Abstract
Purpose: :
To analyze and compare previously reported age-related macular degeneration (AMD) risk alleles in a group of AMD patients and a group of patients with basal laminar drusen (BLD).
Methods: :
DNA samples of 609 AMD patients, 112 patients with BLD and 238 control individuals were genotyped for 11 SNPs in 9 genes previously associated with AMD: CFH, CFB, C3, ARMS2, TLR3, TLR4, SERPING1, ABCA4 and APOE. Fifty-one of the 112 patients with BLD had extensive, innumerable small drusen in the macula and/or peripheral retina, and were additionally analyzed as a separate subgroup. Data from all AMD and control subjects were obtained from EUGENDA, a multicentre database for clinical and molecular analysis of AMD.
Results: :
In the BLD patients and in the subgroup of patients with extensive BLD, we found a significant association with the CFH, ARMS2 and C3 genotypes. The frequency of the Y402H risk allele in the CFH gene was 60% in the AMD group, 62% in the BLD group, and 68% in the extensive BLD group, compared to 35% in the control group. The allele frequency of the ARMS2 A69S risk allele was 46% in the AMD group, compared to 38% in the BLD group, 41% in the extensive BLD subgroup, and 23% in the control group. The allele frequency of the C3 R102G risk allele was 27% in the AMD group, 31% in the BLD group and 40% in the extensive BLD group, compared to 23% in the control group.
Conclusions: :
The CFH and C3 risk allele frequencies are higher in the BLD group compared with the AMD cohort. In contrast, the ARMS2 risk allele frequency is lower in BLD compared with AMD. In the extensive BLD group the allele frequencies of CFH and C3 are even higher. This suggests that the complement cascade may play a greater role in the pathogenesis of BLD compared to AMD.
Keywords: age-related macular degeneration • genetics • choroid: neovascularization