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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed September 2008

What is the official name of the F2 gene?

The official name of this gene is “coagulation factor II, thrombin.”

F2 is the gene's official symbol. The F2 gene is also known by other names, listed below.

What is the normal function of the F2 gene?

The F2 gene provides instructions for making a protein called prothrombin (also called coagulation factor II). Coagulation factors are a group of related proteins that are essential for normal blood clotting (hemostasis). After an injury, clots protect the body by sealing off damaged blood vessels and preventing further blood loss.

Prothrombin is made chiefly by cells in the liver. The protein circulates in the bloodstream in an inactive form until an injury occurs that damages blood vessels. In response to injury, prothrombin is converted to its active form, thrombin. Thrombin then converts a protein called fibrinogen into fibrin, the primary protein that makes up blood clots.

Thrombin is also thought to be involved in cell growth and division (proliferation), tissue repair, and the formation of new blood vessels (angiogenesis).

Does the F2 gene share characteristics with other genes?

The F2 gene belongs to a family of genes called endogenous ligands (endogenous ligands).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? ( in the Handbook.

How are changes in the F2 gene related to health conditions?

prothrombin deficiency - caused by mutations in the F2 gene

More than 50 mutations in the F2 gene have been found to cause prothrombin deficiency. Most of these mutations change one protein building block (amino acid) in prothrombin. Some mutations drastically reduce the activity of prothrombin and can lead to severe bleeding episodes. Other mutations allow for a moderate amount of activity of prothrombin, typically causing mild bleeding episodes. None of the mutations identified eliminate prothrombin function. Researchers believe that people cannot live with a complete absence of prothrombin.

prothrombin thrombophilia - caused by mutations in the F2 gene

The mutation that causes most cases of prothrombin thrombophilia changes one DNA building block (nucleotide) in the F2 gene. Specifically, it replaces the nucleotide guanine with the nucleotide adenine at position 20210 (written G20210A or 20210G>A). This mutation, which occurs in a region of the gene called the 3' untranslated region, causes the gene to be overactive and leads to the production of too much prothrombin. An abundance of prothrombin leads to more thrombin, which promotes the formation of blood clots.

Where is the F2 gene located?

Cytogenetic Location: 11p11

Molecular Location on chromosome 11: base pairs 46,719,192 to 46,739,506

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The F2 gene is located on the short (p) arm of chromosome 11 at position 11.

The F2 gene is located on the short (p) arm of chromosome 11 at position 11.

More precisely, the F2 gene is located from base pair 46,719,192 to base pair 46,739,506 on chromosome 11.

See How do geneticists indicate the location of a gene? ( in the Handbook.

Where can I find additional information about F2?

You and your healthcare professional may find the following resources about F2 helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the F2 gene or gene products?

  • Blood Coagulation Factor II
  • coagulation factor II
  • coagulation factor II (thrombin)
  • prothrombin B-chain
  • PT
  • Q7Z7P3_HUMAN
  • serine protease

See How are genetic conditions and genes named? ( in the Handbook.

What glossary definitions help with understanding F2?

adenine ; amino acid ; angiogenesis ; biomarker ; blood clotting ; blood coagulation ; blood coagulation factor ; cell ; clotting ; coagulation ; coagulation factors ; deficiency ; DNA ; fibrin ; fibrinogen ; gene ; guanine ; hemostasis ; injury ; mutation ; nucleotide ; pharmacogenetics ; proliferation ; protease ; protein ; serine ; thrombin ; thrombophilia ; tissue

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • Akhavan S, Mannucci PM, Lak M, Mancuso G, Mazzucconi MG, Rocino A, Jenkins PV, Perkins SJ. Identification and three-dimensional structural analysis of nine novel mutations in patients with prothrombin deficiency. Thromb Haemost. 2000 Dec;84(6):989-97. (
  • Danckwardt S, Hartmann K, Gehring NH, Hentze MW, Kulozik AE. 3' end processing of the prothrombin mRNA in thrombophilia. Acta Haematol. 2006;115(3-4):192-7. Review. (
  • Jayandharan G, Viswabandya A, Baidya S, Nair SC, Shaji RV, Chandy M, Srivastava A. Molecular genetics of hereditary prothrombin deficiency in Indian patients: identification of a novel Ala362 --> Thr (Prothrombin Vellore 1) mutation. J Thromb Haemost. 2005 Jul;3(7):1446-53. (
  • McGlennen RC, Key NS. Clinical and laboratory management of the prothrombin G20210A mutation. Arch Pathol Lab Med. 2002 Nov;126(11):1319-25. Review. (
  • NCBI Gene (
  • 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. (
  • Varga EA, Moll S. Cardiology patient pages. Prothrombin 20210 mutation (factor II mutation). Circulation. 2004 Jul 20;110(3):e15-8. (


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.

Reviewed: September 2008
Published: February 1, 2016