Vitamin D Receptor Genotype Research Articles

The Effect of Vitamin D Supplementation with or without Calcium on Vitamin D Epimer and Metabolites.

A possible role of vitamin D epimers and metabolites in the measurement and response to treatment of vitamin D has been reported recently. Furthermore, the influence of underlying vitamin D receptor (VDR) genetic polymorphisms which have been linked to diseases such as obesity remains unclear. We therefore aimed to examine the influence of vitamin D3 and calcium supplements on vitamin D epimer and metabolite concentrations in subjects with and those without vitamin D receptor (VDR) gene polymorphisms. A total of 277 participants who were part of a randomized intervention trial of vitamin D3 and calcium or a placebo for 6 months had clinical and anthropometric assessments. Blood samples were taken for measurements of vitamin D, epimers and metabolites of vitamin D, four vitamin D receptor gene polymorphism SNPs, namely, BsmI, FokI, TaqI, and ApaI, metabolic and inflammatory markers, and related biochemical variables. Repeated-measures analysis of variance was used to assess the between-group difference in cumulative changes in vitamin D epimers and metabolites at 6 months after adjusting for the presence of the 4 VDR genotypes and allele gene polymorphisms. Overall, 277 participants, with a mean (±SD) age of 41 ± 12 and 204 (74%) of whom were female, were included in the study. We found no statistically significant differences in vitamin D metabolites or (epimers) between male and females or younger subjects compared to those over 40 years of age except in 7C4 BL (p < 0.05). There was a statistically significant difference in 1,25(OH)2D3 concentrations between subjects with and those without genotypes AG and the allele G SNP2_Taql VDR gene polymorphism. Vitamin D3 concentrations were also significantly lower in subjects with the CC SNP3_Apal gene polymorphism compared to those without the CC SNP3 gene. No statistically significant effects were seen on vitamin D epimers and metabolites concentration in response to supplements before or after adjusting for the presence of the 4 VDR genotypes and allele gene polymorphisms. The CC SNP3 gene had statistically significant influence on vitamin D3 levels. Vitamin D and/or calcium supplements, however, had no effects on vitamin D epimer and metabolite concentration before or after adjusting for the presence of the 4 VDR genotypes and alleles.

Association between partial remission phase in type 1 diabetes and vitamin D receptor Fok1 rs2228570 polymorphism.

The aim of the current study was to assess the natural course of partial remission (PR) phase of type 1 diabetes (T1D) and to highlight the putative association between vitamin D receptor (VDR) (Fok1) gene polymorphism and PR phase. Ninety participants with newly diagnosed T1D were followed up for a total of 12months. The VDR (Fok1) rs2228570 gene polymorphism was genotyped using allelic discrimination (AD) assay. Fifty-four patients (60 %) reached PR with an average duration of 5.63±2.9months. Among remitters, the frequency of CC "FF" genotype and allelic frequency of C "F" were significantly higher (p<0.001). Furthermore, participants expressing "CC" genotype had earlier onset of PR and spent a significantly longer duration in remission (p<0.001). Younger age (p<0.001; OR 41.6; CI 12.12-142.99), absence of DKA (p<0.001; OR 16, CI 4.36-50.74), higher C-peptide levels (p<0.001; OR 19.55; CI 6.52-58.63), and presence of CC "FF" genotype of VDR (p<0.001; OR 6.74; CI 2.41-18.86) best predicted the overall occurrence of PR. Younger age, less extent of metabolic derangements, and expression of a CC "FF" genotype were found to influence the occurrence of PR. Data from the current study showed that the "C" allele could have a protective role on preserving residual β-cell mass and could predict both onset and duration of PR among newly diagnosed T1D. These findings support the growing concept of future tailored precision medicine.

Association of vitamin D status and vitamin D receptor polymorphism in diabetic foot ulcer patients: A prospective observational study in a South-Indian tertiary healthcare facility.

Objective of the study was to find the association of vitamin D receptor (VDR) polymorphisms (Fokl, Taql and Apal) with vitamin D levels in diabetic foot ulcer (DFU) patients in South India. In this case-control study, plasma vitamin D levels and VDR genotype frequencies of 70 cases (DFU patients) were compared with 70 diabetic (diabetes mellitus [DM] [non-DFU]) patients and 70 apparently healthy controls (HC) from South India. Plasma vitamin D levels were measured using the ELISA technique, and genotyping of VDR polymorphisms was carried out using real-time polymerase chain reaction. Logistic regression was used to find the association between DFU versus HC and DFU versus DM traits. Association analysis was performed based on additive, dominant and recessive models with age and gender as covariates. A 45.7% of DFU patients have sufficient vitamin D levels than 48.6% and 40% of DM patients and HC, respectively. Linkage disequilibrium analysis for DFU versus HC and DFU versus DM traits shows that single nucleotide polymorphisms (SNPs) Taq1 (rs731236) and Apal (rs7975232) are in strong linkage disequilibrium in DFU patients. The alleles and genotype frequencies were similar in all three groups. Although the additive model does not show statistical significance, age and sex correlate with the three SNPs (Fokl, Taql and Apal). No association was found between VDR gene polymorphisms and vitamin D levels in DFU patients in Southern India. On the other hand, age and sex correlate with the three SNPs.

