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Factor V resistance to activated protein C: causes, symptoms, diagnosis, treatment

Medical expert of the article

Dr. Fredi AVIV.

Hematologist, oncohematologist

Alexey Kryvenko, medical expert
Last reviewed: 05.07.2025

Epidemiology

Causes
Diagnostics
Treatment

Activated protein C cleaves factors Va and VIIIa, thereby inhibiting the blood clotting process.

Epidemiology

The prevalence of this mutation in the European population is about 5%, but this gene anomaly is extremely rare in Asian and African populations. In patients with spontaneous venous thrombosis, the Leiden mutation occurs in 20 to 60% of cases.

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Causes of factor V resistance to activated protein C

Any of several mutations of factor V causes its resistance to activated protein C, thereby increasing the susceptibility to thrombosis. The most common mutation of factor V is the Leiden mutation. Homozygous mutations increase the risk of thrombosis to a greater extent than heterozygous mutations.

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Diagnostics of factor V resistance to activated protein C

The diagnosis is based on functional studies of plasma coagulation (absence of prolongation of the PTT test in the presence of snake venom activating protein C) and molecular analysis of the factor V gene.

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Treatment of factor V resistance to activated protein C

If treatment is necessary, heparin is prescribed first, followed by warfarin.