Association of FokI, Tru91, and ApaI vitamin D receptor gene polymorphisms with the development of polycystic ovarian syndrome: A molecular genetic study

Background and objective Polycystic ovarian syndrome (PCOS) is an endocrine disorder in women of reproductive age. The study aims to identify the impact of vitamin D receptor encoding genes (FokI, Tru91, and ApaI) on the contribution and development of PCOS, in addition to their effect on AMH levels. Methodology The study included 80 patients and 25 healthy individuals. The concentrations of free testosterone, vitamin D, and AMH were determined. PCR-RFLP was applied to identify vitamin D receptors in the FokI, Tru91, and ApaI SNPs. Sanger sequencing was performed on each of these patients. Results Increase free testosterone and AMH levels 48 (60 %) and 65 (81.3 %), respectively and reduced vitamin D levels (56 (70 % were predictors of PCOS. Regarding FOKI polymorphisms, the frequency of the heterozygous genotype (CT) was significantly greater (OR = 2.96, P < 0.05) in the PCOS group than in the healthy group. There was a three-fold increase in the prevalence of the ApaI genotype in PCOS patients versus controls (the odds ratio for the CC homozygous genotype was 3.43 with P > 0.05). In Tru91 polymorphism, the AA and GG were associated with risk factors for PCOS susceptibility (OR = 2.78, P < 0.05) (OR = 3.04, P > 0.05), whilst AG was a protective factor (OR = 0.24, P < 0.05). Conclusions A relationship between high levels of free testosterone, AMH levels, and vitamin D deficiency was observed. Furthermore, all genetic models’ VDR FokI, ApaI, and VDR Tru91 polymorphisms are linked to PCOS susceptibility.