Abstract
Purpose:
We have recently identified an association between a single nucleotide polymorphism (SNP) rs57137919 in the ABCG1 gene and polypoidal choroidal vasculopathy (PCV). In this study, we investigated the association of haplotype-tagging SNPs in ABCG1 with both neovascular age-related macular degeneration (nAMD) and PCV in an expanded Chinese cohort.
Methods:
In a cohort of 200 nAMD patients, 200 PCV patients and 350 controls, we genotyped 11 haplotype-tagging SNPs and rs57137919 in ABCG1, and two major AMD-associated SNPs in CFH and HTRA1, using TaqMan genotyping technology.
Results:
The ABCG1 SNP rs57137919 was only associated with PCV. In contrast, a novel association was found of another ABCG1 SNP with both nAMD and PCV; the odds ratio for the minor allele was about 1.3. The association remained significant after adjusting for the CFH and HTRA1 SNPs. Haplotype-based association analysis identified a significant omnibus association with nAMD (P<0.01) in a 2-SNP window, containing the new SNP. A haplotype (G-A), which presented in about 2 % of patients and 0.4% of controls, showed a significant association with nAMD (P<0.01), conferring a ~6 fold of increased risk. No haplotype was associated with PCV.
Conclusions:
Our results provide new evidence to support ABCG1 as a susceptibility gene for nAMD and PCV, and its effect is independent of CFH and HTRA1. Further replications in other ethnic populations are warranted to confirm the role of ABCG1 in nAMD and PCV.