Vitamin D Receptor TaqI Research Articles

The association between vitamin D receptor polymorphism and phases of chronic hepatitis B infection in HBV carriers in Thailand.

Vitamin D receptor (VDR) polymorphism partly regulates the immune system and is associated with hepatic flare in chronic Hepatitis B virus infection (HBV). Our study identified the association between two distinct phases, VDR polymorphisms and HBV inactive carrier (IC) and chronic hepatitis (CH). Chronic HBV patients were enrolled from February to August 2020. An HBV viral load (VL) < 2,000 IU/ml twice for 6 months apart, with no prior history of HBV treatment, defined the IC phase. Six common polymorphisms in the VDR gene, including CdX-2, GATA, FokI, Bsml, ApaI, and TaqI, were studied using real-time PCR. The different outcomes in allele, genotype, and haplotype frequencies in between groups and linkage disequilibrium (LD) mapping were analyzed. Among 324 enrolled patients, there were 163 patients in IC and 161 patients in CH phases. The mean vitamin D levels were not statistically different between groups. The proportion of allele frequencies of CdX-2 in IC and CH was 53.7% and 62.7% for G allele, and 46.3% and 37.3% for A allele (p 0.019). The proportion of GG genotype of CdX-2 was less frequently found in patients with IC compared to that in patients with CH (27% vs 41%, p 0.028). By multivariate analysis, CdX-2 G/A genotypes were independently associated with IC, with adjusted odd ratio (OR) 1.83 (1.10-3.04), p 0.019. The LD mapping of single nucleotide polymorphisms (SNP) revealed high LD scores in Bsml/ApaI/TaqI (BAT) haplotype in both groups while, CdX-2/GATA and GATA/FokI demonstrated high LD score only in CH group. CdX-2 G/A genotypes were independently associated with IC status in Thai patients with chronic HBV infection. The difference in LD of the CdX-2/GATA and GATA/FokI haplotypes in between groups may represent a non-random selection resulting in the variation of immune control.

Association between vitamin D receptor polymorphisms and vitiligo susceptibility: An updated meta-analysis.

Vitamin D receptor (VDR) polymorphisms may play an important role in the vitiligo susceptibility. There have been many studies looking at the associations between VDR polymorphisms and vitiligo risk, but the conclusions are still up for debate. This study aimed to determine whether polymorphisms in the VDR are associated to the susceptibility to vitiligo. Vitamin D receptor polymorphisms in vitiligo patients and controls were identified using PubMed/Medline and Embase databases. The relationships between the VDR ApaI, TaqI, BsmI, and TaqI polymorphisms and vitiligo were investigated using meta-analyses of all participants and Asian, Arab, European, and Latin American groups. This meta-analysis included 13 papers with 2034 patients and 2771 controls. In all individuals, there was no link between vitiligo and the VDR ApaI A allele (OR=0.889, 95% CI=0.713-1.109, p=0.298). However, in Asians (OR=0.721, 95% CI=0.553-0.940, p=0.016) but not in Europeans or Arabs, there was a link between the VDR ApaI A allele and vitiligo. Utilizing recessive, dominant, and homozygote contrast models, a link between vitiligo and the VDR ApaI polymorphism was discovered in Asians. Meta-analysis of the VDR BsmI polymorphism showed a significant association between vitiligo and the B allele (OR=0.812, 95% CI=0.686-0.961, p=0.015). In contrast, no connection between vitiligo and VDR polymorphisms was identified for TaqI and FokI polymorphisms. In the Asian population, ApaI and BsmI polymorphisms in VDR have been correlated to vitiligo susceptibility. However, TaqI and FokI polymorphisms in VDR are not associated with vitiligo susceptibility in European, Asian, Arab, and Latin American populations.

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.

Significant association between TaqI and FokI VDR gene polymorphisms and chronic spontaneous urticaria in a Colombian Caribbean population.

