Myeloperoxidase and CYBA genetic variants in polycystic ovary syndrome

Background Oxidative stress plays a pivotal role in the pathogenesis of polycystic ovary syndrome (PCOS). Genetic variations in myeloperoxidase (MPO; G‐463A) and NADPH oxidase p22phox subunit (CYBA; C242T) cause inter‐individual variability in enzyme activities. Here, we investigated the associations between MPO activity and the MPO G‐463A and CYBA C242T polymorphisms in Chinese women with PCOS. Methods This case‐control study included 1003 patients with PCOS and 810 controls. The G‐463A and C242T polymorphisms were detected by polymerase chain reaction and restriction analysis, and clinical, hormonal, metabolic and oxidative stress parameters and MPO activity were analysed. Results The frequencies of the GA + AA genotype and A allele frequency of the MPO G‐463A polymorphism were significantly higher in the PCOS group than in the control group. Logistic regression analysis showed that the MPO‐463A allele is a risk factor for PCOS (OR = 1.261, 95% CI: 1.042‐1.526, P = .017). Patients with the AA genotype tended to have higher plasma MPO activity than those with the GG genotype. No statistical significance was found in the genotype and allele frequencies of the CYBA C242T polymorphism between the PCOS and control groups. However, we demonstrated that the coexistence of the MPO A allele (GA + AA genotypes) and the CYBA CC genotype was associated with an increased risk of PCOS when compared with the wild‐type GG/CC genotypes (OR = 1.302, 95% CI: 1.030‐1.646, P = .027). Conclusion The MPO G‐463A variant, but not CYBA C242T variant, is associated with a risk of PCOS in Chinese women.