Advances in Genetic Diagnosis and Treatment of Hearing Loss — A Thirst for Revolution

Despite the significant advances in understanding the molecular basis of hearing loss, precise identification of genetic cause still presents some difficulties, owing to pheno‐ typical variation. Gene discovery efforts for hearing disorders are complicated by ex‐ treme heterogeneity. Mutations in some of these genes, such as GJB2, MYO7A, CDH23, OTOF, SLC26A4, TMC1, are quite common and responsible for hearing loss. Clinical exome sequencing is a highly complex molecular test that analyzes the exons or coding regions of thousands of genes simultaneously, using next-generation se‐ quencing techniques. The development of a biological method for the repair, regener‐ ation, and replacement of hair cells of the damaged cochlea has the potential to restore normal hearing. At present, gene therapy and stem cells are two promising therapeutic applications for hearing disorders. Gene therapy and stem cell treatment have still a long way to go before these treatments will be available to use in humans. Therefore, existing measures must focus on the prevention of hearing loss to decrease the frequency of genetic hearing loss. Over time, genetic diagnostic tests will become available most rapidly, followed by targeted gene therapy or various permutations of progenitor cell transplantation, and eventually, the preventive interventions for a wider range of hearing impaired patients.