03-07-2025
Deaf people are regaining their hearing thanks to groundbreaking new treatment
A new gene therapy could restore hearing in deaf children and adults, a groundbreaking study suggests.
Researchers from several Chinese hospitals looked at 10 patients who were either born deaf or developed severe hearing loss due to a genetic mutation.
All of them, who ranged from infants to young adults, were injected one time with modified version of adeno-associated viruses (AAV). The viruses are not meant to spread disease but instead help deliver gene therapies to cells.
The researchers found the treatment improved hearing in all 10 participants within a year, and most noticed a difference in just one month.
On average, sounds only needed to be half as loud as previously played for participants to pick them up.
Young children had the most significant improvements. One seven-year-old deaf girl was able to hold a conversation with her mother four months after treatment.
The shot is thought to help restore functional copies of the OTOF gene, which helps transmit sound and was mutated in all of the participants.
The team suspects the study 'is just the beginning' in developing treatments for the 200,000 deaf people worldwide who have a mutation in their OTOF gene.
Maoli Duan, study author and consultant docent at the Karolinska Institutet in Sweden, said: 'This is a huge step forward in the genetic treatment of deafness, one that can be life-changing for children and adults.'
The study, published Wednesday in the journal Nature Medicine, included 10 people ages one to 24 with either congenital deafness - meaning they were born with it - or severe hearing impairment.
All participants had mutations of their OTOF gene, which provides instructions for making the protein otoferlin. Otoferlin helps transmit sound from the inner ear to the auditory nerve.
Each participant received hearing and genetic testing prior to the experiment.
All of the participants received injections containing two AAV viruses in the cochlea of each of their ears. The cochlea is a fluid-filled cavity in the inner ear that converts auditory vibrations into electrical signals, which the brain interprets as sound.
Before treatment, participants on average could only hear sounds at least 106 decibels, about the volume of a motorcycle, car horn or sporting event. After a year, they were able to hear sounds 52 decibels or louder, the same as a normal conversation.
The seven-year-old girl in the study went from only being able to hear 101 decibels to 40 after only two weeks.
Within two months, she could detect sounds above 25 decibels, about the volume as a whisper.
After four months, the girl could have daily conversations with her mom with no assistive hearing devices.
Only one participant was an adult, about 24 years old. The treatment allowed him to identify certain spoken words and the sound of hands clapping after several months.
Dr Duan said: '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.
'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.'
There were also no severe adverse reactions to the injections.
Experts believe the injections may have helped provide the bodies of participants with functional copies of mutated genes, which may have helped their OTOF genes produce more otoferlin needed for hearing.
OTOF mutations account for about two to eight percent of genetic deafness cases.
Dr Duan said the new treatment 'is just the beginning.'
She added: 'We and other researchers are expanding our work to other, more common genes that cause deafness, such as GJB2 and TMC1. These are more complicated to treat, but animal studies have so far returned promising results.
'We are confident that patients with different kinds of genetic deafness will one day be able to receive treatment.'
