Gene Therapy Breakthrough: Children with Inherited Deafness Hear for the First Time

In a remarkable medical breakthrough, gene therapy has enabled several children born with inherited deafness to hear, marking a new era in the treatment of genetic hearing loss. Recent studies, including one published in 'The Lancet' on Wednesday, have shown significant hearing restoration in children treated in China and at the Children's Hospital of Philadelphia.

These experimental therapies currently focus on a rare condition caused by mutations in the otoferlin gene, accounting for 2% to 8% of inherited deafness cases. This gene is crucial for transmitting sound from the inner ear's hair cells to the brain. The treatment involves a one-time delivery of a functional copy of the gene directly to the inner ear.

So far, the results are promising. In one instance, a baby who previously couldn't hear responded to sounds just six weeks post-treatment. Another child began repeating words 13 weeks after therapy. While one patient in the study did not respond to treatment, the others, who had complete deafness before, can now hear and engage in regular conversations.

Zheng-Yi Chen of Boston's Mass Eye and Ear, a senior author of the study, expressed excitement about the results, emphasizing the absence of major side effects and an estimated hearing improvement to about 60% to 70% of normal levels.

Other preliminary results have been equally encouraging. Regeneron Pharmaceuticals and Decibel Therapeutics reported hearing improvements in a child under two, and the Children's Hospital of Philadelphia shared a similar success story. However, the level of hearing restoration varies, with some children experiencing muffled sounds similar to wearing foam earplugs.

These advancements in gene therapy for deafness are significant in a field where 34 million children globally suffer from deafness or hearing loss, with genes responsible for up to 60% of cases. However, the approach also raises ethical concerns. Teresa Blankmeyer Burke, a deaf philosophy professor and bioethicist, highlighted the need for dialogue with the deaf community, as some view gene therapy for deafness as a potential threat to the flourishing of signing Deaf communities.

Despite these concerns, researchers are optimistic about the future of gene therapy in treating hereditary deafness. As the field progresses, this groundbreaking research not only opens new therapeutic avenues but also ignites debates on the broader implications of genetic interventions in the deaf community.