A number of bleeding disorders may be associated with normal prothrombin time (PT) and activated partial thromboplastin time (aPTT).


Coagulation factor disorders:

(1) dysfibrinogenemia

(2) Factor 13 (XIII) deficiency

(3) mild deficiency in one or more coagulation factors, especially if part of a mixed disorder


Platelet and vascular disorders:

(1) qualitative platelet disorder (platelet dysfunction), including von Willebrand's disease and drug effects

(2) thrombocytopenia

(3) vascular disorder

(4) elevated fibrin degradation products

(5) monoclonal gammopathy (may be associated with acquired von Willebrand's disease)


Increased fibrinolysis:

(1) deficiency in alpha-2-antiplasmin


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