DEFB4A Promoter Polymorphism Is Associated with Chronic Periodontitis: A Case-Control Study

Abstract

Background: Human beta-defensin-2 is an antimicrobial weapon peptide with antibiotic properties secreted by the oral cavity to protect the host against microbial attack. The interindividual differences of defensin expression profiles due to genetic variation might be partly responsible for differences in disease susceptibility. Aims: The objective of this study was to examine whether variation in the human beta-defensin-2 gene (DEFB4A) is associated with chronic periodontitis (CP). Materials and Methods: This case-control study analyzed two promoter polymorphisms in DEFB4A with potential functional consequences in DNA samples collected from 200 unrelated individuals using Sanger sequencing. Results: The DEFB4A rs1339258595 promoter polymorphism is associated with CP risk and clinical attachment level (CAL) but the rs3762040 polymorphism is not. Carriers of the T allele (rs1339258595) were approximately three times less likely to develop periodontitis compared with noncarriers (p = 0.0004, odds ratio = 0.35). Consistent with a protective role, the carriers of T allele had a lower CAL compared with the wild-type (G) allele. Moreover, the wild-type diplotype (GGGG) had a significantly higher risk of tooth loss compared with other diplotypes (p = 0.016). Conclusion: This study demonstrates that genetic variation in the promoter region of DEFB4A likely affects resistance to periodontal infection and might be a potential marker for CP risk and severity.