RESUMO
We present a case of suprarenal & infrarenal absence of inferior vena cava combined with hyperhomocysteinemia in a 39-year-old woman who presented with symptoms of deep venous thrombosis. The patient has also C677T methylenetetrahydrofolate reductase homozygous mutation. Deep vein thrombosis has multifactorial etiology involving both genetic and acquired factors. Absence of inferior vena cava is a rare congenital anomaly, but recently it was confirmed as important risk factor for the development of deep vein thrombosis especially young person. Hypercoagulability by the hyperhomocysteinemia with suggested tendency to venous stasis mediated by agenesis of inferior vena cava must have caused the deep vein thrombosis in our patient. To our knowledge, such an association has not been reported. Clinical features and prognosis of this entity are discussed.