[Fibrinogen Quebec I and Quebec II: two new families of dysfibrinogenemia (author's transl)].

Two new families of congenital dysfibrinogenemia originating from French Canada are reported. The dysfibrinogenemia in the first family is characterized by an abnormal aggregation of the fibrin monomers; the defect in the second family is due to a faulty release of fibrinopeptides during the proteolytic phase of the thrombin-fibrinogen reaction.