Researchers partially restored hearing in deaf mice with a certain kind of genetic hearing loss by inserting working copies of the mutated genes. Eventually the technique could lead to gene therapy for certain causes of human deafness.
The Columbia University Medical Center scientists report their results in the journal Science Translational Medicine. From Science News:
The ear's sound-sensing hair cells (see image above) convert noises into information the brain can process. Hair cells need specific proteins to work properly, and alterations in the genetic blueprints for these proteins can cause deafness. To combat the effects of two such mutations, the scientists injected viruses containing healthy genes into the ears of deaf baby mice. The virus infected some hair cells, giving them working genes…
The mice that recovered hearing received a partial fix. Most of their inner hair cells, which allow basic hearing, used the new genes. But few outer hair cells, which amplify noises, accepted the viral delivery. It's hard to get outer hair cells to respond to gene therapy, (otolaryngologist Lawrence) Lustig says. Still, inner hair cells control most sound transmission, he says.
"Gene therapy restores hearing in mice" (Science News)