Relationships between vitamin D receptor genetic polymorphisms and endometriosis in Korean women

Abstract

Objectives: Vitamin D and vitamin D receptor (VDR) are closely associated with both various immune system functions and estrogen-related pathways. The authors hypothesized that VDR genetic polymorphisms are associated with endometriosis risk. In this case-control study, the authors investigated the associations between polymorphisms in the VDR gene (Fold, Bsml, Apal, and Tagl) and endometriosis risk. Materials and Methods: This case-control study included 30 women with endometriosis and 30 women without endometriosis. Genotyping of VDR polymorphisms was conducted using polymerase chain reaction and DNA sequencing. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the association between the four VDR polymorphisms and endometriosis risk using Fisher's exact test. Results: The four VDR genetic polymorphisms showed no significant associations with endometriosis risk. Similarly, a combination analysis indicated that no combinations of polymorphisms were associated with endometriosis risk. However, the present analysis combining three polymorphisms revealed very low ORs (CGGT: 0.536, TGTT: 0.250, and CCITT: 0.321). Conclusion: The present results suggest that VDR polymorphisms do not affect endometriosis risk in Korean women. However, the genotype frequencies of Apal and Tagl differed between endometriosis patients and controls. Therefore, it is necessary to further validate the relationship between VDR polymorphisms and endometriosis risk in large-scale samples.