Association between FokI, ApaI and TaqI RFLP polymorphisms in VDR gene and Hashimoto's thyroiditis: preliminary data from female patients in Serbia.

Hashimoto's thyroiditis (HT) is the most prevalent autoimmune thyroid disorder caused by an interaction between genes and environmental triggers. Intrathyroid lymphocytic infiltration may lead to progressive destruction of thyroid tissue and consequently to hypothyroidism. Many studies in different populations have shown association between vitamin D receptor (VDR) gene polymorphisms and various autoimmune diseases, including HT. The study included 44 female patients (mean age ± standard deviation 38 ± 5.4) with Hashimoto's thyroiditis and 32 healthy age-matched, sex-matched and geographically matched controls without personal history of autoimmune and endocrine diseases. Genomic DNA was isolated from peripheral blood-EDTA, and the target VDR gene was genotyped by PCR-RFLP technique after VDR-FokI (rs2228570), VDR-ApaI (rs7975232) and VDR-TaqI (rs731236) restriction enzymes digestion. We used spss 20.0 integrated software for data analysis and found a significant difference in the genotype distribution of VDR-FokI polymorphism between patients with HT and controls (P = 0.009). For ApaI and TaqI, we observed a higher frequency of variant allele in patients with HT, which was not significantly different compared to control women (P > 0.05). The current first and preliminary results identified the association between VDR-FokI gene polymorphism and Hashimoto's thyroiditis in Serbian population. Results need to be supported by further investigations that define haplotype patterns for VDR gene polymorphisms in a larger group of HT patients of both sexes.