National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Prothrombin-related thrombophilia


Other Names:
Prothrombin 20210G>A thrombophilia; Hyperprothrombinemia; Prothrombin G20210A thrombophilia; Prothrombin 20210G>A thrombophilia; Hyperprothrombinemia; Prothrombin G20210A thrombophilia; Factor II-related thrombophilia; Thrombophilia due to factor 2 defect; F2-Related Thrombophilia; Prothrombin thrombophilia See More
Prothrombin thrombophilia is a genetic disorder of blood clotting. Individuals who have a thrombophilia have an increased risk to form abnormal blood clots in blood vessels. Those with prothrombin thrombophilia are at somewhat higher than average risk for a type of clot that typically occurs in the deep veins of the legs (deep venous thrombosis). There is additionally an increased risk of developing a clot that  lodges in the lungs (pulmonary embolism); however, most people with prothrombin thrombophilia never develop abnormal blood clots. This condition is caused by a particular mutation (written G20210A or 20210G>A) in the F2 gene. People can inherit one or two copies of the gene mutation from their parents.[1] The treatment for this condition is dependent on whether a blood clot has occurred and if there are additional risk factors. In individuals with a history of one or more blood clots, blood thinning medications may be used.[2]
Last updated: 5/22/2017

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance 0000006
Cerebral venous thrombosis
Blood clot in cerebral vein
0005305
Childhood onset
Symptoms begin in childhood
0011463
Deep venous thrombosis
Blood clot in a deep vein
0002625
Pulmonary embolism
Blood clot in artery of lung
0002204
Recurrent thrombophlebitis 0004419
Thromboembolism 0001907
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Last updated: 7/1/2020
Prothrombin thrombophilia is inherited in an autosomal dominant manner. For this condition, this means that having one mutated copy of the disease-causing gene (F2) in each cell may be sufficient to cause signs or symptoms of the condition. The mutation in the F2 gene that causes prothrombin thrombophilia is called 20210G>A (also called the 20210G>A allele).[3] An individual can be heterozygous (having the mutation in only one copy of the F2 gene) or homozygous (having a mutation in both copies of the F2 gene). Heterozygosity results in an increased risk for thrombosis; homozygosity results in more severe thrombophilia and/or increased risk for thrombosis.[3]

All individuals reported to date with prothrombin thrombophilia who are heterozygous for the 20210G>A allele have had an affected parent. Because of the relatively high prevalence of this allele in the general population, occasionally one parent is homozygous or both parents are heterozygous for this allele.[3]

When an individual who is heterozygous for the 20210G>A allele has children, each child has a 50% (1 in 2) risk to inherit that allele and also be heterozygous. An individual who is homozygous will always pass one of the 20210G>A alleles to each of his/her children. If two heterozygotes have children together, each child has a 25% (1 in 4) risk to be homozygous (having 2 mutated copies), a 50% risk to be heterozygous like each parent, and a 25% risk to inherit 2 normal copies of the F2 gene.
Last updated: 4/10/2013
No clinical signs or symptoms are specific for prothrombin thrombophilia. A confirmed diagnosis of this condition requires specific genetic testing via DNA analysis of the F2 gene, which provides instructions for making the protein prothrombin. The test identifies the presence of a common change (mutation) called 20210G>A.[3] An individual can be a heterozygote (having one mutated copy of the F2 gene) or a homozygote (having two mutated copies).

Most heterozygotes have a mildly elevated plasma concentration of prothrombin (which can be measured in a blood test) that is approximately 30% higher than normal. However, these values can vary greatly, and the range of prothrombin concentrations in heterozygotes overlaps significantly with the normal range. Therefore, plasma concentration of prothrombin is not reliable for diagnosis of this condition.[3]

Individuals interested in learning more about testing for prothrombin thrombophilia should speak with a genetics professional or other healthcare provider.
Last updated: 4/15/2013

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Prothrombin-related thrombophilia. This website is maintained by the National Library of Medicine.

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Prothrombin-related thrombophilia. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • My daughter found out she is a carrier for this condition by going through genetic testing for IVF. I would like to know how I can be tested to see if I have it, but without going through all the genetic testing. Is there a single blood test I can take? See answer


  1. Prothrombin thrombophilia. Genetics Home Reference. August 2008; http://ghr.nlm.nih.gov/condition/prothrombin-thrombophilia.
  2. Kujovich JL. Prothrombin-Related Thrombophilia. GeneReviews. August 14, 2014; https://www.ncbi.nlm.nih.gov/books/NBK1148.
  3. Jody L Kujovich. Prothrombin-Related Thrombophilia. GeneReviews. March 29, 2011; http://www.ncbi.nlm.nih.gov/books/NBK1148/. Accessed 4/9/2013.