DefinitionAtaxia-telangiectasia is rare childhood disease that affects the brain and other parts of the body.Ataxia refers to uncoordinated movements, such as walking. Telangiectasias are enlarged blood vessels (capillaries) just below the surface of the skin. Telangiectasias appear as tiny, red, spider-like veins.Alternative NamesLouis-Bar syndromeCauses, incidence, and risk factorsAtaxia-telangiectasia is inherited, which means it is passed down through families. It is an autosomal recessive trait. This means that both parents must provide a defective gene for the child to have symptoms of the disorder.The disease results from defects in the ataxia telangiectasia mutated (ATM) gene. Defects in this gene can lead to abnormal cell death in various places of the body, including the part of