Researchers identified 48 genes that are associated with hearing loss, including 10 new variants.
Hearing loss is a common problem caused by noise, age, disease, and genetics. While using ear protection can help prevent hearing loss due to noise, you may think there is nothing you can do when the cause is age and genetics. However, scientists are working on developing new medicines and gene therapies for these conditions.
Research shows that one in eight people in the United States (13%, or 30 million) aged 12 years or older has hearing loss in both ears, based on standard hearing examinations. Conversations with friends and family can be difficult for those with hearing loss. They may also have difficulty understanding medical advice, reacting to warnings, and hearing doorbells and alarms.
Scientists from King’s College London, the Karolinska Institute, and Erasmus University have recently discovered ten additional genes connected to hearing loss, and located the part of the ear affected.
The results, which were published in the American Journal of Human Genetics on May 16th, 2022, put doubt on the notion that age-related hearing loss is primarily caused by sensory hair cells. The stria vascularis, a region of the cochlea in the ear, is a new target for medicines to aid patients with hearing loss, according to researchers.
As people grow older, they lose part of their hearing capacity, and by 2050, an estimated 2.4 billion people will have some sort of hearing loss. Hearing loss as people become older is a major contributor to the number of years they spend being disabled, and it’s also a major risk factor for dementia.
The team studied genetic analyses previously carried out in centers around the world using samples from 723,266 people from 17 studies who had clinically diagnosed or self-reported hearing impairment. This meta-analysis is one of the largest conducted in hearing genetics to date. The researchers identified 48 genes linked to hearing loss, including 10 new variants newly linked to hearing.
Further analysis looking at mouse genetics indicated that age-related hearing loss is due to changes in the stria vascularis which is necessary for hearing. The results provide targets for the basis of future research which could improve therapies against hearing loss.
Co-main author Frances Williams, Professor at King’s College London, said: “Our findings identify 10 genes newly linked with hearing loss. This study points to genes we could target for screening purposes, drug development, and even gene therapy in the future. This study provides a solid foundation for ultimately improving therapies against hearing loss.”
Co-main author Christopher R. Cederroth, Associate Professor at the Karolinska Institute, said: “It was hypothesized since the 1970s that the stria vascularis may play a role in hearing loss in humans, but the molecular evidence for this was missing until today.”
Reference: “Genome-wide association meta-analysis identifies 48 risk variants and highlights the role of the stria vascularis in hearing loss” by Natalia Trpchevska, Maxim B. Freidin, Linda Broer, Berthe C. Oosterloo, Shuyang Yao, Yitian Zhou, Barbara Vona, Charles Bishop, Argyro Bizaki-Vallaskangas, Barbara Canlon, Fabio Castellana, Daniel I. Chasman, Stacey Cherny, Kaare Christensen, Maria Pina Concas, Adolfo Correa, Ran Elkon, Estonian Biobank Research Team, Jonas Mengel-From, Yan Gao, Anne B.S. Giersch, Giorgia Girotto, Alexander Gudjonsson, Vilmundur Gudnason, Nancy L. Heard-Costa, Ronna Hertzano, Jacob v.B. Hjelmborg, Jens Hjerling-Leffler, Howard J. Hoffman, Jaakko Kaprio, Johannes Kettunen, Kristi Krebs, Anna K. Kähler, Francois Lallemend, Lenore J. Launer, I-Min Lee, Hampton Leonard, Chuan-Ming Li, Hubert Lowenheim, Patrik K.E. Magnusson, Joyce van Meurs, Lili Milani, Cynthia C. Morton, Antti Mäkitie, Mike A. Nalls, Giuseppe Giovanni Nardone, Marianne Nygaard, Teemu Palviainen, Sheila Pratt, Nicola Quaranta, Joel Rämö, Elmo Saarentaus, Rodolfo Sardone, Claudia L. Satizabal, John M. Schweinfurth, Sudha Seshadri, Eric Shiroma, Eldad Shulman, Eleanor Simonsick, Christopher Spankovich, Anke Tropitzsch, Volker M. Lauschke, Patrick F. Sullivan, Andre Goedegebure, Christopher R. Cederroth, Frances M.K. Williams and Andries Paul Nagtegaal, 16 May 2022, American Journal of Human Genetics.