Multiple Arterial Thrombosis in Anti Thrombin III Deficiency

Antithrombin III (AT III) inhibits thrombin and activated clotting factors like factor Xa, IXa and VIIa. AT III deficiency increases risk for thromboembolic diseases. Inherited deficiency of AT III is relatively rare with prevalence in general population between 1500 to 150001. AT III deficiency is transmitted in autosomal dominant manner. Thrombosis appears at around 20 years of age and by 4th-5th decade majority of the patients are symptomatic. Thrombosis usually occurs in venous system2 and arterial thrombosis is less reported3. We report a case of a young male having multiple episodes of arterial thrombosis. First he developed Myocardial Infarction (MI) due to coronary artery thrombosis and had second episode of pulmonary artery thrombosis. He was diagnosed as having AT III deficiency as a cause for these multiple arterial thrombotic events. He was put on anticoagulant therapy with gradual recovery.