Association of Vitamin D and its Receptor (VDR) Gene Single Nucleotide Polymorphism (ApaI and TaqI) with Risk of Psoriasis

Abstract

Introduction: Psoriasis is one of the skin related inflammatory diseases that affects a low percentage of population around the globe. Vitamin D through Vitamin D Receptor (VDR) also regulates the function of white blood cells in psoriasis. Mutations in VDR gene have shown abnormalities in immune responses like psoriatic arthritis. To determine the possible association between Vitamin D Receptor (ApaI and TaqI) gene polymorphism and psoriasis, a case-control study was designed and conducted at the Institute of Basic Medical Sciences (IBMS), Khyber Medical University (KMU) Peshawar and health units of Peshawar. Method: This multi-centre study included 220 samples (110 cases of psoriatic disease and 110 healthy controls). DNA was extracted using modified salting out protocol. VDR gene polymorphisms (TaqI and ApaI) were genotyped using amplification refractory mutation system using polymerase chain reaction (ARMSPCR) method. Results were statistically analyzed. Result: Our study showed significant association between VDR gene (TaqI, ApaI) polymorphisms and psoriasis with p-value of 0.009 (0.0019 and 0.0162) and odds ratios (95% confidence interval) for psoriasis of CC vs CT (TaqI) and AA vs AC (ApaI) were 2.963 (95% CI: 1.508-5.743) and 2.293 (95% CI:1.22-4.246) respectively. Conclusion: Findings indicate that VDR gene polymorphisms (TaqI, ApaI) are significantly associated with onset and progression of psoriasis, and mutations in these loci are risk factors for development of psoriasis. Key words: Psoriasis, VDR polymorphism, TaqI, ApaI, South Asia, Pakistan