The Effects of MMP3 (rs679620) and VDR (rs731236) Gene Polymorphisms on Dental Caries: A Pilot Study.

Caries formation is a process affected by various factors. Studies have shown that genetic factors also play a role in caries formation. The aim of our study is to examine the effects of matrix metalloproteinase (MMP)3 (rs679620) and vitamin D receptor (VDR) (rs731236) gene polymorphisms on caries formation. Following routine oral examinations in individuals aged between 20 and 44 years, the diagnosis was made according to the decayed, missing, and filled teeth (DMFT) index, and experimental group was defined as "high caries risk" (DMFT ≥ 14, n = 28), and the control group as "no caries" (DMFT = 0, n = 28). Plaque index and bleeding on probing were measured from participants with a detailed anamnesis. Periodontally healthy individuals with less than 10% bleeding on probing were included in the study (n = 56). After DNA isolation from blood samples taken from the participants, the genotyping of MMP3 (rs679620) and VDR (rs731236) gene polymorphisms were determined using the real-time polymerase chain reaction technique. Data were analyzed with IBM SPSS V23.0. Data distribution was evaluated with Kolmogorov-Smirnov's test. Pearson's chi-square test was used to compare categorical data according to groups. The results were evaluated using a significance level of p < 0.05. Regarding MMP3 and VDR gene polymorphisms, there was a statistically significant difference between the groups in terms of MMP3 (rs679620) (p < 0.001). There was no statistically significant difference between the VDR (rs731236) genotype distributions of the groups (p = 0.659). Within the limits of this study, MMP3 rs679620 gene polymorphism may have an effect on caries formation.

Relationship between vitamin D receptor genotypes (FOK1rs2228570) and IL18 gene expression in sample of multiple sclerosis Iraqi patients

BACKGROUND: Multiple Sclerosis known as MS, this chronic inflammatory demyelinating condition affects the nervous system. It is a heterogenic and multifactorial disease. The goal of the current study was to investigate the relationship between MS patients’ IL18 gene expression and the vitamin D receptor gene polymorphism (FOK1rs2228570). OBJECTIVE: The aim of the study to investigate the association of vitamin D receptor (FOK1rs2228570) gene polymorphism and pro inflammatory cytokine (IL18) gene expression among multiple sclerosis Iraqi patients. Detection VDR polymorphism and determine whether this SNP is involved in susceptibility to multiple sclerosis and estimation IL18 gene expression and explore its relation with multiple sclerosis susceptibility. METHODS: Blood samples were taken from 75 MS patients in Iraq (30 men and 45 women), as well as from 75 volunteers who seemed to be in a favorable state of health and fell within the age range of 20 to 50 years. Tetra-ARMS Polymerase Chain Reaction (Tetra-ARMS PCR) was used to find polymorphisms in the vitamin D receptor (VDR) gene, and Real-time Polymerase Chain Reaction (RT-PCR) was used to measure IL18 gene expression. RESULTS: The findings from the analysis of VDR gene polymorphism in patients with MS indicated that the wild-type genotype T/T was present in 8 individuals, accounting for 10.6%, the heterogeneous genotype TC was 36 (48%), and the homogeneous genotype CC was 31 (41.3%), whilst T allele frequency was 52(34.6%) and C allele was 98(65.3%) with (P⩽ 0.01) significant difference and even as in control T/T genotype was 49(65.3%), TC genotype was 21(28%), CC genotype was 5(6.66%), T allele frequency was 119(79.3%) and C allele was 31(20.6%) with significant difference (P⩽ 0.001). While estimation of IL18 expression showed high elevation in patients’ group (2.59 ± 0.51 fold) by significance difference (P⩽ 0.5) when compared to control group (1.35 ± 0.14 fold). The relationship between IL18 gene expression with VDR variant in MS patients demonstrated a significant rise (2.9 ± 0.51 fold) at CC genotype patients in IL18 folding gene expression, followed by (4.6 ± 0.17 fold) in TC genotype patients and finally (1.4 ± 0.08 fold) in TT genotype patients with highly significant (P⩽ 0.01). CONCLUSION: The VDR(FOK1rs2228570) genotype was significantly correlated with IL18 expression in MS patients from Iraq.

