Journal of Clinical Case Reports

The FokI Polymorphism of the VDR Gene is a Protective Factor for Psoriasis Vulgaris.

Abstract

Ricardo E Vega- Hernandez, Marina MJ Romero- Prado, Lucila Sandoval- Ramirez, Maria G. Moreno- Trevino, Oscar RFajardo- Ramirez and Julio C Salas- Alanis

Introduction: Vitamin D receptor (VDR) plays a key role in the metabolism and differentiation of keratinocytes; thus, associations between VDR polymorphisms with Psoriasis vulgaris (PsV) onset have been sought for many years. The results of these studies have not been conclusive. To date there are no studies in Mexico regarding the association between these polymorphisms and the clinical manifestations of PsV. Objective: The aim of this study was to determine the association between polymorphisms in the VDR gene (FokI, BsmI, ApaI and TaqI) and the clinical manifestations of PsV in a group of Mexican patients. Methods: The study group consisted of 52 patients from north (NPsV n=24) and western (OPsV n=28) regions of the country diagnosed with PsV. This group of patients were compared with healthy donors from the western (POc n=50) and northern (PN n=50) regions. RFLPs were identified to determine allelic and genotypic frequencies for all the groups. Hardy-Weinberg equilibrium (HWE) as well as haplotype distributions were estimated. Statistical tests were X2 and Fisher’s exact test. Haplotype distribution was carried out with SNPstats software. Results: There was no significant difference when the genotypic frequencies between patients and controls are compared; however, there is an association between the TT(ff) genotype of FokI polymorphism and clinical manifestations. The most frequently observed haplotypes of polymorphisms (FokI, BsmI, ApaI and TaqI) have significantly different distributions (p>0.0001) between patients with PsV and controls. Conclusions: Our results show that the polymorphisms FokI, ApaI, BsmI and TaqI in the VDR gene are not associated with the risk of presenting PsV in Mexican population, but the TT(ff) genotype of the FokI polymorphism is significantly more common in patients with late onset of PsV (after age 40) and those without nail affection. More studies including a greater number of samples and other polymorphisms must be analyzed.