In particular, single nucleotide polymorphisms (SNPs) in FCGR2A (R131H), FCGR2B (I232T) FCGR3A (V158F) and FCGR3B (NA1/NA2), have been reported in association with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and/or idiopathic thrombocytopenia purpura (ITP) [9]–[17]. The gene discussed is FCGR2A; the disease is autoimmune thrombocytopenic purpura.