Functional Polymorphisms in the Matrix Metalloproteinase‐9 Gene in Relation to Severity of Chronic Periodontitis

Background: Members of the matrix metalloproteinase (MMP) family are implicated in the chronic remodeling in periodontal diseases. Therefore, we performed a case‐control study to investigate a plausible association between susceptibility to chronic periodontitis (CP) and the polymorphisms in the MMP‐9 (gelatinase B) gene. Methods: Using polymerase chain reaction with subsequent restriction analyses, MMP‐9 −1562C/T and R+279Q variants were determined in 304 subjects (169 patients with CP, 76 with a mild to moderate form and 93 with severe generalized CP, and 135 age‐ and gender‐matched unrelated control subjects). Results: The distribution of the MMP‐9 −1562C/T and R+279Q genotypes and alleles did not significantly differ between cases and controls. However, the frequency of the T variant at position −1562 was marginally higher in patients with severe disease compared to those with mild to moderate forms ( P <0.05; P corr >0.05). In further analysis, the −1562T allele was associated with a severe form of CP in men (odds ratio: 3.87; 95% confidence interval: 1.40 to 10.65; P <0.01 and P corr <0.05 for allele; P <0.05 and P corr >0.05 for genotype) but not in women. Conclusion: These findings suggest that genetic polymorphisms of the MMP‐9 gene are not associated with the susceptibility to CP in the Czech population; however, the promoter variant may influence the severity of the disease in men.