Exploration and detection of potential regulatory variants in refractive error GWAS

Refractive error (RE) is a complex multifactorial disease. Genome-wide association studies (GWAS) have provided significant insight into the genetic architecture and identified plenty of robust genetic variations or single nucleotide polymorphisms (SNPs) associated with complex disease. A major current challenge is to convert those resources into causal variants and target genes. We used RegulomeDB and HaploReg to annotate regulatory information onto associated SNPs derived from the two largest RE GWAS, and additional SNPs in linkage disequilibrium (LD) with GWAS significant SNPs. Overall 868 SNPs were investigated, out of which 662 returned RegulomeDB scores of 1 to 6. It was observed that 36 out of those SNPs show strong evidence of regulatory effects with a RegulomeDB score of 1, while only four of them were GWAS significant SNPs (CD55/rs1652333, CNDP2/rs12971120, RDH5/rs3138142 and rs3138144). The results encourage us to explore those putative pathogenic variants, both GWAS significant SNPs as well as the SNPs in LD, for future discernment of functional consequence. This study offers the attractive approach for prioritizing potential functional variants by combining ENCODE data and GWAS information, and provide further insights into the pathogenesis and mechanism and ultimately therapeutics.