An 11-year-old boy heard his father’s voice or the sound of cars “for the first time in his life” after a new gene therapy, a hospital in the North American city of Philadelphia said Tuesday.
This therapy, unprecedented in the United States, offers hope for patients around the world suffering from hearing loss caused by genetic mutations, explained a press release from Children’s Hospital of Philadelphia (CHOP), which provided the treatment.
Aissam Dame was born “profoundly deaf” due to a very rare abnormality in one gene.
“Gene therapy for hearing loss is a goal that we as hearing loss physicians and scientists have been pursuing for more than 20 years. And we have finally achieved our goal,” said surgeon John Germiller, director of clinical research in the field of otolaryngology, quoted in the press release.
The treatment given to the child was “aimed at correcting an abnormality in a very rare gene, but these studies could pave the way for the future use of more than 150 other genes involved in hearing loss in children.”
In patients like Aissam Dam, the 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 account for 01 to 08% of cases of hearing loss at birth.
On October 4, 2023, the boy underwent surgery: the eardrum was partially tightened, and then a harmless virus, modified to carry functional copies of the otoferlin gene, was injected into the internal fluid of the cochlea.
The hair cells then began producing the missing protein.
Nearly four months later, Aissam’s hearing has improved to the point where he now has only mild to moderate hearing loss.
Aissam, who was born in Morocco and then moved to Spain with his family, may never be able to speak because the part of the brain responsible for language acquisition “switches off” around the age of five, the New York Times reports.
Other similar studies with children are underway or about to begin in the US, Europe and China, some of which have been successful.