Extremely rare gene variants point to a potential cause of age-related macular degeneration

Monday, April 3, 2023

A study from the National Eye Institute (NEI) identified rare genetic variants that could point to one of the general mechanisms driving age-related macular degeneration (AMD), a common cause of vision loss in older adults. The variants generate malformed proteins that alter the stability of the membrane attack complex (MAC), which may drive a chronic inflammatory response in the retina. The findings, published in the journal iScience, point to MAC as a potential therapeutic target to slow or prevent the development of AMD. NEI is part of the National Institutes of Health.

There are many known genetic variants that raise or lower an individual’s risk of getting AMD; however, the contribution of each of these genetic changes to AMD is small.

To discover genetic variants — and proteins — with a direct tie to the disease, Anand Swaroop, Ph.D., chief of NEI’s Neurobiology, Neurodegeneration and Repair Laboratory, and lead author of the study, undertook a collaboration with Michael Klein, M.D., a leading AMD clinician at the Oregon Health Sciences University (OHSU), Portland. Klein has collected clinical information for hundreds of patients, as well as families with a high number of individuals with AMD. Swaroop, Klein and colleagues looked for families carrying very rare AMD-causing variants, where the effect of the gene variant is very strong, and where the variant directly affects protein structure and function. This type of rare variant can reveal the root cause of disease.