Chromosome 9p21 genetic variants are associated with myocardial infarction but not with ischemic stroke in a Taiwanese population.

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.