Variations of two common genes are associated with progression to more advanced forms of age-related macular degeneration (AMD), according to researchers at Tufts-New England Medical Center.
The investigators set out to assess whether certain genetic variants have prognostic importance for progression to advanced AMD and related visual loss. The study included 1,466 white participants. During the study, 281 volunteers progressed to advanced AMD in one or both eyes, which included geographic atrophy, exudative disease, or AMD causing visual loss.
The scientists found that the genetic polymorphisms, CFH Y402H and LOC387715 A69S, were associated with progression to more advanced AMD. The risk of progression was 2.6 times higher for CFH and 4.1 times more for LOC387715 risk genotypes after controlling for other factors associated with AMD. The probability of progression was 48% for the highest-risk genotype compared to 5 % for the low-risk genotypes. The presence of all adverse factors, both risk genotypes, smoking, and BMI of 25 or greater, increased risk 19-fold. Smoking and high BMI increased odds of progression within each risk genotype.
The researchers caution, however, that, “it is premature at this time to consider genotyping individuals with various stages of AMD because genotyping of about 30 individuals with drusen/pigment changes would be required to identify one individual who is homozygous for the risk allele for both genes, and many but not all individuals with those genotypes will develop the disease.”
The study was published in the April 25 issue of JAMA.