JAK2

JAK 2 Mutation Test

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JAK2 V617F mutation is a gain-of-function mutation that leads to clonal proliferation; it is present in about 95% of polycythemia Vera cases and about half of Essential Thromocythemia and Idiopathic Myelo Fibrosis cases.

The JAK2 test promises to be very useful in distinguishing between clonal myeloproliferative disorders and reactive cellular proliferations.

Diagomet gene testing helps to identify Jak2 v617F exon 14 mutation indicative of Polycythemia Vera (PV).

Purpose of the Test

The presence of JAK2 mutations can be used for diagnosis and may provide information that can determine the potential for JAK2 inhibitor treatment.

Background

Janus kinase 2 (JAK2) is a tyrosine kinase that plays an important role in hematopoietic growth factor signaling. A V617F mutation in the JAK2 gene leads to clonal proliferation and has been detected in myeloproliferative disorders, such as polycythaemia (PV), essential thrombocythaemia (ET) and idiopathic myelofibrosis (MF).1 The JAK2 allele burden varies, depending on the disease and the stage of the disease.

This mutation has not been reported in persons with BCR/ABL positive chronic myeloid leukemia, acute or chronic lymphoid disorders, secondary polycythemia or reactive blood count elevation.

Exceptions

JAK2 mutational burden detection is limited in this assay by the detection limit of Sanger sequencing (which is at least 10%).

Test Method

PCR and sequencing of the coding JAK2 exons that are hotspot of mutations in cancers will be performed using patient derived tumor and DNA.

Sample Requirements

We require 1 slide stained with hematoxylin-and-eosin and 10 unstained, non-baked slides with 10-µ thick sections of FFPE tumor tissue. The tumor section should contain at least 70% tumor content as verified by a qualified pathologist. Pathology report and a scanned copy of the slides used to assess tumor content should accompany specimen in order for testing to be performed. We can also accept fresh frozen tumor sample. However, we require that the tumor is sectioned and a pathology report be generated that includes an assessment of tumor content - Please call +91-484-2413399/97 or email askus@medgenome.com if you have questions.

References

1. Kralovics R., Passamonti F., Buser A., Soon-Siong T., Tiedt R., Passweg J., Tichelli A., Cazzola M., Skoda R. A Gain of Function Mutation of JAK2 in Myeloproliferative Disorders. N Engl J Med 2005; 352:1779-1790

2. Passamonti F., Rumi E. Clinical relevance of JAK2 (V617F) mutant allele burden. Haematologica 2009 January; 94(1): 7-10

3. Goldman J., Green A., Holyoake T., Jamieson C., Mesa R., Mughal T., Pellicano F., Perrotti D., Skoda R., Vannucci A. Chronic myeloproliferative diseases with and without the Ph chromosome: some unresolved issues. Leukemia 2009 Oct; 23(10): 1708-15

4. Musolino C., Allegra A., Penna G., Centorrino R., Cuzzola M., D'Angelo A., Lacopino P., Alonci A. Absence of the V617F JAK2 mutation in the lymphoid compartment in a patient with essential thrombocythemia and B-chronic lymphocytic leukemia and in two relatives with lymphoproliferative disorders.