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Test Code PTV DNA Prothrombin Variant DNA

Clinical System Name

Prothrombin Variant DNA


Factor 2 Gene Mutation

Factor II Gene Mutation

Prothrombin 20210

Prothrombin II Mutation

PT 20210


The common c.20210G>A mutation in the F2 gene is associated with elevated prothrombin levels, which promotes development of fibrin clots.


This test is indicated for:

  • Individuals with family history of the prothrombin 20210G>A mutation in the F2 gene
  • 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
Preferred Vol: 3 mL

Minimum Vol: 1 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 Sendout Lab (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.


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



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: Send Outs

Phone Number: (206) 987-2563

Reference Range

Interpretive report will be provided


Method: PCR


Analysis of the F2 gene for the 20210G>A mutation.

CPT Codes


Special Instructions

Links: Prothrombin-Related Thrombophilia GeneReview

Clinical Utility

The common c.20210G>A mutation in the F2 gene is associated with elevated prothrombin levels, which promotes development of fibrin clots. 2-4 % of the population is heterozygous for this mutation. Heterozygotes may have an estimated 3-11 fold increased risk of thrombosis. The risk of venous thrombosis recurrence is higher in individuals who also carry other thrombosis risk factors.


Send Out Instructions


Reference Test Name: Prothrombin DNA Screen
Reference Test Number: PRODS
Instructions: Send out M - F with the UW courier.


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