Abstract

Factor V Leiden gene mutation is the most common inherited risk factor for deep venous thrombosis (DVT). The prevalence of Factor V Leiden and Factor II prothrombin gene mutations was reported at about 5-10% and 2% (as heterozygous mutations), respectively in whites. Homozygosity for these mutations is less common, with a prevalence of 0.02% for Factor V Leiden and 0.014% for Factor II mutation.

We diagnosed homozygous Factor V Leiden G 1691 A gene mutation in a a 52-yr-old female patient taking oral anticoagulation therapy following the diagnosis of Pulmonary Embolism (PE) and recurrent DVT (3 times) for 7 years with different treatment regimens. To date, the underlying etiology was unknown and her compliance with the treatment was poor. The treatment protocol was reviewed and it was decided that the anticoagulation therapy should be lifelong, maintaining INR as 2.0-3.0 unless a contraindication or complication developed.