FCGR2C and autoimmune thrombocytopenic purpura: Furthermore, in agreement with our analysis of CNV of FCGR2C gene in patients with the most severe Stage IV of sarcoidosis, an increased copy number of this gene, corresponding to an elevated number of functional, open reading frame 57Q variant of FCGR2C, has been revealed in idiopathic thrombocytopenic purpura [19].