Ordering Recommendation

Order to detect prothrombin c.*97G>A (G20210A) pathogenic variant.

Mnemonic
PT PCR
Methodology

Polymerase Chain Reaction/Fluorescence Monitoring

Performed

Sun-Sat

Reported

2-5 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation

Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Plasma or serum; collection of specimen in sodium heparin tubes.

Remarks
Stability

Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable

Reference Interval
Interpretive Data

Background Information for Prothrombin (F2) c.*97G>A (G20210A) Pathogenic Variant:
Characteristics: The Factor II, c.*97G>A (G20210A) pathogenic variant is a common genetic risk factor for venous thrombosis associated with elevated prothrombin levels leading to increased rates of thrombin generation and excessive growth of fibrin clots. The expression of Factor II thrombophilia is impacted by coexisting genetic thrombophilic disorders, acquired thrombophilic disorders (eg, malignancy, hyperhomocysteinemia, high factor VIII levels), and circumstances including: pregnancy, oral contraceptive use, hormone replacement therapy, selective estrogen receptor modulators, travel, central venous catheters, surgery, and organ transplantation.
Incidence: Approximately 2 percent of Caucasians and 0.3 percent of African Americans are heterozygous; homozygosity occurs in 1 in 10,000 individuals.
Inheritance: Incomplete autosomal dominant.
Penetrance: The risk of thrombosis is increased 2-4 fold for heterozygotes and further increased for homozygotes.
Cause: Homozygosity or heterozygosity for F2 c.*97G>A (G20210A).
Pathogenic Variant Tested: F2 c.*97G>A (G20210A).
Clinical Sensitivity for Venous Thrombosis: Approximately 10 percent.
Methodology: Polymerase chain reaction and fluorescence monitoring.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. F2 gene variants, other than c.*97G>A (G20210A), will not be detected.

Compliance Statement C: For human genetic inheritable conditions and mutations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Note
Hotline History
N/A
CPT Codes

81240

Components
Component Test Code* Component Chart Name LOINC
0056060 Prothrombin (F2) G20210A Variant 24475-6
2001334 PT PCR Specimen 31208-2
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • F2 DNA assay
  • Factor II (PT) 20210 Variant
Prothrombin (F2) c.*97G>A (G20210A) Pathogenic Variant