Dry Macular Degeneration Gene Identified

Armen Hareyan's picture

A joint team of US and Chinese researchers has identified a gene linked to a particular form of age-related macular degeneration (AMD), which is leading to elderly blindness.

Dry macular degeneration is one of the two types of AMDs, which currently affect 9 million Americans older than 60. Researchers found that TLR3 protein can attack infected eye retinal cells when activated and boost dry macular degeneration risk. At the same time researchers found that a mutated form of the protein - called inactive TLR3 - can slow down retinal cell damage process and protect from eye diseases.


Scientists were already going to publish the finding in New England Journal of Medicine, but they delayed the release because of a controversial treatment for wet age-related macular degeneration - the second form of AMD. The treatment is new and is known as RNA interference - RNAi - which is working by slowing wet AMD progression down. The treatment is found to trigger TLR3 protein, which means that the treatment boosts dry AMD while slowing the white one.

Researchers reported that RNAi increases retinal cell death risk by 60% in mice, which means that people with AMD history should not be prescribed RNAi treatment.

"I think these results have to be taken with caution, because the association effect of TLR3 with AMD is very small when compared to the disease's association with some other genes," said Rando Allikmets, a professor of ophthalmology, pathology and cell biology at Columbia University. "And there has been already one study saying there is absolutely no association of the TLR3 genetic variant with AMD. So, this raises a question and a need for further edification. It could be that this is just a spurious finding, and there is, in fact, no association with AMD."

Although this research doesn't come up with hope, it's still very useful because researchers just made a step forward to understand the nature of age-related macular degeneration. This research helps understand how genes can affect AMD and opens doors for scientists to develop eye disease treatment methods.