Complement factor H variant increases the risk for early age-related macular degeneration

To investigate whether a polymorphism in the complement factor H gene determines the risk for the development of early age-related macular degeneration (AMD).

In this retrospective case-control study, we enrolled 133 unrelated Taiwan Chinese patients with early AMD and 180 age- and sex-matched control subjects. Early AMD was defined as the presence of extensive intermediate drusen or any large, soft drusen (> or = 125 microm), possibly accompanied by drusenoid retinal pigment epithelial detachment, and the absence of signs of late AMD. Genomic DNA was extracted from peripheral blood obtained from all the AMD patients and control subjects. Polymerase chain reaction was performed to analyze the complement factor H polymorphism (Y402H, rs1061170).

The genotype distribution differed significantly between the early AMD patients (TT 80%; TC 14%; and CC 6%) and controls (TT 91%; TC 9%; CC 0%; P = 9 x 10(-4)). The C allele frequency was significantly higher in the early AMD patients than in the controls (13% vs. 4%, P = 1 x 10(-4), odds ratios = 3.26, 95% confidence intervals = 1.76-6.02).

Our study demonstrated that the presence of the Y402H polymorphism in complement factor H is significantly associated with increased susceptibility to early AMD in Taiwan Chinese populations and that the C allele frequency is low in these populations.