Chronic spontaneous urticaria (CSU) is an inflammatory skin disease related to poor quality of life. Previous studies have found that vitamin D deficiency and vitamin D receptor (VDR) TaqI, BsmI, FokI, and ApaI gene single-nucleotide polymorphisms (SNPs) influence immune response and susceptibility to skin disorders. To explore the role of VDR SNPs, and the association of vitamin D serum levels in a sample of Colombian Caribbean CSU patients. Methods: It is a case-control study. A group of CSU patients (n = 100) was compared with healthy individuals as a control group (n = 100). VDR polymorphisms were genotyped by quantitative polymerase chain reaction and Taqman® probes. Allelic, genotypic, and haplotype associations were estimated. Serum vitamin D levels were measured using enzyme-linked-immunosorbent serologic assay. Compared to the control group, the presence of G allele in TaqI and A allele in FokI SNPs of VDR gene was found to be a risk factor for CSU (odds ratio (OR) estimated using logistic regression adjusted by gender: 2.08 and 1.61, respectively, all P values < 0.05). The individuals who carry GCCA haplotype showed decrease in vitamin D levels (11.34 ng/mL; P = 0.002) with the G allele of TaqI and A allele of FokI gene SNPs. We reported for the first time the association of TaqI [rs731236] and FokI [rs2228570] VDR gene SNPs showing as a risk factor for CSU in a sample of multiethnic patients from the Colombian Caribbean population.

Vitamin D Receptor Gene ApaI and TaqI Polymorphisms in Type 2 Diabetes among Saudi Population

Background: Variants of vitamin D receptor (VDR) gene have been linked to a variety of diseases, including metabolic syndrome, cancer, bone disease, and tuberculosis. The relationship between VDR gene mutations and the susceptibility of type 2 diabetes mellitus (T2DM) in different ethnic groups is yet unknown. Vitamin D and its receptor complex have a function in regulating β-cell insulin secretion as a transcription factor.&#x0D; Objectives: The goal of this study was to see if there is a link between VDR Apa1 and Taq1 polymorphisms and T2DM susceptibility in the Saudis of Makkah environ.&#x0D; Materials and Methods: DNA was separated from peripheral blood and genotyped in 110 healthy controls and 110 unrelated people with T2DM for the VDR ApaI (G/T) rs7975232 and TaqI (A/G) rs731236 single nucleotide polymorphisms (SNPs) using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) technique.&#x0D; Results: The distributions of genotypes and alleles of VDR ApaI and TaqI polymorphisms were statistically indifferent across the groups investigated (P &gt;0.05).&#x0D; Conclusion: These findings showed that polymorphisms in the VDR ApaI and TaqI genes may not be linked to T2DM risk in Saudis.

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.

Association of Vitamin D Receptor Genetic Polymorphisms With Nephrolithiasis and End-Stage Renal Disease: A Meta-Analysis

Our objective was to evaluate the association between vitamin D receptor (VDR) BsmI, FokI, TaqI, and ApaI gene polymorphisms and the risk of renal disease. Ameta‑analysis was conducted to determine the correlation between these VDR gene polymorphisms and the renal disease. Meta-analysis was carried out to clarify the association of BsmI (2467 cases and 2651 controls), FokI (2460 cases and 3085 controls), TaqI (3181cases and 3713 controls), and ApaI (2512 cases and 3091 controls) polymorphisms with nephrolithiasis (NL), diabetic nephropathy (DN), and end-stage renal disease (ESRD). The VDR BsmI C allele, under the allele contrast random effect model, was associated with renal diseases calculated for ESRD. Subgroup analysis revealed association of VDR FokI polymorphism with ESRD and no association with NL and DN. The VDR TaqI C allele, under the allele contrast fixed effect model, was associated with renal diseases calculated collectively for DN, ESRD, and NL. Cochran's Q test showed no evidence of heterogeneity for TaqI and ApaI polymorphisms and showed a significant heterogeneity for BsmI and FokI polymorphisms. This meta-analysis identifies BsmI, FokI, TaqI and ApaI polymorphisms of the VDR gene as risk factors for renal diseases.

