Vitamin D receptor gene polymorphism is not associated with psoriasis in the Italian Caucasian population

LETTER TO THE EDITOR. Summary. Psoriasis is a chronic inflammatory skin disorder associated with both genetic, immunologic, and environmental factors. Changes in proliferation and metabolism of keratinocytes, together with neo-angiogenesis and neutrophilic infiltration into the dermis lead to a broad spectrum of clinical manifestations, so that therapeutic strategy has to be adapted in each patient. The chance discovery in 1930s that vitamin D high doses improved psoriasis provided the impetus for investigating the efficacy of vitamin D and its metabolites in treatment of psoriasis… Vitamin D activities are mediated by the vitamin D receptor (VDR), that belongs to the steroid/thyroid hormone receptor super-family… In recent years, some studies reported an association between psoriasis and VDR polymorphisms… In this study, we tested whether BsmI allelic polymorphism could be considered one of the susceptibility genes for psoriasis in the Italian Caucasian people, and whether a correlation could be found between VDR genotypes and epidemiological and clinical characteristics of psoriasis… As regards our results, the frequencies for the BB, Bb and bb genotypes in the psoriasis group and in the control group, as well as the derived allelic frequencies for B and b alleles, were not statistically different. In the psoriasis group, the correlation between sex and VDR genotypes failed to give statistically relevant results. Similarly, no significant differences emerged from the correlation between BsmI polymorphism and age at onset or psoriasis family history… From our observations it could be concluded that, although VDR gene polymorphism is associated with a variety of pathologic conditions in the Italian Caucasian population, psoriasis is not among these diseases.