Medicine:Factor XII deficiency
| Factor XII deficiency | |
|---|---|
| Other names | Hageman factor deficiency |
Factor XII deficiency is a deficiency in the production of factor XII (FXII), a plasma glycoprotein and clotting factor that participates in the coagulation cascade and activates factor XI. FXII appears to be not essential for blood clotting, as individuals with this condition are usually asymptomatic and form blood clots in vivo. FXII deficiency tends to be identified during presurgical laboratory screening for bleeding disorders.[1]
The condition can be inherited or acquired.[citation needed]
Symptoms and signs
While it is indicated that people with FXII deficiency are generally asymptomatic,[2] studies in women with recurrent miscarriages suggest an association with FXII deficiency.[3] The condition is of importance in the differential diagnosis to other bleeding disorders, specifically the hemophilias: hemophilia A with a deficiency in factor VIII or antihemophilic globulin, hemophilia B with a deficiency in factor IX (Christmas disease), and hemophilia C with a deficiency in factor XI. Other rare forms of bleeding disorders are also in the differential diagnosis.[citation needed]
There is concern that individuals with FXII deficiency are more prone to thrombophilic disease,[1] however, this is at variance with a long-term study from Switzerland.[4]
Causes
Inherited or congenital FXII deficiency is usually passed on by autosomal recessive inheritance.[2] A person needs to inherit a defective gene from both parents. People who have only one defective gene are asymptomatic, but may have lower FXII levels and can pass the gene on to half their offspring.[citation needed]
In persons with congenital FXII deficiency the condition is lifelong. People affected may want to alert other family members as they may also carry the gene. A 1994 study of 300 healthy blood donors found that 7 persons (2.3%) had FXII deficiencies with one subject having no detectable FXII (0.3%).[5] This study is at variance with estimates that only 1 in 1,000,000 people has the condition.[2]
The acquired form of FXII deficiency is seen in patients with the nephrotic syndrome, liver disease, sepsis and shock, disseminated intravascular coagulation, and other diseases.[1]
Diagnosis
The condition is diagnosed by blood tests in the laboratory when it is noted that special blood clotting test are abnormal. Specifically Activated Partial Thromboplastin Time (aptt) is prolonged.[2] The diagnosis is confirmed by an assay detecting very low or absent FXII levels.[citation needed]
The FXII (F12) gene is found on chromosome 5q33-qter.[2] In hereditary angioedema type III an increased activity of factor XII has been described.[6]
Treatment
In congenital FXII deficiency treatment is not necessary. In acquired FXII deficiency the underlying problem needs to be addressed.[citation needed]
History
The condition was first described in 1955 based by blood testing of a patient named John Hageman.[7]
References
- ↑ 1.0 1.1 1.2 Riley RS (April 2005). "Factor XII Deficiency". Pathology, Virginia Commonwealth University. http://www.pathology.vcu.edu/media/pathology/clinical/coag/FXIIDeficiency.pdf.
- ↑ 2.0 2.1 2.2 2.3 2.4 "Factor XII Deficiency". National Organization for Rare Disorders(NORD). https://rarediseases.org/rare-diseases/factor-xii-deficiency/.
- ↑ "Factor XII deficiency is strongly associated with primary recurrent abortions". Fertility and Sterility 80 (3): 590–594. 2003. doi:10.1016/S0015-0282(03)00788-X. PMID 12969703.
- ↑ "Reevaluation of the Incidence of Thromboembolic Complications in Congenital Factor XII Deficiency A Study on 73 Subjects from 14 Swiss Families". Thrombosis and Haemostasis 82 (4): 1240–1246. 1999. doi:10.1055/s-0037-1614368. PMID 10544906. https://th.schattauer.de/en/contents/archive/issue/special/manuscript/5062.html. Retrieved February 20, 2017.
- ↑ "The prevalence of moderate and severe FXII (Hageman factor) deficiency among the normal population: evaluation of the incidence of FXII deficiency among 300 healthy blood donors". Thromb Haemost 71 (1): 68–72. 1994. doi:10.1055/s-0038-1642386. PMID 8165648.
- ↑ "Increased Activity of Coagulation Factor XII (Hageman Factor) Causes Hereditary Angioedema Type III". Am J Hum Genet 79 (6): 1098–1104. 2006. doi:10.1086/509899. PMID 17186468.
- ↑ "Hageman trait: an asymptomatic disorder of blood coagulation". Transactions of the Association of American Physicians 68: 149–54. 1955. PMID 13299324.
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