No additional inherited or acquired pro-thrombotic conditions were detected however screening for these conditions was not universally performed (50% screened for PNH, 43% for Factor V Leiden, 71% for antiphospholipid syndrome, 36% for anti-thrombin deficiency and 29% for protein C or protein S deficiency). Here, PROS1 is linked to paroxysmal nocturnal hemoglobinuria.