The dysfibrinogenemias are a group of autosomal dominant disorders of qualitatively abnormal fibrinogens. There are more than 350 different fibrinogen abnormalities, each named after the place where it was discovered. Each dysfibrinogenemia is associated with slightly different effects on the thrombin time and on normal clotting. Some dysfibrinogenemias cause abnormal bleeding or even thrombosis, while others have no effect on either bleeding or thrombosis. Some examples are:
Amsterdam is a major defect, characterized by aggregation of fibrinmonomers, prolonged thrombin time, and an inhibitory effect on normal clotting - but it is asymptomatic.
Detroit is a major defect, there is fibrinopeptide release, the thrombin time is prolonged, there is an inhibitory effect on normal clotting and there is abnormal bleeding.
Wiesbaden is a major defect, there is aggregation of fibrin monomers, the thrombin time is prolonged, there is an inhibitory effect on normal clotting and there is both bleeding and thrombosis.
^McDonagh, J (2001). "Dysfibrinogenemia and other disorders of fibrinogen structure or function". In Colman R, Hirsh J, Marder V, Clowes A, George J. Hemostasis and Thrombosis (4th ed.). Philadelphia, PA: Lippincott Williams & Wilkins. pp. 855–892.