The factor V Leiden variant (HGVS nomenclature NM_000130.4 c.1601G>A p.R534Q; legacy nomenclature R506Q, p.Arg506Gln, 1691G>A) in the factor V gene (F5) is present in approximately 3% of the general population, and in about 20-50% of patients with a history of unexplained recurrent venous thrombosis. The presence of a glutamine instead of an arginine residue removes a site in factor V that is normally cleaved by activated protein C, and is associated with resistance to activated protein C. Presence of this polymorphism substantially increases the lifetime risk of venous thrombosis. This test detects the underlying defect present in almost all cases of resistance to activated protein C.
Indications for testing include:
**Laboratory Medicine resident's approval is required for hospital inpatients and patients in Emergency Department.
**See also Activated Protein C Resistance [APCR].
Code | Name |
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FVRSLT | Factor 5 Result |
FVINT | Factor 5 Interpretation |
FVMETH | Factor 5 Methods |
FVDI | Factor 5 Director |
Next-generation sequencing
The presence of either normal or variant (NM_000130.4 c.1601G>A p.R534Q, legacy nomenclature Gln506/1691A; also known as Factor V Leiden) alleles of the F5 gene are detected by next-generation sequencing. This test was developed and its performance characteristics determined by the Department of Laboratory Medicine at the University of Washington.
Normal result: no mutations detected.
BLOOD:
SALIVA: Contact laboratory for validated collection kit
Outside Laboratory: Ship whole blood at ambient temperature to arrive within 1 week of specimen collection.
**Laboratory Medicine resident's approval is required for hospital inpatients and patients in Emergency Department.**
Approval is NOT required for hospital outpatients, clinic patients or outside clients. Refrigerate whole blood up to 1 week.
UW-MT |
Genetics
Attention: Genetics Lab Tel: 206-598–6429 M–F (7:30 AM–4:00 PM) Tel (EXOME only): 206-543-0459 |
Faculty |
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