TaqI polymorphism T/t genotypes at the vitamin D receptor gene (VDR) are associated with increased serum vitamin D levels in mild and moderate psoriasis vulgaris: A pilot study

Abstract

Background: Several types of polymorphisms in vitamin D receptor (VDR) have been found in psoriasis.

Aim: This study looked at the role of the TaqI polymorphism in the VDR gene as a factor in changing plasma 25-hydroxyvitamin D [25(OH)D] levels in psoriasis patients and to see if it had any relationship with disease severity.

Subjects and methods: Clinical examination, serum 25(OH)D level measurement, molecular studies and TaqI genotyping by PCR and RFLP were performed for the two groups.

Results: The T/t genotypes of TaqI polymorphism genotypes were most common in patients, while the t/t genotypes were more abundant in healthy subjects. The T allele was high in the patient group in comparison with the normal subjects, but there were no significant differences (p = 0.421). Patients with T/t TaqI genotypes had higher levels of 25(OH)D than those with T/T and t/t (p = 0.004). Moderate psoriatic patients with the T/t genotype had relatively high 25(OH)D levels compared with moderate patients with the T/t and t/t genotypes (p = 0.001).

Conclusion: The increase in 25(OH)D titers in moderate patients is greater than that in mild and severe patients. T/t genotypes are associated with increased 25(OH)D levels in moderate and mild patients.

Keywords: TaqI polymorphism; VDR; psoriasis; vitamin D.