ARUP's Laboratory Test Directory
| 0056060: Prothrombin Nucleotide 20210 G/A Gene Mutation (Factor II) |
![[ image for: Patient History For Molecular Genetics]](icon_21.jpg){kind=icon} | Patient History For Molecular Genetics |
| Test Mnemonic: PT PCR | |
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Methodology: Polymerase Chain Reaction/Fluorescence Monitoring
Performed: Sun-Sat Reported: 2-7 days |
| Specimen Required: | |
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Collect: One 5 mL lavender (EDTA) or pink (K2EDTA). Also acceptable: yellow (ACD Solution A), lt. blue (sodium citrate), green (sodium or lithium heparin).
Transport: 5 mL whole blood at 2-8°C. Do not freeze. (Min: 3 mL) Pediatric Collection/Transport: 1 mL whole blood at 2-8°C. Do not freeze. Unacceptable Conditions: Plasma, serum, frozen whole blood, and severely hemolyzed samples. Stability: Ambient: 3 days; Refrigerated: 1 week; Frozen: Unacceptable |
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| Reference Interval: |
| Negative: This sample is negative for the factor II, prothrombin 20210A mutation. |
| Interpretive Data: | |
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The factor II, prothrombin 20210A mutation is a common genetic risk factor for thrombosis and is associated with elevated prothrombin levels. Higher concentrations of prothrombin lead to increased rates of thrombin generation, resulting in excessive growth of fibrin clots. It is an autosomal dominant disorder, with heterozygotes being at a three- to elevenfold greater risk for thrombosis. Although homozygosity is rare, inheritance of two 20210A mutations would increase the risk for developing thrombosis. If a patient is heterozygous for both the prothrombin 20210A and the factor V Leiden mutation, the combined heterozygosity leads to an earlier onset of thrombosis and tends to be more severe than single-gene heterozygotes. Mutations in other genes or other mutations in the prothrombin gene that may cause elevated prothrombin and hereditary forms of venous thrombosis are not ruled out. Patient DNA is assayed for the G20210A mutation in the prothrombin gene by polymerase chain reaction (PCR), and fluorescence monitoring using hybridization probes. Sensitivity and specificity for detection of this mutation are 99.9%. Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com. Please refer to Statement C in the Compliance Statements section in the front of the Laboratory Test Directory. |
| Note: | |
| For a complete description of the Reference Interval, please refer to ARUP's Guide to Clinical Laboratory Testing, which can be found on our Web site at www.aruplab.com. |
| CPT Code(s): | |
| 83890 Isolation; 83898 Amplification; 83896 Nucleic acid probe; 83912 Interpretation and report - Additional CPT code modifiers may be required for procedures performed to test for oncologic or inherited disorders. |