Many people experience age-related hearing loss. In fact, it is estimated that one in three adults between the ages of 65 and 75 suffer from age-related hearing loss, and almost half of adults over the age of 75 have difficulty hearing.
Some factors that contribute to age-related hearing loss are well known, such as exposure to repeated loud noises. Other factors are less commonly known, such as using certain medications and drugs that can contribute to age-related hearing loss.
Researchers at the University of Virginia School of Medicine, however, have identified a new factor that may potentially contribute to age-related hearing loss. This newly discovered factor has nothing to do with loud noises or medications.
Instead, this contributor to age-related hearing loss is all about a person’s genes. In the study, Jung-Bum Shin, PhD, from the University of Virginia’s Department of Neuroscience, focused on a specific structure in the inner ear: the cuticular plate. The study was conducted by researchers at the University of Virginia, working with other laboratories at UVA, the National Institutes of Health, and Stanford University.
Within the inner ear are auditory receptors called hair cells. The hair cells pick up sounds using a vibration-sensing antenna, known as the hair bundle. The hair bundle is supported by a foundation: the cuticular plate. Shin explains, “We find that it [the cuticular plate] is important for the ability of the hair cells to detect sound but also for the overall vibrations that happen in the cochlea. Defects in this cuticular plate appear to lead to progressive hearing loss.”
Shin and the team of researchers at the University of Virginia not only found that the cuticular plate is essential to hearing; they also discovered that a specific gene is linked to the proper structure and function of the cuticular plate. Researchers found that in mice, gene Lmo7 is key to the plate’s long-term stability and function. When researchers blocked the effects of gene Lmo7, the mice developed age-related hearing loss over time. It appears that the gene contributes to the structure of the cuticular plate, and when the gene is blocked, the stability and function of the plate gradually deteriorate and lead to age-related hearing loss.
You might be wondering how a gene found in mice can relate to age-related hearing loss in humans. However, gene Lmo7 is found in all vertebrates, including humans; therefore, the researchers believe their findings can be applied to humans as well as mice. This means that mutations or defects in the gene Lmo7 may contribute to age-related hearing loss in humans.
Shin and the researchers acknowledge that other genes may play a part in age-related hearing loss as well. They also understand that many factors contribute to age-related hearing loss. However, they remain optimistic that their research will prove helpful. For instance, Shin believes that genetic screening may be used one day to determine a person’s genetic predisposition to age-related hearing loss. If a person finds that they carry genetic risk factors for age-related hearing loss, they could ensure that they receive proper hearing testing and treatment as they age.
If you have any questions about the causes of age-related hearing loss, or if you believe that you or a loved one may have developed age-related hearing loss, we encourage you to contact our audiologist office today. We look forward to caring for you.