Ataxia-Telangiectasia
Ataxia-telangiectasia is a hereditary disorder characterized by incoordination, dilated capillaries, and increased susceptibility to infections.
The increased susceptibility to infections in people with ataxia-telangiectasia results from malfunction of B and T lymphocytes. Often, levels of the antibody classes IgA and IgE are also deficient. Sinus and respiratory infections recur, often leading to pneumonia and chronic lung disorders such as bronchitis. The risk of cancer, especially leukemia, brain tumors, and stomach cancer, is increased.
Abnormalities in the cerebellum (which are unrelated to the immunodeficiency disorder) lead to incoordination (ataxia). Incoordination usually develops when the child begins to walk but may be delayed until age 4. Speech becomes slurred, and muscles progressively weaken, leading to severe disability. Mental retardation may develop and progress. Between the ages of 1 and 6, capillaries in the skin and eyes become dilated and visible. The dilated capillaries (telangiectasia), called spider veins, are usually most obvious on the eyeballs and ears. The endocrine system may be affected, resulting in small testes (in boys), infertility, and diabetes.
Antibiotics and immune globulin help prevent infections but do not relieve the problems with the nervous system. Ataxia-telangiectasia usually progresses to paralysis, dementia, and death, usually by age 30.
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