Photo credit: Lukas
by Daniel Fink, MD, Chair, The Quiet Coalition
The Fierce Biotech website reported that the biotech company Regeneron has a new gene therapy that restored hearing in 11 of 12 children born with a rare congenital genetic form of deafness. The children had a defect in the otoferlin gene, which provides instructions for protein that is essential for hearing. The results were reported at a meeting of the Association for Research in Otolaryngology.
Genetics are an important cause of hearing loss in children, which is great news for children born with this kind of congenital deafness. The goal of those doing research in treating hearing loss, though, is to develop a treatment for the much more common form of hearing loss, what is commonly known as presbycusis or age-related hearing loss. It’s not clear if Regeneron’s new gene therapy would work for age-related hearing loss, but even if it did, administering the gene therapy isn’t as simple as taking a pill or getting an injection or infusion over several hours. Gene therapy for hearing loss requires a major surgical procedure to inject the new gene directly into the cochlea, where the hair cells that allow us to hear are located. The cochlea is protected by the temporal bone, a dense piece of the skull. Widespread use of gene therapy to treat hearing loss in the general population just doesn’t seem feasible for cost and safety reasons.
There are many genes associated with hearing loss in adults but as of yet, no genome-wide association studies showing what percent of age-related hearing loss has a genetic origin. I am convinced, though, that hearing loss is not part of normal physiological aging and that presbycusis or age-related hearing loss is really noise-induced hearing loss*.
Prevention of noise-induced hearing loss is simple and inexpensive. If it sounds loud, it’s too loud and one’s auditory health is at risk. Turn down the volume, leave the noisy environment or use hearing protection and one’s ears should last a lifetime.
*Noise-induced auditory disorders include hearing loss, tinnitus (ringing in the ears) and hyperacusis (a sensitivity to noise that doesn’t bother others). There are thousands of studies in humans and animals about the noise exposure levels that will cause noise-induced hearing loss, but as best as I can tell none delineating the noise exposure levels causing tinnitus or hyperacusis. Most experts think that if one avoids loud noise, that will also prevent tinnitus and hyperacusis.
