Association of Matrix Metalloproteinase-1 -1607 1G/2G and C-Reactive Protein -717 C/T Gene Polymorphisms in Iranian Patients with Chronic Periodontitis: A Clinical Trial

An imbalance in the expression of matrix metalloproteinases (MMPs) and tissue inhibitor metalloproteinases initiate the destructive process in chronic periodontitis (CP). C-reactive protein (CRP) is a systemic inflammatory mediator that reflects an acute immune response. The purpose of this investigation was to analyze the association between the MMP-1 -1607 1G/2G (rs1799750) and CRP 717 A/G (rs2794521) gene polymorphisms and chronic periodontitis in Iran. This analytical case-control study was performed among 141 participants including 63 CP cases and 78 matched healthy individuals. Five milliliters of peripheral blood was collected for DNA isolation. Restriction fragment length polymorphism- polymerase chain reaction (RFLP-PCR) was performed for single-nucleotide polymorphism (SNP) analysis. The frequencies were analyzed by chi-squared test (95% CI, P < 0.05). In addition, genetic data were assessed by the Hardy-Weinberg principle, linkage disequilibrium, and haplotype analysis. Our findings presented no significant relationship between genotype/alleles of MMP-1 -1607 1G/2G (rs1799750) (0.73: 0.27 - 1.95, P = 0.48) or CRP 717 A/G (rs2794521) (0.384: 0.104 - 1.414, P = 0.303) and the presence of CP (P = 0.47 and P = 0.30, respectively). The analysis of genetic distribution among various severities of CP and controls revealed no significant association between various severities of CP and MMP-1 -1607 1G/2G (rs1799750) (P = 0.52) and CRP 717 A/G (rs2794521) (P = 0.67). Our results suggest no association between the occurrence or severity of chronic periodontitis and MMP-1 -1607 1G/2G (rs1799750) and CRP 717 A/G (rs2794521) polymorphisms. Further studies with larger sample sizes may provide a more generalizable evidence-based overview of the relationship between these gene polymorphisms and periodontitis.