Five single-nucleotide polymorphisms, rs4977574 (CDKN2A/2B), rs12526453 (PHACTR1), rs646776 (CELSR2-PSRC1-SORT1), rs2259816 (HNF1A), and rs11206510 (PCSK9) showed directionally consistent associations with CHD in the 3 studies, with combined odds ratios (ORs) ranging from 1.17 to 1.25 (p = 0.03 to 0.0002).
Recent genome-wide association studies (GWAS) in European populations have indicated that the rs12526453 polymorphism located in phosphatase and actin regulator 1 gene (PHACTR1), mapping to chromosome 6p24 and rs7865618 polymorphism in the cyclin-dependent kinase inhibitor B antisense RNA 1 gene (CDKN2B-AS1) on 9p21.3 are associated with coronary heart disease (CHD).
Besides the CAD/MI SNP at 9p21 (rs4977574, P = 3.1 × 10(-10)), two additional loci at ADAMTS7 (rs3825807, P = 6.5 × 10(-6)) and at PHACTR1 (rs12526453, P = 1.0 × 10(-3)) show a nominally significant association with coronary artery calcification with MI/CAD risk alleles increasing the degree of arterial calcification.
The rs12526453 CC homozygotes (previously associated with increased risk of myocardial infarction) showed, in 2 independent samples, better long-term survival.
Significant heterogeneity of SNP effects (p het < 1.4 × 10(-3)) was observed between the MA and MO subgroups (for SNP rs9349379), and between the clinic- and population-based subgroups (for SNPs rs10915437, rs6790925 and rs6478241).
The second strongest association with CAC was with rs9349379 in the phosphatase and actin regulator 1 gene, PHACTR1, (Beta=0.30; 95% CI=0.22-0.40; p=4.67x10-11).
In summary, our results suggest that the PHACTR1 rs9349379 polymorphism plays an important role in the risk of developing premature CAD in the Mexican population.
This result suggests that rs9349379 may in part influence CAD by modulating the expression of intermediate PHACTR1 transcripts in endothelial or vascular smooth muscle cells found in hCA.
In primary human macrophages, we identified a novel expression quantitative trait locus (eQTL) specific for this short transcript, whereby the risk allele at CAD risk SNP rs9349379 is associated with reduced PHACTR1 expression, similar to the effect of an inflammatory stimulus.