Association of FCGR2/3 variants with prognosis in newly diagnosed childhood ITP. (A) Overview of the human Fc γ receptor gene (FCGR) locus. CNV occurs in regions encompassing multiple genes (CNR). (B) Association of FCGR2C*ORF/STOP with complete recovery rates in patients that were carefully observed (Obs) or treated with IVIg. Complete recovery was defined by the International Working Group criteria as a platelet count of at least 100 × 10⁹/L, which correlates strongly with absence of bleeding symptoms. FCGR2C*ORF enriched for children with favorable response to IVIg and a high rate of spontaneous recovery, and carried a low chance of chronic disease at 12 months’ follow-up. The FCGR2B/FCGR2C promoter variant 2B.4 (C) and FCGR2A*27Q/W SNPs (D), which are in linkage disequilibrium with FCGR2C*ORF, showed similar effects. In particular, FCGR2A*27Q/W did not differentiate as well between course of disease as the other 2 variants. P values are given for a log-rank test, stratified by treatment allocation.