Behçet's syndrome and factor XII deficiency.

Several mechanisms have been proposed to explain thrombotic tendency in Behçet's syndrome. We report the case of a 43-year old woman presenting retinal-vein thrombosis, factor XII deficiency and Behçet's syndrome. This kind of association has thus far never been reported. Factor XII deficiency is known to possibly induce various types of thrombosis and might explain the prevalence of ocular symptoms in our patient.