Vitamin D Receptor Genetic Polymorphisms Associate With a Decreased Susceptibility to Extremity Osteomyelitis Partly by Inhibiting Macrophage Apoptosis Through Inhibition of Excessive ROS Production via VDR-Bmi1 Signaling.

Background: Previous studies had reported that vitamin D receptor (VDR) gene polymorphisms were related to the development of several inflammatory disorders. However, potential links between such variations and the risk of developing a bone infection and underlying mechanisms remain unclear. This study aimed to analyze potential associations between VDR genetic variations and susceptibility to extremity osteomyelitis (OM) in a Chinese Han population and investigate potential mechanisms. Methods: Between January 2016 and August 2020, altogether 398 OM patients and 368 healthy controls were genotyped for six VDR gene polymorphisms, including ApaI (rs7975232), BsmI (rs1544410), FokI (rs2228570), TaqI (rs731236), GATA (rs4516035), and Cdx-2 (rs11568820) by the SNaPshot genotyping method. Then, male C57BL/6 mice were randomly divided into vitamin D–standard, –excess, –deficient, and –rescued groups. One week after making the model surgery, OM occurrence and severity were assessed using the bacterial count and histopathological staining. In vitro, phagocytosis, apoptosis, and bactericidal ability of macrophages were evaluated by overexpression or knockdown of VDR protein. Results: Significant associations were found among rs7975232, rs1544410, and OM development by the recessive model (AA vs. AC + CC, p = 0.037, OR = 0.594), homozygous model (AA vs. CC, p = 0.033, OR = 0.575), and heterozygous model (CT vs. CC, p = 0.049, OR = 0.610), respectively. Patients with the AA genotype of rs7975232 had a relatively higher mean level of vitamin D than those with AC and CC genotypes (22.5 vs. 20.7 vs. 19.0 ng/ml). Similarly, patients with CT genotype of rs1544410 had a relatively higher mean vitamin D level than those with CC genotype (20.94 vs. 19.89 ng/ml). Outcomes of in vivo experiments showed that the femoral bacterial load of vitamin D–deficient mice was highest among different vitamin D dose groups, with the most severe histopathological features of infection, and vitamin D supplementation partly reversed the changes. While in vitro experiment results revealed that active vitamin D promoted phagocytosis and sterilization of macrophages and inhibited apoptosis during infection. Reactive oxygen species (ROS) inhibitor inhibited apoptosis of macrophages induced by bacterial infection. Active vitamin D inhibited excessive ROS production in macrophages via the VDR-Bmi1 signaling pathway. Conclusion: In this Chinese cohort, ApaI and BsmI are associated with a decreased risk of OM development by influencing serological vitamin D level, the latter of which reduced macrophage apoptosis with inhibition of excessive ROS production via the VDR-Bmi1 signaling pathway.

The relationship between vitamin D receptor gene polymorphisms and periodontitis in turkish individuals with type 2 diabetes mellitus.

Vitamin D receptor (VDR) gene polymorphisms have been implicated in the pathogenesis of many diseases, such as periodontitis and diabetes mellitus (DM). The present study aimed to evaluate the distributions of VDR polymorphisms in diabetic individuals with healthy periodontium (DMH), diabetic individuals with periodontitis (DMP), nondiabetic individuals with healthy periodontium (H), and nondiabetic individuals with periodontitis (P). A total of 200 individuals (DMH = 40, DMP = 60, H = 40, and P = 60) were recruited. All clinical periodontal parameters, demographical, and biochemical variables were recorded. Blood samples were collected, and genomic DNA was isolated by Purelink® Genomic DNA Mini Kit. Genotyping of VDR polymorphisms ApaI, BsmI, FokI, and TaqI were determined by real-time polymerase chain reaction (PCR) using allele-specific probes. The distribution of the BsmI variant showed differences between DMH and H groups (P = 0.034). In addition, carrying the GG genotype (OR = 0.317; 95% CI = 0.126-0.797; P = 0.013) and the G allele (OR = 2.373; 95% CI = 1.203-4.681; P = 0.012) increased the risk of type 2 DM. Moreover, it was determined that the frequency of CC genotype of FokI variant was higher in DMP compared to DMH (P = 0.046). It was determined that having the CC genotype (OR = 2.706; 95% CI = 1.185-6.176; P = 0.017) and the C allele (OR = 1.917; 95% CI = 0.995-3.694; P = 0.049) increased the risk of periodontitis among diabetic individuals. No differences were detected among groups in the genotype and allele distributions of ApaI and TaqI variants (P > 0.05). The present study showed that the BsmI variant was a risk factor for DM among periodontally healthy individuals and the FokI variant for periodontitis among diabetic individuals.

