Interleukin 1β (+3954; -511) Genotype Polymorphism and its Association with Severe Chronic Generalized Periodontitis in the Malaysian Population

INTRODUCTION: Single-nucleotide polymorphisms (SNPs) in interleukin 1β (IL-1β) gene have been known to be associated with increased susceptibility to chronic periodontitis among various ethnic populations. SNPs are more commonly observed at loci + 3954 and - 511. The aim of this study was to evaluate the role of IL-1β gene polymorphism at loci +3954 and - 511, and its association with severe chronic generalized periodontitis among the ethnic Malay, Chinese, and Indians within the Malaysian population.

MATERIALS AND METHODS: Saliva samples from 120 subjects (60 cases and 60 controls) in the age group of 25-50 years were collected for isolation of genetic material using Norgen technique. Clinical attachment loss of ≥5 mm was considered as severe chronic generalized periodontitis. SNP's at loci +3954 and - 511 were identified and analyzed using Kompetitive Allele Specific Polymerase Chain Reaction Genotyping System (KASP™). Differences in the allele/genotype frequencies were assessed by Chi-square test (P < 0.05).

RESULTS: On the comparison between cases and controls of IL-1β genotype polymorphism (+3954 and - 511), the difference in the genotype frequencies was statistically insignificant in all the three ethnicities. The genotype frequency in both groups in all three ethnicities of the Malaysian population was similar.

CONCLUSION: IL-1β genotype polymorphism at +3954 and - 511 was found to be not associated with severe chronic generalized periodontitis among the three ethnicities in Malaysia. Studies with larger sample size should be done to confirm the findings of this study.