What is JAK2 V617F test?
The JAK2 V617F test may be ordered along with other tests when a healthcare practitioner suspects that a person has a myeloproliferative neoplasm (MPN). Testing may be done when routine laboratory test results, such as from a complete blood count (CBC), reveal abnormal results associated with these MPNs.
What does JAK2 V617F mutation detection mean?
The JAK2 V617F mutation is an acquired, somatic mutation present in the majority of patients with myeloproliferative cancer (myeloproliferative neoplasms) i.e. nearly 100% of patients with polycythemia vera and in about 50% of patients with essential thrombocytosis and primary myelofibrosis.
How do they test for JAK2 mutation?
Most people with polycythemia vera have a problem in one of their genes called the JAK2 gene. Your doctor can use a blood sample or a bone marrow sample from a biopsy to check your JAK2 gene. You can get results in four to six days, but your lab may take longer.
What is JAK2 V617F mutation qualitative?
The JAK2 V617F mutation is present in approximately 90% of polycythemia vera (PV) cases and approximately 40% of primary myelofibrosis (PMF) or essential thrombocythemia (ET). Mutation analysis helps differentiate reactive conditions from myeloproliferative neoplasms (MPNs).
What causes JAK2 V617F mutation?
The JAK2 V617F mutation is a result of a single change in the DNA nucleotide base pair that causes a substitution of a valine amino acid for a phenylalanine amino acid at the 617 position on exon 14 within the JAK2 kinase regulatory domain.
How accurate is JAK2 test?
The JAK2-tree algorithm demonstrated a sensitivity of 91% (95% CI 82% to 97%) and a negative predictive value of 99% (95% CI 99% to 100%).
What if JAK2 test is negative?
One reason it might be negative is that the proportion of your cells that have the JAK2 V617F mutation may be low. Currently, the test is not nationally standardized, so the sensitivity of the test may vary somewhat from laboratory to laboratory.