Impact of Vitamin D Receptor Gene Polymorphism on Systemic Lupus Erythematosus Susceptibility: A Pooled Analysis.

Background: This study was designed to evaluate the influence of vitamin D receptor (VDR) gene polymorphisms on systemic lupus erythematosus (SLE) susceptibility. Methods: All eligible investigations were identified, the number of the various genotypes in the case and control groups were reviewed. A pooled analysis was performed using the Stata software. The study was carried out according to the Ethics Review Committee of The Third Xiangya Hospital, Central South University. Results: This meta-analysis included 19 studies. In our analysis, the VDR Apal polymorphism was correlated with SLE susceptibility in the overall population (AA vs. aa: odds ratio [OR] = 1.374, 95% confidence interval [CI]: 1.115-1.692, p = 0.003; AA + Aa vs. aa: OR = 1.342, 95% CI: 1.139-1.583, p < 0.01). The VDR Bsml and Apal polymorphisms were correlated with SLE susceptibility in Caucasian subjects (BB vs. Bb + bb: OR = 0.734, 95% CI: 0.593-0.909, p = 0.005; B vs. b: OR = 0.865, 95% CI: 0.760-0.983, p = 0.026; AA vs. aa: OR = 1.329, 95% CI: 1.016-1.740, p = 0.038). The VDR BsmI and FokI polymorphisms were correlated with SLE in African subjects (B vs. b: OR = 1.898, 95% CI: 1.458-2.470, p＜0.01; BB + Bb vs. bb: OR = 2.935, 95% CI: 1.944-4.430, p < 0.01; FF vs. Ff + ff: OR = 2.424, 95% CI: 1.673-3.512, p < 0.01; F vs. f: OR = 1.720, 95% CI: 1.417-2.087, p < 0.01; FF vs. ff: OR = 3.154, 95% CI: 2.083-4.774, p < 0.01; FF + Ff vs. ff: OR = 1.803, 95% CI: 1.363-2.384, p < 0.01). In addition, the VDR Apal polymorphism was correlated with SLE in female subjects (AA vs. aa: OR = 1.392, 95% CI: 1.049-1.849, p = 0.022) when stratified by gender. But there was no association between the VDR TaqI polymorphism and SLE susceptibility in our analysis. Conclusions: The VDR Apal polymorphism was associated with SLE susceptibility in general populations; in addition, Apal polymorphism was associated with SLE in female subjects. The VDR Bsml gene polymorphism was correlated with SLE susceptibility in Caucasian and African populations, whereas the VDR FokI polymorphism was correlated with SLE in African populations. But there was no association between the VDR TaqI polymorphism and SLE susceptibility in our analysis.

Association of vitamin D receptor gene TaqI polymorphism with Alzheimer's disease in a Southeastern European Caucasian population.

