“…13 It has been suggested that agenesis of the IVC should be considered in young patients with proximal DVT that is idiopathic, bilateral, and recurrent, in the absence of predisposing risk factors such as thrombophilia and especially in patients under the age of 30. [1][2][3]7,8,10,11,13,15,16 Known risk factors for DVT also have an influence, acting in synergy if combined with IVC agenesis. These include genetic factors that lead to hypercoagulability, such as deficiencies of proteins C and S and antithrombin; factor V Leiden, high concentrations of factor VIII and hyperhomocysteinemia, in addition to acquired risk factors such as traumas, surgery, immobilization, and pregnancy.…”