PURPOSE: Turner syndrome (TS) patients display considerable immune misregulation, and it is hypothesized that Vitamin D (VTD) activity may fluctuate according to Vitamin D receptor (VDR) polymorphisms and/or expression profile. To uncover a possible relationship between VDR genotype and clinical conditions in TS patients, we investigated two functional VDR variants (Cdx-2 and FokI) for allele and genotype frequencies, as well as expression profile in TS individuals versus healthy controls (HC). METHODS: We performed a genetic association study including 100 TS patients and 116 HC. Genotyping for VDR Cdx-2 G > A (rs11568820) and FokI C > T (rs2228570) was performed using Taqman Genotyping Assays. VDR gene expression was also evaluated in 15 TS and 15 HC, using fluorogenic probes by qPCR. Statistical analyses were performed using nonparametric Mann-Whitney test, with a 5% significance level (p < 0.05) to uncover differences between groups. In addition, we investigated whether shifted VDR mRNA levels were associated with Cdx-2 and FokI variants in TS patients. RESULTS: We detected a significantly higher frequency of T allele (p = 0.006) as well as T/T genotype (p = 0.01) for FokI in TS patients when compared to HC. When assessing VDR expression, we identified a downregulation in TS woman (- 2.84 FC) versus HC (p < 0.001). Furthermore, C/T (11.24 FC; p = 0.01) and T/T (9.20 FC; p = 0.01) FokI genotypes were upregulated when compared to C/C reference genotype. CONCLUSION: TS patients show different distribution of FokI polymorphism. Downregulation of VDR gene expression may contribute to immunological imbalance in TS.

Department of Genetics Federal University of Pernambuco Av da Engenharia s n Cidade Universitária Recife Pernambuco 50740 600 Brazil

Department of Genetics Federal University of Pernambuco Av da Engenharia s n Cidade Universitária Recife Pernambuco 50740 600 Brazil Department of Ecology Faculty of Science Charles University Vinicna 7 Praha 2 128 44 Prague Czech Republic

Department of Genetics Federal University of Pernambuco Av da Engenharia s n Cidade Universitária Recife Pernambuco 50740 600 Brazil Laboratory of Immunopathology Keizo Asami LIKA Federal University of Pernambuco Av Prof Moraes Rego Cidade Universitária Recife Pernambuco 52171 011 Brazil

Medical Genetic Service Institute of Integral Medicine Professor Fernando Figueira Rua dos Coelhos 300 Boa Vista Recife Pernambuco 50070 050 Brazil

Pediatric Endocrinology Service at Clinical Hospital Federal University of Pernambuco Av da Engenharia s n Cidade Universitária Recife Pernambuco 50740 600 Brazil

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