National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

TAR syndrome

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Has TAR syndrome been associated with white cell abnormalities in the bone marrow? What about cancer?

The following information may help to address your question:


Has TAR syndrome been associated with abnormalities with white cells in the bone marrow?

In addition to problems with platelets, some individuals with TAR syndrome may, at times, make too many white cells. This is not leukemia in the sense of being a malignancy, but rather is called a leukamoid reaction - a reaction of the leukocytes or white cells during which large numbers (often exceeding 35,000 cells/mm3) of them are made.[1][2] This most often occurs along with low platelets in infants and children who are very sick.[1] Leukemoid reactions are generally short-lived.[2]

The bone marrow may also make too much of a type of blood cell called the eosinophil. The eosinophil is a white blood cell that is easily identified under the microscope because of its reddish granules. It is usually associated with allergies and asthma. The reason that eosinophils are increased in some individuals with TAR syndrome is unknown.[1]

Last updated: 10/26/2012

Has TAR syndrome been associated with an increased risk for cancer?

While the National Cancer Institute lists leukemia (cancer of the blood and bone marrow) as a possible associated cancer, they clearly state that it is not clear whether patients with TAR syndrome are truly at increased risk for developing cancer.[3]
Last updated: 10/26/2012

We hope this information is helpful. We strongly recommend you discuss this information with your doctor. If you still have questions, please contact us.

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GARD Information Specialist

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  1. Hall JG. TAR Syndrome. TAR Syndrome Support Group. March 2003; http://www.ivh.se/TAR/?page_id=40. Accessed 10/26/2012.
  2. Toriello, HV. Thrombocytopenia absent radius syndrome. GeneReviews. June 28, 2012; http://www.ncbi.nlm.nih.gov/books/NBK23758/.
  3. Inherited Bone Marrow Failure Syndromes: Thrombocytopenia Absent Radii (TAR). National Cancer Institute (NCI). http://www.marrowfailure.cancer.gov/TAR.html. Accessed 10/26/2012.