Associations between granulysin and ovarian endometriosis: A 2-sample Mendelian randomization study

Endometriosis (EMS) is a chronic inflammatory disease defined by the presence of endometrial-like tissue outside the uterine cavity. Ovarian EMS is considered the most prevalent disease phenotype. However, the causal relationship between granulysin and ovarian EMS remains unclear. We investigate the potential causal relationship between granulysin and ovarian EMS using a 2-sample Mendelian randomization analysis. Genome-wide association study data for granulysin and ovarian EMS were obtained from publicly available online databases. A 2-sample Mendelian randomization analysis was conducted using the inverse-variance weighted method. The causal effect was further validated through weighted median and MR-Egger regression analyses, and a leave-one-out sensitivity analysis was performed. The odds ratio and its 95% confidence interval were used to evaluate the causal relationship between granulysin and the risk of ovarian EMS. Our findings suggest a direct causal relationship between granulysin expression and ovarian EMS. The inverse-variance weighted analysis revealed that a 1-standard deviation increase in granulysin was associated with a 10.7% reduction in the risk of ovarian EMS (odd ratio = 0.892, 95% confidence interval: 0.824-0.966, P = .004). There may exist a negative causal relationship between granulysin expression and ovarian EMS.