In a landmark study hailing from Fudan, China, a team of researchers has reached a pivotal breakthrough in gene therapy, granting the gift of hearing to five congenitally deaf children. As Harvard Gazette reports, The children aged between 1 and 7, suffered from a mutation in the OTOF gene, which left untreated, translates to complete deafness.
The collaborative effort by Zheng-Yi Chen of the Massachusetts Eye and Ear Infirmary and Harvard Medical School, and colleagues at Fudan University's Eye & ENT Hospital, involved a 26-week trial where the novel approach underwent a critical test. Five of the six children involved displayed an increasingly effective improvement in hearing, and critically in speech perception, said Chen, according to the publication. However, one of the six participants showed no improvement, an outcome that perplexes the team.
Deafness affects millions worldwide, with about 30 million children grappling with genetic hearing impairments. The condition, DFNB9, is characterized by a single genetic mutation with no damage to the cochlear cells, making it an ideal target for gene therapy. Before the trial, researchers faced the challenge of the gene's size being too large for the standard viral vector used in gene therapy. Their solution: split the gene into two parts, deliver them individually, and let the cellular machinery do the rest, as explained in the Harvard Gazette.
"This really opens the door to developing other treatments for different kinds of genetic deafness," Chen told the Harvard Gazette. The impact was evident as four of the five responsive children, despite having cochlear implants turned off, could understand and respond to speech within 26 weeks. The parents, noticing improvements even before official testings could begin, were reportedly moved to tears upon witnessing their children respond to auditory stimuli for the first time.
Conducted in December 2022, this groundbreaking study marks a significant stride forward in gene therapy treatments. The research, funded by multiple Chinese science and health agencies, not only represents a leap in battling congenital deafness but serves as a prototype for similar genetic conditions. The team is set to continue monitoring the participants, as well as commence a new study that includes a more diverse demographic with an eye on potential U.S. federal approval in the next few years, according to Yilai Shu, a researcher involved in the study.
