Preliminary Evidence of an Association between the Interleukin-13 Gene Polymorphisms and Periodontal Disease in the Japanese Population

Chronic periodontitis is a common dental inflammatory disease partly attributed to environmental factors in the oral cavity. As the genetic background of the host also plays a part in the etiology of this disease, the possible relationships between polymorphisms of several genes and periodontitis have been studied. Interleukin (IL)-13 is functionally and genetically implicated in inflammatory and immune systemic diseases, including asthma and atopy. We investigated whether polymorphisms of the IL-13 gene are associated with chronic periodontitis. Our study included 105 Japanese individuals, of which 52 were controls and 53 were periodontitis patients. Genomic DNA from subjects was assessed for polymorphisms of the IL-13 gene at positions -1510, -1111 and +389 using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). We found that genotype frequencies between the controls and periodontitis patients at positions -1111 and +389 were statistically significant (P= 0.00724 and 0.0313, respectively). Allelic distributions at positions -1111 and +389 between the two groups were also statistically significant (P= 0.0398 and 0.0432, respectively). These results suggest that polymorphisms of the IL-13 gene at positions -1111 and +389 are associated with periodontitis in the Japanese population.