Association between vitamin D receptor (APAI rs7975232) genotypes and vitamin D serum levels in Iraqi multiple sclerosis patients

BACKGROUND: Multiple sclerosis (MS) is a long-term condition characterized by chronic inflammation, damage to the myelin sheath, and progressive nerve cell degeneration. It is a heterogeneous and multifactorial disease. The aim of the present investigation was to analyze the connection between variations in the vitamin D receptor gene. (APAI rs7975232) and vitamin D serum levels among MS patients. METHODS: Blood samples were collected from 75 Iraqi patients with MS (33 male, 42 female), and 75 control group volunteers who appeared to be in good health with an age range of 20–50 years. Vitamin D receptor (VDR) gene polymorphism was detected by HRM RT-PCR and vitamin D serum levels were assessed by ELISA. RESULTS: Detection of VDR gene polymorphism in MS patients discovered that the wild genotype was C/C 15 (20%), the heterozygous genotype CA was 27(36%), and the homozygous genotype AA was 33(44%), whilst allele C occurrence was 57(38%) and allele A was 93(62%), compared per control genotype C/C was 40(53.3%), CA genotype was 20(26.6%), AA genotype was 15(20%), C allele frequency was 100(66.6%) and A allele was 50(33.3%) with highly significant difference (P≤0.001). Analysis of vitamin D serum levels showed much higher levels in the control group (43.40±0.85 pg/ml) than in the MS patients group (15.46±0.93 pg/ml; P≤0.001). Result of relationship between Vitamin D serum level with genotype of VDR among individuals with MS was found to be significant decrease (5.3±0.52) at AA genotype of MS patients, followed by (11.79±0.68) in CA genotype and finally (15.52±0.93) in CC genotype, all highly significant (P≤0.01). CONCLUSION: There was a notable correlation observed with VDR (APAI rs7975232) genotypes and Vitamin D serum level in MS Iraqi patients.

Vitamin D Deficiency and Its Association With Vitamin D Receptor Gene Variants Among Malaysian Women With Hypertensive Disorders in Pregnancy: Protocol for a Nutrigenomics Study.

Vitamin D deficiency has been associated with hypertensive disorders in pregnancy (HDP). The risk of developing HDP was reported to be further augmented among individuals with a vitamin D receptor (VDR) genetic variant. However, the reported roles of VDR variants in hypertensive disorders are inconsistent among different populations. Given the relatively higher incidence of vitamin D deficiency among Malaysian pregnant women and the high incidence of HDP in this population, we hypothesize that there may be associations between the risk of vitamin D deficiency and HDP with VDR genetic variants. This paper outlines the protocol for a study to determine the association of vitamin D status and VDR sequence variants among Malaysian pregnant women with HDP. This prospective study consists of two phases. The first phase is a cross-sectional study that will entail gathering medical records, a questionnaire survey, and laboratory testing for vitamin D status, with a planned recruitment of 414 pregnant women. The questionnaire will be utilized to assess the risk factors for vitamin D deficiency. The vitamin D status will be obtained from measurement of the vitamin D (25-hydroxyvitamin D3) level in the blood. The second phase is a case-control study involving a Malay ethnic cohort with vitamin D deficiency. Participants will be divided into two groups with and without HDP (n=150 per group). Genomic DNA will be extracted from the peripheral blood monocytes of participants using the Qiagen DNA blood kit, and VDR sequence variants will be determined using polymerase chain reaction-high-resolution melting (PCR-HRM) analysis. Sanger sequencing will then be used to sequence randomly selected samples corresponding to each identified variant to validate our PCR-HRM results. The VDR genotype and mutation frequencies of BsmI, ApaI, TaqI, and FokI will be statistically analyzed to evaluate their relationships with developing HDP. As of December 2023, 340 subjects have been recruited for the phase 1 study, 63% of whom were determined to have vitamin D deficiency. In the phase 2 study, 50 and 22 subjects have been recruited from the control and case groups, respectively. Recruitment is expected to be completed by March 2024 and all analyses should be completed by August 2024. The outcome of the study will identify the nonmodifiable genetic components contributing to developing vitamin D deficiency leading to HDP. This will in turn enable gaining a better understanding of the contribution of genetic variability to the development of HDP, thus providing more evidence for a need of customized vitamin D supplementation during pregnancy according to the individual variability in the response to vitamin D intake. ClinicalTrials.gov NCT05659173; https://clinicaltrials.gov/study/NCT05659173. DERR1-10.2196/53722.

