Low Prevalence of a Periodontitis-Associated Interleukin-1 Composite Genotype in Individuals of Chinese Heritage

Background: Polymorphisms in the interleukin-1 (IL-1) gene cluster have been associated with an increased risk of developing certain diseases. A specific composite genotype of IL-1A and IL-1B polymorphisms, consisting of allele 2 of both IL-1A +4845 and IL-1B +3954 (formerly +3953) has been associated with an increased risk of severe adult periodontitis. Approximately 30% of the European population carry this genotype. The prevalence of the above IL-1A and IL-1B composite genotype in populations of different ethnic origins is unknown. Therefore, the primary aim of this study was to determine the prevalence of the IL-1 composite genotype in individuals of Chinese heritage, since epidemiologic studies indicate that periodontitis is widespread among ethnic Chinese. An additional aim was to evaluate if there was an association between the composite genotype and the severity of periodontal disease. Methods: A convenience sample of 300 volunteers of Chinese heritage (ages 21 to 69 years) received a periodontal ...