Factor XII (FXII) deficiency is a rare autosomal recessive disorder. Although FXII deficiency is not associated with a clinical bleeding tendency, FXII is an important protease that plays a major role in the initiation of the intrinsic pathway of blood coagulation. Venous or arterial thrombosis, recurrent miscarriages, and placental abruption were reported in cases with FXII deficiency.
