[Deletions in Mitochondrial DNA from the Peripheral Blood of Mayak PA Workers Exposed to Long-Term Ionizing Radiation].

The number of large deletions of mitochondrial DNA in whole peripheral blood of the former Mayak PA workers occupationally exposed to prolonged γ-radiation has been determined in the long term period after irradiation (mean cumulative dose 135.40 ± 22.03 cGy, age range at the time of blood sampling 67-76 years) and compared with the number of deletions in groups of "young" (19-33 years) and "adult" (66-73 years) individuals who had no contact with radiation sources. Samples of the total DNA from the peripheral blood were obtained from the Radiobiological Human Tissue Repository of the Southern Urals Biophysics Institute (Ozyorsk, Chelyabinsk region) and used for carrying out a long-distance PCR. The analysis of the data showed a statistically significant increase in the number of large deletions in the peripheral blood of "adult" donors of the control group as compared with the control group of "young" donors (51.6 and 14.3%, respec- tively). No statistically significant difference in the number of large deletions in the group of former Mayak PA workers occupationally subjected to prolonged exposure to γ-radiation as compared with the control do- nors of similar age was found (53.6 and 43.8% respectively).