Factor V (F5) Leiden (p.R506Q) Variant Analysis

CPT Code(s)

81241, G0452


Factor V, F5, Leiden,   R506Q, hypercoagulability, coagulation factor V


Molecular Diagnostics Laboratory

Clinical Indication and Relevance

The assay is recommended in patients with venous thromboembolism (VTE) when the results will influence treatment and clinical management decisions. It is also useful in patients and certain asymptomatic relatives to reduce the risk of VTE through counseling about preventative measures in circumstances of elevated risk.


DNA is isolated and amplified by PCR using the Invivoscribe T-cell Receptor Gamma Gene Rearrangement Assay 2.0. Primers target the conserved regions of the variable (V) and joining (J) sequences of TRG. The gene rearrangements are detected by analyzing the PCR products by capillary gel electrophoresis. The assay sensitivity for detection of clonal T-cell populations is 10% of lymphocytes.

Minimum Specimen Requirements


  • Peripheral blood (PB): 3-5 mL, in purple top (EDTA) tube
  • Yellow top (ACD) tube also acceptable


Room temperature or 2-8°C (wet ice or cold packs). Do not freeze.

Room temperature: 8 hours. Refrigerated: 48 hours.

Unacceptable Samples
Serum or plasma; frozen PB or BM; clotted blood; severely hemolyzed samples.

Turnaround time

Five to seven working days 

View Requisition Sheet