Gene therapy shows promise for people with deafness
Hearing by delivering a working version of the otoferlin gene to a child born in a tumor with an inherited blindness
The treatment the children received works by delivering a working version of the otoferlin gene to the inner ear. The cells of the inner ear are able to read a gene. In the US and Europe, a handful of these cutting-edge therapies have been approved, including one for a type of inherited blindness. Given just once, they’re designed to correct disease-causing genes—hopefully permanently.
For the deafness treatment, researchers at the Eye & ENT Hospital of Fudan University in Shanghai collaborated with a team at Mass Ear and Eye, a Harvard-affiliated hospital in Boston.
Within weeks, five of the six children, who were between the ages of 1 and 7, began to be able to hear and the oldest child has been able to say simple words, Chen says. The children are being treated at a hospital in China.
“Before the treatment they couldn’t hear a thing. You could put the loudest sound in the ear and they don’t hear anything,” Chen says. “And now they can hear.”
As many as 100 children in the US are born each year with an otoferlin defect, meaning that it accounts for 1% to 8% of genetic deafness.
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. He spoke for the first time five months later.
“It’s remarkable,” says Lawrence Lustig, a hearing loss expert at Columbia University who was not involved in the trial. We have never had a therapy that can give someone partial hearing except for a cochlear implant.
The children were born with a variation in a gene that makes otoferlin, which is needed for hearing. 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. The ear doesn’t communicate with the brain without it.
Researchers in China have given working versions of a gene that makes otoferlin, which is needed for hearing, to inner ear cells of children born with an inherited deafness. “Before the treatment they couldn’t hear a thing. You could put the loudest sound in the ear and they don’t hear anything,” researchers said. Five of the six children began hearing within weeks.