Associations of the C2-CFB-RDBP-SKIV2L locus with age-related macular degeneration and polypoidal choroidal vasculopathy

Abstract

Purpose: To investigate the associations of the C2-CFB-RDBP-SKIV2L region with neovascular age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV).

Design: Cross-sectional, case-control association study.

Participants: A Chinese case-control group of 200 neovascular AMD patients, 233 PCV patients, and 275 control subjects.

Methods: An association analysis was performed of the C2-CFB-RDBP-SKIV2L locus with both neovascular AMD and PCV in a Chinese population using 19 haplotype-tagging single nucleotide polymorphisms (SNPs) and 6 previously reported SNPs across the C2-CFB-RDBP-SKIV2L region. All SNPs were genotyped using the TaqMan genotyping technology (TaqMan; Applied Biosystems [ABI], Foster City, CA).

Main outcome measures: Allele and haplotype frequencies of the SNPs in the C2-CFB-RDBP-SKIV2L region.

Results: The SKIV2L SNPs rs429608 and rs453821 were significantly associated with neovascular AMD (P = 7.39 × 10(-5); odds ratio [OR], 0.22; 95% confidence interval [CI], 0.10-0.50; and P = 0.001; OR, 0.38; 95% CI, 0.21-0.70, respectively), whereas borderline associations were detected for C2 rs547154 (P = 0.002) and RDBP rs760070 (P = 0.003). Conditional haplotype analysis revealed that SKIV2L rs429608 could account fully for the global haplotype association identified in this region. The association of SKIV2L rs429608 with neovascular AMD remained significant after adjusting for CFH rs800292 and HTRA1 rs11200638. No individual SNP or haplotype was associated significantly with PCV.

Conclusions: In this concurrent investigation of the associations of the entire C2-CFB-RDBP-SKIV2L region with neovascular AMD and PCV, the results suggested that SKIV2L is a likely causal gene for neovascular AMD, conferring a significant protective effect independent of CFH and HTRA1. These data do not support a significant role of this region in PCV, suggesting different molecular mechanisms between neovascular AMD and PCV.