Residual iliofemoral thrombosis in a 31‑year‑old woman on oral contraceptives possessing heterozygous factor V Leiden, factor XIII Val34Leu allele and α-fibrinogen Thr312Ala allele

We present the case of a 31‑year‑old woman on oral contraceptives with a 3‑year history of iliofemoral thrombosis resistant to recanalization despite satisfactory anticoagulation therapy and absence of concomitant diseases. Thrombophilia screening revealed heterozygous factor V Leiden mutation. We also detected the presence of factor XIII (FXIII) Leu34 allele and α‑chain fibrinogen 312Ala allele, which are known to adversely affect fibrin clot structure and lysis. It might be speculated that the presence of 3 polymorphisms in this patient could contribute to proximal thrombosis resistant to treatment. We postulate that determination of FXIII and α-fibrinogen polymorphisms can be useful in the evaluation of some young patients with deep vein thrombosis.