The role of vitamin D in Alzheimer's Disease (AD) has been studied over the past years. The results from numerous studies have indicated that the molecular pathways involved in the development of AD are closely related to the molecular pathways of the mechanisms of action of vitamin D. However, only a limited number of studies have described the key role of vitamin D receptor (VDR) in the regulation of the functions of vitamin D and the potential effect of single nucleotide polymorphisms (SNPs) of the VDR gene. Thus, the aim of the present study was to investigate the VDR TaqI polymorphism in relation to AD in a Southeastern European Caucasian (SEC) cohort. Further, the present study aimed to compare the results obtained with those of other AD populations. For this purpose, blood samples from 90 confirmed patients with AD [median age, 74 years; median mini-mental state examination (MMSE) score of 21; median frontal assessment battery (FAB) score of 10] and 103 healthy controls (median age, 57 years) were analyzed to determine the genotypes of TaqI (rs731236) using quantitative PCR. The frequencies (%) of the TaqI TT, TC and CC genotypes in the controls/patients were 34/48.9, 47.6/41.1 and 18.4/10.0, respectively. Statistically significant differences were observed for the TaqI C allele [odds ratio (OR). 0.54; 95% confidence interval (CI), 0.30-0.96; P=0.035], the TaqI TT genotype (OR, 1.86; 95% CI, 1.04-3.32; P=0.035) and the TaqI CC genotype (OR, 0.119; 95% CI, 0.014-0.995; P=0.032,) in relation to the MMSE score <21 in the patient's group. The TaqI TT allele was found to increase the risk of developing AD by 1.86-fold in the SEC population, while the TaqI C allele may act protectively, with a 46% lower risk of developing the disease. Patients with the TaqI CC genotype were found to have an 88% less likelihood of developing severe cognitive impairment based on the MMSE score. On the whole, the present study did not confirm the results of previous studies on the VDR TaqI C allele in patients with AD.

Genetic impact of vitamin D receptor TaqI polymorphism on the risk of osteoporotic fractures in diabetic patients

The influence of vitamin D receptor (VDR) gene and the risk of fractures especially osteoporotic fractures remain to be elucidated in Egyptian adult male population. Therefore, this case control study aimed to investigate the linkage between VDR gene polymorphism, primary idiopathic osteoporotic fractures and secondary type 2 diabetes mellitus (T2DM) osteoporotic fractures. Hence, VDR TaqI gene rs731236 polymorphism is assessed with real time polymerase chain reaction (PCR). Moreover, bone mineral density (BMD), fasting plasma glucose (FPG) and serum 25-OH vitamin D, albumin, total calcium and ionized calcium were measured. The results revealed that VDR TaqI, the recessive genotype, GG (tt) is predominant in healthy participants over primary idiopathic osteoporotic fractures and secondary T2DM osteoporotic fractures. Moreover, AG (Tt) genotype was significantly found in secondary T2DM osteoporotic fractures compared to primary idiopathic osteoporotic fractures.Therefore, VDR TaqI GG (tt) genotype, proved its protective role against primary osteoporotic fractures and secondary T2DM osteoporotic fractures. Moreover, the heterozygous genotype, AG (Tt) is predominant in the secondary T2DM osteoporotic fractures. Hence, A (T) allele in T2DM patients may contribute to osteoporotic fractures.

BsmI gene polymorphism of vitamin D receptor in obese Egyptian male medical students and its relationship with vitamin D deficiency

