Chinese scientists have claimed some children in the country who were born entirely deaf are now able to hear after undergoing a breakthrough gene therapy trial.
The deaf children’s inner ears were fitted with an implant of a harmless virus carrying a new genetic code, the journal Science reported.
Researchers from Fudan University in China claimed the experimental treatment has led to four out of five children being able to hear.
The children who were part of the trial were born deaf.
They had inherited two defective copies of a gene which helps the body make a protein that gives hair cells of inner ears the ability to transmit sounds to the brain, according to The MIT Technology Review.
In accompanying video footage, the report shows a six-year-old child from the trial chatting with her mother after removing her cochlear implant.
Deafness related to this particular protein – Otoferlin (Otof) – is very rare and causes only 1-3 per cent of cases of inherited deafness.
Estimates suggest about 20,000 people across the US and EU, including UK, Germany, France, Spain and Italy, may have auditory neuropathy due to malfunctioning versions of the Otof protein.
Doctors and psychologists have noted that children with hearing loss face barriers in developing communication skills and may miss developmental milestones if the right support is not provided from the start.
Researchers said the recent trial results offer further hope for future treatment for those with hearing impairment since birth.
There are currently a number of trials attempting to treat inherited deafness with gene therapy.
Addenbrooke’s Hospital in Cambridge is participating in a world-first trial to see whether gene therapy can provide hearing for children with severe to profound inherited hearing loss.
“Children with a variation in the Otof gene are born with severe to profound hearing loss, but they often pass the new-born hearing screening so everyone thinks they can hear,” Manohar Bance, an ear surgeon at Cambridge University Hospitals, said in a statement.
“The hair cells are working, but they are not talking to the nerve,” Dr Bance said.
“Gene therapy for otoferlin deficiency is the right starting point for young children because it’s among – if not the most – simple approaches for treating hearing loss; everything else should be intact and working normally.”
If proven widely successful for treating hearing loss due to defective Otof genes, gene therapy treatments can offer hope for hearing loss caused by other more common genetic conditions.
“It’s really important that we get the first gene therapy treatment right because it will allow us to proceed to treating other genetic conditions,” Dr Bance said.
