Gene mutation protects against dry AMD

Lexington, KY-Researchers have identified a link between toll-like receptor 3 (TLR3), a protein that alerts the body's immune system to infections and, the dry form of age-related macular degeneration (AMD) and will report their results in the online edition of the New England Journal of Medicine.

"This is yet another breakthrough in our continuing appreciation that AMD is a genetic disease," said Philip Rosenfeld, MD, PhD, a professor of ophthalmology at the Bascom Palmer Eye Institute at the University of Miami. He was not involved in the study.

A mutated form of TLR3 protects against dry AMD, and when TLR3 is activated it causes infected cells to die. "If you have this mutation, your TLR3 gene doesn't work properly," Jayakrishna Ambati, MD, a retinal surgeon in University of Kentucky's Department of Ophthalmology and Visual Sciences. "These people are protected."

Dr. Rosenfeld said that it was premature to assume that short-interfering RNAs, as the drugs are called, would predispose people to dry AMD. The risk should be tracked but it doesn't negate the potential of the drugs, he said.

"We must await the study results before jumping to any conclusions," said Dr. Rosenfeld, who is doing phase I clinical trials for an siRNA.