Laboratory Services

Prothrombin G20210A Mutation, Blood

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Updated Test Information:

Test Description
Prothrombin G20210A Mutation, Blood
Synonym(s)

G20210A; Factor II 20210 variant; Prothrombin 20210 varient; Prothrombin nucleotide; Factor II 20210 mutation; Prothrombin mutation

Test ID
PTNT
General Information

Useful for:



  • Patients with clinically suspected thrombophilia

  • Determination of the duration of anticoagulation therapy of venous thromboembolism patients

  • Screening for women contemplating hormone therapy

  • This test detects the F2 c.*97G>A variant (legacy G20210A)

Specimen Type

Whole Blood

Specimen Requirements

  • Preferred: Lavender Top (EDTA)

  • Acceptable: Yellow top (ACD solution B), light-blue top (sodium citrate)

Minimum Sample Volume

1.0 mL

Additional Processing Details

Send specimen in original tube - do not aliquot

Stability

  • Ambient (preferred): 7 days

  • Frozen: 14 days

  • Refrigerated: 14 days

Unacceptable Specimen Conditions

Extracted DNA

Limitations

  • A previous bone marrow transplant from an allogenic donor will interfere with testing. Call 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.

  • This assay will only detect the F2 c.*97G>A (rs1799963) variant associated with thrombophilia. To detect other pathogenic alterations in the F2 gene of a patient with a laboratory diagnosis of thrombophilia, order F2NGS (F2 Gene Next Generation Sequencing, Varies)

  • This assay will not detect alterations in individuals with thrombophilia caused by mechanisms other than the F2 c.*97G>A variant. For those situations consider ordering AATHR (Thrombophilia Profile, Plasma and Whole Blood)

  • This assay will not detect alterations in individuals with thrombophilia caused by mechanisms other than the prothrombin F2 c.*97G>A variant

  • Rare single nucleotide variants under the primers can cause preferential amplification of one allele. In many cases, there is no indication that this interference has occurred. Consequently, the analysis could be done on data from only one allele, which may cause a false-negative result or an incorrect allele frequency (homozygous instead of heterozygous)

  • Patients receiving allogenic stem cell transplants prior to having blood drawn for DNA based testing may have falsenormal or abnormal results depending on the genotype of the stem cell donor

  • Consultations with the Mayo Clinic Special Coagulation Clinic Thrombophilia Center, and/or Medical Genetics are available and may be especially helpful in complex cases or in situations in which the diagnosis is atypical or uncertain. Genetic counseling is recommended before testing asymptomatic family members

Methodology

Direct Mutation Analysis

Estimated TAT

3-5 days

Testing Schedule

Monday-Friday

Retention

14 days

CPT Code(s)

81240

Reference Range

Negative

Performing Lab

Mayo

LOINC Code(s)

24475-6, 69049-5, 18771-6

Additional Information