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Research into macular degeneration genetics has shown that one particular genetic variant is associated with an increased risk for macular degeneration. Two other genetic variants can help protect against the disease. Scientists will continue to study macular degeneration genetics in an attempt to discover additional information pertaining to these genes.
A team of macular degeneration research scientists has determined that variations in certain genes involved in fighting infection can successfully predict the risk of developing age-related macular degeneration, the leading cause of blindness in Caucasian Americans over the age of 60.
These scientists identified a genetic variant that is associated with an increased risk of developing macular degeneration. They also found two genetic variants that protect against developing this disease.
The genes analyzed in this study -- Complement Factor B (BF) and Complement Component 2 (C2) -- contain the instructions to make proteins that activate the body's immune system against microbial infections. These defense responses are part of a system called the complement pathways. These pathways involve numerous proteins in the blood that work in association with the body's immune cells and antibodies to destroy bacteria, viruses, or fungi invading the body. Some complement proteins can stimulate inflammation -- the redness and swelling that occurs in tissues when they are infected.
Previous studies have shown that genetic variations in complement pathway genes can cause a dysfunction in the inflammatory response that plays a central role in the pathology of macular degeneration.
Based on these findings, investigators initiated this study, which screened almost 900 patients with macular degeneration and 400 unaffected individuals for genetic variants in the BF and C2 genes. Data analysis revealed that specific variants in each gene were associated with macular degeneration. One genetic variant conferred an increased risk for macular degeneration, while two genetic variants indicated protection against developing macular degeneration.
These results, when analyzed in association with results linking macular degeneration and genetic variants of Complement Factor H (a gene that contains the instructions to make a protein that inhibits the complement system), showed that 56 percent of the unaffected individuals had a variant that conferred protection to macular degeneration, while 74 percent of those with macular degeneration had no protective variants.
These studies confirm that macular degeneration has a strong genetic component.