In addition; pretransplant hypercoagulable states as vascular access thromboses, prior venous thromboembolism, essential thrombocytemia, ischemic heart disease on antiplatelet therapy, atrial fibrillation on vitamin K antagonist therapy, factor V Leiden and prothrombin G20210A mutation and the presence of antiphospholipid antibodies have all been defined as independant risk factors for renal allograft thrombosis but not for posttransplant SVT in patients with optimal graft function [13,16,17]. The gene discussed is F5; the disease is essential thrombocythemia.