Genetic variants of chromosome 9p21.3 region associated with coronary artery disease and premature coronary artery disease in an Asian Indian population

INTRODUCTION: Asian Indians have a propensity for premature, severe, and diffuse coronary artery disease (CAD). Several single-nucleotide polymorphisms (SNPs) in the ‘core CAD’ region of the chromosomal region 9p21.3 are known to be strongly associated with CAD. OBJECTIVES: We aimed to study SNPs in the 9p21.3 region associated with CAD and premature CAD and identify their association with demographic and clinical characteristics in an Asian Indian population. METHODS: SNP genotyping was performed for 30 SNPs of the 9p21.3 region using MassARRAY(®) technology. Along with demographic and SNP data analysis, we also performed multivariate logistic regression analysis and multifactor dimensionality reduction analysis to study SNP–SNP and SNP–demographic/clinical variable interactions. RESULTS: Our results suggest that females are at a higher risk of premature CAD. We found that SNPs rs1333045 (CC), rs16905599 (AA), rs2383206 (GG), rs2383208 (AG), and rs4977574 (GG) were significantly associated with premature CAD. When adjusted for covariates/confounders, we found that rs2383206 showed the strongest risk association with CAD followed by rs16905599 and rs2383208. Further, SNPs rs1333049 (CC) and rs4977574 (GG) were found to be exclusively associated with premature CAD cases, suggesting their potential as genetic markers for premature CAD in the local population. Upon gender-based stratification, it was found that rs10757272 (TT and TC) is significantly associated with eightfold to ninefold CAD risk specifically among females. SNP rs7865618 (GG) is significantly associated with more than 2.5-fold CAD risk specifically among males. CONCLUSION: Our study suggests that SNPs at the 9p21 risk locus may be used to generate a reliable genetic risk score along with markers at other loci.