Which disease would typically show a normal partial thromboplastin time (PTT)?

Factor V Leiden is associated with a mutation that leads to an increased risk of thrombosis due to resistance to activated protein C. This condition often results in a normal partial thromboplastin time (PTT). The PTT assesses the intrinsic and common pathways of coagulation, and since Factor V Leiden does not affect these pathways in a way that prolongs PTT, it remains within the normal range.

In contrast, Von Willebrand disease typically results in a prolonged PTT due to the associated deficiencies in factor VIII. Hemophilia A also prolongs PTT since it is caused by a deficiency of factor VIII, which is a critical component of the intrinsic pathway. Chronic liver disease can affect multiple coagulation factors, often leading to a prolonged PTT because of impaired synthesis of clotting factors.

Understanding the specific pathways affected by different coagulation disorders is key to interpreting PTT results and associating them with various conditions accurately.