Could genetic hearing loss no longer be a life sentence?
Scientists have made a groundbreaking discovery in treating genetic hearing loss. Using gene editing techniques, researchers have successfully restored hearing in adult mice with inherited deafness.
Why it matters
This study is the first instance of gene editing successfully treating hearing loss in adult animals, raising the possibility of a similar approach for treating humans.
“We thought that if we could show we could treat deafness in a fully mature mouse model, we might increase the likelihood it would work in humans.” —Dr. Zheng-Yi Chen, Mas Eye and Ear, Boston
The big picture
Led by Dr. Zheng-Yi Chen at Mass Eye and Ear in Boston, the study focused on a rare type of genetic deafness, autosomal dominant deafness-50 (DFNA50). People with this condition typically develop hearing loss in their teens.
How it works
- Researchers targeted a specific mutation in the MIR96 gene using CRISPR/Cas9 gene editing
- The treatment was delivered to inner ear hair cells using a virus
- Gene editing "turned off" the mutation in the MIR96 gene, allowing the normal gene to function
A closer look
- The gene editing treatment was tested on both newborn and adult mice
- Hearing was restored in both groups, with earlier intervention showing better results
- The effects lasted for at least nine months
- There were no negative side effects
"Gene editing is useful for this type of genetic deafness because only one gene copy mutation is needed to prevent the entire gene from working properly and causing disease. Using gene editing techniques, we prevented the mutation’s effects, essentially eliminating the bad gene copy. The normal gene copy continues to work, and this restores function to the gene. —[Dr. Zheng-Yi Chen]
Next up
The researchers emphasized the need for further preclinical tests in different animal models to ensure safety and efficacy. They must also refine the method to ensure it targets the correct cells in the human inner ear.
The takeaway
Dr. Chen and his team have not only demonstrated the possibility of gene editing for treating adult-onset hearing loss but also developed a method that could potentially address multiple forms of hearing loss.