Potential interplay between tumor size and vitamin D receptor (VDR) polymorphisms in breast cancer prognosis: a prospective cohort study.

Vitamin D has some anticancer properties that may decrease breast cancer risk and improve prognosis. The aim was to investigate associations between four previously studied VDR SNPs (Taq1, Tru91, Bsm1, and Fok1) and prognosis in different groups of breast cancer patients. VDR genotyping of 1,017 breast cancer patients included 2002-2012 in Lund, Sweden, was performed using Oncoarray. Follow-up was until June 30, 2019. Clinical data and patient information were collected from medical records and questionnaires. Cox regression was used for survival analyses. Genotype frequencies were as follows: Fok1 (AA 15.7%, AG 49.1%, GG 35.1%), Bsm1 (CC 37.2%, CT 46.1%, TT 16.7%), Tru91 (CC 77.8%, CT 20.7%, TT 1.5%), and Taq1 (AA 37.2%, AG 46.2%, GG 16.6%). During follow-up there were 195 breast cancer events. The homozygous variants of Taq1 and Bsm1 were associated with reduced risk of breast cancer events (adjusted HR = 0.59, 95% CI 0.38-0.92 for Taq1 and adjusted HR = 0.61, 95% CI 0.40-0.94 for Bsm1). The G allele of the Fok1 was associated with increased risk of breast cancer events in small tumors (pT1, adjusted HR = 1.83, 95% CI 1.04-3.23) but not in large tumors (pT2/3/4, adjusted HR = 0.80, 95% CI 0.41-1.59) with a borderline interaction (Pinteraction = 0.058). No interactions between VDR genotypes and adjuvant treatments regarding breast cancer prognosis were detected. VDR genotypes were associated with breast cancer prognosis and the association might be modified by tumor size. Further research is needed to confirm the findings and elucidate their potential clinical implications.

ApaI and Fok1 Variants of Vitamin D Receptor Gene Associated with Metabolic Syndrome Among Jordanian Women.

The association between vitamin D receptor (VDR) polymorphisms and metabolic syndrome (MS) remains debatable. The current study aimed to determine the correlation of VDR gene polymorphisms with MS among Jordanian women. This case-control study enrolled 100 women with MS and 100 age-matched women as control at Al-Hikma Modern Hospital in Jordan between January 2019 and January 2020. The levels of glycated hemoglobin, fasting glucose, triglyceride, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and 25-hydroxy vitamin D (25(OH)D) were determined from serum samples of all participants. DNA was extracted from whole blood samples, and VDR gene polymorphisms Apa1, Taq1, Bsm1, and Fok1 were analyzed by polymerase chain reaction and restriction fragment length polymorphism. There was a significant difference between MS patients and control in terms of body mass index (34.3±3.1 vs. 28.1±2.5), glycated hemoglobin (5.9±1.1 vs. 4.6±1.2), fasting blood glucose (6.4±1.6 vs. 5.2±1.4), and total cholesterol (6.5±1.2 vs. 5.3±1.8). The results also demonstrated a statistical difference in the number of MS patients and control with 25(OH)D deficiency (69.0 vs. 33.0), 25(OH)D insufficiency (25.0 vs. 42.0), and 25(OH)D sufficiency (6.0 vs. 25.0) (p < 0.001). MS was significantly associated with VDR polymorphisms among Apa1 and Fok1 genes. The genotype distribution for CC (47.0% vs. 53.0%; p = 0.002) and CA (37.0% vs. 45.0%; p = 0.001) genotypes among Apa1 VDR polymorphism, as well as among TT genotype (38.0% vs. 20.0%; p = 0.025) among Fok1 VDR gene polymorphism significantly differed between MS patients and healthy individuals. However, no associations were detected among Taq1 and Bsm1 VDR genotypes. VDR gene polymorphism of Apa1 and Fok1 variants may increase the risk of metabolic syndrome among Jordanian women.

