Mean onset of thrombotic symptoms In heterozygotes, the mean age of onset is 44. In homozygotes, the mean age of onset is 31. 5. There is no increased risk of myocardial infarction or stroke. E. Clinical Features - smiliar to Antithrombin III, Protein C, and Protein deficiencies. Increased risk of venous thrombosis and pulmonary embolism.
Venous thrombosis occurs most frequently in the deep veins of the lower extremities.
Thrombotic events begin in mid-late teenage years. Mesenteric veins, IVC, renal veins are all susceptible. Cerebral vein thrombosis can occur. Thrombosis may be precipitated by surgery, trauma, pregnancy, OCP use, or infection. Arterial thrombosis is not increased.