Abstract: Objective: To investigate the possible genetic association of the Val125Leu polymorphism of the PECAM-1 gene and chronic periodontitis in Heilongjiang. Methods: Genomic DNA was isolated from oral mucosa of 146 periodontal patients (57 with mild ,53with moderate and 36 with severe chronic periodontitis) and 91 healthy individuals. Samples were genotyped and analyzed for the single-nucleotide polymorphisms (SNPs) of PECAM-1 using the multiplex SNaPshot technique. The differences of the genotype and allele frequencies were calculated and analyzed. Results: All genotypes distribution of the PECAM-1 rs281865545polymorphism were in Hardy-Weinberg equilibrium in both the cases and the controls; PECAM-1 rs281865545 GG, GC, and nCC genotype frequencies were 24.7%,52.7%,22.6% in case samples, and 13.2%,57.1%,29.7% in control samples, respectively. Two groups genotype frequencies distribution were not significantly different. The allele G, C distribution frequencies were 51.0% and 49.0% in the periodontitis group and 41.8%,58.2% in the control group, a statistically difference was seen in the allele frequencies among the different groups (P<0.05). Conclusion: No significant association was found between the polymorphism tested and the subgroups of periodontitis, further research is still necessary to determine whether this polymorphism can be used as a genetic marker of periodontitis.

Key words: Chronic periodontitis, Gene polymorphism , Platelet-endothelial cell adhesion molecule-1(PECAM-1)