Monday, March 06, 2006
Previous work had shown that several variants of a gene called Factor H significantly increase the risk of AMD.
Factor H controls production of a protein that helps shut down the body's immune response to infection once it has been successfully fought off.
People with these inherited variants of Factor H are less able to control inflammation caused by infectious triggers, which may spark AMD in later life.
....A genetic analysis of 1,300 people quickly identified a second gene, Factor B, as playing a significant role.
While Factor H is an inhibitor of the immune response to infection, Factor B is an activator.
Because of the complementary roles of the these two genes, a protective Factor B variation can protect against AMD, even if one carries a risk-increasing variant of Factor H, and vice versa.
The researchers found 74% of the people with AMD had either the Factor H or Factor B risk factor or both - but no protective variants of either gene.
Lead researcher Dr Rando Allikmets said "I am not aware of any other complex disorder where nearly 75% of genetic causality has been identified.
Here's a picture of Factor H in the retina. And here's a schematic of the Factor B protein.
At the moment, the only treatment we have for macular degeneration is to try to arrest the development as it occurs, and we aren't all that great at doing that. The good news about this finding is that we might some day be able to develop drugs that can prevent it from happening. The drawback is that since they would have to work on gene expression, they're likely to have body-wide side effects.
posted by Sydney on 3/06/2006 08:44:00 AM 2 comments
Interesting. Macular degeneration runs in my family, and so do autoimmune diseases. We're an autoimmune disaster zone. Connection?
By 1:56 PM, at
Going blind is one of my worst fears.. it has never shown up in my family thank goodness..