F5 and Rare hereditary thrombophilia: Thrombophilia workup showed anti-phosphatidyl serine antibodies in one patient [8], and the presence of heterozygous mutations for Factor V Leiden, prothrombin and PAI-1 antibodies in another [9] Heparin-induced thrombocytopenia (HIT) was suspected in one patient; however, antibodies were negative [10].