Analysis of VDR Gene Polymorphism in Beta Thalassemia Major (Beta Thalassemia Major / Vitamin D / Calcium / 825T/T Vitamin D Receptor Gene)

Abstract

Eriska Riyanti, Muhammad Harun Achmad, Mieke Hemiawati Safari, Meirina Gartika, Yunita Feby Ramadhany.

Vitamin D Receptor (VDR) Gene has an important role in calcium and bone metabolism because is required in mineralization of normal bone, calcium absorption, organizing calcium and phosphate homeostasis, and regulating the secretion of parathyroid hormone. Genetics research found that BsmI polymorphism region in VDR gene relates to osteoporosis, other bone diseases, and cartilage metabolism in particular allele. The aim of this research is to analyze polymorphism of VDR (825G/T) gene in the eighth intron of beta thalassemia major on Sundanese population. In this case-control study, SNP 825G/T of 66 beta thalassemia major patients (case group) and 15 controls (control group) were evaluated using PCR-RFLP with restriction of enzyme BsmI. Vitamin D and calcium level were analyzed using ELISA. Genotype distributions and allele frequencies were analyzed chi-squared test. This study found that the vitamin D level was significantly lower on case group than on control group (vitamin D 56.1 pmol/L 80.30%; p<0.001), and calcium level was significantly higher on case group than on control group (>8.5 mg/dL; p=0.025). Genotype frequency 825 VDR on case group was compared with control group, and there was no BB genotype in control group. There is only one case on case group (OR, 2.63; 95%CI, 0.73-9.64). B allele is significant in both case and control groups. There was no significant difference between case and control groups (OR, 2, 95%CI, 0.71-5.92). There was a significant difference in level of vitamin D and calcium, and also in allele frequency between on case and control groups.