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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Factor V Leiden Gene Mutation Analysis

Test Code(s): FVPCR / XFAC5

CPT Code(s): 81241

Test Description: Test Component:

Factor V  Leiden gene mutation analysis by real-time PCR amplification and melting point analysis

Methodology: Real-Time PCR followed by Melting Point Analysis

Clinical Significance: Factor V Leiden Gene Mutation Analysis is useful for confirming the diagnosis of resistance to APC as identified by functional coagulation testing. It can also be used to establish the diagnosis of resistance to APC in patients in whom functional coagulation testing may not be feasible, for example, patients on anticoagulant therapy (especially heparin) or positive for Lupus anticoagulants. Usually ordered with the Factor V is a test for the Prothrombin G20210A allele, which has been associated with elevated plasma prothrombin levels and moderately increased risk of first venous thrombotic events.

Days Performed: Once a week.

Turnaround Time: Routine: 10 days.

Specimen Requirements

Specimen: Blood

Collection Instructions: For UWMF - ordering source must fill out the UWMF Genetic Lab Request prior to specimen collection.

Collection Container: Preferred: Lavender top
Also Acceptable: Light blue top (3.2% NaCitrate)

Collection Volume: Preferred: 4 mL
Pediatrics: 2 mL

Sample Analyzed: Whole Blood

Volume Required: Preferred: 2 mL
Pediatrics: 1.2 mL

Specimen Transport: Transport specimen to UWHC Core Laboratory (B4/220) immediately. Refrigerate specimen if not delivered immediately. Transport specimen with coolant pack if coming from outreach location; avoid freezing. Specimen must be received within 7 days of collection date.

Stability: Ambient: 7 days
Refrigerated: 3 weeks
Frozen: Not acceptable


A written interpretive report is provided by the laboratory.

Additional Information:

This test was performed using a modification of an FDA approved method. The performance characteristics of this test were determined by the UWHC Clinical Laboratories and meet the standards for clinical testing.


A professional fee is associated with this test.

Factor V Leiden PCR

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