[Ataxia telangiectasia].

Ataxia-telangiectasia(AT), an autosomal recessive disorder characterized by cerebellar degeneration, immunodeficiency, cancer predisposition and radiation sensitivity, is caused by mutations in a gene named ATM(AT, mutated), which encodes a 370 kDa serine-threonine kinase, whose catalytic domain is structurally related to the catalytic subunit of phosphatidylinositol 3-kinase(PI3K). ATM has been recently revealed to be involved in DNA damage recognition and cell cycle control in response to ionizing radiation damage. Further investigations of the multiple roles of ATM will explain other disease features, such as cerebellar degeneration in ATM in the near future. This review summarizes some of the recent research developments in ATM functions and their relationship to the clinical phenotypes of AT.