Congenital heterozygous plasminogen deficiency associated with a severe thrombotic tendency.

Heterozygous plasminogen deficiency was found in 2 patients (mother and daughter). The mother, aged 55 years, was symptomatic while the daughter, aged 10 years, was asymptomatic so far. The thrombotic tendency presented by the proposita (mother) was severe and included recurrent superficial, portal, mesenteric, subclavian thrombophlebitis. No arterial thrombosis was noted. Oral anticoagulants have been of some benefit. The main laboratory features were: plasminogen activity about 50% of normal in two amidolytic methods and in a caseinolytic method. Plasminogen antigen was also about 50% of normal using electroimmunoassay and radial immunodiffusion. Crossed immunoelectrophoresis revealed a normal, even though reduced pattern, thus excluding dysplasminogenemia. Routine coagulation tests were negative. Euglobulin lysis time, fibrinogen level and fibrinogen degradation products (FDP) were within normal limits. Antithrombin III, protein C and protein S were also within normal limits.