Correlation of vitamin D receptor genotypes, specific IgE levels and other variables with asthma control in children

Introduction Asthma is a common condition affecting millions of children globally. The main goal of this study is to assess factors related to asthma management, particularly atopy level and the impact of genetic variants of the vitamin D receptor (VDR) gene. Methods Asthmatic children were enrolled in an outpatient respiratory clinic. Information on patients’ medication adherence, medical and medication factors, and sociodemographic were gathered. Spirometry FEV1% and FVC% measurements, and the asthma control test were used to evaluate the severity of asthma, and genotyping of the VDR gene and radioallergosorbent test (RAST) were conducted. Regression analyses were conducted to evaluate variables associated with asthma control and spirometry measures. Results A total of 313 participants (67.4% males) were recruited in the current study. The mean age was 9.37 (±3.45) years. The mean score for adherence was 4.26 (±2.52), and only 46% of the participants had controlled asthma. Forward conditional stepwise binary regression showed that low and moderate Inhaled corticosteroids (ICS) dose (OR= 0.42 (95% CI 0.20–0.90), p = 0.026; OR = 0.371 (95% CI 0.2–0.72), p = 0.003, respectively) decreased the odds of being in the controlled asthma group, while higher inhaler score (OR = 2.75 (95% CI 2.17–3.49, p < 0.001)) increased the odds of being in the controlled asthma group. However, results found no association between VDR genotype and asthma control, spirometry values or hospitalization due to asthma. Conclusions The results indicated that many of the asthma patients had poorly controlled asthma. Factors that were associated with poor asthma control included poor inhaler technique.

Association of vitamin D levels and VDR variant (rs2228570) with allergic rhinitis: A meta-analysis and trial sequential analysis

BackgroundAllergic rhinitis (AR) is a most common allergic condition characterised by cough, sneezing and flu-like symptoms. The aetiology of AR is not known. A deficiency of vitamin D has been associated with various allergic diseases. The role of vitamin D in allergic rhinitis has been explored in different populations, but the results remained inconsistent. Furthermore, vitamin D exerts its effect through the vitamin D receptor (VDR), and genetic variations in the VDR gene significantly alter vitamin D. We performed a meta-analysis to investigate the role of vitamin D levels and VDR polymorphisms with a predisposition to the development of AR. Materials and methodsAll published articles were searched using databases such as PubMed, Google Scholar, and Science Direct. Based on rigorous inclusion and exclusion, appropriate studies were identified. Vitamin D levels, VDR genotype and allele frequencies were extracted from the eligible reports. The meta-analysis was performed by comprehensive meta-analysis software v3.3. ResultsThe present meta-analysis comprised 14 reports with 1504 AR patients and 1435 healthy controls. Compared to healthy controls, AR had significantly lower levels of vitamin D (P = 0.000, standard difference of means = −1.287, 95% CI = −1.921 to −0.652). The meta-analysis of two separate investigations, which included 917 cases and 847 controls, showed no predisposition to allergic rhinitis. The trial sequential analysis also demonstrated the need for future case-control studies of VDR polymorphism to examine their involvement in AR. ConclusionsLower vitamin D levels are associated with allergic rhinitis, and vitamin D supplementation might be advantageous in addition to standard treatment. The connection of VDR polymorphism (rs2228570) remained equivocal, and additional research is needed. SummaryVitamin D exerct its beneficial effect through the vitamin D receptor (VDR) and role of vitamin D and VDR variant in the allergic rhinitis has been contradictories. We performed a meta-analysis to draw a definitive conclusion of importance of vitamin D and VDR polymorphisms in predisposition to development of allergic rhinitis. The observations of the meta-analysis revealed a significant association of lower vitamin D with allergic rhinitis. In addition the VDR rs2228570 variant predisposed subject to develop rhinitis. Collectively, the results of the present investigation redirect requirement of individualized vitamin D supplementation in the management of allergic rhinitis.

Serum vitamin D concentration, vitamin D-related polymorphisms, and colorectal cancer risk.

Serum 25-hydroxyvitamin D (25(OH)D) has been demonstrated to be associated with risk of colorectal cancer (CRC). However, it remains unclear whether this association was modified by vitamin D-related polymorphisms. We evaluated association of serum 25(OH)D concentration with CRC risk among 403 170 participants from UK Biobank Project. Two variants of vitamin D binding protein (VDBP), rs4588 and rs7041, were included to estimate the binding affinity of 25(OH)D to VDBP, and three variants of vitamin D receptor (VDR), rs11568820, rs2228570 and rs1544410, which may influence VDR activity, were also investigated. Multivariable Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). During 4 957 677 person-years of follow-up, 5053 incident CRC cases were documented. Higher serum 25(OH)D concentrations were significantly associated with lower CRC incidence in a dose-response manner, with HR (95% CIs) being 0.94 (0.91-0.97) per 1 SD increment of serum 25(OH)D level (Ptrend < .001). When separated by anatomic site, we observed a significant association between higher 25(OH)D and lower incidence of colon cancer (Ptrend < .001), but not rectal cancer (Ptrend = .880). The inverse associations between 25(OH)D level and CRC risk were demonstrated in almost all individuals carrying different GC or VDR genotypes, except for those with rs1544410 TT or rs4588 TT genotypes. There was no significant interaction between any single variant, or haplotypes of GC or VDR, and 25(OH)D level. Our findings suggest the potential benefits of maintaining adequate vitamin D for CRC prevention, particularly for tumors from colon.

