Factor V DNA Screen
General Information
Lab Name
Factor V DNA Screen
Lab Code
F5DNA
Epic Name
Factor V DNA Screen
Description
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:
- Evaluation of recurrent or familial venous thrombosis
- Carrier testing in family already known to carry the factor V Leiden mutation
- Evaluation of recurrent pregnancy loss
**Laboratory Medicine resident's approval is required for hospital inpatients and patients in Emergency Department.
**See also Activated Protein C Resistance [APCR].
References
- Coppola A, Tufano A, Cerbone AM, and Di Minno G. Inherited thrombophilia: implications for prevention and treatment of venous thromboembolism. Semin Thromb Hemost 2009, 35:683-94. 20013535
- Segal JB, et al. Predictive value of factor V Leiden and prothrombin G20210A in adults with venous thromboembolism and in family members of those with a mutation: a systematic review. JAMA 2009, 301:2472-85. 19531787
- Kujovich JL, Goodnight SH. Factor V Leiden thrombophilia. In: Pagon RA, Bird TC, Dolan CR, Stephens K, editors. GeneReviews [Internet]. Seattle (WA): University of Washington, Seattle; 1993-. 1999 May 14 [updated 2018 Jan 4]. 20301542
Synonyms
APC CoFactor-DNA, DNA-Factor V, Factor 5 DNA Screen, Factor 5 Leiden, Factor V Leiden, Factor V PCR
Components
| Code | Name |
|---|---|
| FVRSLT | Factor 5 Result |
| FVINT | Factor 5 Interpretation |
| FVMETH | Factor 5 Methods |
| FVDI | Factor 5 Director |
Interpretation
Method
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.
Reference Range
See individual components
Ref. Range Notes
Normal result: no mutations detected.
Guidelines
Ordering & Collection
Specimen Type
Collection
BLOOD:
- Adult: 3 mL LAVENDER TOP tube
- Child: 2 mL LAVENDER TOP tube- Also acceptable: YELLOW TOP (ACD) or blue top tube
- Unacceptable: Heparin green top tubes.
SALIVA: Contact laboratory for validated collection kit
Forms & Requisitions
Handling Instructions
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.
Quantity
requested: Entire specimen
minimum: 1 mL whole blood
Processing
Performance
LIS Dept Code
Genetics (GEN)
Performing Location(s)
| UW-MT |
Genetics
Attention: Genetics Lab Tel: 206-598–6429 M–F (7:30 AM–4:00 PM) Tel (EXOME only): 206-543-0459 |
Manager Variant Review Scientist Faculty |
|---|
Frequency
Performed weekly. Results within 2 weeks.
Available STAT?
No
Billing & Coding
CPT codes
81241
Billing Comments
For pricing information, contact Client Support Services 206-520-4600 or 800-713-5198.
LOINC
Interfaced Order Code
UOW1681