The Frequency of Vitamin D Receptor Gene Polymorphisms in Pulmonary tuberculosis (TB) Patients and Its Relation with Susceptibility to TB

Many genetic studies on predisposing factors for active tuberculosis have been conducted. Study on human leukocyte antigens (HLA), vitamin D receptor (VDR), NRAMP1, mannose binding lectin (MBL), and tumor necrotizing factor (TNF) are the most studies in this field. This study was planned to identify any relationship between VDR polymorphisms (Apa I, Bsm I, Fok I and Taq I) and susceptibility to TB. This case-control study was performed on blood samples from tuberculosis cases (n=164) and controls (n=50). DNA was extracted from white blood cells and the sequences were amplified by PCR followed by restriction digestion (PCR-RFLP technique) using specific primers and enzymes for each polymorphism. VDR polymorphisms were evaluated for two mentioned groups. Two genotypes of AbfT and AabbFfTT were the only statistically significant genotypes which had a dfferent frequency between the study and control groups. Results of this study showed that genotypes of AbfT and AabbFfTT are protective factors against TB in our patients. We could not find any genotype as a predisposing factor for TB in our study group. However, other studies with larger group of samples are needed to find such a relationship.