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Reviewed September 2008
What is prothrombin deficiency?
Prothrombin deficiency is a bleeding disorder that slows the blood clotting process. People with this condition often experience prolonged bleeding following an injury, surgery, or having a tooth pulled. In severe cases of prothrombin deficiency, heavy bleeding occurs after minor trauma or even in the absence of injury (spontaneous bleeding). Women with prothrombin deficiency can have prolonged and sometimes abnormally heavy menstrual bleeding. Serious complications can result from bleeding into the joints, muscles, brain, or other internal organs. Milder forms of prothrombin deficiency do not involve spontaneous bleeding, and the condition may only become apparent following surgery or a serious injury.
How common is prothrombin deficiency?
Prothrombin deficiency is very rare; it is estimated to affect 1 in 2 million people in the general population.
What genes are related to prothrombin deficiency?
Mutations in the F2 gene cause prothrombin deficiency. The F2 gene provides instructions for making the prothrombin protein (also called coagulation factor II), which plays a critical role in the formation of blood clots in response to injury. Prothrombin is the precursor to thrombin, a protein that initiates a series of chemical reactions to form a blood clot. After an injury, clots protect the body by sealing off damaged blood vessels and preventing further blood loss.
F2 mutations reduce the amount of prothrombin in cells, which prevents clots from forming properly in response to injury. Problems with blood clotting can lead to excessive bleeding. Some mutations drastically reduce the activity of prothrombin and can lead to severe bleeding episodes. Other mutations allow for a moderate amount of prothrombin activity, typically causing mild bleeding episodes.
Read more about the F2 gene.
How do people inherit prothrombin deficiency?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Where can I find information about diagnosis or management of prothrombin deficiency?
These resources address the diagnosis or management of prothrombin deficiency and may include treatment providers.
General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.
Where can I find additional information about prothrombin deficiency?
You may find the following resources about prothrombin deficiency helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
What other names do people use for prothrombin deficiency?
What if I still have specific questions about prothrombin deficiency?
Where can I find general information about genetic conditions?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding prothrombin deficiency?
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (4 links)
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.