Bilateral Superficial Femoral Artery Thrombosis in a 15-Year-Old Caucasian Male with Homozygous Prothrombin G20210A Genotype and Associated Antiphospholipid Syndrome

Prothrombin mutation was usually associated with other well-established predisposing factors for venous thrombosis such as antiphospholipid antibodies. Recently, even isolated prothrombin gene mutation G20210A has been reported to present severe or unusual vein thrombosis. Less clear is the role of prothrombin mutation in the formation of arterial thrombosis. We present a case of a 15-year-old healthy White male with acute bilateral femoral artery thrombosis. The patient presented with increasing left leg pain for about 1 week. He was a physically very active teenager with a new onset of leg pain aggravated by exercise. Physical examination revealed a pale and cold left foot with dorsal foot necrosis (2 × 2 cm) that started 2 days ago. In addition, he complained of moderate rest pain. No symptoms were noticed on the right lower extremity. The ankle brachial index was 0.3 on the left and 0.6 on the right. Duplex sonography showed bilateral superficial femoral artery thrombosis, which was confirmed by angiography. Subsequently, he undergoes left superficial femoral and popliteal artery lysis with rt-PA (Actilyse boehringer ingelheim, Ingelheim am Rhein, Germany) and full heparinization. Treatment was discontinued after 24 hours with no significant improvement of symptoms. Full anticoagulation with Coumadin (Bristol-Myers Squibb Company, New York, NY) and alprostadil (Prostavasin UCB, Brussels, Belgium) infusion for 2 weeks was initiated and eventually patient's symptoms improved. Laboratory testing revealed a homozygous prothrombin G20210A mutation and antiphospholipid syndrome. Homozygous prothrombin G20210A mutation in conjunction with antiphospholipid syndrome is a rare combination of coagulation disorder. Early intervention with full anticoagulation and subsequent lifelong anticoagulation should be considered in treatment strategy.