[Diagnostics of ataxia-telangiectasia by the express-test found on the method of indirect immunofluorescence].

Ataxia-telangiectasia (AT) is a hereditary severe neurodegenerative disease developing, when mutations take place in both alleles of the atm gene, which encodes the key protein of the cellular response to DNA damage (DDR)--ATM proteinkinase. In response to the occurrence of double-strand DNA breaks, the ATM proteinkinase pass the autophosphorylation, and its active form--the phospho-ATM (P-ATM) appears in cells. In the nuclei of cells having the atm gene, P-ATM is revealed, being absent in cells with mutated forms of this gene, by means of the application of the modified method of indirect immunofluorescence. This peculiarity may be applied in the clinic, in order to confirm the diagnosis of AT.