New Delhi: An international team of researchers has developed a new gene therapy that significantly improves hearing in children and adults with congenital deafness or severe hearing impairment, according to a recent study. The treatment showed promising results in 10 patients and was well-tolerated.
The study, published in the journal Nature Medicine, involved patients aged 1 to 24 with genetic hearing loss caused by mutations in the OTOF gene. This gene mutation leads to a deficiency of the otoferlin protein, which is crucial for transmitting sound signals from the ear to the brain.
Researchers from Sweden and China used a synthetic adeno-associated virus (AAV) to deliver a functional copy of the OTOF gene directly to the inner ear. The therapy was administered through a single injection into the cochlea via the round window membrane.
The gene therapy showed rapid effects, with most patients experiencing hearing improvement within one month. A six-month follow-up revealed significant gains in hearing ability, with the average volume of perceivable sound improving from 106 decibels to 52 decibels.
“Younger patients, especially those aged five to eight, responded best to the treatment,” the study noted. One seven-year-old girl regained nearly all her hearing and was able to hold daily conversations with her mother just four months after the treatment.
“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.
Duan also highlighted that while smaller studies in China had shown positive results in children before, this is the first time the therapy has been tested in teenagers and adults. “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,” she added.
Importantly, the gene therapy was safe and well-tolerated by all patients during the study period. The results mark a significant advancement in treating genetic forms of deafness and severe hearing impairment.