Abstract
BACKGROUND: Diminished ovarian reserve (DOR) is a major cause of female infertility, marked by reduced oocyte quantity and quality. STAG3 and DMC1 are meiosis-specific genes essential for chromosomal integrity and homologous recombination. While their downregulation in granulosa cells of DOR women has been reported, expression in peripheral blood remains unexplored. OBJECTIVE: To evaluate peripheral blood STAG3 and DMC1 expression as potential non-invasive biomarkers in DOR. MATERIALS AND METHODS: This case-control study included 50 women at Yazd Research Institute, Yazd, Iran, comprising 25 DOR women (anti-Müllerian hormone < 1.1 ng/mL) and 25 age-matched controls. Peripheral blood mononuclear cells were isolated, RNA extracted by column-based silica method, and gene expression analyzed by quantitative real-time polymerase chain reaction using the 2 ∧ - Δ Ct method. RESULTS: Demographic analysis revealed no significant differences in age or body mass index between DOR women and controls. As expected, anti-Müllerian hormone levels (0.61 vs. 2.12 ng/mL) and antral follicle counts (3.52 vs. 8.64) were significantly lower in the DOR group. Quantitative real-time polymerase chain reaction analysis revealed a significant downregulation of STAG3 expression in peripheral blood mononuclear cells of DOR women compared with controls (p = 0.0011). DMC1 expression showed a downward trend but did not reach statistical significance (p = 0.1132). These results suggest a potential role of STAG3 dysregulation in DOR pathogenesis. CONCLUSION: These findings indicate differential expression of meiotic genes in the peripheral blood of DOR women, supporting STAG3 as a promising non-invasive biomarker for early detection of DOR and contributing to a better understanding of its molecular basis in reproductive medicine.