Thrombosis associated with the prothrombin G-->A20210 mutation in Behçet's disease.

We describe 2 cases of Behcet's disease (BD) and thrombosis who were heterozygous for the prothrombin G-->A20210 mutation. In one case, progressive uncontrolled thromboses led to death. Case-control studies are needed to support the hypothesis of the role of the prothrombin A20210 allele as a risk factor for venous thrombosis in some patients with BD.