Born deaf, child hears for the very first time thanks to gene therapy

Born deaf, child hears for the very first time thanks to gene therapy

Thanks to a clinical trial carried out in the United States, Aissam Dam, an 11-year-old boy born profoundly deaf, can now hear his parents’ voices and his entire environment. A global success bringing hope for patients suffering from hearing loss caused by genetic mutations.

Aissam Dam, an 11-year-old Moroccan boy, can now hear his parents’ voices, the wind in the trees, the television… Ordinary sounds? Not for Aissam who was profoundly deaf from birth due to a rare gene abnormality. But a clinical trial with gene therapy carried out by Akouos has now restored his hearing.

Carrying a missing protein into the faulty eardrum

Aissam Dam’s disability is quite rare: it is linked to a defective gene that prevents the production of otoferlin, a protein necessary for hair cells in the inner ear to convert sound vibrations into chemical signals sent to the brain. But a year ago, Aissam’s parents, then living in Spain, received a call: their son was eligible for a clinical trial of gene therapy in the United States.

So on October 4, 2023, the boy underwent surgery at Children’s Hospital of Philadelphia that involved partially lifting his eardrum and then injecting the internal fluid of his cochlea with a harmless virus that had been modified to carry functional copies of the otoferlin gene. Successfully: the hair cells then began to produce the missing protein.

Three and a half months after the procedure, Aissam’s hearing improved significantly. He can hear, and now has only mild to moderate hearing loss. On the other hand, the boy may never be able to speak: the part of the brain intended for the acquisition of speech closes around the age of five, indicates the New York Times.

Gene therapy, a growing hope

However, the feat is almost incredible and represents real hope for all people affected by genetic deafness.

“Gene therapy for hearing loss is a goal that we, as hearing loss doctors and scientists, have pursued for over twenty years. And we finally got there”said surgeon John Germiller, director of clinical research in the division of otolaryngology (ENT).

Abnormalities of the otoferlin gene are in fact very rare, accounting for around 1 to 8% of birth deafness cases. Today the usual treatment for this deafness is bilateral cochlear implantation. But other targeted genes could indeed benefit from the progress of this clinical trial: 150 other genes are currently responsible for hearing loss in children.

“As more patients of different ages are treated with this gene therapy, researchers will learn more about the degree of hearing improvement and whether this level of hearing can be maintained for many years “ predicted the surgeon.

There is hope, especially since the hospital is not the only one working on this anomaly: other similar studies with children are underway or about to begin in the United States, Europe and China.

In Europe, a clinical trial called Audiogene was launched to test a gene therapy drug, SENS-501, developed by Biotech Sensorion, to treat hereditary deafness in children, known as DFNB9, due to mutations in the OTOF gene which It also encodes the protein called otoferlin.