Ataxia Telangiectasia

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What is ataxia telangiectasia?

Ataxia Telangiectasia (AT)—also known as Louis-Bar syndrome, cerebello-oculocutaneous telangiectasia, or immunodeficiency with ataxia telangiectasia—is a rare inherited childhood neurological disorder that affects the part of the brain that controls motor movement (intended movement of muscles) and speech. AT also affects the spine and immune system. It usually begins in early childhood before age 5.

AT is caused by mutations in the ATM (ataxia-telangiectasis mutated) gene. Some children with AT develop cancer, most frequently acute lymphocytic leukemia or lymphoma.

Neurological symptoms include:

  • Unsteady walking and lack of balance
  • Lack of coordination of movement
  • Slurred speech
  • Difficulty swallowing
  • Unintentional movement, such as tremor or jerky movement
  • Difficulty coordinating eye movement

Other symptoms may include:

  • Frequent respiratory infections
  • Red “spider” veins around the eyes, ears, or cheeks (telangiectasias)
  • Increased sensitivity to ionizing radiation (such as X-rays or gamma rays)
  • Diabetes
  • Premature graying of the hair
  • Fatigue
  • Delayed physical and sexual development

There is no cure for AT and, currently, no way to slow the progression. Treatment is symptomatic and supportive, such as physical therapy to help maintain flexibility and speech therapy to teach children how to control breathing. Additionally, high-dose vitamins, antioxidants, and gamma-globulin injections may be useful. The severity of the ATM mutation adjusts the average lifespan. Those who had a later onset and slower progression of AT typically survive into their 50s.

Learn About Clinical Trials
Clinical trials are studies that allow us to learn more about disorders and improve care. They can help connect patients with new and upcoming treatment options.

How can I or my loved one help improve care for people with ataxia telangiectasis?

Consider participating in a clinical trial so clinicians and scientists can learn more about AT and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.

All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

For information about participating in clinical research visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with AT at

Where can I find more information about ataxia telangiectasia?

Information is available from the following resources:



National Ataxia Foundation
Phone: 763-553-0020

Order publications from the NINDS Catalog
The NINDS Publication Catalog offers printed materials on neurological disorders for patients, health professionals, and the general public. All materials are free of charge, and a downloadable PDF version is also available for most publications.