Evaluation of DEFB1 polymorphisms in individuals with chronic periodontitis and diabetes mellitus type 2 in a population of northeastern Brazil

Aims: The role of genetic variations in genes related to innate response, as β-defensin-1 (DEFB1), in the context of chronic periodontitis (CP) and diabetes mellitus type 2 (DM2), is still not clear. The present study evaluates the distribution of DEFB1 single nucleotide polymorphisms (SNPs) 5′-untranslated (5′UTR) region and its relation with the CP in DM2 individuals in northeastern Brazilians. Methods: Two hundred and eighty individuals participated in the study, being 116 DM2+CP, 95 CP, and 69 healthy individuals. Three known DEFB1 functional SNPs [-52 G > A (rs1799946), -44 C > G (rs1800972), -20 G > A (rs11362)] were genotyped with allele-specific assays. Results: Association was found for the DEFB1 -20 G > A SNP. The G allele, the GA and GG genotypes were significantly (P < 0.05) more frequent in the DM2+CP (59.5%, 50%, and 34.5%, respectively) and CP (61%, 44.2%, and 38.9%, respectively) than in healthy individuals (26.8%, 36.2%, and 8.7%, respectively). The GCG and ACG combinations (-52, -44, -20) were significantly more frequent among DM2+CP and CP than in the healthy individuals. Conclusion: The results indicate that genetic variations of DEFB1 gene (SNP-20: G allele and GA and GG genotypes) and the DEFB1 5′UTR haplotypes (GCG and ACG) may be associated with a susceptibility to CP in DM2 individuals as well as CP individuals without DM2.