Gene Variant Can Double Risk of AMD

Finding could one day lead to new treatments for degenerative eye condition.

By Amanda Gardner
HealthDay Reporter
Wednesday, July 18, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

WEDNESDAY, July 18 (HealthDay News) -- A newly discovered gene variant can more than double the risk of developing age-related macular degeneration (AMD), a degenerative eye condition that is the leading cause of blindness in the United States and Europe.

The finding could one day have implications for the prevention and treatment of the disease.

"There are no immediate practical applications for patients with AMD," said study senior author Dr. Anthony Moore, a professor of ophthalmology at the Institute of Ophthalmology at the University College of London. "The aim of our research is to identify genetic factors which predispose to AMD in order to understand the causes of the problem. Improved understanding of disease mechanisms should lead in the longer term to improved treatments," he added.

"This proves that there's a genetic inherited tendency that some people have toward getting macular degeneration," said Dr. Robert Cykiert, a professor of ophthalmology at New York University School of Medicine in New York City. "What it means right now is really not that much, because there's no medication we have to treat this."

But Cykiert said he's hopeful that a simple blood test to detect the variant will emerge in the next five years and that a medication to neutralize the gene's effect will be developed within a decade.

The findings are expected to be published in the Aug. 9 issue of the New England Journal of Medicine but were to be published online Thursday.

AMD involves damage to the macula at the center of the retina. The causes of the condition are not well understood, but, in recent years, several genes have been identified that may play a role.

There are two forms of the eye disease. "Wet" AMD is caused by an overgrowth of blood vessels that creates a dead spot in the macula. "Dry" AMD, which accounts for 90 percent of all cases, causes less sight loss.

The authors of this study, based in England and Scotland, compared 847 patients with AMD with 701 unaffected people.

A variant in the complement C3 gene affected the risk of developing AMD.