Harvard Researchers Use Gene Therapy to Restore Hearing in Deaf Children

A new gene therapy may bring back hearing and speech in deaf patients, according to a study conducted in Fudan, China by Harvard Medical School and Fudan University.

A team from HMS-affiliated Massachusetts Eye and Ear worked with researchers from the Shanghai Eye & ENT Hospital at Fudan University to treat six children with a genetic mutation causing deafness.

The children — ranging from one to seven years old — each received an injection in one ear containing a virus, which inserted a gene into cells in the cochlea. The insertion allowed target cells to manufacture a missing protein, which brought back hearing.

Five of the six children had their hearing restored over a 26-week trial.

“We can say they recover about 60 to 70 percent of the hearing,” co-senior author and HMS associate professor Zheng-Yi Chen said in an interview.

Chen called the study “truly significant,” remarking that it was “the first time ever it’s been shown there is a treatment for hearing loss.”

In particular, Chen emphasized the impact of restoring hearing loss in young children.

“If a child within the first three years doesn’t hear — if they don’t have other communication going on — their brain will develop abnormally,” Chen said.

“Once the hearing’s back and the speech is back, they’ll grow up absolutely normally, and I have no doubt they’ll become just like you and me,” he added.

Chen said the research also holds broader implications for animal-based research.

In many cases, Chen explained, research done on animals cannot be translated to humans. But in this study, “in humans, it worked almost as well as in mice,” he said.

“That’s why I’m saying it is going to be a watershed event to open up the field and to help a lot of people down the road,” Chen added.

Chen said he hopes to conduct similar studies on a larger group of participants in the future, as well as find ways to improve hearing in situations where traditional cochlear implants fail.

“I think it is a defining moment in human history to develop treatment for [the] hearing loss population,” Chen said.

“It’s one of the best things I can ever imagine,” he added.

—Staff writer Veronica H. Paulus can be reached at veronica.paulus@thecrimson.com. Follow her on X @VeronicaHPaulus.

—Staff writer Akshaya Ravi can be reached at akshaya.ravi@thecrimson.com. Follow her on X @akshayaravi22.