Association of heat shock protein70-2 (HSP70-2) gene polymorphism with coronary artery disease in an Iranian population

Background: Coronary artery disease (CAD) is an inflammatory process and a major cause of mortality and morbidity. The (heat shock protein70-2) HSP70-2 gene is reported to be associated with coronary artery disease possibly by affecting the regulation of pro-inflammatory cytokines such as TNF-alpha. The association between CAD and the HSP70-2 gene +1267A>G polymorphism has been studied in some populations but there are no data about this association in the Iranian population. Aim: We have investigated the association between the HSP70-2 gene +1267A>G polymorphism and angiographically defined CAD within an Iranian population. Methods: We determined the presence of the HSP70-2 gene +1267A>G polymorphism in 628 patients with CAD and 307 healthy individuals using PCR-RFLP. Of the patients, 433 (68%) had >50% stenosis (CAD+) and the remaining 195 patients had <50% stenosis (CAD), based on coronary angiography. Angiogram positive patients were subdivided into three groups: those with single (n = 113), double (n = 134), and triple vessels (n = 186) disease. Results: A significant higher frequency of AG + GG genotypes (G allele carriers) was observed in angiogram positive and angiogram negative groups compared to controls in a dominant analysis model of the HSP70-2 gene +1267A>G position (51.2 vs. 43.2, P = 0.002, OR = 137) (51.0 vs. 43.2, P = 0.01, OR = 1.37). The allele frequency of the HSP70-2 G was also significantly higher in angiogram positive and angiogram negative groups compared to the control group (512 vs. 43.2, P = 0.002, OR = 1.37) (51.0 vs. 432, P = 0.01, OR = 1.37). Conclusion: These results suggest that HSP70-2 +1267 polymorphism may influence the risk of CAD in Iranian population, however further studies are needed to clarify the role of other HSP70-2 gene polymorphisms in the pathogenesis of the CAD.