NAPLES, Italy — Nine of 11 children who were born profoundly deaf because of a single faulty gene can now hear well enough to follow a conversation, after a single injection into each inner ear delivered a working copy of the gene, doctors in Naples reported on Wednesday. Several of the children, who were between 1 and 7 years old at treatment, are now speaking.
The trial, published in The Lancet and led by a pediatric hospital here with partners in Milan and Tübingen, Germany, treated children with mutations in a gene called OTOF, which produces a protein that hair cells in the cochlea need to signal the auditory nerve. Without it, the ear’s machinery is intact but silent. The condition accounts for between 1 and 8 percent of congenital deafness, depending on the population, and until recently could be addressed only with cochlear implants.
“The implant replaces the ear with a machine. This repairs the ear,” said Francesca Esposito, the otolaryngologist who led the trial. “Within 26 weeks, nine children went from hearing nothing to hearing a voice at a normal distance in a quiet room. Two did not respond, and we are trying to understand why. But I have been doing this for 22 years, and I did not expect to see this before I retired.”
The therapy packages the gene into a harmless virus and infuses it through a membrane into the fluid of the cochlea during a 40-minute operation. The children were tested at intervals for a year; the nine responders reached hearing thresholds of 25 to 45 decibels across speech frequencies, within or near the normal range. Two of the youngest, treated before they were 2, have begun to speak in short sentences, the paper reports.
Rosaria Iovine’s daughter, Chiara, was treated at 3. “The first time she turned around when I said her name, I did not believe it, so I said it again. Then I said it maybe 100 times,” Ms. Iovine said. “Now she tells me to stop talking.”
The results are consistent with smaller trials in China and the United States, but the Naples study is the largest in Europe and the first to include children as old as 7, which bears on a long-standing question of whether the brain can learn to process sound after years of silence. The two oldest responders, both 6 at treatment, made slower progress but can now hear speech, the authors wrote.
Dieter Hagemann, a professor of hearing research at the University of Tübingen who collaborated on the trial, cautioned that OTOF deafness was a narrow target. “Most inherited deafness involves genes that are much larger or that damage the hair cells themselves. Those are harder,” he said. “But this is proof that the door opens.”
Dr. Esposito said the next trial, enrolling 30 children across four countries, would begin in the spring. A price for the therapy has not been set. Ms. Iovine has one. “Whatever it is,” she said, “it is less than it is worth.”
A version of this article appears in print on Oct. 12, 2026, Section A, Page 9 of the European edition with the headline: Gene Therapy Restores Hearing in 9 of 11 Children Born Deaf, Italian Trial Reports.
