Gene Therapy Trial Enables 5 Deaf Children to Hear

A groundbreaking clinical trial utilizing gene therapy has successfully restored hearing in five children who were born deaf. Within six months, these children regained the ability to recognize speech and engage in conversations, sparking optimism for broader application in the near future.

The participants in the trial were afflicted with autosomal recessive deafness 9 (DFNB9), a genetic condition stemming from a mutation in the OTOF gene. This gene is responsible for producing the otoferlin protein, essential for transmitting electrical pulses from the cochlea to the brain, where they are interpreted as sound. In the absence of this protein, these signals fail to reach the brain. Due to its singular mutation nature and the absence of physical cell damage, the research team deems DFNB9 an ideal candidate for this type of gene therapy.

Gene Therapy’s Intricate Process in Restoring Otoferlin Protein

The gene therapy procedure entails encapsulating the OTOF gene within viral carriers, which are then injected into the inner ear fluid. Subsequently, the viruses locate cells in the cochlea, introducing the gene to enable these cells to produce the lacking otoferlin protein, thereby restoring hearing.

Conducted in China, the study involved collaboration among researchers from Harvard Medical School, Massachusetts Eye and Ear, and Fudan University. The six participants, aged one to seven years old, all suffered from complete deafness due to DFNB9. Despite having cochlear implants, which typically help individuals recognize speech and other sounds, the implants were deactivated for this study.

Throughout the 26-week follow-up period post-gene therapy, five out of six participants exhibited notable improvements. The three older children could comprehend and respond to speech, while two could discern it in noisy environments and engage in phone conversations. Although some of the younger children were too small for standard tests, they demonstrated responsiveness to sounds and even began uttering basic words like “mama.” The progress was gradual, with improvements evident before the initial test at the four-week mark.

Yilai Shu’s Heartwarming Encounter with Initial Responses to Restored Hearing

Yilai Shu, the senior author of the study, shared an anecdote: “We first found out when the parents told us: When her mother called her, she turned back. All of them are very hopeful. They were very, very excited, and all of them cried when they first found that their child can hear.”

Regrettably, one participant did not respond to the treatment. While the precise cause remains uncertain, researchers suspect an immune reaction disrupted the viral vector. Further investigation may offer insights into overcoming this challenge.

The researchers indicate ongoing monitoring for participants in this trial, with additional studies planned for different individuals. The team estimates that approval for the treatment in the United States might be three to five years away. Similar gene therapies have undergone testing for hearing loss attributed to genetic or age-related factors.

Read the original article on: New Atlas

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