A Breakthrough from Karolinska Institutet
Groundbreaking research from Karolinska Institutet, in collaboration with Chinese institutions, has demonstrated a significant breakthrough in reversing congenital deafness. A new gene therapy, delivered via a single injection, has shown dramatic results, restoring hearing within weeks in both children and adults.
Targeting the OTOF Gene
The study focused on a specific type of genetic deafness caused by mutations in the OTOF gene, which leads to a deficiency in the otoferlin protein essential for transmitting sound signals to the brain. Researchers utilized a synthetic adeno-associated virus (AAV) to deliver a functional copy of the OTOF gene directly into the inner ear through a single injection into the round window membrane at the base of the cochlea.
Rapid Recovery and Remarkable Results
The effects of this gene therapy were remarkably rapid, with most patients experiencing some hearing recovery within just one month. A six-month follow-up revealed considerable improvement in all ten participants, with the average volume of perceptible sound improving from 106 decibels (profound deafness) to 52 decibels. While all age groups benefited, younger patients, particularly those between five and eight years old, showed the most significant responses. One seven-year-old girl, for instance, regained almost full hearing and was able to engage in daily conversations within four months of the treatment.
Safety and Future Directions
Crucially, the treatment proved to be safe and well-tolerated, with no serious adverse reactions reported during the 6 to 12-month follow-up period. The most common side effect observed was a temporary reduction in neutrophils, a type of white blood cell.
This pioneering work represents a monumental step forward in the genetic treatment of deafness. Researchers at Karolinska Institutet emphasize that this is “just the beginning,” as they now aim to expand their work to target other, more common genes that cause various forms of deafness, such as GJB2 and TMC1. While these are more complex to treat, promising results in animal studies offer hope for future advancements.
