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


Reviewed April 2009

What is the official name of the F12 gene?

The official name of this gene is “coagulation factor XII.”

F12 is the gene's official symbol. The F12 gene is also known by other names, listed below.

What is the normal function of the F12 gene?

The F12 gene provides instructions for making a protein called coagulation factor XII. Coagulation factors are a group of related proteins that are essential for normal blood clotting (coagulation). After an injury, clots protect the body by sealing off damaged blood vessels and preventing further blood loss. Factor XII circulates in the bloodstream in an inactive form until it is activated, usually by coming in contact with damaged blood vessel walls. Upon activation, factor XII interacts with coagulation factor XI. This interaction sets off a chain of additional chemical reactions that form a blood clot.

Factor XII also plays a role in stimulating inflammation, a normal body response to infection, irritation, or other injury. When factor XII is activated, it also interacts with a protein called plasma prekallikrein. This interaction initiates a series of chemical reactions that lead to the release of a protein called bradykinin. Bradykinin promotes inflammation by increasing the permeability of blood vessel walls, allowing more fluids to leak into body tissues. This leakage causes the swelling that accompanies inflammation.

How are changes in the F12 gene related to health conditions?

hereditary angioedema - associated with the F12 gene

At least two mutations in the F12 gene are associated with hereditary angioedema type III. These mutations change single protein building blocks (amino acids) in factor XII, which increases the activity of the protein. As a result, more bradykinin is produced, which allows additional fluids to leak through blood vessel walls. The accumulation of fluids in body tissues leads to the episodes of swelling in people with hereditary angioedema type III.

other disorders - caused by mutations in the F12 gene

Approximately 20 mutations in the F12 gene that cause factor XII deficiency have been identified. Factor XII deficiency is an inherited condition characterized by a shortage of factor XII in the blood. Individuals with this condition usually do not experience abnormal bleeding or other symptoms. Factor XII deficiency is typically discovered during routine blood testing because reduced levels of factor XII cause the blood to take longer to clot in a test tube. Most of the mutations that cause factor XII deficiency change single amino acids, which alters the structure of factor XII. It remains unclear why individuals with factor XII deficiency do not experience abnormal bleeding like those with deficiencies of other coagulation factors.

Where is the F12 gene located?

Cytogenetic Location: 5q35.3

Molecular Location on chromosome 5: base pairs 177,402,138 to 177,416,524

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

The F12 gene is located on the long (q) arm of chromosome 5 at position 35.3.

The F12 gene is located on the long (q) arm of chromosome 5 at position 35.3.

More precisely, the F12 gene is located from base pair 177,402,138 to base pair 177,416,524 on chromosome 5.

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

Where can I find additional information about F12?

You and your healthcare professional may find the following resources about F12 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 F12 gene or gene products?

  • coagulation factor XII (Hageman factor)
  • FA12_HUMAN
  • HAE3
  • HAEX
  • HAF
  • Hageman factor

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

What glossary definitions help with understanding F12?

acids ; blood clotting ; bradykinin ; clotting ; coagulation ; coagulation factors ; deficiency ; gene ; hereditary ; infection ; inflammation ; inherited ; injury ; permeability ; plasma ; protein

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


  • Cichon S, Martin L, Hennies HC, Müller F, Van Driessche K, Karpushova A, Stevens W, Colombo R, Renné T, Drouet C, Bork K, Nöthen MM. Increased activity of coagulation factor XII (Hageman factor) causes hereditary angioedema type III. Am J Hum Genet. 2006 Dec;79(6):1098-104. Epub 2006 Oct 18. (
  • Dewald G, Bork K. Missense mutations in the coagulation factor XII (Hageman factor) gene in hereditary angioedema with normal C1 inhibitor. Biochem Biophys Res Commun. 2006 May 19;343(4):1286-9. (
  • Lombardi AM, Bortoletto E, Scarparo P, Scapin M, Santarossa L, Girolami A. Genetic study in patients with factor XII deficiency: a report of three new mutations exon 13 (Q501STOP), exon 14 (P547L) and -13C>T promoter region in three compound heterozygotes. Blood Coagul Fibrinolysis. 2008 Oct;19(7):639-43. doi: 10.1097/MBC.0b013e32830d8629. (
  • Martin L, Raison-Peyron N, Nöthen MM, Cichon S, Drouet C. Hereditary angioedema with normal C1 inhibitor gene in a family with affected women and men is associated with the p.Thr328Lys mutation in the F12 gene. J Allergy Clin Immunol. 2007 Oct;120(4):975-7. Epub 2007 Sep 7. (
  • NCBI Gene (
  • Renné T, Gailani D. Role of Factor XII in hemostasis and thrombosis: clinical implications. Expert Rev Cardiovasc Ther. 2007 Jul;5(4):733-41. Review. (
  • Schmaier AH. The elusive physiologic role of Factor XII. J Clin Invest. 2008 Sep;118(9):3006-9. doi: 10.1172/JCI36617. Review. (


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: April 2009
Published: February 8, 2016