Genetics, in combination with environmental influences, has been found to play a key role in the development of AMD. Consequently, much attention is being directed to this area to increase our understanding of the basic mechanisms of the disease.
Research labs at Casey and elsewhere are working on identifying gene defects that make individuals more susceptible to developing AMD. In 2005, research groups found a gene variation that substantially raises the risk of AMD. This variant in the complement factor H gene (CFH) is more common in people with AMD than in those without the condition. Both the wet and dry forms of AMD were associated with the CFH gene variation. Another gene variant currently known as LOC387715 - or HTRA1 on chromosome 10 - has also been identified.
The CFH gene is located on chromosome 1 in a region repeatedly linked to AMD in family-based studies, including the ongoing Genetics of Age-Related Macular Degeneration Study at Casey. Investigators at Casey are continuing to actively recruit large families affected by AMD for this study.
It is expected that other gene variants will soon be uncovered, leading to a better ability to predict susceptibility for AMD and ultimately to advances in treatment and prevention.
The Role of Genes and Lifestyle Behaviors in Progression to Advanced AMD
Casey scientists, in collaboration with researchers at Tufts-New England Medical Center and Harvard Medical School, have discovered that carriers of the CFH and LOC gene variants are more likely to progress to the advanced form of the disease. The study, which was published in the Journal of the American Medical Association in April 2007, also found that lifestyle factors, such as smoking and body weight, increased the risk.
This is the first study to examine the relationship between these genes
and the progression from the earlier to the later stages of the disease.
However, genetic screening for AMD is not recommended at this time.
Large numbers of individuals would need to be screened to identify the
comparatively few who are at greatest risk, and while most individuals
with these gene variations will develop advanced AMD, not all will.
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text about this study.
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