Up to three in every 1,000 newborns is born with hearing loss in one or both ears. While cochlear implants have long been a life-changing option, they involve surgery and can’t fully replicate the subtlety of natural hearing. But researchers may have finally opened the door to an alternative option.
According to new research, scientists have successfully used gene therapy to restore hearing in adults with congenital deafness, marking a major milestone in the quest to restore hearing in people of all ages.
A true hero in hearing restoration
We know that gene therapy can be extremely powerful. Not only has gene editing opened the door for many potential treatments, but it has also paved the way for groundbreaking research like hypoallergenic cats, and more.
This new treatment can restore hearing loss in adults by targeting a rare form of genetic hearing loss called OTOF-related deafness. This condition stems from mutations in the OTOF gene, which normally produces a protein called otoferlin. Otoferlin is critical for transmitting sound signals from the inner ear to the brain.
That signal chain is broken in patients with this mutation. This leads to hearing loss from birth onward. Because the inner ear structures remain healthy, though, the condition is well suited for gene therapy treatments. To deliver a working copy of the OTOF gene, researchers used a harmless, modified virus that was released directly into the inner ear’s sensory cells. This virus essentially acted as a courier, carrying the fixed gene into the cells so they can begin producing otoferlin and hopefully restore sound signaling.
Rapid improvements
Initial tests in children showed promising results, but a bigger question remained: Could gene therapy work in older patients? To find out, the team launched a clinical trial involving 10 participants between the ages of 1 and 24, all diagnosed with OTOF-related deafness. The results were encouraging across the board—and especially noteworthy in older participants.
Hearing improvements were both rapid and significant. On average, participants showed a 62% improvement in brainstem response tests and a 78% gain in behavioral hearing assessments. Some were able to detect the sounds of speech within just a few weeks. This research marks the first time gene therapy has been shown to restore hearing in both adolescents and adults.
Side effects were reportedly mild and temporary, with no serious complications observed. Most commonly, patients experienced a brief drop in white blood cell counts. A full write-up on the research is available at The Conversation, as well as in the official published study available in Nature Medicine.
