Molecular Genetics
Factor V (Leiden) Mutation (R506Q)
Background:
Factor V Leiden thrombophilia is an inherited disorder of blood clotting. Factor V Leiden is the name of a specific gene mutation that results in thrombophilia, which is an increased tendency to form abnormal blood clots that can block blood vessels. Afflicted persons present with a history of venous thromboembolism (VTE) manifesting as deep vein thrombosis (DVT) or of pulmonary embolism, especially in women with a history of VTE during pregnancy (or in association with oral contraceptive use) and in persons with a personal or family history of recurrent thrombosis.
A coagulation screening test or DNA analysis of the F5 gene can be used to diagnose factor V Leiden thrombophilia. Factor V Leiden refers to the specific G-to-A substitution at nucleotide 1691 in the gene for factor V that predicts a single amino-acid replacement (R506Q) at one of three APC cleavage sites in the factor V(a) molecule1.
Methodology:
Polymerase chain reaction/Fluorescence monitoring.
Specimen Requirements:
Blood: 6.0 mL in EDTA (purple-top) or ACD (yellow-top) tube
DNA: 10ng at a minimum of 100ng/µL (DNA must be extracted in a CLIA-certified laboratory or a laboratory meeting equivalent requirements as determined by the CAP and/or CMS)
A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES. Please include detailed clinical information, including ethnicity, clinical history, and family history.
Test Performed (Days):
Weekly
Turn Around Time:
7 – 10 Days
Shipment Sensitivity Requirements:
- Keep specimen cold during transit, but do not ship on dry ice.
- Please use the cold pack provided in the KDL shipping kit.
- Contact Client Services at (855) 535-1522 for shipping kits and instructions.
- Ship the specimen overnight express, using the FedEx priority overnight label provided.
References:
- Kujovich, JL. Factor V Leiden Thrombophilia. Gene Reviews. http://www.ncbi.nlm.nih.gov/books/NBK1368/ Initial Posting: May 14, 1999; Last Update: March 9, 2010.
Additional Info:
PCR-based direct detection of codon 506 Factor V mutation causing resistance to activated protein C and familial thrombosis. Call the lab at (855)535-1522 for more information.