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Factor V leiden
MessageWilford Hall
Test Code
WH27
Preferred Specimen
Whole Blood 3 mL
Minimum Volume
1.5 mL
Other Acceptable Specimens
Tissue
Instructions
"COLLECT 1 EDTA WHOLE BLOOD SAMPLE; ONLY COLLECT MONDAY through
THURSDAY;
DO NOT COLLECT a sample for LEIDEN DNA ON HOLIDAYS, THE DAY PRIOR TO
THE HOLIDAY, or WEEKENDS
SEND TO LAB WITHIN 30 MINUTES OF COLLECTION DO NOT CENTRIFUGE SPECIMEN"
THURSDAY;
DO NOT COLLECT a sample for LEIDEN DNA ON HOLIDAYS, THE DAY PRIOR TO
THE HOLIDAY, or WEEKENDS
SEND TO LAB WITHIN 30 MINUTES OF COLLECTION DO NOT CENTRIFUGE SPECIMEN"
Transport Container
LAV/EDTA
Transport Temperature
Refrigerated
Specimen Stability
Refrigerated
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
"NCORRECT ANTICOAGULANT OTHER THAN EDTA SPECIMEN VOLUME LESS THAN 1.5mL EDTA SPECIMEN NOT RECEIVED WITHIN 30 MINUTES OF
COLLECTION "
COLLECTION "
Clinical Significance
"Factor V Leiden is a specific mutation (R506Q) in the factor V gene that is associated with an increased risk of venous thrombosis. Factor V Leiden is more resistant to inactivation by activated Protein C. As a result, Factor V persists in the circulation leading to a mild hypercoagulable state. Factor V Leiden has been reported in patients with deep vein thrombosis,pulmonary embolus, central retinal vein occlusion, cerebral sinus thrombosis, and hepatic vein thrombosis. The relative risk of venous thrombosis is increased approximately 4-8 fold in individuals who are heterozygous. The risk of venous thrombosis increases exponentially in patients with more than one risk factor, including: age, surgery, oral contraceptive use, pregnancy, elevated homocysteine levels, or Factor II/prothrombin mutation (G20210A). Factor V Leiden is one of the most common causes of inherited thrombophilia.
The R506Q mutation leads to resistance to degradation of the Factor V protein by activated protein C (APC). Individuals who have one copy of the mutation are at a 4-to 8-fold increased risk of thrombosis and individuals who have two copies are at a 50-to 100-fold increased risk.
Since genetic variation and other factors can affect the accuracy of direct mutation testing, these results should be interpreted in light of clinical and familial data."
The R506Q mutation leads to resistance to degradation of the Factor V protein by activated protein C (APC). Individuals who have one copy of the mutation are at a 4-to 8-fold increased risk of thrombosis and individuals who have two copies are at a 50-to 100-fold increased risk.
Since genetic variation and other factors can affect the accuracy of direct mutation testing, these results should be interpreted in light of clinical and familial data."
