Meta-analysis for the association of FCGR2/3 variants with susceptibility to childhood ITP. Previous studies analyzing the association of FCGR2/3 with childhood ITP were identified in PubMed and EMBASE by systematic literature search (supplemental Table 1). The study by Bruin et al¹⁶  was not included because these patients were also included by Breunis et al.¹⁷  Study characteristics are reported in supplemental Table 2. (A) FCGR2C*ORF is significantly associated with susceptibility to childhood ITP. In comparison with FCGR3A*158F/F, FCGR3A*158V/F (B) and FCGR3A*158V/V (C) confer susceptibility to childhood ITP. This genetic variant is in linkage disequilibrium with FCGR2C*ORF, FCGR2A*27Q/W, and the FCGR2B/FCGR2C promoter polymorphism 2B.4. Mantel-Haenszel (MH) estimates of the ORs are given for fixed effect models. *Data were only analyzed from childhood ITP cases included in this study. ^§Patients with CNV in FCGR3A were excluded, whereas other studies did not supply such data.