Endometriosis is a common estrogen-dependent inflammatory disease characterized by the presence of endometrial-like tissue outside the uterine cavity, which causes infertility and pelvic pain. Polymorphisms in MALAT1 have been demonstrated to play crucial roles in many diseases. However, the roles of MALAT1 polymorphisms in the etiology of endometriosis have not been well documented. We genotyped three MALAT1 polymorphisms in 555 endometriosis patients and 535 female control participants using quantitative polymerase chain reaction with TaqMan probes. To estimate the associations between MALAT1 polymorphisms and endometriosis risk, an unconditional logistic regression model was conducted to calculate an odds ratio (OR) and the 95% confidence interval (CI), adjusting for age, abortion history, number of deliveries, Body Mass Index (BMI), and The International Federation of Gynecology and Obstetrics (FIGO) stage. We found that the MALAT1 rs591291 C > T polymorphism significantly enhanced endometriosis risk (heterogeneous: adjusted OR = 1.36, 95% CI = 1.00–1.85, P = 0.050; homogenous: adjusted OR = 1.55, 95% CI = 1.03–2.33, P = 0.037; dominant: adjusted OR = 1.41, 95% CI = 1.05–1.88, P = 0.021). In stratification analyses, these associations were more predominant in the patients younger than 35 years old, with a relatively high number of deliveries and with a BMI between 25 and 29.9. Compared with wild-type CCG haplotype carriers, individuals with TCC haplotypes had a higher risk of developing endometriosis. The MALAT1 rs591291 C > T polymorphism was associated with a significant increase in endometriosis risk.

Summary sentence

We genotyped three MALAT1 polymorphisms (rs591291 C > T, rs664589 C > G, and rs4102217 G > C) in 555 endometriosis cases and 535 female controls using quantitative polymerase chain reaction with TaqMan probes to estimate the association between MALAT1 polymorphisms and the risk of endometriosis.