A new international study has shown that gene therapy can significantly improve hearing in children and adults born with a specific genetic form of deafness.
All ten participants in the trial, aged between 1 and 24, experienced improved hearing after receiving the treatment. The results were published in Nature Medicine and mark a major step forward in the treatment of inherited hearing loss.
The research, which involved scientists from Karolinska Institutet in Sweden and several hospitals in China, focused on patients with mutations in the OTOF gene. This gene produces otoferlin, a protein critical for passing sound signals from the inner ear to the brain.
Without otoferlin, the ear can detect sound but cannot communicate it properly to the nervous system, leading to severe or total hearing loss from birth.
To treat this, researchers used a harmless virus called adeno-associated virus (AAV) to deliver a healthy copy of the OTOF gene directly into the cochlea—the spiral-shaped part of the inner ear. The gene was injected through a tiny membrane called the round window, allowing the treatment to reach the cells that needed it.
The results were fast and encouraging. Most participants began to notice improvements in their hearing within one monthof the single injection. After six months, all ten patients showed significant improvement, with the average volume of sounds they could hear dropping from 106 decibels (the sound of a chainsaw) to 52 decibels (similar to a normal conversation). For many of these patients, this improvement meant being able to hear voices, music, and environmental sounds for the first time in their lives.
Children showed the best results, especially those between the ages of 5 and 8. One seven-year-old girl regained nearly all her hearing and was having normal conversations with her mother just four months after the treatment. But teenagers and adults also benefited, showing that this therapy can work even after years of deafness.
“This is a huge step forward in the genetic treatment of deafness,” said Dr. Maoli Duan from Karolinska Institutet, one of the lead researchers. “For children and adults, this treatment can be life-changing.”
Equally important, the therapy was found to be safe and well-tolerated. The most common side effect was a mild drop in neutrophils, a type of white blood cell, but no serious health problems were reported. Patients are now being monitored long-term to see how long the benefits last.
While this study targeted a rare type of deafness caused by OTOF gene mutations, researchers say it’s just the beginning. Teams are already working on similar gene therapies for more common forms of genetic hearing loss, including those linked to the GJB2 and TMC1 genes. These cases may be more complex, but early results in lab animals have been promising.
The study was a collaboration between Swedish and Chinese scientists, with major contributions from Zhongda Hospital, Southeast University in China, and funding from Chinese research programs and Otovia Therapeutics, the biotech company that developed the therapy.
For many families affected by genetic hearing loss, these findings offer new hope. Gene therapy, once experimental, is now showing real-world potential to restore hearing—and change lives.
If you care about hearing health, please read studies about antibiotic drug that can lead to hearing loss, and whether you should get an hearing aid or see a specialist.
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The research findings can be found in Nature Medicine.
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