Residual iliofemoral thrombosis in a 31-year-old woman on oral contraceptives possessing heterozygous factor V Leiden, factor XIII Val34Leu allele and alpha-fibrinogen Thr312Ala allele: case report.

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 alpha-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 alpha-fibrinogen polymorphisms can be useful in the evaluation of some young patients with deep vein thrombosis.