A mutation is a change in a genes structure that can result in a number of problems. The JAK2 V617F gene mutation, which is frequently linked to myeloproliferative illnesses such polycythemia vera (PV), essential thrombocythemia (ET), and myeloproliferative malignancies, is detected by this test. Blood malignancies of the myeloproliferative subtype start in the bone marrow. DNA that was isolated from the blood sample is used for the test. A positive JAK2 V617F mutation test, along with other supporting clinical signs, means it is likely that the person tested has an MPN. Other testing, such as a bone marrow biopsy, may need to be performed to determine which MPN the person has and to evaluate its severity.