BackgroundVitamin D regulates cell proliferation and differentiation and exhibits immunoregulatory, antiangiogenic, and antioxidant characteristics. Vitamin D deficiency and vitamin D receptor (VDR) gene polymorphisms have been associated with an increased risk of metabolic syndrome components such as abdominal obesity, with both vitamin D deficiency and VDR gene polymorphisms contributing to its development. Obesity, metabolic disorders, and bone mass defects are associated with VDR alleles. The importance of VDR in the etiology of obesity has been related to the existence of the VDR polymorphisms FokI, BsmI, ApaI, and TaqI. VDR expression in adipocytes affects energy metabolism and aids in obesity development.ObjectiveThe aim of this study was to examine a possible association between BsmI (B, b allele) polymorphism in the VDR gene and vitamin D status in obese Egyptian male medical students.Patients and methodsThis study was based on a comprehensive experiment known as “Nutritional Assessment of Medical Educational Students (NAMES)” that was completed in 2018 with 700 healthy participants (men and women). In total, out of the 700 participants 30 healthy men were enrolled in this study who matched our inclusion criteria. They attended Ain Shams University Hospital in Cairo between April 2019 and November 2020. This study was conducted at the Clinical Pathology Department of Ain Shams University Hospital, which is a part of the Faculty of Medicine. Participants were divided into two groups: Group I consisted of 12 obese men with nondeficient vitamin D levels (> 20 ng/dl), and Group II consisted of 18 obese men with deficient vitamin D levels (20 ng/dl). Peripheral blood samples were collected into EDTA tubes from all groups, and DNA was extracted and purified using spin purification for PCR (QIA amp DNA Mini Kit). A commercial real-time polymerase chain reaction (PCR) kit with predesigned TaqMan probes was used to analyze the single nucleotide polymorphism (SNP) (BsmI) rs 1544410 in the VDR gene.ResultsNo statistically significant relationship was observed between vitamin D levels and all InBody bioelectrical impedance characteristics, as well as BsmI gene polymorphism and all InBody bioelectrical impedance parameters (P > 0.05). Regarding Bb and BB genotypes, no statistically significant difference was observed between Groups I and II. The prevalence of BB genotype was higher in vitamin-D-deficient individuals, and Bb genotype was more common among obese participants than BB genotype, which showed a higher prevalence of the “b” gene; however, these were not significant. Iron profile (iron level, ferritin level, TIBC, and transferrin saturation) and BsmI gene polymorphism showed no statistically significant relationship (P > 0.05). Glycated hemoglobin (HbA1c) level and BsmI gene polymorphism showed a statistically significant relationship (P = 0.002), with a higher mean value among Bb genotype carriers than among BB genotype carriers. Eosinophil count showed a statistically significant difference between BB and Bb genotype carriers (P = 0.045), with a higher mean value among Bb genotype carriers than among BB genotype carriers. Bsml gene polymorphism showed no statistically significant relationship with any other complete blood count parameters (P > 0.05.)ConclusionThere was no significant relationship between VDR gene polymorphism (BsmI) and body mass index (BMI) nor between the different InBody bioelectrical impedance parameters. We noticed the prevalence of BB genotype among vitamin-D-deficient obese students and the frequency of the “b” allele among obese candidates according to the findings of our study. There was also no significant relationship between BsmI gene polymorphism and vitamin D levels. However, BsmI gene polymorphism and HbA1c levels and eosinophil count showed a relationship, which requires further investigation.

Vitamin D Receptor Genetic Variations May Associate with the Risk of Developing Late Fracture-Related Infection in the Chinese Han Population.

Variations in the vitamin D receptor (VDR) gene are related to several inflammatory disorders. However, the potential links between such alternations and the risk of developing late fracture-related infection (FRI) remain unclear. This study investigated associations between genetic variations in the VDR and susceptibility to late FRI in the Chinese Han population. Between January 2016 and December 2019, 336 patients with late FRI and 368 healthy controls were genotyped six VDR genetic variations, including ApaI (rs7975232), BsmI (rs1544410), FokI (rs2228570), TaqI (rs731236), GATA (rs4516035), and Cdx-2 (rs11568820). Significant associations were observed between rs7975232 and FRI susceptibility in the recessive (P = 0.019, OR = 0.530, 95% CI 0.310–0.906) model. Patients with AA genotype had a relatively higher level of serological vitamin D (20.6 vs. 20.3 vs. 17.9 ng/ml) (P = 0.021) than those of AC and CC genotypes. Although no statistical differences were observed, potential correlations may exist between rs1544410 (dominant model: P = 0.079, OR = 0.634), rs2228570 (dominant model: P = 0.055, OR = 0.699), and rs4516035 (dominant model: P = 0.065, OR = 1.768) and the risk of FRI development. In the Chinese cohort, ApaI was associated with a decreased risk of developing FRI, and patients with the AA genotype had a higher vitamin D level. Further studies are required to assess the role of genetic variations in BsmI, FokI, and GATA in the pathogenesis of late FRI.

