Advances in Biology & Earth Sciences

The BRCA1 Gln356Arg (rs1799950) polymorphism has been investigated in various populations for its potential role in breast cancer susceptibility, yet findings remain inconsistent and no prior data exist for the Azerbaijani population. This study aimed to evaluate the association between the BRCA1 Gln356Arg variant and breast cancer risk and tumor characteristics in Azerbaijani women. A total of 144 breast cancer patients and 152 healthy controls were recruited from the Oncology Clinic of Azerbaijan Medical University between 2021 and 2024. Genotyping was performed using the PCR-RFLP method and amplified fragments were visualized by electrophoresis on a 2% agarose gel. The heterozygous AG genotype (OR = 1.36; 95% CI: 0.80-2.30; p = 0.24) and the minor G allele (OR = 1.14; 95% CI: 0.76-1.73; p = 0.53) were slightly more frequent in patients than in controls; however, no statistically significant association with breast cancer risk was observed. No correlation was identified between tumor stage and genotype distribution, whereas a statistically significant association was found between tumor grade and genotype (p = 0.025), suggesting a potential influence on tumor differentiation. In conclusion, the BRCA1 Gln356Arg variant does not appear to significantly influence overall breast cancer susceptibility in the Azerbaijani population but may be involved in tumor differentiation. Further large-scale, multi-center and functional studies are warranted to confirm these findings and elucidate the biological relevance of this polymorphism in breast cancer development.