Wednesday, April 9, 2008
New genetic discoveries linking to Macular Degeneration
Macular degeneration also known as MD or AMD affects one in seven people over the age of fifty with case numbers increasing as age increase (Macular Degeneration Foundation, n.d). MD is the leading cause of vision impairment in the elderly population. This disease causes a progressive painless loss of the central vision. This is a disease of the retina in the eye. The retina connects what we see, to our brains. There are both wet and dry forms of MD. Both forms start by the retinal Pigment Epithelium which passes oxygen, sugar and other essential products into the retina which in turn disposes of waste produces. However the retina of people with MD can not dispose of this waste. The waste builds up which can be seen as yellow spots. This waste causes pressure build up on the eye which in turn causes the macular cells to die off. As this disease affects so many people The University of Columbia began looking into whether genetics plays a role in who is diagnosed with the disease. The University has discovered this disease is linked to three in four cases to the genetic codes in our bodies. Scientists have discovered what they call as Factor H and Factor B. These factors code for specific proteins. It is when these the Factor H proteins mutate that people have a greater increased chance of having MD. This is because people with the mutant Factor H “are less able to control inflammation caused by infectious triggers” (Streich.E, 2005). Meanwhile the Factor B is an activator of the immune response. Thus Factor B people are at lower risk of developing MD. This only holds true to three in four cases. It is yet to be discovered why the other 25% of people get MD.
Craig Leoult, Columbia University, University of Iowa, n.d, ‘Variation In Gene That Regulates Immune Response Causes Age-Related Macular Degeneration When Triggered, Study Shows’, 8-04-2008,
Elizabeth Streich, 5th March 2005, ‘New genetic discovery explains 74 percent cases of age-related macular degeneration’, 8-04-2008, http://www.eurekalert.org/pub_releases/2006-03/cumc-ngd022406.php.
Macular Degeneration Foundation, n.d, ‘What is Macular Degeneration?’, 8-04-2008,
Alexandra Henderson 41724626