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Essential Thrombocythemia

National Organization for Rare Disorders, Inc.

Important
It is possible that the main title of the report Essential Thrombocythemia is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.

Synonyms

  • ET
  • essential hemorrhagic thrombocythemia
  • essential thrombocytosis
  • idiopathic thrombocythemia
  • idiopathic thrombocytosis
  • primary thrombocythemia

Disorder Subdivisions

  • None

General Discussion

Essential thrombocythemia (ET) is a rare, chronic disorder characterized by the overproduction of platelets. Platelets (also known as thrombocytes) are specialized blood cells that clump together to form clots to stop bleeding at the site of injury to blood vessels Although the overproduction of platelets is the or characteristic of ET, red blood cells and white blood cells may be overproduced to some degree as well.

Individuals with ET are at risk for the formation of blood clots (thrombosis), which can restrict blood flow to vital organs, and episodes of uncontrolled bleeding (hemorrhaging). Additional symptoms associated with ET include headaches, dizziness, bleeding from the gums or gastrointestinal tract, an enlarged spleen (splenomegaly) and a condition known as erythromelalgia, which is characterized by a reddened or purplish appearance to the skin of the hands and feet sometimes associated with a painful, burning sensation. Approximately two-thirds of individuals with ET do not have symptoms (asymptomatic) when initially diagnosed. In fact, a diagnosis of ET is often made incidentally during a routine examination. Many individuals eventually present with symptoms related to small or large vessel thrombosis or minor bleeding. Presentation with a major bleeding episode is very unusual. The exact, underlying cause of ET is unknown. However, more than half of the people with this disorder have a mutation of the JAK2 gene. The exact role that this gene plays in the development of ET is not fully understood.

Essential thrombocythemia belongs to a group of diseases known as the myeloproliferative disorders (MPDs). This group of disorders is characterized by the overproduction (proliferation) of one or more of the three main blood cell lines - red or white blood cells or platelets. Red blood cells carry oxygen to the body. White blood cells fight infection. Platelets are involved in clotting of the blood in response to injury. Three other disorders are commonly classified as MPDs: chronic myelogenous leukemia, polycythemia vera and idiopathic myelofibrosis. Because the MPDs are characterized by uncontrolled cell growth, they may also be classified as blood cancers.

Resources

Leukemia & Lymphoma Society
1311 Mamaroneck Avenue
Suite 310
White Plains, NY 10605
Tel: (914)949-5213
Fax: (914)949-6691
Tel: (800)955-4572
Email: infocenter@LLS.org
Internet: http://www.LLS.org

American Cancer Society, Inc.
250 Williams NW St
Ste 6000
Atlanta, GA 30303
USA
Tel: (404)320-3333
Tel: (800)227-2345
TDD: (866)228-4327
Internet: http://www.cancer.org

NIH/National Heart, Lung and Blood Institute
P.O. Box 30105
Bethesda, MD 20892-0105
Tel: (301)592-8573
Fax: (301)251-1223
Email: nhlbiinfo@rover.nhlbi.nih.gov
Internet: http://www.nhlbi.nih.gov/

NIH/National Heart, Lung and Blood Institute ~ Hematology Branch
10 Center Dr, Building 10-CRC
3-5140, MSC-1202
Bethesda, MD 20892-1202
Tel: (301)496-5093
Fax: (301)496-8396
Tel: (800)644-2337
Email: YoungNS@mail.nih.gov
Internet: http://dir.nhlbi.nih.gov/labs/hb/index.asp?

Platelet Disorder Support Association
133 Rollins Avenue, Suite 5
Rockville, MD 20852
USA
Tel: (301)770-6636
Fax: (301)770-6638
Tel: (877)528-3538
Email: pdsa@pdsa.org
Internet: http://www.pdsa.org

Genetic and Rare Diseases (GARD) Information Center
PO Box 8126
Gaithersburg, MD 20898-8126
Tel: (301)251-4925
Fax: (301)251-4911
Tel: (888)205-2311
TDD: (888)205-3223
Internet: http://rarediseases.info.nih.gov/GARD/

CMPD Education Foundation
P.O. Box 4758
Scottsdale, AZ 85261
Email: ian.sweet@homemail.com.au
Internet: http://www.mpdinfo.org/CMPD_foundation.html

Madisons Foundation
PO Box 241956
Los Angeles, CA 90024
Tel: (310)264-0826
Fax: (310)264-4766
Email: getinfo@madisonsfoundation.org
Internet: http://www.madisonsfoundation.org

Myeloproliferative Disease Support and Daily Email Digest
2011 Flagler Ave.
Key West, FL 33040
USA
Tel: (305)295-4444
Email: roberttollen@gmail.com
Internet: http://www.mpdsupport.org/

MPN Research Foundation
180 N. Michigan Avenue, Suite 1870
Chicago, IL 60601
Tel: (312)683-7249
Fax: (312)332-0840
Email: mwoerhle@MPNResearchFoundation.org
Internet: http://www.mpnresearchfoundation.org

For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, go to www.rarediseases.org and click on Rare Disease Database under "Rare Disease Information".

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.

It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report

This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P.O. Box 1968, Danbury, CT 06813-1968; phone (203) 744-0100; web site www.rarediseases.org or email orphan@rarediseases.org

Last Updated:  1/3/2012
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