Impact of hMLH1 −93G>A (rs1800734) and hMSH2 1032G>A (rs4987188) Polymorphisms on Colorectal Cancer Susceptibility

Background: This study is the first to investigate the association between colorectal cancer (CRC) risk and the hMLH1 −93G>A and hMSH2 1032G>A polymorphisms of mismatch repair (MMR) genes in the Azerbaijani population. Methods: Peripheral blood samples containing EDTA were collected from the study subjects (134 patients and 137 controls), and genomic DNA was extracted using the non-enzymatic salting-out method. Genotypes were determined by polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP), and the results were visualized through agarose gel electrophoresis. Results: Overall, no statistically significant correlation was observed between CRC risk and the hMLH1 −93G>A polymorphism in the heterozygous GA (OR = 0.760; 95% CI = 0.374–1.542; p = 0.446), the mutant AA (OR = 1.474; 95% CI = 0.738–2.945; p = 0.270), or the A allele (OR = 1.400; 95% CI = 0.984–1.995; p = 0.062). However, in contrast to the dominant model, a statistically significant association was found between the recessive model and an increased CRC risk, with an odds ratio of 1.788 (95% CI = 1.102–2.900; p = 0.018). The hMLH1 −93G>A polymorphism was identified at a significantly higher frequency across the TNM stages, with the distribution showing statistical significance (p < 0.05). Additionally, no statistically significant association was observed between the hMSH2 1032G>A polymorphism and CRC risk. Conclusions: Although no overall association was observed for hMLH1 −93G>A, our findings suggest a potential link with increased colorectal cancer risk under the recessive model in the Azerbaijani population. Further studies are warranted to confirm this model-specific association and investigate the underlying biological mechanisms.