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molecular Analysis:
Thrombophilia Panel
The Thrombophilia Panel tests for mutations that are associated with increased risk for venous thrombosis. The panel tests for the following mutations/variants: Factor V Leiden (R506Q), Prothrombin (G20210A), and MTHFR (C677T). Genetic predisposing factors for venous thrombosis include resistance to activated protein C (APC), elevated plasma prothrombin, and elevated plasma homocysteine. APC resistance is the most common factor associated with inherited thrombophilia. Up to 90% of APC resistant individuals have the Factor V Leiden mutation. Heterozygous individuals for the Factor V Leiden mutation have a 5 - 10 fold increase in risk for venous thrombosis. Elevated plasma prothrombin is another factor associated with inherited thrombophilia and has been linked to the presence of the Prothrombin (G20210A) mutation. Heterozygous individuals for the Prothrombin (G20210A) mutation have a 2 - 3 fold increase in risk for venous thrombosis. A third risk factor associated with inherited thrombophilia is elevated plasma homocysteine. Increased plasma homcysteine has been linked to homozygosity of the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene.
Molecular analysis for these three mutations/variants may be ordered as a thrombophilia panel or individually.
See Factor V Leiden (R506Q) Mutation, Prothrombin (G20210A) Mutation (Factor II), and MTHFR (C677T) Variant for testing information.
- Individuals with a personal or family history of venous thrombosis
Direct mutation analysis: Our laboratory utilizes polymerase chain reaction and fluorogenic target-specific hybridization. Melting curve analysis is performed to discriminate between the normal and mutant genotype.
Approximately 90% of individuals with APC resistance have the Factor V Leiden mutation.
Approximately 6 - 8% of individuals with a first episode of venous thrombosis have the prothrombin (G20210A) mutation. Approximately 20% of families with history of venous thrombosis have the prothrombin (G20210A) mutation.
Approximately 30 – 40% of the population is heterozygous for the MTHFR (C677T) variant. Approximately 10 – 15% of individuals are homozygous for this variant.
Blood: 5 cc collected in a purple top (EDTA) or yellow top (acid citrate dextrose) vacutainer tube. For children, 2 cc is sufficient. Do not centrifuge or freeze. Specimen may be refrigerated or stored at room temperature.
14 days
83891, 83898 (3X), 83912
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> Standard DNA Consent Form
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