Genome Wide Association Study of an Association between Gene Polymorphisms and the Increased Frequency of Cytogenetic Abnormalities in the Persons Exposed to Long-Term Irradiation

Abstract

Purpose: To conduct genome wide association study of the association of 750,000 SNPs and an increased frequency of different types of chromosomal aberrations, induced by chronic irradiation in the dose range of 100–300 mSv.
 Material and methods: The study was conducted among Siberian Group of Chemical Enterprises healthy employees (n = 37) exposed to professional external γ-radiation in a dose range of 100–300 mSv. The de novo induced CNVs were previously detected in these persons. Mean dose – 188.8 ± 8.3 mSv, median – 185 mSv, interquartile range – 147.8–218.7 mSv, min – 103.4 mSv, max – 295.8 mSv. Genotyping of DNA samples from 37 employees was carried out by microarray CytoScan™ HD Array (Affymetrix, USA), containing 750,000 SNP-markers of 36,000 genes. The standard cytogenetic analysis was performed in the entire examined group.
 Results: We analyzed the association of these SNPs with the frequencies of aberrant cells and following chromosomal aberrations: single chromatid fragments, chromatid exchanges, paired fragments, dicentrics, rings, and translocations. We have found that 8 SNPs (rs10779468, rs158735, rs158710, rs158712, rs11131536, rs528170, rs9533572, rs10512439) are associated with the frequency of aberrant cells.
 Conclusion: We have discovered polymorphic variants that are associated with an increased frequency of aberrant cells in workers of Siberian Group of Chemical Enterprises exposed to irradiation at a dose of 100–300 mSv. This polymorphic variants can be considered as potential markers of individual radiosensitivity. To confirm identified associations, further validation studies on an extended sample of people exposed to radiation are needed.