A Reduced Interval of Chromosome 9p21 Locus is Associated with Ischemic Stroke in Chinese Northern Han Population

The 9p21 locus, a strong risk locus for coronary arterial disease, has been also associated with other cardiovascular disease including ischemic stroke (IS) in Caucasians. However, the association between 9p21 locus and IS in Chinese Han population is still debatable because of ambiguous results reported previously. Genetic heterogeneity between Southern and Northern Chinese Han populations could be one of the reasons for this uncertainty. Four genetic variants selected from the three conjunctional LD blocks within the 44 kb candidate region on chromosome 9p21 were genotyped in 1,429 IS patients and 1,191 healthy controls from the Northern Chinese Han population. Among the four studied variants, the G allele of the SNP rs2383207 was significantly associated with IS with allele frequency 66.8% in patients and 63.4% in controls. This association appears to be dominant with an OR of 1.417 (p=0.003) for people with either GG or AG genotypes. We did not find any association for the other three SNPs (rs1333049, rs10757274, and rs10116277). Based our results, we conclude that the 9p21 locus is a susceptibility locus for IS in the Northern Chinese Han population; and the core risk region for IS is within an interval of less than 28kb.