Factor V Leiden

Learning objectives

Factor V Leiden is an autosomal dominant inherited mutation of the F5 gene that controls the production of factor V, one of the clotting factors in the blood
Resulting in resistance to activated protein C thereby leading to thrombosis
It is the most common inherited blood clotting disorder
Factor V Leiden increases the chance of developing a deep vein thrombosis or pulmonary embolism
However, most people with factor V Leiden never develop abnormal blood clots

The factor V Leiden mutation does not itself cause any symptoms and the first indication is the development of a blood clot
Deep vein thrombosis
- Pain
- Swelling
- Redness
- Warmth
- Tenderness
- Abdominal pain
- A severe, sudden headache and/or seizures
Pulmonary embolism
- Sudden shortness of breath
- Chest pain when breathing in
- A cough that produces bloody or blood-streaked sputum
- Wheezing
- Tachycardia
- Feeling light-headed or fainting

Anticoagulants are not routinely recommended for factor V Leiden
If DVT or PE is diagnosed, anticoagulantherapy is started as soon as possible
Consider that the patient:
- May be on chronic anticoagulant therapy
- Is at increased risk of perioperative clotting events and need a DVT prophylaxis plan
See pulmonary embolism