Encyclopedia
Coagulation factor II, thrombin
- genes
1. Normal Function
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).
2. Health Conditions Related to Genetic Changes
2.1 Prothrombin Deficiency
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.
2.2 Prothrombin Thrombophilia
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.
3. Other Names for This Gene
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Blood Coagulation Factor II
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coagulation factor II
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coagulation factor II (thrombin)
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prothrombin B-chain
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PT
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Q7Z7P3_HUMAN
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serine protease
This entry is adapted from the peer-reviewed paper https://medlineplus.gov/genetics/gene/f2
References
- Akhavan S, Mannucci PM, Lak M, Mancuso G, Mazzucconi MG, Rocino A, Jenkins PV,Perkins SJ. Identification and three-dimensional structural analysis of ninenovel mutations in patients with prothrombin deficiency. Thromb Haemost. 2000Dec;84(6):989-97.
- Danckwardt S, Hartmann K, Gehring NH, Hentze MW, Kulozik AE. 3' end processingof 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 Indianpatients: 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 prothrombinG20210A mutation. Arch Pathol Lab Med. 2002 Nov;126(11):1319-25. Review.
- Spector EB, Grody WW, Matteson CJ, Palomaki GE, Bellissimo DB, Wolff DJ,Bradley LA, Prior TW, Feldman G, Popovich BW, Watson MS, Richards CS. Technicalstandards and guidelines: venous thromboembolism (Factor V Leiden and prothrombin20210G >A testing): a disease-specific supplement to the standards and guidelinesfor clinical genetics laboratories. Genet Med. 2005 Jul-Aug;7(6):444-53.
- Varga EA, Moll S. Cardiology patient pages. Prothrombin 20210 mutation (factorII mutation). Circulation. 2004 Jul 20;110(3):e15-8.
