Interactive effects of XRCC3 codon 241 and MSH3 codon 1036 genes in the ICS group. Individuals carrying both wild-type alleles for XRCC3 and MSH3 polymorphisms showed a significantly lower MN frequency compared to exposed individuals with one or two variant alleles for XRCC3 and MSH3 polymorphisms. ^*Significant at p = 0.04 vs. one variant genotypes (−+ or +−) and at p = 0.01 vs. homozygous variant (++) genotypes. (−−): both wild genotypes, (−+ or +−): one variant genotypes and (++): homozygous variant genotypes.