NIH-backed study reveals genetic links to age-related macular degeneration
AMD reduces visual acuity in victims by compromising the retinal photoreceptors, which are light-sensitive cells located at the back of the eye. Most notably, this occurs in the macula, the part of the retina that controls vision sharpness for tasks such as reading, driving and other daily activities.
Involving individuals worldwide, the study identified additional genetic factors, increasing the known number of genome regions, or loci, from 21 to 34 after analyzing data from 43,566 people of mostly European ancestry. It was performed by the International AMD Genomics Consortium.
“The investigation is akin to looking at a Google map of the United States and attempting to pinpoint several leaders and satellite operations in a crime syndicate,” National Eye Institute’s Anand Swaroop, co-leader of the study, said. “It’s possible to find the key players by zooming in … but first you have to know where to look. Pooling the genetic information from such a large population is what allowed us to look across the genome for possible culprits in AMD — even very small, very rare ones.”
While no FDA-approved treatments exist for the “dry” type of AMD, called geographic atrophy, therapies for neovascular or “wet” AMD do not always work and do not cure the condition. Additionally, AMD is triggered not only by genetic predisposition, but also by environment and lifestyle. Risk for developing the disease is heightened by smoking, but lowered by consuming leafy greens and fish.
“These variants provide a foundation for genetic studies of AMD going forward,” Jonathan Haines of Cleveland’s Case Western Reserve University, one of the study’s authors, said. “The next step is to investigate what the variants are doing to the genes and how they affect gene function.”