSRD), autosomal dominant inheritance (NSAD) accounts for a further 10 to 20% of cases, while X-linked inheritance for 2-3% only. Many genes are involved in the different types of deafness. Among them Connexin 26 (GJB2) play a major role in NSRD. Anyway, either for NSRD and NSAD the vast majority of genes causing disease still need to be identified and additional loci either for sensorineural and conductive (otosclerosis) hearing loss need to be mapped. For these reasons we are proposing a research project aimed to map new loci, to identify new causing diseases genes, and to better understand the genetic and functional role of connexins in hearing loss. Moreover, we plan to carry out accurate genotype-phenotype correlations either in patients and obligate carriers of GJB2 mutations in order to develop new prognostic protocols, and if possible, to define new therapeutic guidelines.