Background: Genome Wide Association Studies (GWAS) have evaluated several genes related to vitamin D synthesis, metabolism and transport. They have proposed a genetic basis for low levels of vitamin D in the blood. The current study aims to investigate the relationship between certain vitamin D-associated gene variants and vitamin D deficiency in Iranian adolescents. Methods: In this case-control study, the genomic DNA was extracted by Real Time PCR High Resolution Melt (HRM). All measurements were carried out with triple repetition. The following factors were assessed: single nucleotide polymorphisms (SNPs) in Vitamin D binding protein (DBP, rs2282679), 7-Dehydrocholesterol reductase (DHCR7, rs12785878) and Cytochrome P450 2R1 (CYP2R1, rs10741657). Results: the genomic DNA of blood samples obtained from 481 adolescents. Participants with hypovitaminosis D were compared with a control group. The average vitamin D level of sufficient subjects (controls) was 44.88±14.01 ng/mL, while subjects who were insufficient (cases) had an average vitamin D level of 7.03±1.24 ng/mL. No statistically significant differences were found in the allelic and genotypic distributions between genders. The SNP frequency in CYP2R1 (rs10741657) and DBP (rs2282679) in the vitamin D deficient group was significantly higher than in the control group (p-values < 0.001 and 0.01 respectively). There were no statistically significant differences in the DHCR7 SNP (rs12785878) distributions between the Vitamin D deficient group and control group. Conclusion: The present study demonstrated evidence of the ability of the SNPs under investigation to predict circulating vitamin D concentration. Further study is needed to better understand if and how genetic factors contribute to vitamin D levels, and certain skeletal-associated disorders in adolescents.
Keywords: Vitamin D; cholecalciferol; rs10741657; rs12785878; rs2282679.