The Fc gamma receptor genotype as a risk factor for generalized early-onset periodontitis in Japanese patients

Background: Genetic polymorphisms of immunoglobulin G (IBG) Fc receptors (Fc gammaR) were recently shown to be associated with recurrence rates of adult periodontitis (AP). The purpose of this study was to evaluate whether Fc gammaR polymorphisms are also associated with generalized early-onset periodontitis (G-EOP) in Japanese patients. Methods: Thirty-eight Japanese patients with G-EOP and 83 Japanese patients with AP were identified according to established clinical criteria, including measurements of probing depth, clinical attachment level, and alveolar bone level. Fc gammaR genotypes for 3 bi-allelic polymorphisms were determined in these G-EOP and AP patients and 104 race-matched healthy controls by means of allele-specific polymerase chain reactions. Results: There was a significant difference in the distribution of Fc gamma RIIIb genotypes between G-EOP patients and healthy controls (P = 0.02), Additionally, a significant over-representation of Fc gamma RIIIb-NA2 allele was observed in G-EOP patients as compared to AP patients and controls (P = 0.02, P = 0.009, respectively). Moreover, we found a strong association between G-EOP and the composite genotype comprising Fc gamma RIIIb-NA2 and Fc gamma RIIIa-158F (G-EOP versus controls: odds ratio 2.4, 95% CI 1.0-6.0, chi (2) = 4.13, P = 0.04). Conclusions: This study indicates that the Fc gamma RIIIb-NA2 allele and possibly Fc gamma RIIIa-158F could be associated with susceptibility to G-EOP in Japanese patients.