Health Topics
Official websites use .gov
A
.gov website belongs to an official government
organization in the United States.
Secure .gov websites use HTTPS
A
lock (
) or https:// means you’ve safely connected to
the .gov website. Share sensitive information only on official,
secure websites.
Description
Prothrombin thrombophilia is a disorder that increases the risk of developing blood clots. Thrombophilia is the term used to describe an increased tendency to form blood clots. After an injury, clots protect the body by sealing off damaged blood vessels and preventing further blood loss. People with thrombophilia can develop clots when they are not needed. These clots can block normal blood flow and cause harm.
People who have prothrombin thrombophilia have a higher-than-average risk of developing a type of clot called a deep vein thrombosis
, which typically occurs in the blood vessels of the arms or legs. People with prothrombin thrombophilia also have an increased risk of developing a pulmonary embolism
, which is a clot that travels through the bloodstream and lodges in the lungs.
Research suggests that pregnancy loss may be somewhat more likely in people with prothrombin thrombophilia than in those who do not have the condition. Some researchers have suggested that prothrombin thrombophilia may also increase the risk of other complications during pregnancy, though this remains controversial.
While many people with prothrombin thrombophilia will never have clotting issues, several factors increase a person's risk of blood clots. Some risk factors that contribute to the development of harmful blood clots include surgery, injury or trauma, air travel, obesity, and a family history of blood clots. Additional risk factors include pregnancy, using contraceptives such as birth control pills or patches that contain estrogen, and receiving post-menopausal hormone replacement therapy. The combination of prothrombin thrombophilia and other clotting disorders may also increase a person's risk.
Frequency
Prothrombin thrombophilia is the second most common inherited form of thrombophilia after factor V Leiden thrombophilia.
Prothrombin thrombophilia is most common in people of European ancestry. Two to five percent of Americans of European ancestry have the particular genetic variant (also called a mutation) that causes most cases of prothrombin thrombophilia. This condition is much less common in African, Asian, and Native American populations.
Causes
A particular variant in the F2 gene causes most cases of prothrombin thrombophilia. The F2 gene plays a critical role in the formation of blood clots in response to injury. The protein produced from the F2 gene is called prothrombin (also known as coagulation factor II). Prothrombin is the precursor to a protein called thrombin that initiates a series of chemical reactions to form a blood clot.
The variant in the F2 gene that causes most cases of prothrombin thrombophilia triggers the production of too much prothrombin. More prothrombin leads to more thrombin, which promotes the formation of blood clots.
Inheritance
Prothrombin thrombophilia is typically inherited in an autosomal dominant pattern
, which means one copy of the altered gene in each cell is sufficient to increase the risk of developing harmful blood clots.
Individuals who have a variant in one of the two copies of the F2 gene have a risk of developing harmful blood clots that is two to five times greater than average.
Because the F2 gene variant that causes most cases of prothrombin thrombophilia is common in certain populations, it is possible for an individual to inherit this variant from both parents. Though many people who inherit a variant in both copies of their F2 gene will never develop a harmful blood clot, these individuals have a higher risk than people who inherit only one F2 gene variant. People with two F2 gene variants may also develop harmful blood clots more frequently and at a younger age than people with just one F2 gene variant.
Other Names for This Condition
- Prothrombin G20210A thrombophilia
- Prothrombin-related thrombophilia
- Thrombophilia 1 due to thrombin defect
Additional Information & Resources
Genetic Testing Information
Genetic and Rare Diseases Information Center
Patient Support and Advocacy Resources
Catalog of Genes and Diseases from OMIM
Scientific Articles on PubMed
References
- Bosler D, Mattson J, Crisan D. Phenotypic Heterogeneity in Patients with Homozygous Prothrombin 20210AA Genotype. A paper from the 2005 William Beaumont Hospital Symposium on Molecular Pathology. J Mol Diagn. 2006 Sep;8(4):420-5. doi: 10.2353/jmoldx.2006.060014. Citation on PubMed or Free article on PubMed Central
- Kujovich JL. Prothrombin Thrombophilia. 2006 Jul 25 [updated 2021 Feb 4]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2025. Available from http://www.ncbi.nlm.nih.gov/books/NBK1148/ Citation on PubMed
- McGlennen RC, Key NS. Clinical and laboratory management of the prothrombin G20210A mutation. Arch Pathol Lab Med. 2002 Nov;126(11):1319-25. doi: 10.5858/2002-126-1319-CALMOT. Citation on PubMed
- Spector EB, Grody WW, Matteson CJ, Palomaki GE, Bellissimo DB, Wolff DJ, Bradley LA, Prior TW, Feldman G, Popovich BW, Watson MS, Richards CS. Technical standards and guidelines: venous thromboembolism (Factor V Leiden and prothrombin 20210G >A testing): a disease-specific supplement to the standards and guidelines for clinical genetics laboratories. Genet Med. 2005 Jul-Aug;7(6):444-53. doi: 10.1097/01.gim.0000172641.57755.3a. Citation on PubMed
- Varga EA, Moll S. Cardiology patient pages. Prothrombin 20210 mutation (factor II mutation). Circulation. 2004 Jul 20;110(3):e15-8. doi: 10.1161/01.CIR.0000135582.53444.87. No abstract available. Citation on PubMed
The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.