Thrombophilia targeted mutation analysis
|Genes:||Factor V, prothrombin/Factor II, MTHFR|
|Lab method:||Sanger Sequencing|
|Specimen requirements:||2-4 ml of blood with anticoagulant EDTA
300 ng DNA in TE, AE or pure sterile water at 100-250 ng/µl
|Ordering information:||Go to online ordering or download sample submission form|
Indications for genetic testing:
- Venous thrombosis before the age of 50
- Recurrent venous thrombosis in family
- Identified genetic variant for higher risk of venous thrombosis in family
For women in addition to the above named:
- Myocardial infarction in 50-year-old women who are smoking
- Venous thrombosis in the period of taking oral contraceptives
- The presence of pregnancy complications, for example multiple miscarriages, preeclampsia and stillbirth.
Thrombophilia characterized by venous thromboembolism (VTE) manifests most commonly as deep vein thrombosis in the leg, but may progress to pulmonary embolism, if the clot dislodges and travels to the lung. Pulmonary embolism is a life-threatening condition, requiring quick medical help.
VTE is a multifactorial disorder resulting from the interaction between an array of acquired and genetic factors. The influence of the acquired factors are stronger if the presence of genetic factors. Most important acquired risk factors are extensive surgery and/or trauma. Medium risk factors are pregnancy, hormone replacement therapy and use of oral contraceptives, puerperium and cancers. Mild risk factor is immobility, caused either by confinement to bed, plaster cast or long-distance travel.
Inherited genetic factors predisposing tendency to develop VTE are Factor V Leiden mutation (FVL) in the F5 (factor V) gene, mutation 20210G>A in the F2 (factor II, prothrombin) gene, two common variations 677C>T and 1298A>C in the MTHFR gene. Addition to 4 more common genetic risk factors analysed, several other risk factors with either very low frequency or low risk are described.
Castro R et al 2003. 5,10-Methylenetetrahydrofolate Reductase 677C–>T and 1298A–>C Mutations Are Genetic Determinants of Elevated Homocysteine. QJM. 2003 Apr;96(4):297-303. doi: 10.1093/qjmed/hcg039.
Den Heijer M et al. 2005. Homocysteine, MTHFR and Risk of Venous Thrombosis: A Meta-Analysis of Published Epidemiological Studies. J Thromb Haemost. 2005 Feb;3(2):292-9. doi: 10.1111/j.1538-7836.2005.01141.x.
Kumar J et al 2005. Homocysteine Levels Are Associated With MTHFR A1298C Polymorphism in Indian Population. J Hum Genet. 2005;50(12):655-63. doi: 10.1007/s10038-005-0313-1. Epub 2005 Oct 22.
Price DT and Ridker PM. 1997. Factor V Leiden Mutation and the Risks for Thromboembolic Disease: A Clinical Perspective.Ann Intern Med. 1997 Nov 15;127(10):895-903. doi: 10.7326/0003-4819-127-10-199711150-00007.
Varga EA and Kujovich JL 2012. Management of Inherited Thrombophilia: Guide for Genetics Professionals.Clin Genet. 2012 Jan;81(1):7-17. doi: 10.1111/j.1399-0004.2011.01746.x. Epub 2011 Jul 25.