Gene Therapy Offers 'Astounding' Results in Deaf Kids

A handful of children in China are experiencing sound for the first time, thanks to scientists who employed gene therapy to help alleviate their hereditary hearing issues. The Guardian reports on the "astounding" research, published Wednesday in Nature Medicine, in which doctors at Shanghai's Fudan University treated five kids, ages 1 to 11, who were born deaf due to genetic mutations. Those mutations upend the body's ability to produce a protein called otoferlin, needed for auditory signals to effectively move from the ear to the brain.

The doctors in this trial treated the two girls and three boys, who have a condition called DFNB9, in both ears by introducing a normal copy of the mutated gene into the children via an inactive virus in a minimally invasive procedure, per New Scientist. Within six months' time, hearing for the kids had reached 50% to 60% of normal levels. They were able to tell which direction sounds were coming from and hear voices at conversational volumes. "When we whisper, they have a difficult time, but normal conversation is fine," says study co-author Zheng-Yi Chen. "We're very happy."

One little boy, age 2, can be seen in a set of videos not responding at all before the procedure to the sound of his own name or music. After the gene therapy, however, the boy can be seen turning his head when his grandparents call out his name, as well as dancing to music that's playing (check out the footage here). The same US-China team had carried out a similar trial earlier this year, but only in one ear for each subject.

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It was important to expand on that study, as hearing out of both ears is a capability "important for everyday situations such as talking in groups and being aware of traffic when crossing the road," per the Guardian. The researchers, who want to expand on their research and plumb more ways to treat other kinds of deafness with gene therapy, also think the children in this trial may continue to see better hearing as time goes on. "What we see now is not the peak of the improvement," Chen tells New Scientist. "We expect it to improve further." (A little girl in the UK now has near-perfect hearing after gene therapy.)