Factor II (2) or prothrombin deficiency is a hereditary 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.
Factor II deficiency is an autosomal recessive disorder, occurring in the very rare situation when both parents carry the gene change causing the condition and pass it on to their child. It also means that the disorder affects both males and females.
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 warfarin 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)
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, 2023.
NB We provide these links as a service to the haemophilia community. As web sites can change or should you find a site to be no longer active please notify hfaust@haemophilia.org.au. Haemophilia Foundation Australia is not responsible for the content of any external web sites. The featuring of a site on this page is not an endorsement by HFA of the information or views expressed therein.