Coagulation factor XII (Hageman factor) (F12)

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.

What is the official name of the F12 gene?

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

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

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: 5q33-qter

Molecular Location on chromosome 5: base pairs 176,761,744 to 176,769,182

The F12 gene is located on the long (q) arm of chromosome 5 between position 33 and the end (terminus) of the arm.

More precisely, the F12 gene is located from base pair 176,761,744 to base pair 176,769,182 on chromosome 5.

What other names do people use for the F12 gene or gene products?

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

External Links

Where can I find additional information about F12?

You and your healthcare professional may find the following resources about F12 helpful.

• MedlinePlus - Health information
• Encyclopedia: Factor XII deficiency
• Educational resources - Information pages (3 links)

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

• PubMed - Recent literature
• OMIM - Genetic disorder catalog (2 links)
• Research Resources - Tools for researchers (3 links)

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

Where can I find general information about genes?

The Handbook provides basic information about genetics in clear language.

• What is DNA?
• What is a gene?
• How do genes direct the production of proteins?
• How can gene mutations affect health and development?

These links provide additional genetics resources that may be useful.

• Genetics education
• Human Genome Project
• Resources for Genetic Researchers

What glossary definitions help with understanding F12?

acids ; amino acid ; blood clotting ; Bradykinin ; clotting ; coagulation ; coagulation factors ; deficiency ; gene ; infection ; inflammation ; injury ; mutation ; protein ; symptom ; tissue

References

• 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. PubMed citation
• 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. PubMed citation
• Entrez Gene
• 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. PubMed citation
• 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. No abstract available. PubMed citation
• OMIM: F12 gene
• OMIM: Factor XII deficiency
• 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. PubMed citation
• Schmaier AH. The elusive physiologic role of Factor XII. J Clin Invest. 2008 Sep;118(9):3006-9. Review. PubMed citation