Genetic variations in the matrix metalloproteinase-1 promoter and risk of susceptibility and/or severity of chronic periodontitis in the Czech population

Objectives: Matrix metalloproteinase-1 (MMP-1) is a potent enzyme degrading extracellular matrix that was implicated in the pathogenesis of chronic periodontitis. Therefore, the aim of our study was to examine the association between three promoter polymorphisms of the MMP-1 gene and chronic periodontitis susceptibility and/or severity in a Czech population. Materials and Methods; A total of 329 Caucasian subjects were enrolled in this study. They were 133 patients with mild to severe chronic periodontitis and 196 unrelated control subjects. MMP-1 promoter polymorphisms (-1607 1G/2G, -519A/G, and -422A/T) were genotyped using standard polymerase chain reaction-restriction fragment length product methods. Results: Genotype analysis of the three single nucleotide polymorphisms across 27 different combinations showed significant association with chronic periodontitis (p<0.05). Analyses of individual polymorphisms showed no differences in distribution of the -519A/G and -422A/T variants between periodontitis and control groups. However, a trend to increased frequency of the -1607 1G allele was observed in patients with chronic periodontitis compared with the controls (p=0.054). When the groups were further stratified by smoking status, the 1G allele was associated with chronic periodontitis among non-smokers but not among smokers (p=0.033). On the contrary, the distribution of genotype frequencies of the MMP-1 -422A/T polymorphism was different between the patient and control smokers with respect to heterozygotes (73.91% versus 50.91%; p=0.017). Conclusions: Our results demonstrate that the polymorphisms in the MMP-1 promoter may have only a small effect on the etiopathogenesis of chronic periodontitis.