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Factor V Leiden thrombophilia

Reviewed July 2007

What is factor V Leiden thrombophilia?

Factor V Leiden thrombophilia is an inherited disorder of blood clotting. Factor V Leiden is the name of a specific mutation that results in thrombophilia, or an increased tendency to form abnormal blood clots in blood vessels. People who have the factor V Leiden mutation are at somewhat higher than average risk for a type of clot that forms in veins, such as the deep veins of the legs (deep venous thrombosis), or a clot that travels through the bloodstream and lodges in the lungs (pulmonary embolism). Most people with the factor V Leiden mutation never develop abnormal blood clots, however.

The factor V Leiden mutation is associated with a somewhat increased risk of pregnancy loss (miscarriage), and some research suggests that it may also increase the risk of other complications during pregnancy. These complications may include pregnancy-induced high blood pressure (preeclampsia), slow fetal growth, and early separation of the placenta from the uterine wall (placental abruption). It is important to note, however, that most women with the factor V Leiden mutation have normal pregnancies.

How common is factor V Leiden thrombophilia?

Factor V Leiden is the most common inherited form of thrombophilia. Between 3 percent and 8 percent of the Caucasian (white) population in the United States and Europe carry one copy of the factor V Leiden mutation in each cell, and about 1 in 5,000 people have two copies of the mutation. The mutation is less common in other populations.

What genes are related to factor V Leiden thrombophilia?

Mutations in the F5 gene cause factor V Leiden thrombophilia.

The F5 gene plays a critical role in the formation of blood clots in response to injury. The protein made by the F5 gene, coagulation factor V, is involved in a series of chemical reactions that hold blood clots together. A molecule called activated protein C (APC) prevents blood clots from growing too large by inactivating factor V. In people with the factor V Leiden mutation, APC is unable to inactivate factor V normally. As a result, the clotting process continues longer than usual, increasing the chance of developing abnormal blood clots.

Other factors also increase the risk of blood clots in people with the factor V Leiden mutation. These factors include increasing age, obesity, trauma, surgery, smoking, the use of oral contraceptives (birth control pills) or hormone replacement therapy, and pregnancy. The combination of the factor V Leiden mutation and mutations in other genes involved in blood clotting can also influence risk.

How do people inherit factor V Leiden thrombophilia?

The risk of developing a clot in a blood vessel depends on whether a person inherits one or two copies of the factor V Leiden mutation. Inheriting one copy of the mutation increases by fourfold to eightfold the chance of developing a clot. People who inherit two copies of the mutation, one from each parent, may have up to 80 times the usual risk of developing this type of blood clot. Considering that the risk of developing an abnormal blood clot averages about 1 in 1,000 people per year in the general population, the presence of one copy of the factor V Leiden mutation increases that risk to 4 to 8 in 1,000, and having two copies of the mutation may raise the risk as high as 80 in 1,000.

Where can I find information about treatment for factor V Leiden thrombophilia?

You may find information on treatment or management of factor V Leiden thrombophilia or some of its symptoms in the links below, particularly the links for Gene Reviews, MedlinePlus Encyclopedia, Educational resources, and Patient support.

Where can I find additional information about factor V Leiden thrombophilia?

You may find the following resources about factor V Leiden thrombophilia helpful. These materials are written for the general public.

  • MedlinePlus - Health information
    • Encyclopedia: Deep Venous Thrombosis (http://www.nlm.nih.gov/medlineplus/ency/article/000156.htm)
    • Encyclopedia: Pulmonary Embolus (http://www.nlm.nih.gov/medlineplus/ency/article/000132.htm)
    • Health Topic: Bleeding Disorders (http://www.nlm.nih.gov/medlineplus/bleedingdisorders.html)
  • Genetic and Rare Diseases Information Center - Information about genetic conditions and rare diseases (http://rarediseases.info.nih.gov/GARD/Disease.aspx?PageID=4&DiseaseID=6403)
  • Additional NIH Resources - National Institutes of Health
    • National Center for Biotechnology Information: Mutations and Blood Clots (http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=coffeebrk.chapter.22)
    • National Heart, Lung, and Blood Institute: Deep Vein Thrombosis (http://www.nhlbi.nih.gov/health/dci/Diseases/Dvt/DVT_WhatIs.html)
  • Educational resources - Information pages
    • American College of Medical Genetics Consensus Statement on Factor V Leiden Mutation Testing (http://www.acmg.net/StaticContent/StaticPages/Factor_V.pdf)
    • Ask the Geneticist: Factor V Leiden and risk of heart attack (http://www.genetics.emory.edu/ask/question.php?question_id=977)
    • Ask the Geneticist: Factor V Leiden thrombophilia and pregnancy (http://www.genetics.emory.edu/ask/question.php?question_id=2108)
    • Ask the Geneticist: Genetic testing for factor V Leiden thrombophilia (http://www.genetics.emory.edu/ask/question.php?question_id=561)
    • Centers for Disease Control and Prevention: Thrombophilia (http://www.cdc.gov/ncbddd/hbd/clotting.htm)
    • Factor V Leiden Cardiology Patient Page (http://circ.ahajournals.org/cgi/content/full/107/15/e94)
    • Lab Tests Online (http://labtestsonline.org/understanding/analytes/factor_v_and_pt20210/)
    • Merck Manual of Medical Information, Second Home Edition (http://www.merck.com/mmhe/sec14/ch173/ch173g.html)
    • NetWellness (http://www.netwellness.org/healthtopics/clotting/genthromb.cfm)
  • Patient support - For patients and families
    • FVL Thrombophilia Support Page (http://www.fvleiden.org/ask/)
    • National Alliance for Thrombosis and Thrombophilia (http://www.stoptheclot.org)
    • Resource list from the University of Kansas Medical Center (http://www.kumc.edu/gec/support/leiden.html)

