Aissam Dam, 11 years old, the son of a Moroccan family who emigrated to Barcelona, has regained his hearing thanks to gene therapy experimented in the USA. The researchers responsible for the clinical trial, conducted at the Children's Hospital of Philadelphia, could not guarantee that the treatment would work against the type of congenital deafness the little boy suffered; and if so, neither is the extent of hearing restoration that would be achieved.
Aissam, who was deaf from birth due to a condition that affects only 200,000 people worldwide, heard the first words of his life in a language that was foreign to those around him. They were not fluent in his family's native Amazigh or Berber language, nor in Spanish or Catalan, which were spoken in the place where they now live. The sign language used in the United States also does not resemble the Spanish sign language he learned in the special school in Barcelona where he was enrolled for the first time in his life after coming to the city from Morocco. After moving to Barcelona three years ago, his family went to an ENT doctor who deemed Aissam suitable for the clinical trial and recommended him for it.
This Tuesday reported the New York Times, which, with the help of interpreters, managed to speak with the boy and his father, a construction worker. Unlike disabling forms of deafness, Aissam deafness is extremely rare and is caused by a mutation in a single gene, otoferlin. The aim of gene therapy is to replace the mutated or defective otoferlin gene in the patient's ear with a functional gene.
The clinical trial's success opens the door to new gene therapies targeting other forms of congenital deafness, including in younger patients, although researchers at the Philadelphia hospital warn that process could take years. On October 4, Aissam became the first person in the United States to receive gene therapy for congenital deafness. The trial, one of five underway (the others are being conducted in China and Europe) or nearing launch, is funded by the pharmaceutical company Eli Lilly and Akouos, a small biotechnology company it owns. The researchers hope to expand the study to six centers in the United States.
Researchers from the five ongoing studies will present their conclusions at a meeting of the Otolaryngology Research Association on February 3, explains The New York Times. Experts say these tests represent a new frontier for gene therapy, which previously had not focused particular attention on hearing loss. “There has never been a biological, medical or surgical way to correct the underlying biological changes that cause the inner ear to stop functioning,” said University of California otolaryngologist Dylan K. Chan, who did not attend Newspaper was involved in the clinical trial, as a result of which the child's hearing was restored.
Although otoferlin mutations are not the most common cause of congenital deafness, there is a reason why so many researchers have focused on them. According to John A. Germiller, an otolaryngologist who led the hospital study in Philadelphia, this form of congenital deafness was the most accessible. The mutated otoferlin gene destroys a protein in the hair cells of the inner ear that is necessary for sound transmission to the brain. In many other mutations that cause deafness, the hair cells die in infancy or even the fetal period. But in otoferlin deafness, hair cells can survive for years, giving time to replace the defective gene with gene therapy. It uses a harmless virus that carries new otoferlin genes in two drops of liquid that are carefully injected along the cochlea and deliver the genes to each hair cell.
Until his family arrived in Barcelona, Aissam had not gone to school. He grew up in a poor city surrounded by complete silence and expressed himself through a sign language he invented that allowed him to communicate with those around him. After moving to Spain, he was educated at a special school for children with hearing impairments, where he learned sign language in Spanish. When Aissam was eligible to be Patient No. 1 in the clinical trial, Lilly and Akouos paid for him and his father to stay in Philadelphia for four months while he underwent treatment. A treatment that will allow you to hear the first sounds of your life – the first words, even the first music or even the annoying traffic noise – in silence, thousands of kilometers away from your life.
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