Born deaf, the 1-year-old boy had never responded to sound or speech before. But after receiving an experimental treatment injected into one of his ears, he started turning his head when his parents called his name. Five months later, he spoke his first words.
The boy is one of six children with a type of hereditary deafness who are part of a gene therapy trial in China. Five of the children can now hear, according to results reported today in the scientific journal The Lancet. The news follows an announcement this week that yet another child born with profound deafness can hear after receiving a similar treatment developed by US drugmaker Eli Lilly.
“It’s remarkable,” says Lawrence Lustig, a hearing loss expert at Columbia University who was not involved in the trials. “We’ve never had a therapy that restores even partial hearing for someone who’s totally deaf other than a cochlear implant.”
Video: The Eye & ENT Hospital of Fudan University/The Lancet
The children were all born with a mutation in a gene that makes a protein needed for hearing called otoferlin. We hear things when sound waves in the air cause the thousands of sensory hair cells in our inner ears to vibrate and release a chemical that relays that information to the brain. Otoferlin is necessary for the release of this chemical messenger. Without it, the ear can’t communicate with the brain.