Gene therapy improved hearing in 90% of participants with a rare inherited form of deafness

A gene therapy has helped people born with a rare inherited form of deafness gain hearing, with researchers reporting improvement in 90% of participants. The treatment targets a genetic fault that prevents the inner ear from properly passing sound signals to the brain. Research report

The study, published in Nature on April 22, 2026, followed 42 participants at eight centres in China. Their ages ranged from under one year to 32 years, allowing researchers to investigate how the treatment worked across different stages of life. Original study

The condition involves a gene called OTOF, which provides instructions for making a protein called otoferlin. This protein helps specialised cells inside the ear communicate with the hearing nerve. When it does not work properly, sound can reach the ear, but the message struggles to get through.

Gene therapy aims to restore that missing connection. It delivers working genetic instructions so the cells can produce the protein they need. Think of it as repairing a communication link inside the ear. How hearing gene therapy works

In this trial, researchers used an engineered virus to carry the OTOF instructions. Hearing improved gradually, and participants who responded also became better at recognising speech. Children and adolescents generally experienced greater improvements than adults. However, the 90% figure describes hearing recovery—it does not mean that 90% achieved normal hearing. Original study

The findings also come with limits. Everyone received the treatment, so there was no untreated comparison group. The study recorded severe drops in neutrophils, a type of white blood cell that helps fight infection, although no events met its criteria for limiting the treatment dose. Longer follow-up is needed to understand lasting benefits and risks. Study results

This approach addresses one specific genetic cause of deafness. It does not establish a treatment for hearing loss caused by ageing or loud noise. Its promise is more focused: helping the ear regain a biological function that a faulty gene had disrupted. NIDCD explanation