Common genetic polymorphisms linked to macular degeneration
BMJ 2007; 334 doi: https://doi.org/10.1136/bmj.334.7600.926-b (Published 03 May 2007) Cite this as: BMJ 2007;334:926
Researchers have found two common genetic variants that help predict which patients with age related macular degeneration will progress to the sight threatening form of the disease. Polymorphisms of the CFH and LOC387715 genes were both significantly and independently associated with progression in an analysis of data from a randomised trial of vitamin and mineral supplements. The odds ratios were 2.6 (95% CI 1.7 to 3.9) for the CFH risk genotype and 4.1 (2.7 to 6.3) for LOC387715 risk genotype after adjusting for other risk factors and for the treatment arm of the randomised trial⇑.
Half (48%) of those patients who were homozygous for the risk alleles of both genes progressed to severe macular degeneration during a mean follow-up of six years. Only 5% of patients with neither risk genotype progressed. Smokers with both risk genotypes who were also overweight were 19 times more likely to develop severe disease than people with none of these three risk factors.
We still don't know why these polymorphisms affect macular degeneration, although the CFH gene does have a role in some inflammatory and immune pathways. We know next to nothing about the function of LOC387715.