His father’s voice, the roar of cars, the sound of scissors cutting his hair… Aissam Dam, an 11-year-old boy, hears “for the first time in his life”, after a genetical therapy unprecedented, a hospital in Philadelphia, in the United States, announced on Tuesday.
This achievement, a first in the country, represents hope for patients around the world suffering from hearing loss caused by genetic mutations, said in a press release the Children’s Hospital of Philadelphia (CHOP), which carried out the treatment.
Aissam Dam was born “profoundly deaf” due to a very rare anomaly, present in a single gene.
“Gene therapy for hearing loss is a goal that we, as hearing loss doctors and scientists, have pursued for more than 20 years. And we’re finally there,” said surgeon John Germiller, director of clinical research in the Division of Otolaryngology (ENT).
“Correct a gene abnormality”
“The gene therapy we applied to our patient aimed to correct the abnormality of a very rare gene, but these studies could pave the way for future use for more than 150 other genes responsible for hearing loss in children “, he rejoiced in the press release.
In patients like Aissam Dam, a defective gene prevents the production of otoferlin, a protein needed by hair cells in the inner ear to convert sound vibrations into chemical signals sent to the brain. Abnormalities of the otoferlin gene are very rare and represent between 1 and 8% of cases of hearing loss at birth.
On October 4, 2023, the boy underwent surgery that partially raised his eardrum and then injected the internal fluid of his cochlea with a harmless virus that had been modified to carry working copies of the otoferlin gene.
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The hair cells then began to produce the missing protein. Almost four months later, Aissam’s hearing has improved to the point where he now has only mild to moderate hearing loss. “There isn’t a sound I don’t like,” Aissam rejoiced to the New York Times, with the help of interpreters, during an interview last week. “They are all good. »
Born in Morocco before moving to Spain with his family, Aissam may never be able to speak, however, as the part of the brain intended for speech acquisition shuts down around the age of five, reports the New York Times. Other similar studies with children are underway or about to begin in the United States, Europe and China, some of which have been successful.