What reflex test should be done on a patient with an abnormal APTT who is suspected of having hemophillia?

Question

Quizplus · Accepted Answer

An abnormal APTT (activated partial thromboplastin time) suggests a deficiency in the coagulation factors that are involved in the intrinsic pathway of coagulation. Hemophilia is a disorder that affects the intrinsic pathway, specifically the deficiency of Factor VIII or Factor IX. Therefore, a factor assay is the best reflex test to confirm a diagnosis of hemophilia. Platelet function assay, quantitative fibrinogen assay, and assay for D-dimer are not relevant tests for diagnosing hemophilia.

What Reflex Test Should Be Done on a Patient with an Abnormal