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HIV & AIDS Health Center

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HTLV Type I and Type II

It is possible that the main title of the report HTLV Type I and Type II 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.


  • ATL
  • HTLV-I associated myelopathy
  • acute T-cell leukemia
  • acute T-cell lymphoma
  • tropical spastic paraparesis

Disorder Subdivisions

  • None

General Discussion

HTLV-I was first isolated in 1980 from a patient originally thought to have a cutaneous lymphoma. It became clear that it was a distinct form of lymphoma, which was designated as acute T-cell leukemia/ lymphoma (ATL). Some years later, different groups in Martinique and Japan described an association between a chronic disease of the spinal cord and HTLV-I infection, which was later named HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP). Since then, several other conditions have been linked to HTLV infection.

It is estimated that between 10 and 20 million people are infected by HTLV-I in the world. Only 0.25-2% of the infected individuals will develop a progressive neurologic disease named HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP). Approximately 2-5% of HTLV-I carriers will develop ATL. More rarely, HTLV-I may lead to arthropathy, uveitis (inflammation of the eye), pneumonitis and thyroid problems. Areas of the world that are endemic to the HTLV-1 virus are the Caribbean, southern Japan, equatorial Africa, Middle East, South America, and Melanesia.


WE MOVE (Worldwide Education and Awareness for Movement Disorders)
5731 Mosholu Avenue
Bronx, NY 10471
Tel: (347)843-6132
Fax: (718)601-5112

Transverse Myelitis Association
1787 Sutter Parkway
Powell, OH 43065-8806
Tel: (614)766-1806

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

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 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 or email

Last Updated: 5/4/2012
Copyright 2008, 2012 National Organization for Rare Disorders, Inc.

WebMD Medical Reference from the National Organization for Rare Disorders

Last Updated: 8/, 015
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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