Family cohorts with hereditary antithrombin, protein C, or protein S deficiencies. *Deep vein thrombosis at 14 years of age after a posttraumatic fracture of the lower limbs (antithrombotic prophylaxis was not used in this circumstance). ^†Idiopathic VTE event at 8 years of age. ^‡Thrombosis of the cerebral venous sinuses after birth.