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
