Related Experiment Video For clotting factor v deficiency
Updated: Jan 16, 2026

Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
Incidental Finding of Combined Factor V and VIII Deficiency in the Setting of a Preoperative Evaluation: A Case
Joseph L Luzarraga1, Jeremy I Purow2, Aron Berkman3
1Medicine, Florida International University, Herbert Wertheim College of Medicine, Miami, USA.
Abstract:
We present a case of a patient who was found to have incidental deficiencies of combined factor V (F5) and factor VIII (F8) identified on pre-operative screening. Our patient is a 61-year-old male with a past medical history of hyperparathyroidism, hypercalcemia, and mild kidney dysfunction. He was referred to the hematology clinic as he was found to have an abnormal activated partial thromboplastin time (aPTT) while being evaluated preoperatively for a parathyroidectomy. The patient did not have any significant history of bleeding, bruising, or hemarthrosis but recalls occasional nosebleeds in childhood. The patient was screened with PT/aPTT by his primary care prior to surgery. This revealed a mildly prolonged aPTT and a normal prothrombin time (PT), and the patient was referred to hematology. Further studies one week later revealed decreased F5 and F8 activity. von Willebrand Factor antigen levels were normal. CBC, protein C and S activity, and antiphospholipid antibody screening were normal as well. This is postulated to arise from a monogenic mechanism, classically through biallelic variants in LMAN1 or MCFD2, leading to combined F5 and F8 deficiency. Rarely, it can be of digenic inheritance with separate defects in F5 and F8. We outline considerations for perioperative evaluation and family counseling in the setting of a rare coagulopathy.
Related Concept Videos
Venous Thrombosis II: Clinical Manifestations and Diagnostic Studies
Venous Thrombosis III: Interprofessional Care
Anticoagulant Drugs: Vitamin K Antagonists and Direct Oral Anticoagulants
Warfarin, a prominent vitamin K antagonist family member, exerts its effect by inhibiting the enzyme VKORC1 (vitamin K epoxide reductase complex 1). By hindering this enzyme, warfarin...
Anticoagulant Drugs: Low-Molecular-Weight Heparins
Disorders of Hemostasis
Thromboembolic Disorders
Two factors primarily cause thromboembolic conditions.
Extrinsic and Intrinsic Pathways of Hemostasis
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which...

