NCCN Guidelines for Patients® | Myeloproliferative Neoplasms
19 NCCN Guidelines for Patients ® : Myeloproliferative Neoplasms, 2018 half of people with ET or PMF. Testing for JAK2 V617F is needed for anyone who may have a MPN. A small subset of people with PV may have another JAK2 mutation. This mutation occurs in exon 12. If the JAK2 V617F mutation is absent, testing for the JAK2 exon 12 mutation should be done. CALR mutations The CALR gene is on chromosome 19. CALR mutations occur in 20 to 30 out of every 100 people with ET or MF (20% to 30%). If the JAK2 V617F mutation is absent, testing for the CALR mutations is needed for ET and MF. MPL mutations The MPL gene is on chromosome 1. MPL W515 mutations are less common than CALR mutations. They occur in 5 to 10 out of every 100 people with ET or MF (5% to 10%). If the JAK2 V617F mutation is absent, testing for the MPL mutations is needed for ET and MF. Other mutations About 10 out of every 100 people with MF or ET do not have JAK2 , MPL , and CALR mutations. These cancers are called triple-negative MPN. Mutations in ASXL1 , EZH2 , TET2 , IDH1 , IDH2 , SRSF2 , and SF3B1 genes may help to diagnosis PMF. HLA typing HLAs ( h uman l eukocyte a ntigens) are proteins found on the surface of most cells. They are markers of your body’s cells. They allow your body to tell which cells are its own and which are foreign. HLAs do not differ between cells within a person. In other words, all your cells have the same set of HLAs. Each person’s set of HLAs is called the HLA type or tissue type. HLA typing is a test that detects a person’s HLA type. You will receive this test if a transplant of healthy stem cells from a donor may be a treatment option. This treatment is described more in Part 5. HLA typing is performed on a blood sample. HLA typing is needed to find the right donor for you. A donor’s HLA type must be a near-perfect match to you for treatment to work. Otherwise, your body will reject the donor’s stem cells. 2 Testing for MPN HLA typing Figure 6 Karyotype A karyotype is a picture of the chromosomes in cells. It is a test that shows abnormal changes in chromosomes.