Myeloproliferative Neoplasm, JAK2 V617F with Reflex to CALR and MPL, Varies

Casandra

Casandra Test Code MC38977Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID MPNRCPT Codes 81219, 81270, 81339

Myeloproliferative Neoplasm, JAK2 V617F with Reflex to CALR and MPL, Varies

Clinical Use

Use

This reflex test is mainly used to help in the distinction between reactive cytosis and a chronic myeloproliferative disorder. It evaluates for variants in JAK2, CALR, and MPL genes using an algorithmic approach. The presence of JAK2 V617F variant is found in a high percentage of patients with specific myeloproliferative neoplasms such as polycythemia vera, primary myelofibrosis, and essential thrombocythemia. A CALR variant is associated with decreased thrombosis risk in both ET and PMF and confers a favorable clinical outcome in PMF.

Special Instructions

It is essential to provide pertinent clinical history, clinical or morphologic suspicion, date of collection, and specimen source. Specimen must arrive within 7 days of collection. If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request with the specimen.

Limitations

A positive result does not specify a particular subtype of myeloproliferative neoplasm and necessitates clinicopathologic correlation in all cases. A negative result does not exclude the presence of a myeloproliferative neoplasm or other neoplastic processes. Variants other than JAK2 V617F may be present in areas that interfere with primer or probe binding, potentially causing false-negative results. Interpretation requires correlation with a concurrent or recent prior bone marrow evaluation in certain clinical scenarios.

Test Details

New York Approved