MMP-1 promoter polymorphism: association with chronic periodontitis severity in a Brazilian population

Background: A single nucleotide polymorphism was described in the promoter region of the human MMP-1 gene, and this polymorphism has been associated with risk of cancer metastasis and inflammatory diseases. In this paper, we studied the possible relationship between the MMP-1 promoter polymorphism and the severity of chronic periodontitis. Methods: Genomic DNA from oral mucosa was amplified by PCR and analyzed by restriction endonuclease. The alleles were separated by polyacrylamide gel electrophoresis. The significance of the differences in observed frequencies of polymorphism in moderate and severe disease and healthy groups was assessed by Chi-squared test. Results: In the healthy group, the 2G allele was observed with a frequency of 48.7%, while in severely diseased patients the 2G allele was seen in 69.2% (P = 0.0344). The genotype 2G/2G was found in 46.15% of the group with severe periodontitis, and 24.3% and 25.0%, respectively, of the healthy and moderate groups (P = 0.0647). Conclusion: These results show that a polymorphism in the promoter region of MMP-1 gene is associated with the severe chronic periodontitis phenotype in non-smokers.