Background Genetic variants on chromosome 9p21 confer a robust risk for coronary artery disease but inconsistent risk for stroke. This study investigated whether such genetic variants exert differential risks on myocardial infarction (MI) and ischemic stroke in a Taiwanese population.
Methods The study recruited 425 MI patients, 687 patients with ischemic stroke, and 1377 healthy controls. Four key single nucleotide polymorphisms (SNPs) on chromosome 9p21 were genotyped.
Results Multivariate permutation analyses demonstrated that the risk T allele of rs1333040 and G allele of rs2383207 were associated with MI (P = 0.045 and 0.002, respectively). Subjects with the rs2383207 GG genotype had a 1.85-fold (P = 0.021) risk for MI when compared with the subjects with the AA genotype. Further analysis showed that significant results only exist in the young MI group (<65 years) but not in the old MI group (≥65 years). These SNPs were not statistically significant for stroke (adjusted P ranged from 0.097 to 0.540). Haplotype analysis showed global P values of 0.032 for MI and 0.290 for stroke.
Conclusions Genetic variations in the 9p21 region are associated with MI but not with stroke in a Taiwanese population. Early-onset MI was more likely to carry the risk genotypes of 9p21 SNPs.