Ataxia-telangiectasia (AT) is an autosomal recessive disorder characterized by cerebellar ataxia, telangiectases, immune defects, and a predisposition to malignancy. Chromosomal breakage is a feature. AT cells are abnormally sensitive to killing by ionizing radiation (IR), and abnormally resistant to inhibition of DNA synthesis by ionizing radiation. The latter trait has been used to identify complementation groups for the classic form of the disease. At least 4 of these (A, C, D, and E) map to chromosome 11q23 and are associated with mutations in the ATM gene.
Immune Deficiency, Ataxia
Confirmation of a clinical diagnosis, Carrier testing in unaffected family members