Gene Therapy Shows Lasting Results for Inherited Deafness
An experimental gene therapy has demonstrated durable hearing improvements in people with an inherited form of deafness, according to a new study published in Nature. The treatment, which targets mutations in the OTOF gene, restored hearing in both children and adults, with over half of participants achieving normal hearing levels after two and a half years.
How the Therapy Works
The therapy corrects mutations in the OTOF gene, one of approximately 200 genes known to cause congenital deafness. Babies with OTOF mutations are born completely deaf, which can impair speech acquisition and cognitive development. By delivering a functional copy of the gene, the treatment enables the production of otoferlin, a protein essential for transmitting sound signals from the inner ear to the brain.
Study Results and Outcomes
In the largest and longest study to date evaluating gene therapy for hearing loss, 90 percent of recipients experienced improved hearing. By the study’s end at 2½ years, more than half of the participants reached normal hearing levels—defined as the ability to hear a whisper. Patients aged 18 and younger showed the strongest gains in both hearing and speech recognition, though adults also experienced measurable improvements.
“The results are really remarkable,” said Zheng-Yi Chen, an associate scientist at Mass Eye and Ear in Boston who led the study. “After 2½ years, more than half of them reached a normal level. They can hear a whisper. At that level, it’s better than mine.”
Broader Implications and Future Research
Worldwide, about 430 million people live with disabling hearing loss, including 34 million children, according to the World Health Organization. Genetic factors account for 60 percent of deafness in newborns, with OTOF mutations responsible for 2 to 8 percent of these cases.
Researchers believe the success of this OTOF-targeted approach could pave the way for treatments targeting other genetic causes of hearing loss. Teams are already adapting the platform to address mutations in the GJB2 gene, the most common cause of genetic hearing loss.
The progress has also spurred increased interest in newborn screening for genetic deafness, enabling earlier intervention when treatment is most effective.
Conclusion
This gene therapy represents a significant step toward the first approved treatment for genetic hearing loss. With durable results and a strong safety profile, it offers hope for children born with OTOF-related deafness and lays the groundwork for future therapies targeting other forms of inherited hearing impairment.