Abstract:Aim Heme oxygenase 1 (HO-1) is a rate-limiting enzyme in the degradation of heme and has potent anti-oxidant and anti-injury effects. The HO-1 gene promoter has different (GT)n repeats (STR) and single nucleotide polymorphisms (SNP) associated with its expression. In this study, we aimed to assess the association between combination of STR and SNP in the HO-1 gene promoter and the susceptibility for coronary heart disease. Methods 171 patients with coronary heart disease and 70 control subjects with sex and age matching were collected Capillary electrophoresis and Sanger sequencing were used for genotyping. Classification tree was performed to distinguish patients from controls. Multiple factors regression was employed to detect the association between genotyping and disease susceptibility, and multifactor dimensionality reduction method was used to identify best factor interacting with STR-SNP haplotype. Results The classification tree distinguished patients with coronary heart disease from controls with 71% of correct prediction (P<0.001). STR-SNP haplotype was an independent risk factor for coronary heart disease (OR: 1.890, 95%CI: 1.162~3.076, P0.010), and interacted with smoking to increase risk (OR: 6.994, 95%CI: 3.428~14.272, P0.001). Conclusion STR and SNP functional polymorphisms in HO-1 promoter could be a marker for screening susceptibility individual of coronary artery disease.