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

  • Gene Reviews - Clinical summary (http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=factor-v-leiden)
  • Gene Tests - DNA tests ordered by healthcare professionals (http://www.genetests.org/query?testid=2616)
  • Genetic Tools - Teaching cases (http://www.genetests.org/servlet/access?fcn=y&filename=/tools/cases/thrombophilia-39/)
  • ClinicalTrials.gov - Linking patients to medical research (http://clinicaltrials.gov/search/condition=%22factor+V+Leiden+thrombophilia%22+OR+%22Thrombophilia%22)
  • PubMed - Recent literature (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=PubMed&term=((factor+V+Leiden[TI])+AND+(thrombophilia[TIAB]))+AND+english[la]+AND+human[mh]&orig_db=PubMed&filters=ON&pmfilter_EDatLimit=1080+Days)
  • OMIM - Genetic disorder catalog (http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=188050)

What other names do people use for factor V Leiden thrombophilia?

  • APC resistance, Leiden type
  • Hereditary resistance to activated protein C

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What if I still have specific questions about factor V Leiden thrombophilia?

  • See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.
  • Ask the Genetic and Rare Diseases Information Center (http://rarediseases.info.nih.gov/GARD/).
  • Submit your question to Ask the Geneticist (http://www.askthegen.org/).

What glossary definitions help with understanding factor V Leiden thrombophilia?

blood clotting ; cell ; clotting ; coagulation ; coagulation factors ; complication ; embolism ; gene ; hormone ; hormone replacement therapy ; injury ; molecule ; mutation ; placenta ; population ; protein ; pulmonary ; pulmonary embolism ; surgery ; thrombophilia ; thrombosis ; trauma ; vein

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://ghr.nlm.nih.gov/glossary).

References
  • Calderwood CJ, Greer IA. The role of factor V Leiden in maternal health and the outcome of pregnancy. Curr Drug Targets. 2005 Aug;6(5):567-76. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=16026277)
  • Gene Review (http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=factor-v-leiden)
  • Horne MK 3rd, McCloskey DJ. Factor V Leiden as a common genetic risk factor for venous thromboembolism. J Nurs Scholarsh. 2006;38(1):19-25. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=16579319)
  • Juul K, Tybjaerg-Hansen A, Schnohr P, Nordestgaard BG. Factor V Leiden and the risk for venous thromboembolism in the adult Danish population. Ann Intern Med. 2004 Mar 2;140(5):330-7. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=14996674)
  • Major DA, Sane DC, Herrington DM. Cardiovascular implications of the factor V Leiden mutation. Am Heart J. 2000 Aug;140(2):189-95. Review. No abstract available. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=10925328)
  • Mann KG, Kalafatis M. Factor V: a combination of Dr Jekyll and Mr Hyde. Blood. 2003 Jan 1;101(1):20-30. Epub 2002 Aug 08. Review. No abstract available. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=12393635)
  • Ornstein DL, Cushman M. Cardiology patient page. Factor V Leiden. Circulation. 2003 Apr 22;107(15):e94-7. No abstract available. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=12707252)
  • Rosendorff A, Dorfman DM. Activated protein C resistance and factor V Leiden: a review. Arch Pathol Lab Med. 2007 Jun;131(6):866-71. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=17550313)

 

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? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: July 2007
Published: May 4, 2009