New Delhi, July 5
In a significant scientific breakthrough, an international team of researchers has developed a novel gene therapy that can improve hearing in children and adults with congenital deafness or severe hearing impairment.

In the study, Swedish and Chinese used gene therapy and improved hearing in 10 patients, and the treatment was well-tolerated.

“This is a huge step forward in the genetic treatment of deafness, one that can be life-changing for children and adults,” said Maoli Duan, consultant and docent at the Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Sweden.

The study, published in the journal Nature Medicine, comprised 10 patients between the ages of 1 and 24 at five hospitals in China, all of whom had a genetic form of deafness or severe hearing impairment caused by mutations in a gene called OTOF.

These mutations cause a deficiency of the protein otoferlin, which plays a critical part in transmitting auditory signals from the ear to the brain.

The gene therapy involved using a synthetic adeno-associated virus (AAV) to deliver a functional version of the OTOF gene to the inner ear via a single injection through a membrane at the base of the cochlea called the round window.

The gene therapy worked rapidly and helped the majority of the patients to recover some hearing in just a month.

A six-month follow-up showed considerable hearing improvement in all participants, with the average volume of perceptible sound improving from 106 decibels to 52.

The younger patients, especially those between the ages of five and eight, responded best to the treatment.

One of the participants, a seven-year-old girl, quickly recovered almost all her hearing and was able to hold daily conversations with her mother four months afterward. However, the therapy also proved effective in adults.

“Smaller studies in China have previously shown positive results in children, but this is the first time that the method has been tested in teenagers and adults, too,” Duan said.

“Hearing was greatly improved in many of the participants, which can have a profound effect on their life quality. We will now be following these patients to see how lasting the effect is,” the expert said.

Importantly, the results also show that the treatment was safe and well-tolerated.

New gene therapy shows potential for restoring hearing loss