Dual AAV-mediated gene therapy restores hearing in a DFNB9 mouse model

Abstract

Significance In humans, inner ear development is completed in utero, with hearing onset at ∼20 weeks of gestation. However, genetic forms of congenital deafness are typically diagnosed during the neonatal period. Gene therapy approaches in animal models should therefore be tested after the period of hearing onset, to determine whether they can reverse an existing deafness phenotype. Here, we used a mouse model of DFNB9, a human deafness form accounting for 2–8% of all cases of congenital genetic deafness. We show that local gene therapy in the mutant mice not only prevents deafness when administered to immature hearing organs, but also durably restores hearing when administered at a mature stage, raising hopes for future gene therapy trials in DFNB9 patients.