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Test Code FV LEIDEN Factor V Leiden

Clinical System Name

Factor V Leiden Mutation - DNA

Synonyms

Factor 5 Leiden

Description

The factor V Leiden mutation in the F5 gene is the most common cause of activated protein C (APC) resistance, and most common genetic risk factor for thrombosis.

 

This test is indicated for:

  • Individuals with family history of the factor V Leiden mutation
  • Individuals with a history of venous thromboembolism (VTE), as part of thrombophilia work up

Sample Requirements

Specimen: Whole blood

Container(s): Lavender/EDTA, Yellow/ACD A or B, or Lt. Blue Top/Citrate
Preferred Vol: 3 mL

Minimum Vol: 2 mL

Only one sample is needed to perform both Factor V Leiden and Prothrombin Variant.

  

Specimen: Buccal Swab

Container(s): Buccal Swab

Preferred Vol: 4-6 swabs

Minimum Vol: 2 swabs

Note:  For swabs, call Send Outs (M-F, 8-5), 987-2563

 

Specimen: Cells

Container(s): Lt. Blue/Citrate

Preferred Vol: 3 mL

Minimum Vol: 1 mL

Note:  Cells separated from plasma.

Processing Instructions

Reject due to: Heparin

Spin: No

Aliquot: No

Temp: Refrigerate

Storage location: CPA refrigerator sendouts rack

Stability

Specimen Type Temperature Time
Whole blood Room temp 3 days
Whole blood Refrigerated 7 days
Buccal swab Refrigerated 1 day

 

Availability

STAT Performed TAT
Contact lab Weekly 1 - 2 w

 

Performing Laboratory

University of Washington

Dept of Laboratory Medicine

UW Genetics Lab
1959 NE Pacific St, NW220
Seattle, WA 98195

 

Phone Number: (206) 520-4600

Department

Department: Send Outs
 

Phone Number: (206) 987-2563

Reference Range

Interpretive report will be provided

Methodology

Method: PCR

 

Analysis of the F5 gene for the Leiden (p.R506Q) mutation.

CPT Codes

81241

Special Instructions

Links: Factor V Leiden Thrombophilia Gene Review

 

Clinical Utility

The factor V Leiden mutation in the F5 gene is the most common cause of activated protein C (APC) resistance, and most common genetic risk factor for thrombosis. Approximately 3-8% of the population is heterozygous, and have an estimated 5-10 fold increased risk of thrombosis. Homozygotes have a 50-100 fold increased risk.

 

Note that this test can be ordered individually or as part of a thrombosis risk panel that includes the prothrombin 20210G>A mutation in the F2 gene.

Send Out Instructions

 

Reference Test Name: Factor V DNA Screen
Reference Test Number: F5DNA
Instructions: Send out M - F with the UW courier.