Factor XII

Jump to: navigation, search
coagulation factor XII
Identifiers
Symbol F12
Entrez 2161
HUGO 3530
OMIM 234000
RefSeq NM_000505
UniProt P00748
Other data
EC number 3.4.21.38
Locus Chr. 5 q33-qter

WikiDoc Resources for Factor XII

Articles

Most recent articles on Factor XII

Most cited articles on Factor XII

Review articles on Factor XII

Articles on Factor XII in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Factor XII

Images of Factor XII

Photos of Factor XII

Podcasts & MP3s on Factor XII

Videos on Factor XII

Evidence Based Medicine

Cochrane Collaboration on Factor XII

Bandolier on Factor XII

TRIP on Factor XII

Clinical Trials

Ongoing Trials on Factor XII at Clinical Trials.gov

Trial results on Factor XII

Clinical Trials on Factor XII at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Factor XII

NICE Guidance on Factor XII

NHS PRODIGY Guidance

FDA on Factor XII

CDC on Factor XII

Books

Books on Factor XII

News

Factor XII in the news

Be alerted to news on Factor XII

News trends on Factor XII

Commentary

Blogs on Factor XII

Definitions

Definitions of Factor XII

Patient Resources / Community

Patient resources on Factor XII

Discussion groups on Factor XII

Patient Handouts on Factor XII

Directions to Hospitals Treating Factor XII

Risk calculators and risk factors for Factor XII

Healthcare Provider Resources

Symptoms of Factor XII

Causes & Risk Factors for Factor XII

Diagnostic studies for Factor XII

Treatment of Factor XII

Continuing Medical Education (CME)

CME Programs on Factor XII

International

Factor XII en Espanol

Factor XII en Francais

Business

Factor XII in the Marketplace

Patents on Factor XII

Experimental / Informatics

List of terms related to Factor XII

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]


Overview

Hageman factor is a plasma protein now usually known as factor XII. It is an enzyme (EC 3.4.21.38) of the serine protease (or serine endopeptidase) class.

Function

It is part of the coagulation cascade and activates factor XI and prekallikrein.

The coagulation cascade.

Genetics

The gene for factor XII is located on the tip of the long arm of the fifth chromosome (5q33-qter).

Role in disease

Hageman factor deficiency is a rare hereditary disorder with a prevalence of about one in a million, although it is a little more common among Asians. Deficiency does not cause excessive hemorrhage as the other coagulation factors make up for the it. It may increase the risk of thrombosis, due to inadequate activation of the fibrinolytic pathway. The deficiency leads to activated partial thromboplastin times (PTT) greater than 200 seconds.

Two missense mutations have been identified in F12, the gene encoding human coagulation factor XII. These mutations are thought to be the cause of a very rare form of hereditary angioedema (HAE), called HAE type III.[1]

History

Hageman factor was first discovered in 1955 when a routine preoperative blood sample of the 37-year-old railroad brakeman John Hageman was found to have prolonged clotting time in test tubes, even though he had no hemorrhagic symptoms. Hageman was then examined by Dr. Oscar Ratnoff who found that Mr. Hageman lacked a previously unidentified clotting factor.[2] Dr. Ratnoff later found that the Hageman factor deficiency is autosomal recessive disorder, when examining several related people which had the deficiency. Paradoxically, pulmonary embolism contributed to Hageman's death after an occupational accident. Since then, case series clinical studies have identified an association of thrombosis and Factor XII deficiency, though the pathophysiology of the relationship is unclear.

References

  1. Cichon S, Martin L, Hennies HC; et al. (2006). "Increased activity of coagulation factor XII (Hageman factor) causes hereditary angioedema type III". Am. J. Hum. Genet. 79 (6): 1098–104. PMID 17186468. doi:10.1086/509899. 
  2. Ratnoff OD, Margolius A (1955). "Hageman trait: an asymptomatic disorder of blood coagulation". Trans. Assoc. Am. Physicians. 68: 149–54. PMID 13299324. 

External links

de:Hageman-Faktor

Linked-in.jpg