ПРОГНОСТИЧЕСКАЯ ВОЗМОЖНОСТЬ ИММУНОГЕНЕТИЧЕСКИХ ИССЛЕДОВАНИЙ В ИЗУЧЕНИИ ЗАБОЛЕВАЕМОСТИ МОЧЕКАМЕННОЙ БОЛЕЗНЬЮ У ДЕТЕЙ

Objective: To determine the genetic polymorphism associated with the development of urolithiasis (UL) in children of the Uzbek population. Methods: The study was conducted in the Specialized Children's Surgical Hospital of the Samarkand State Medical University between 2012 and 2019. In the first stage, a retrospective analysis of the case histories of 652 admitted patients was undertaken. In the second stage, 200 children aged 1 to 17 years were enrolled in the study, of which 100 were diagnosed with UL (main group), and 100 comprised the control group without UL (hospitalized for minor planned surgical interventions, such as circumcision or hernia repair). Immunogenetic studies of the vitamin D receptor (VDR), IL-1β, and IL-18 genes were carried out. Results: The obtained results indicate that polymorphism of the VDR and IL-1β genes plays an important role in susceptibility to UL. In the study groups, a statistically significant association of F/f+f/f genotypes of the VDR gene (Fok-1) with UL was found, which was 1.3 times more frequent in the main group than in the control one (p=0.033; χ2 =4.56). The C/C allele of the IL-1β gene was significantly more frequently detected in the main vs. control group (p=0.027; χ2 =7.23; df=2). The distribution of frequency of IL-18 (+105A/C) gene polymorphism for all models of inheritance was not statistically significantly different in the main and control groups (p&gt;0.05; χ2 =3.93; df=2). Conclusion: : The role of the immunogenetic method in the detection of susceptibility to UL development was determined in the study of the distribution of polymorphic markers of the VDR and IL-1β genes, indicating the significance of the immunogenetic factors for the predisposition to UL in children of the Uzbek population which may predict the disease at its preclinical stage. Therefore, in the interests of the early diagnosis of UL in children of the Uzbek population, it is reasonable to include testing for FokI genotype and polymorphism of VDR and IL-1β genes in the complex program of examination.

Association of vitamin D receptor gene polymorphisms with breast cancer risk.

Recent literature suggests that vitamin D signaling has a protective effect against breast cancer risk. Thus, the aim of the present study was to find the association of vitamin D receptor (VDR) gene polymorphisms with breast cancer risk. Fok1, Bsm1, Apa1, and Taq1 polymorphisms were performed by polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) method, and Poly A polymorphism was carried out using PCR-SSCP in 140 breast cancer patients and 155 controls. Odds ratio was significantly higher in both homozygous variant genotypes (LL) of Poly A polymorphism of VDR (odds ratio [OR] = 5.42, 95% confidence interval [CI] = 1.19-23.31, P = 0.02) and heterozygous variant genotypes (SL) of Poly A polymorphism of VDR (OR = 3.89, 95% CI = 1.10-13.7, P = 0.03). Fok1, Bsm1, Apa1, and Taq1 polymorphisms of VDR gene were not significantly associated with breast cancer risk. Poly A polymorphism at the 3' untranslated region (UTR) of VDR gene was significantly associated with breast cancer risk in West Indian population.

Vitamin D Receptor (VDR) Genetic Variants: Relationship of FokI Genotypes with VDR Expression and Clinical Disease Activity in Systemic Lupus Erythematosus Patients.

Vitamin D (VD) deficiency is more frequent in systemic lupus erythematosus (SLE) patients than in control subjects (CS); genetic variants in the VD receptor (VDR) could contribute to the clinical disease activity. This study was aimed to determine the association of the VDR variants FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232), and TaqI (rs731236) with susceptibility to the disease, VD status, VDR mRNA expression, and clinical disease activity in SLE patients. A cross-sectional study was conducted in 194 SLE and 196 CS Mexican women. Immunoassays quantified serum calcidiol and calcitriol. Genotyping was performed by allelic discrimination assays and mRNA VDR expression by qPCR. The FokI variant was not in linkage disequilibrium with BsmI, ApaI, and TaqI&nbsp;VDR variants. SLE patient carriers of the TT FokI genotype showed higher clinical disease activity scores. Notably, the mRNA VDR expression was higher in SLE patients vs. CS, in active vs. inactive SLE patients, and in participants of both study groups with vitamin D deficiency, higher calcitriol levels, and TT FokI genotype carriers. In conclusion, the TT FokI VDR genotype was related to high VDR expression and clinical disease activity in systemic lupus erythematosus patients.

