Hearing restored with a single injection: revolutionary gene therapy restores hearing in children and adults
Researchers from the Karolinska Institute in Sweden have successfully restored hearing in ten individuals born deaf. This breakthrough was achieved through a single injection of gene therapy into the inner ear. The study, conducted in partnership with Chinese universities and hospitals, was published in the esteemed Nature Medicine journal.
“This marks a significant advancement in the genetic treatment of deafness and holds the potential to transform the lives of both children and adults,” stated the lead researcher and associate professor at the Karolinska Institute, Dr Maoli Duan.
The treatment involves the introduction of a healthy copy of the OTOF gene, delivered via an adeno-associated virus (AAV). This is injected into the cochlear fluid through a membrane at the base of the cochlea, also known as the round window. This gene is responsible for the production of the protein otoferrin, which is crucial for transmitting sound signals to the brain.
A month following the injection, all patients demonstrated improvement. Six months later, the average sound perception had decreased from 106 to 52 decibels, indicating enhanced hearing abilities.
The treatment was found to be most effective in younger children. For instance, a seven-year-old participant regained almost full hearing and was able to engage in daily conversations with her mother without the need for assistive devices, just four months post-treatment.
“Previous smaller studies had shown improvement in children, but this is the first time the treatment has been tested in both adolescents and adults,” Dr Duan explained. “Enhancing hearing can have a profound impact on quality of life. We plan to monitor the patients to determine the duration of the treatment’s effects.”
No serious side effects were noted during the six to twelve month follow-up period. The most common minor side effect was a decrease in the number of neutrophils, a type of white blood cell.
Dr Duan emphasized that the OTOF gene is just the starting point: “We are expanding our research to include other, more common genes that cause deafness, such as GJB2 and TMC1. These are more challenging to treat, but animal studies have yielded promising results. We are hopeful that patients with various forms of deafness will soon be able to benefit from treatment.”
The study was conducted with the collaboration of Zhongda Hospital and other Chinese institutions. Funding was provided by Chinese research projects and Otovia Therapeutics, the company that developed the treatment and employs several of the researchers.