Evaluation of Association Studies and an Updated Meta-Analysis of VDR Polymorphisms in Osteoporotic Fracture Risk.

Background: Several studies have examined the association between vitamin D receptor (VDR) polymorphisms and osteoporotic fracture risk; however, the results are not uniform. Furthermore, many new articles have been published, and therefore, an updated meta-analysis was performed to further explore these issues. Objectives: The aim of the study was to investigate the association between VDR, BsmI, ApaI, TaqI, FokI, and Cdx2 polymorphisms and osteoporotic fracture risk. Methods: The odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the association between VDR BsmI, ApaI, TaqI, FokI, and Cdx2 polymorphisms and the risk of osteoporotic fracture. We also used the false-positive reporting probability (FPRP) test and the Venice criteria to evaluate the credibility of the statistically significant associations. Results: Overall, this study found that the VDR ApaI and BsmI polymorphisms significantly increased the risk of osteoporotic fracture in European countries and America, respectively. However, when sensitivity analysis was performed after excluding low-quality and Hardy–Weinberg disequilibrium (HWD) studies, it was found that only individuals with the double-mutated genotype have an increased risk of osteoporotic fracture in European countries. In addition, when the credibility of the positive results was assessed, it was found that the positive results were not credible. Conclusion: This meta-analysis indicates that there may be no significant association among the polymorphisms of VDR BsmI, ApaI, TaqI, FokI, and Cdx2 and the risk of osteoporotic fracture. The increased risk of osteoporotic fracture is most likely due to false-positive results.

Vitamin D receptor gene polymorphisms in chronic kidney disease Egyptian children: effect on biochemical markers of bone mineral disorders.

The aim of this study was to assess the association between four vitamin D receptor (VDR) single nucleotide polymorphisms BsmI (rs1544410), ApaI (rs7975232), FokI (rs2228570) and TaqI (rs731236) and the susceptibility to chronic kidney disease (CKD) in Egyptian children and to evaluate their association with mineral status in these patients. The current study included 305 patients with CKD and 100 apparently healthy children. We measured the serum vitamin D (VD), para-thyroid hormone (PTH) level and fibroblast growth factor 23 (FGF-23) levels by ELISA method. The genotyping of the four VDR gene variants was carried out by PCR-RFLP technique. The TaqI AG &amp; the BsmI TT genotypes were associated with a significantly higher risk of CKD. The expression of 25-OH D serum level was decreased in patients with TaqI GG &amp; AG genotypes groups and in patients with BsmI TT genotype group The expression of PTH serum level was increased in patients with BsmI CT genotype group. The expression of FGF-23 serum level was increased in patients with Taq1 AG genotype group. We found 3 specific haplotypes; AGCA, AGCC and GGCA for healthy controls. Our study showed an association between VDR TaqI, BsmI polymorphisms and the susceptibility to CKD. The existence of VDR vari-ants affected the protein expression of VD, FGF-23 and PTH. The AGCA, AGCC and GGCA haplotypes were considered as protec-tive factors against the development of renal nephropathy in our population.

Frequency of Genotypes and Allelic Polymorphisms of Vitamin D Receptor in Egyptian Psoriatic Patients and Their Association With Disease Severity, Immune Modulation of IL-22 Levels and The Response to Topical Calcipotriol Treatment: A Case Control Study.

