A single injection may one day transform the lives of people born without hearing, according to a new scientific study that highlights the potential of gene therapy to treat congenital deafness.
Researchers from the Karolinska Institute, working alongside universities and hospitals in China, tested an experimental gene treatment on ten patients aged between 1 and 24 who had severe hearing loss. All participants showed significant improvement, some within just a few weeks, according to findings published in Nature Medicine.
How the gene therapy works
The treatment targets a rare form of genetic deafness linked to mutations in the OTOF gene, which is responsible for producing a protein essential for transmitting sound signals from the inner ear to the brain.
To address the defect, scientists used a genetically modified virus as a delivery system to carry a functioning copy of the gene directly into the inner ear. The procedure involved a single injection into the delicate membrane of the cochlea, the part of the ear responsible for converting sound vibrations into electrical signals.
Improvements were observed quickly. Most patients began to perceive sound within one month, and after six months all participants showed clear progress. On average, the level of sound they could detect improved significantly, moving from severe impairment to a much more functional range of hearing. Researchers also noted continued improvement beyond the six-month mark, suggesting that benefits may increase over time.
A child hears her mother for the first time
One of the most striking cases involved a seven-year-old girl who regained near-normal hearing and was able to communicate with her mother just four months after receiving the treatment. While adults also experienced meaningful improvements, the results suggest that earlier intervention in childhood may lead to stronger outcomes.
The therapy was also found to be safe during the study period. Side effects were mild, with the most common being a temporary reduction in a type of white blood cell. No serious complications were reported, although researchers note that long-term effects still need further monitoring.
A step toward broader treatments
Scientists emphasise that this approach currently targets only one specific gene linked to hereditary deafness. However, further studies are already underway to explore treatments for more common and complex genetic forms of hearing loss.
Researchers are also investigating whether gene therapy could eventually be combined with other hearing restoration technologies to improve outcomes even further.
If confirmed in larger clinical trials, the findings could mark a major shift in how hearing loss is treated—moving from assistive devices toward therapies capable of restoring natural hearing function.
