[Portal vein thrombosis associated with factor V Leiden mutation in a woman who underwent exchange transfusion at birth].

We report the case of a 18-year-old woman with portal vein thrombosis and chronic hepatitis C virus. Portal vein thrombosis was diagnosed by chance on ultrasound examination during initial hepatitis C virus-positive patient screening. The patient interview revealed a history including exchange transfusion at birth, followed by necrotising ulcerocolitis and septicemia. The investigation of general factors favoring thrombosis showed acquired protein S deficiency and heterozygous factor V Leiden mutation. This case demonstrates the value of systematic investigations for general thrombophilic factors in cases of portal vein thrombosis even when a local cause is found.