Prothrombin G20210A Mutation, Blood

Casandra

Casandra Test Code MC33256Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID PTNTCPT Code 81240

Prothrombin G20210A Mutation, Blood

Clinical Use

Use

This test is useful for patients with clinically suspected thrombophilia, determination of the duration of anticoagulation therapy in venous thromboembolism patients, and screening for women contemplating hormone therapy. It detects the F2 c.*97G>A variant, also known as the G20210A mutation, associated with an increased risk of venous thromboembolism due to increased plasma prothrombin activity. The variant is common among white Americans and particularly frequent in individuals of southern European ancestry.

Special Instructions

This assay will only detect the F2 c.*97G>A variant associated with thrombophilia. It is not applicable for detecting other pathogenic alterations in the F2 gene or for individuals with thrombophilia caused by mechanisms other than this variant. Genetic counseling is recommended before testing asymptomatic family members. Informed consent is required for New York clients. A previous bone marrow transplant from an allogenic donor will interfere with testing, so further instructions should be sought if the patient has had such a transplant.

Limitations

The assay does not detect alterations associated with thrombophilia other than the F2 c.*97G>A variant. Rare single nucleotide variants under the primers can cause amplification issues resulting in false results—potentially mismatching the allele frequency. Patients with allogenic stem cell transplants may have altered results depending on the donor genotype. The test is not FDA-cleared or approved but meets CLIA requirements as a laboratory-developed test.

Test Details

New York Approved