Evaluation of gene polymorphisms of vitamin D metabolism associated proteins in vitamin D deficiencies

INTRODUCTION: Vitamin D, which has well-known effect on calcium metabolism, has recently been associated with other pathologies such as autoimmune diseases and cancers. Some genes involved in vitamin D metabolism are associated with circulating vitamin D status. In this study we aimed to evaluate gene polymorphisms of proteins associated with vitamin D metabolism in patients with vitamin D deficiency/insufficiency. MATERIALS AND METHODS: 161 patients with vitamin D deficiency (80), deficiency (81) and vitamin D normalhealthy (84) subjects were included in the study. Blood samples taken into plain and plastic tube with EDTA were separated and stored at -80°C until analysis. Vitamin D levels were measured by "high performance liquid chromatography (HPLC)" in serum. DNA isolations were made by using commercial kits. Real-time PCR technique was used to investigate the single nucleotide polymorphisms (SNPs) of the CYP24A1-rs2209314, -rs2762939, and CYP3A4-rs2242480 genes. RESULT: Participants were grouped as group I: 84 subjects with normal vitamin D levels (30-110 ng / mL); II. 81 patients with vitamin D deficiency (<20 ng /ml); III. 80 patients with vitamin D insufficiency (20-30 ng/ml). Genotype frequency distributions of studied enzyme SNPs showed no statistically significant difference between the groups. However, when allele frequency distributions of CYP24A1-rs2209314 were compared with group III and group I (control), it was found that T allele was significantly higher in group III (P=0.030). CONCLUSİON: According to the our results, CYP3A4 (24-25-Hydroxylase)-rs2242480 and CYP24A1 (24-α Hydroxylase)-rs2209314, -rs2762939 variants have no statistically significant relationship with vitamin D deficiency/insufficiency risk in the population we worked. However, we have found that the T-allele in the rs2209314 variant of the CYP24A1 may be associated with vitamin D insufficiency. Keywords: CYP3A4, CYP24A1, Gene Polymorphism, Vitamin D, vitaminD deficiency/insufficiency