Effects of Vitamin D Receptor Genotype on Lipid Profiles and Retinopathy Risk in Type 2 Diabetes Patients: A Pilot Study.

Genetic polymorphisms affect lipid profiles and are associated with disease complications. Genetic variants in the vitamin D receptor (VDR) gene are associated with type 2 diabetes mellitus (T2DM). In this study, we investigated the effects of VDR genotypes on the lipid profile and disease complications of T2DM patients in a Jordanian population. Ninety T2DM patients were genotyped for four major functional VDR genetic variants, rs2228570 C > T (FokI), rs7975232 A > C (ApaI), rs731236 T > C (TaqI), and rs1544410 C > T (BsmI), using the polymerase chain reaction–restriction fragment length polymorphism method. Lipid profiles and diabetes complications were analyzed and correlated with VDR genotypes. We found that the VDR rs7975232 and rs1544410 alleles were significantly (p = 0.008–0.04) associated with high-density lipoprotein (HDL) levels and retinopathy among patients. Carriers of the rs7975232 A/A genotype exhibited higher levels (49.68 ± 15.86 mg/dL) of HDL than patients with the A/C (44.73 ± 13.38 mg/dL) and C/C (37.93 ± 9.22 mg/dL) genotypes. Moreover, carriers of the rs1544410 T/T genotype had higher levels of HDL (54.31 ± 16.45 mg/dL) than patients with the C/T (43.57 ± 13.24 mg/dL) and C/C (43.98 ± 13.17 mg/dL) genotypes. T2DM patients who carry the rs7975232 C/C genotype were at higher risk (odds ratio [OR] = 7.88) of developing retinopathy compared with carriers of the rs7975232 C/A and A/A genotypes. In addition, T2DM patients with the rs1544410 C/C genotype had a higher risk (OR = 4.21) of developing retinopathy than patients with the rs1544410 C/T and T/T genotypes. Therefore, we concluded that the VDR rs7975232 and rs1544410 alleles were associated with HDL levels and retinopathy and can be considered as potential genetic biomarkers for the lipid profile and retinopathy complication among T2DM patients in a Jordanian population of Arabic origin. Further studies with larger sample sizes are needed to confirm our findings.

Association between vitamin D receptor gene polymorphisms and fibrosis susceptibility in Greek patients with HCV infection.

Hepatitis C virus (HCV) infection is a prime cause of chronic hepatitis worldwide, that often silently progresses to fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Notably, the majority of individuals infected with HCV develop symptoms at late stages, often associated with liver damage that cannot revert after virus clearance. Thus, current antiviral therapy alone is rather insufficient to eliminate the global burden of HCV in the near future.During the past few years, vitamin D deficiency as well as certain single nucleotide polymorphisms in the vitamin D receptor (VDR) gene have been associated with liver fibrosis. Therefore, the aim of the present study was to investigate the possible correlation between VDR polymorphisms ApaI (rs7975232) and TaqI (rs731236) and the fibrosis stage of patients with HCV infection from Thrace, Greece. Eighty-one patients with HCV infection underwent transient elastography for the assessment of their fibrosis stage, and PCR-restriction fragment length polymorphism (RFLP) genotyping for VDR ApaI and TaqI polymorphisms. VDR genotypes were then statistically associated with the patients' fibrosis stage using ordinal regression models. Non-cirrhotic stages were positively correlated with TaqI TT genotype (p=0.003) and negatively correlated with TaqI TC genotype (p=0.007). In the presence of Hardy-Weinberg equilibrium and linkage disequilibrium between the two VDR polymorphisms, mild fibrosis stages (F0-2) were correlated with ApaI/TaqI GG/TT (p=0.002) and TG/TT (p=0.008) genotypes, while cirrhotic stage F4 was associated with ApaI/TaqI TG/TC genotype (p=0.038). TaqI TT and ApaI/TaqI GG/TT, TG/TT and TG/TC genotypes could be explored as prognostic genetic markers for fibrosis susceptibility in HCV patients.

VDR gene polymorphisms are associated with the increased susceptibility to COVID-19 among iranian population: A case-control study.

