Single Injection Restores Hearing in All Ten Patients in Gene Therapy Trial for Congenital Deafness

A single gene therapy injection restored hearing in all ten patients in a multi-hospital trial published in Nature Medicine, with average hearing thresholds improving from 106 decibels to 52.

Single Injection Restores Hearing in All Ten Patients in Gene Therapy Trial for Congenital Deafness A single gene therapy injection restored hearing in all ten patients in a multi-hospital trial published in Nature Medicine, with average hearing thresholds improving from 106 decibels to 52. Aaron Rafferty April 12, 2026 Key Takeaways: A multi-center clinical trial led by researchers at Karolinska Institutet and hospitals in China delivered hearing improvements in all ten patients treated with a single AAV-OTOF gene therapy injection, with results published in Nature Medicine. Participants, aged 1 to 24 years old with autosomal recessive deafness 9 (DFNB9) caused by OTOF gene mutations, saw average hearing thresholds improve from 106 decibels to 52 decibels at six-month follow-up, moving most from profound deafness to moderate hearing loss. Most patients recovered some hearing within one month. A seven-year-old girl regained nearly full hearing and was having daily conversations with her mother four months after treatment. The study, published in Nature Medicine and covered by ScienceDaily on April 3 , enrolled ten patients between ages 1 and 24 at five hospitals in China. All had a genetic form of deafness or severe hearing impairment caused by mutations in the OTOF gene, which produces a protein called otoferlin that is critical for transmitting auditory signals from the ear to the brain. Researchers used a synthetic adeno-associated virus (AAV) vector to deliver a functional copy of the OTOF gene through a single injection at the round window at the base of the cochlea. The procedure is minimally invasive. "This is a huge step forward in the genetic treatment of deafness, one that can be life-changing for children and adults," said Maoli Duan , consultant and docent a