DNA REPAIR DEFECTS ASSOCIATED WITH IMMUNODEFICIENCY
Ataxia telangiectasia (AT) is a condition characterized by cerebellar ataxia, oculocutaneous telangiectasia, growth retardation and a variable immunodeficiency. AT patients show increased sensitivity to ionized radiation and radiomimetic drugs. Increased susceptibilityto leukemias and lymphomas is also a feature of this syndrome, Patients often fail to produce antibodies to bacterial capsular polisaccharides and therefore develop sinopulmonary infections. Chromosomal translocations, involving immunoglobulin heavy chain and TCR loci, are often detected in the T cells of AT patients.