Association of CYP2R1 gene polymorphisms in pulmonary tuberculosis

The CYP2R1 gene express the enzyme 25-hydroxylase, involved in the synthesis of major circulating vitamin D metabolite 25-hydroxyvitaminD [25(OH)D]. CYP2R1 gene variants have been reported to be associated with altered 25(OH)D level and associated with the development of active disease including tuberculosis (TB). The aim of the present study was to understand the association of rs10741657 (G/A) and rs2060793(A/G) CYP2R1 gene polymorphisms with tuberculosis susceptibility/protection in 104 Healthy controls (HCs) and 105 pulmonary tuberculosis (PTB) patients and to understand the influence of gene variants on 25(OH)D levels in South Indian population. Genotyping was performed by polymerase chain reaction trailed by restriction fragment length polymorphism (PCR-RFLP) method. Plasma samples were used for 25(OH)D level estimation by ELISA method. In rs10741657, under a dominant model (GG vs AG + AA), “AG” and “AA” genotypes as well as in rs2060793 under an overdominant model (GA vs GG + AA), “GA” genotype were significantly associated with protection to pulmonary tuberculosis. Based on sex, rs10741657 “AG” was significantly associated with protection and “GG” was significantly associated with susceptibility to TB in males. A sufficient vitamin D level was found with rs10741657 “AA” and “AG” genotypes and “GG” genotype associated with 81.8% of vitamin D deficiency in PTB individuals. In conclusion, rs10741657 “AG” and “AA” genotypes were associated with higher 25(OH)D levels and protection to TB. The lower 25(OH)D levels associated with rs10741657 “GG” genotype individuals may be recommended for higher vitamin D supplementation for better outcome from the disease. Further studies with large sample size are needed to confirm this study finding.