Portal and mesenteric vein thrombosis in a patient heterozygous for a mutation (Arg(506)-> Gln) in the factor V gen (factor V Leiden)

In 30-50% of patients with portal thrombosis, no underlying etiology is fou nd. The recent reports of new hereditary clotting defects are contributing to the understanding of this problem, but they only justify a small number of idiopathic cases. Instead, anticoagulant protein C resistance, caused by a mutation in the V factor gene, appears to be at least 10 times more comm on than any of the other known inherited deficiencies of anticoagulant prot eins. In spite of that, extensive thrombosis of portomesenteric or hepatic venous circulation has been rarely described in this hereditary clotting de fect. We report a typical case of familial and recidivant deep vein thrombo sis in a young man heterozygous for the factor V Leiden mutation (Arg(506_) Gin), who developed an acute portal and mesenteric vein thrombosis. The pat ient was discharged with an oral anticoagulant treatment and remains asympt omatic 2 years later. In conclusion, the high prevalence of the factor V Le iden in young and aged patients with idiopathic vein thrombosis and the cas e here described makes it obligatory to consider this disorder in patients with portal and/or mesenteric vein thrombosis, especially in those without evident etiology.