Coronavirus disease 2019 (COVID‐19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), but the pathogenesis is unclear. Host genetic background is one of the main factors influencing the patients' susceptibility to several viral infectious diseases. This study aimed to investigate the association between host genetic polymorphisms of two genes, including vitamin D receptor (VDR) and vitamin D binding protein (DBP), and susceptibility to COVID‐19 in a sample of the Iranian population. This case‐control study enrolled 188 hospitalized COVID‐19 patients as the case group and 218 suspected COVID‐19 patients with mild signs as the control group. The VDR (rs7975232, rs731236 and rs2228570) and DBP (rs7041) gene single nucleotide polymorphisms (SNPs) were genotyped by Polymerase Chain Reaction Restriction – Fragment Length Polymorphism (PCR‐RFLP) method. A significant association between rs2228570 SNP in the VDR gene and the susceptibility of COVID‐19 was found between case and control groups. The CT genotype (Heterozygous) of rs2228570 C > T polymorphism showed significant association with a 3.088 fold increased odds of COVID‐19 (p < .0001; adjusted OR: 3.088; 95% CI: 1.902–5.012). In addition, a significant association between CC genotype of rs2228570 CT polymorphism and increased odds of COVID‐19 in male and female groups (p = .001; adjusted OR: 3.125; 95% CI: 1.630–5.991 and p = .002; adjusted OR: 3.071; 95% CI: 1.485–6.354 respectively) were determined. Our results revealed no significant differences in the frequency of genotype and allele of VDR (rs7975232 and rs731236) and DBP (rs7041) between SARS‐CoV‐2‐infected patients and controls (p > .05). Our results showed that polymorphism of VDR (rs2228570) probably could influence individual susceptibility to COVID‐19. The polymorphisms of VDR (rs7975232 and rs731236) and DBP (rs7041) were not associated with SARS‐CoV‐2 infection susceptibility.

Genetic Variability of the Vitamin D Receptor Affects Susceptibility to Parkinson's Disease and Dopaminergic Treatment Adverse Events.

Vitamin D is a lipid-soluble molecule and an important transcriptional regulator in many tissues and organs, including the brain. Its role has been demonstrated also in Parkinson’s disease (PD) pathogenesis. Vitamin D receptor (VDR) is responsible for the initiation of vitamin D signaling cascade. The aim of this study was to assess the associations of VDR genetic variability with PD risk and different PD-related phenotypes. We genotyped 231 well characterized PD patients and 161 healthy blood donors for six VDR single nucleotide polymorphisms, namely rs739837, rs4516035, rs11568820, rs731236, rs2228570, and rs1544410. We observed that VDR rs2228570 is associated with PD risk (p < 0.001). Additionally, we observed associations of specific VDR genotypes with adverse events of dopaminergic treatment. VDR rs1544410 (GG vs. GA + AA: p = 0.005; GG vs. GA: p = 0.009) was associated with the occurrence of visual hallucinations and VDR rs739837 (TT vs. GG: p = 0.036), rs731236 (TT vs. TC + CC: p = 0.011; TT vs. TC: p = 0.028; TT vs. CC: p = 0.035), and rs1544410 (GG vs. GA: p = 0.014) with the occurrence of orthostatic hypotension. We believe that the reported study may support personalized approach to PD treatment, especially in terms of monitoring vitamin D level and vitamin D supplementation in patients with high risk VDR genotypes.

The Association Between FokI Vitamin D Receptor Polymorphisms With Metabolic Syndrome Among Pregnant Arab Women.

Metabolic syndrome (MetS) is a serious health condition that is becoming extremely threatening in Saudi Arabia. The link between vitamin D receptor (VDR) gene polymorphisms and maternal MetS has been observed in several ethnic groups, but is yet to be clarified in the Arabian population. This study aims to investigate the relationship between the FokI VDR genotype and the risk of MetS and its components in pregnant Saudi women. A cross-sectional study was conducted using 368 pregnant Saudi women on first trimester screened for MetS (44 with MetS and 324 without MetS). Measurements included anthropometrics, glycemic and lipid profile and 25(OH)D. TaqMan genotyping assay was used to determine Fokl VDR genotype of participants. Vitamin D deficiency (25(OH)D <50nmol/l) was seen in 85% of the participants. An estimated 12% of participants had MetS. In the MetS group, the FokI VDR genotyping frequencies for FF, Ff, and ff genotypes were 50%, 36.4% and 13.6%, respectively. In controls, the frequencies were 62.7%, 31.4% and 5.9%, respectively. No significant association between the individual MetS components and FokI VDR genotypes were observed. Nevertheless, carriers of the ff allele had a significant risk for full maternal MetS [Odds Ratio 4.2 (95% Confidence Interval 1.4-12.2; adjusted p=0.009). The study suggests that the ff FokI VDR genotype is a genetic marker of maternal MetS in pregnant Arabian women. Prospective studies that include neonatal outcomes may confirm present findings.