Alternative Names
A-T; Ataxia Telangiectasia Syndrome; ATM; Louis-Bar syndrome; Telangiectasia, cerebello-oculocutaneous
Symptoms & Characteristics
Ataxia-telangiectasia is a genetic condition that affects the nervous system, immune system and other body systems.
Ataxia-telangiectasia is characterized by progressive difficulty with coordinating movements (ataxia) beginning in early childhood. Affected children usually develop difficulty walking, problems with balance, abnormal eye movements and slurred speech. Small clusters of enlarged blood vessels called telangiectases, which occur in the eyes and on the surface of the skin, are also characteristic of this disorder.
People with ataxia-telangiectasia often have weakened immune systems, and many develop chronic lung infections. Affected people also have an increased risk to develop cancer, particularly cancer of blood-forming tissue (called leukemia) and cancer of immune system cells (called lymphoma). Affected people are very sensitive to the effects of radiation exposure, including medical x-rays.
Although people with ataxia-telangiectasia typically live into adulthood, their life expectancy is reduced.
Treatment
Early diagnosis, routine surveillance and treatment of ataxia-telangiectasia may help to manage some of the symptoms and sometimes prevent related problems.
How Common Is It?
About 1 in 40,000 to 1 in 100,000 people are affected with ataxia-telangiectasia worldwide.
Genetics & Inheritance
Ataxia-telangiectasia is caused by mutations in the ATM gene cause. The ATM gene produces a protein that helps control cell division and is involved in DNA repair.
Ataxia-telangiectasia is inherited in an autosomal recessive pattern, which means both copies of the ATM gene in each cell have mutations. Most often, the parents of an individual with an autosomal recessive disorder each carry one copy of the mutated gene, but do not show signs and symptoms of the condition.
About 1% of people in the United States (about 2.5 million people) carry one mutated copy and one normal copy of the ATM gene. Although these people do not have ataxia-telangiectasia, they are more likely than people without an ATM mutation to develop cancer, particularly breast cancer. Carriers of a mutation in the ATM gene may also be at increased risk to develop heart disease.
Genetic Testing
Clinical genetic testing for ataxia-telangiectasia may be available through an in person genetic consultation for people who are considered at risk. Use our find a genetic professional directory to locate a trained genetic professional in your area.
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