[Allelic variants of polymorphic genes associated with a higher frequency of chromosome aberrations]

Genotypic associations were studied for the frequency of chromosome aberrations in human peripheral blood lymphocytes. Cytogenetic analysis (1000 metaphase plate per individual) and genotyping at 19 sites of genes involved in detoxification and DNA repair were performed in a sample of 83 Chernobyl liquidators and a matched control sample of 96 volunteers. In either sample, the frequency of chromosome aberrations was higher in carriers of the minor alleles of the XPD gene (sites 2251T > G and 862G > A) and the positive genotypes of the GSTM1-GSTT1 genes. The highest frequency of chromosome aberrations was observed in carriers of a combined genotype including at least one minor allele of the XPD sites + at least one insertion in the GSTM1-GSTT1 genes. The high-risk genotype, which had a prevalence of 64%, was strongly associated with a higher frequency of chromosome aberrations in both volunteers (OR = 6.9, P = 0.008) and Chernobyl liquidators (OR = 5.6, P = 0.002).