Not Ready for Clinical Trials Yet but Gene Therapy May Restore Hearing in the Deaf

Gene therapy on mice suffering from genetic form of deafness has shown successful restoration of hearing in the rodents. This finding has opened doors for researchers to try the same on humans.

Jeffrey Holt of Boston Children's Hospital and Harvard Medical School said, "Our gene therapy protocol wasn't ready yet for clinical trials as we needed to tweak it a bit more but in the not-too-distant future I think it could be developed for therapeutic use in humans."

The researcher team tested gene therapy in two types of mutant mice. One type of the rodent had the TMC1 gene completely deleted and is a good model for recessive TMC1 mutations in humans. Children with two mutant copies of TMC1 have profound hearing loss from a very young age, usually by around 2 years of age.

In the recessive deafness model, gene therapy with TMC1 was found to have restored the ability of sensory hair cells to respond to sound producing a measurable electrical current and also restored activity in the auditory portion of the brainstem. In the dominant deafness model, gene therapy with a related gene, TMC2, was successful at the cellular and brain level, and partially successful in restoring actual hearing in the startle test.

Holt said, "I can envision patients with deafness having their genome sequenced and a tailored, precision medicine treatment injected into their ears to restore hearing."

The study is published in Science Translational Medicine.

Source: ANI