Mayo Clinic Health Manager
Get free personalized health guidance for you and your family.
Get Started
About our e-newsletters
- Free e-newsletters
- Mayo Clinic expertise
- We do not share your e-mail address
Housecall, our weekly general-interest e-newsletter, keeps you up to date on a wide variety of health topics with timely, reliable, practical information, recipes, blogs, questions and answers with Mayo Clinic experts and more. Our biweekly topic-specific e-newsletters also include blogs, questions and answers with Mayo Clinic experts, and other useful information that will help you manage your health.
Housecall Archives
Mayo Clinic Housecall
Stay up to date on the latest health information.
What you get
- Free weekly e-newsletter
- Mayo Clinic expertise
- Recipes, tools and other helpful information
- We do not share your e-mail address
Causes
By Mayo Clinic staffBlood consists of liquid, called plasma, and three types of cells that float within the plasma:
- White blood cells. These blood cells fight infection.
- Platelets. These blood cells help your blood clot after a cut.
- Red blood cells (erythrocytes). These blood cells carry oxygen from your lungs, through your bloodstream, to your brain and your body's other organs and tissues. Your body needs a supply of oxygenated blood to function. Oxygenated blood helps give your body its energy and your skin a healthy glow.
Normally, your body carefully regulates the number of blood cells you have and the ratio of one type to another. But in conditions called myeloproliferative disorders, such as polycythemia vera, the mechanism your body uses to control the production of blood cells becomes impaired, and your bone marrow makes too many or too few of some blood cells.
Mutation causes the disorder
The problem with blood cell production associated with polycythemia vera is caused by a change, or mutation, to DNA in a single cell in your bone marrow. In polycythemia vera, researchers have found this mutation to be a change in a protein switch that tells the cells to grow. Specifically, it's a mutation in the protein JAK2 (the JAK2 V617F mutation). More than 90 percent of people with polycythemia vera, and about half the people with other myeloproliferative disorders, have this mutation. Doctors and researchers don't yet understand the full role of this mutation and its implications for treating the disease.
Your DNA is a set of instructions for your cells, telling them how and when to grow and divide. The DNA mutation responsible for polycythemia vera makes blood cell production go awry. All the cells produced by that first mutant cell have the same problem, and they dominate your blood cell production.
The DNA mutation that causes polycythemia vera occurs after conception — meaning that your mother and father don't have it — so it's acquired, rather than inherited from a parent. Researchers and doctors don't know what causes the mutation.
- Diseases and conditions index: What is polycythemia vera. National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/dci/Diseases/poly/poly_whatis.html. Accessed Jan. 21, 2009.
- Tefferi A, et al. Prognosis and treatment of polycythemia vera. http://www.uptodate.com/home/index.html. Accessed Feb. 5, 2009.
- Sirhan S, et al. Management of polycythemia vera. In: Silver RT. Myeloproliferative Disorders: Biology and Management. New York, N.Y.: Informa Healthcare; 2008:87.
- Polycythemia vera. The Merck Manuals Online Medical Library: The Merck Manual for Healthcare Professionals. www.merck.com/mmpe/sec11/ch141/ch141d.html#sec11-ch141-ch141d-694. Accessed Feb. 5, 2009.
- P-32. National Cancer Institute. http://www.cancer.gov/templates/db_alpha.aspx?CdrID=44869. Accessed Feb. 14, 2009.
