[Research of mutations in oncogenes and tumour suppressor genes as the approach to research of ways of the individual prognosis of delayed effects of exposure to ionizing radiation].

The frequency of mutant forms p53 and N-Ras genes was investigated in DNA from peripheral blood of the patients by method Polymerase Chain Reaction - Single Strand Conformation Polymorphism Analysis. The patients were investigated in late period after radiation accidents exhibited acute radiation syndrome. It is established that the mutations among patients in areas of codons 246-250 exon 7 of p53 gene and codon 12 of N-Ras gene were meet more often than in control group. It is shown that these mutations possibly arise in insignificant number of the cells with the radiation-induced genomic instability. Possibility of use of mutations in protooncogenes and tumour suppressor genes as markers of risk of development of the main thing from delayed effects of exposure to ionizing radiation - malignant tumours is discussed.