Objective: To develop a method of high-resolution melting curve analysis (HRM) for investigating the association of single nucleotide polymorphisms (SNPs) of IL-1β and IL-1Ra genes with susceptibility to coronary heart disease (CHD) and serological indexes in CHD.
Methods: PCR-HRM assays were established for detecting four SNPs (IL-1B-511C>T, IL-1B-31C>T, IL-1B+3954C>T and IL-1RNT>C) in 260 patients with CHD and 274 healthy controls. A case-control study was performed for analyzing the relationships of the four SNPs with CHD risk and serological indexes.
Results: No significant statistical difference was observed between the four SNPs and the susceptibility to CHD, however, the result of gender stratification showed that there was the statistical differences in the male IL-1B-31C>T and the female IL-1B+3954C>T allele frequencies (P=0.039, 0.032, respectively). The result of haplotype analysis of the four SNPs showed that haplotype of IL-1B-511T/IL-1B-31C/IL-1B+3954C/IL-1RN T (TCCT) had a significant correlation with obviously increased CHD risk, but without statistical difference (OR=1.217, 95%CI: 0.950-1.559, P=0.123), while those of CTCC and TTCT had significant correlations with decreased CHD risk (OR=0.612, 95%CI: 0.376-0.994, P=0.046; OR=0.365, 95%CI: 0.154-0.862, P=0.017). No association was found between the four SNPs and the serological indexes in CHD subjects.
Conclusion: The developed PCR-HRM detection assays based on HRM technology has been verified by direct sequencing and clinical specimen detection to be a rapid and homogeneous detection method for genotyping of the four SNPs. The SNPs of IL-1B-31C>T, IL-1B+3954C>T and the haplotypes of CTCC and TTCT are associated with the susceptibility to CHD in Chinese Han population of Lanzhou region.