FCGR3A and periodontitis: The association between chronic periodontitis and PI risk with Fc-gamma receptor IIa (Fc-FCGRIIa) (rs1801274), FCGRIIIa (rs396991), and FCGRIIIb (rs1050501) gene polymorphisms is significant among Iranians.37 On the contrary, the association of FCGR genetic variations with PI or periodontitis did not appear significant in other studies.75,76 In addition, Caucasians carrying polymorphic genotypes of FCGRIIa (rs1801274) and FCGRIIIa (rs396991) represented higher susceptibility to periodontitis, while gene polymorphisms of FCGRIIIb (rs1050501) may give rise to aggressive periodontitis.77