A new study has found an approach to treating hereditary deafness. The study was conducted on mice, and researchers say the findings merit further research in the hope of translating them into clinical trials in humans.
The study was conducted by researchers led by Dr. Cheng-Yi Chen from Eaton-Peabody Laboratories in the United States, and was published in the journal Science Translational Medicine this month, and was written about by the EurekAlert website.
“Our findings provide a promising avenue for developing treatments to modify many forms of hereditary hearing loss,” said Chen, an associate professor of otolaryngology-head and neck surgery at Harvard Medical School.
“With further study, our intervention using genome editing could halt or reverse the progression of hearing loss in affected individuals, including adults,” he added.
About one in 500 newborns has congenital hearing loss, and there are currently no approved treatments to treat deafness.
In the new study, the researchers targeted a specific mutation in a gene called microRNA-96 (miR-96) that causes progressive hearing loss in mice and plays a critical role in regulating gene expression in hair cells (the sensory cells responsible for hearing) of mammals.
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In humans, this mutation has been identified as the cause of a form of autosomal dominant progressive hearing loss called DFNA50.
The researchers created a mouse model carrying a mutation that mirrors the progressive hearing loss seen in humans with DFNA50; by four weeks of age, these models showed complete loss of high-frequency hearing.
The team used the CRISPR/Cas9 genome editing approach to target and disable this mutation, which was delivered to the inner ear by injecting a virus carrying the editing mechanism. They compared injections at two time points during early development and adulthood, and showed strong preservation of hearing function in both cases over the long term, with early intervention proving optimal.
This latest research by Chen and colleagues represents an important step forward in the field of gene therapy for hearing disorders, offering hope for future clinical trials aimed at restoring auditory function in people with genetic forms of hearing loss.
More hope
“With more than 150 forms of hereditary deafness, our research offers more hope for patients who previously lacked any options other than cochlear implants,” Chen said.
“These results indicate the need for proof-of-concept studies to achieve our goal of developing different therapeutic approaches to target each of these mutations,” he added.