Fine-Mapping of ABO Gene Identifies Two Novel SNPs Associated with Large Artery Atherosclerotic Stroke in a Chinese Han Population.

Recently, a single nucleotide polymorphism (SNP) rs505922 in ABO gene was related to large artery atherosclerotic (LAA) stroke in Caucasian populations by genome-wide association study (GWAS). This study aimed to determine whether ABO gene polymorphisms are associated with LAA stroke in Chinese Han population. A case-control study was designed, and 644 patients with LAA stroke and 642 healthy controls were enrolled. Ten tagging SNPs (tSNPs) located in ABO gene were genotyped. Associations between genotypes and LAA stroke were analyzed with logistic regression model after adjustment of potential confounders. Although rs505922 was not associated with LAA stroke (TT genotype, adjusted OR = 1.32; 95 % CI, 0.94 to 1.87), two novel SNPs, rs8176668 (AT genotype, adjusted OR = 0.71; 95 % CI, 0.55 to 0.92) and rs2073824 (AA genotype, adjusted OR = 0.72; 95 % CI, 0.57 to 0.92), were associated with LAA stroke. Haplotype analysis indicated that haplotype TC (adjusted OR = 0.72; 95 % CI, 0.54 to 0.95; P = 0.018) in block 1 and haplotype ACA in block 2 (OR = 0.73; 95 % CI, 0.58 to 0.91; P = 0.005) were associated with LAA stroke. Multifactor dimensionality reduction (MDR) analysis in the single-locus model indicated that rs2073824 was the most important attributor for predicting risk of LAA stroke. No significant SNP-SNP interactions among the tested SNPs were detected. The results indicated that the genetic variants in ABO gene may influence the risk of LAA stroke in Chinese Han population.