Hearing Loss: A Case Study of a Child born with a Genetic Defect in An Adeno-Associated Virus at Fudan University

The study involved children born with a rare genetic defect in a gene that created otoferlin, aprotein needed for sound signals to travel to the brain. The researchers modified an adeno-associated Viruses to carry a functioning form of the genes into the inner ear.

The Eye and ENT Hospital of Fudan University collaborated with a research team at Mass Ear and Eye, a Harvard-affiliated hospital, to treat deafness.

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. Children are treated at the EYE & ENT Hospital of Fudan University.

“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. They can hear it now.

More than half of hearing loss cases in children are due to genetic causes, and otoferlin mutations account for 1 to 8 percent of those, affecting about 200,000 people worldwide.

Born deaf, the 1-year-old boy had never responded to sound or speech before. He turned his head when his parents called his name after he underwent an experimental treatment. Five months later, he spoke his first words.

“It’s remarkable,” says Lawrence Lustig, a hearing loss expert at Columbia University who was not involved in the trial. “We’ve never had a therapy that restores even partial hearing for someone who’s totally deaf other than a cochlear implant.”

The children were born with a genetic problem that made them unable to hear. When sound waves in the air cause the sensory hairs in our ears to vibrate and release a chemical, that information is transmitted to the brain. Otoferlin is needed for this chemical release. Without it the ear cannot communicate with the brain.