Lack of association of vitamin D receptor gene polymorphisms/haplotypes in Sjögren's syndrome.

The vitamin D is involved in a wide variety of biological processes including bone metabolism, modulation of the immune response, and regulation of cell proliferation and differentiation. Vitamin D has several immunomodulatory effects through vitamin D receptor (VDR). A series of common single-nucleotide polymorphisms (SNPs) in the vitamin D receptor gene have been linked to numerous of diseases, including osteoarthritis, diabetes, cancer, cardiovascular diseases, tuberculosis, virus infections, urinary stones, and periodontitis. Several studies have reported that genetic variations of VDR might be a risk factor for the development of autoimmune diseases such as systemic lupus erythematosus (SLE), multiple sclerosis (MS), psoriasis, and autoimmune thyroid diseases (AITD). However, no data is available on the possible relationship between primary Sjögren's syndrome and VDR gene polymorphisms. Our aim was to determine VDR gene BsmI, ApaI, TaqI, and FokI polymorphism genotypes in pSS patients and healthy controls to analyze whether a relationship exists between polymorphisms in the VDR gene and susceptibility to Sjögren's syndrome. In the current study, 105 patients with pSS and 93 healthy controls were tested for VDR gene polymorphisms (BsmI, ApaI, TaqI, and FokI) genotypes. There were no statistical differences in the distribution of BsmI, TaqI, ApaI, and FokI genotypes and the common haplotypes between pSS patients and healthy controls. We hypothesized that the TaqI, BsmI, ApaI, and FokI polymorphisms of the VDR gene are not associated with the development of primary Sjögren's syndrome in the Hungarian population studied.