Factor II Deficiency

Factor II (2) or prothrombin deficiency is an inherited bleeding disorder caused when a person's body does not produce as much of a protein in the blood (factor II) that helps blood clot as it needs to or the factor II doesn't work properly. It is very rare, affecting one out of 2,000,000 people, but is more common in communities where there is marriage between close relatives.

Factor II deficiency may also be acquired later in life if the body’s production of prothrombin is slowed down or stopped by severe liver disease, some blood thinners such as coumadin or vitamin K deficiency. Acquired factor II deficiency is more common than the inherited form.

Links to selected resources:

What Is Factor II Deficiency?
(World Federation of Hemophilia)
See the About Bleeding Disorders section. Explains the causes of FII deficiency, its symptoms, diagnosis and treatment.

Factor II deficiency (Prothrombin deficiency)
(Canadian Hemophilia Society, 2006)
This booklet explains how factor II works, the causes of FII deficiency, symptoms, available treatments, healthy living and prevention.

Factor II deficiency
(National Hemophilia Foundation, USA)

Source: What are rare clotting factor deficiencies? World Federation of Hemophilia, Montreal, Canada, 2009.

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Date last reviewed: 18 September 2020