Gene Therapy Restores Hearing in Deaf Children in China

A groundbreaking gene therapy trial in China has given dozens of children born deaf the gift of hearing for the first time.

The study, led by Shanghai's Eye & ENT Hospital of Fudan University and published in Nature this April, enrolled 42 patients ranging from 9 months to 32 years old. Each had severe-to-profound hearing loss caused by a mutation in the OTOF gene, which prevents sound signals from traveling from the inner ear to the brain.

The treatment uses a modified virus to deliver a working copy of the gene directly into inner ear cells through minimally invasive surgery. Nine out of ten patients responded to the therapy, making it the largest and longest congenital deafness gene therapy trial ever conducted.

The youngest patients saw the most dramatic results. Every child between 6 months and 3 years old gained the ability to hear, with all of them now able to follow everyday conversations after a single treatment.

One 18-month-old boy diagnosed with the condition showed no response to sound before therapy. When he tried to imitate crying, he would open his mouth wide but make no sound. After treatment, he not only gained hearing but also began speaking clearly.

Even older patients benefited. Two-thirds of patients over age 20 reported hearing improvements, proving the therapy can work across different ages. More than half of successfully treated patients can now detect sounds as quiet as a library, while just under half can hear whispers.

The Ripple Effect

This Chinese trial represents more than a medical breakthrough. It opens the door for treating the estimated two to three in every 1,000 newborns worldwide affected by hearing loss, up to 60% of whom have genetic causes.

Until now, families facing congenital deafness had limited options: hearing aids or cochlear implants that offer only partial improvements. This gene therapy actually corrects the underlying problem, restoring natural hearing pathways.

The research team found that earlier treatment and better-preserved inner ear function before therapy predicted the best outcomes. That means early genetic screening could help identify which babies would benefit most from intervention before language development windows close.

Just one day after this paper went online, the U.S. Food and Drug Administration approved a similar gene therapy from Regeneron for clinical use. The momentum is building fast.

"Seeing children and their families transformed from living in a silent world to having clear speech is the driving force behind more than a decade of persistence," the research team told Sixth Tone. That persistence just changed the future for countless families waiting for hope.