NCCN Guidelines for Patients® | Myeloproliferative Neoplasms

10 NCCN Guidelines for Patients ® : Myeloproliferative Neoplasms, 2018 cells in MDS fail to develop into normal blood cells. Thus, there are very few blood cells in MDS. The cause of MPN Cells have a control center called the nucleus. The nucleus contains chromosomes, which are long strands of DNA ( d eoxyribo n ucleic a cid) tightly wrapped around proteins. See Figure 3 . Within DNA are coded instructions for building new cells and controlling how cells behave. These instructions are called genes. There are often abnormal changes in genes within cancer cells. These abnormal changes are called mutations. Mutations cause cancer cells to not behave like normal cells. An example is the making of too many blood cells in MPNs. Also, mutations sometimes cause cancer cells to look very different from normal cells. Read Part 2 to learn more about the known mutations in MPNs. Classic types There are three classic types of MPNs. The most common type is ET ( e ssential t hrombocythemia). The other types are PV ( p olycythemia v era) and PMF ( p rimary m yelo f ibrosis). A key feature of ET is too many megakaryocytes. Megakaryocytes are a type of blood cell within bone marrow. Platelets are tiny pieces of megakaryocytes. Thus, another feature of ET is too many platelets in blood. This is called thrombocythemia. Essential thrombocythemia means the condition is caused by a problem in the blood cell-making process within bone marrow. A key feature of PV is too many red blood cells. High levels of white blood cells and platelets may also be present. The red blood cells amass in bone marrow and blood. As a result, blood becomes thicker than normal (viscous). 1 MPN basics Classic types Figure 3 Genetic material in cells Most human cells contain the “blueprint of life”—the plan by which our bodies are made and work. The plan is found inside of chromosomes, which are long strands of DNA that are tightly wrapped around proteins. Genes are small pieces of DNA that contain instructions for building new cells and controlling how cells behave. Humans have an estimated 20,000 to 25,000 genes. Illustration Copyright © 2017 Nucleus Medical Media, All rights reserved.