Ataxia telangiectasia is a rare, progressive, medical condition that affects a number of different organs in the body, including the brain. Ataxia telangiectasia is an immunodeficiency disease that causes the immune system to break down. Currently, there is no cure for ataxia telangiectasia and there is no way to slow the progression of the disease. Therefore, treatment for ataxia telangiectasia is symptomatic and supportive.