Gene Therapy Restores Hearing in Deaf Children.

A groundbreaking gene therapy trial at Fudan University in Shanghai has given five deaf children, aged between one and 11, the ability to hear in both ears. Before the treatment, these children could not hear due to genetic mutations that prevent the production of a crucial protein needed for hearing.

The trial, involving an inactive virus delivering copies of the gene Otof, showed remarkable results. Within weeks of treatment, the children were able to locate sound sources, understand speech in noisy environments, and even respond to music.

The therapy, described as “astounding” by Dr Zheng-Yi Chen of Massachusetts Eye and Ear, involves a minimally invasive procedure where the gene is delivered directly into the inner ear, allowing it to produce the necessary protein, otoferlin. Children responded positively and very quickly; a two-year-old boy could react to his name and dance to music within three months of treatment.

This trial is significant as it demonstrates the potential for gene therapy to treat bilateral hearing loss, enabling children to hear and precisely locate where sounds are coming from, an essential ability for daily activities like crossing the street or participating in conversations—the successful bilateral treatment followed earlier positive outcomes from unilateral treatment, reinforcing the potential of this approach.

Globally, over 430 million people have disabling hearing loss, with a significant portion being congenital due to genetic factors. The DFNB9 condition, caused by mutations in the Otof gene, represents a substantial percentage of congenital hearing losses. This trial’s success opens doors to potentially treating various genetic and even non-genetic hearing loss types.

Further research and more extensive trials are necessary to understand this therapy’s benefits and risks fully. The team aims to explore this treatment for other forms of deafness and refine the approach to ensure safety, particularly concerning immune reactions to the viral delivery system.

This development marks a promising new era in treating deafness, offering hope that future advancements may allow even more individuals to regain hearing.

By Ian Sample, Science editor for The Guardian.