Objective:This study was performed to determine the genotype and allelic frequencies (polymorphisms) of the four genes of vitamin D receptor (VDR) among Egyptian psoriatic patients and healthy controls to explore their association with disease severity (PASI) score and immune modulation of IL-22 cytokine and to predict the response to topical calcipotriol treatment.Patients and Methods:The frequencies of the four VDR gene polymorphisms (FokI, ApaI, TaqI, and BsmI) in blood samples of 51 adult Egyptian patients with psoriasis vulgaris and 50 healthy controls were evaluated using restriction fragment length polymorphism (RFLP)-PCR. Serum levels of IL-22 were measured by ELISA.Results:The most frequent genotype (wild) in the studied patients was Apa1; AA (88.2%) followed by Fok1; FF (47.1%) and Taq1; TT (47%), while Bsm1; BB genotype was (27.7%). The most frequent allele polymorphisms either in one allele (Bb) or both alleles (bb) in psoriatic patients were 72.5%, followed by Ff, ff (52.9%) and Tt, tt (52.9%). The less frequent allelic polymorphism was Aa, aa (27.7%). Insignificant differences in the frequency of genotype (wild) and allelic polymorphisms were detected between patients and controls (P > 0.05). A significantly higher serum concentration of IL-22 (ng/mL) was detected in patients than controls (P = 0.001). Further, 66.6% of patients displayed a clinical response, while 33.4% were non-responders. A significantly higher expression of TaqI polymorphism was detected in (100%) of non-responders (P < 0.001), which was also correlated with disease severity (r = 0.515, P < 0.01).Conclusion:These results suggest that the VDR TaqI polymorphism is the only gene correlated to psoriasis susceptibility in the Egyptian population, and affects the response to topical calcipotriol treatment but does not affect IL-22 immune modulation.

Relationship Between Vitamin D Receptor TaqI Polymorphism and the Clinicopathological Features of Breast Cancer Patients at Sanglah Hospital, Denpasar, Bali

Introduction: Breast cancer is a malignant tumor of the mammary gland. Breast cancer is associated with vitamin D receptor (VDR) TaqI polymorphism. This study aims to prove the relationship between TaqI polymorphism and the clinicopathology of breast cancer in Bali. Methods: This study is an observational analytic study with a cross-sectional design conducted from February to August 2021. A total of 39 sample DNA isolates from breast cancer patients at Sanglah Hospital were enrolled in the study. The independent variable was the VDR TaqI gene polymorphism, while the dependent variable was the clinicopathological breast cancer (clinical stage and histological grading). The examination was carried out by PCR and sequencing. Clinical staging and histological grading of breast cancer were taken from the patient's medical record. The results were analyzed using descriptive and bivariate analysis. Results: TaqI polymorphism of breast cancer at Sanglah Hospital Denpasar was dominated by the wild type TT genotype as much as 59%. This study did not find the CC genotype. The results of the statistical analysis did not find a significant relationship (p&gt;0.05) between TaqI polymorphisms with TT and TC genotypes and clinicopathology of breast cancer but found a significant relationship (p=0.047) with histological grading. The TT and TC genotypes were found to increase the risk of breast cancer severity by 3,810 compared to individuals without the TT and TC genotypes. Analysis of confounding variables with clinicopathological breast cancer found no significant relationship (p&gt;0.05) between the age of diagnosis, menstrual status, and hormonal contraceptive use with the characteristics of the sample. Conclusion: It was concluded that breast cancer patients at Sanglah Hospital Bali had TaqI polymorphisms with TT and TC genotypes. TT and TC genotypes are associated with histological grading and can increase the severity of histological grading in breast cancer patients at Sanglah Hospital Denpasar Bali.

Effects of vitamin D receptor gene polymorphisms on the prognosis of COVID-19.

Vitamin D deficiency has emerged as another potential risk factor for coronavirus disease (COVID-19) due to the immunomodulatory effects of 25 hydroxyvitamin D [25 (OH)D]. Vitamin D receptor (VDR) gene polymorphisms such as Fok I, Bsm I, Apa I, and Taq I are also associated with different courses of viral infections. This study aimed to evaluate the association between the VDR gene polymorphism at Fok I, Taq I, Bsm I, and Apa I genotypes and the prognosis of COVID-19 in respect to vitamin D deficiency. Two-hundred ninety-seven patients with COVID-19 were enrolled. Serum 25 (OH)D levels were measured. Four variant regions of the VDR gene, FokI, BsmI, ApaI, and TaqI were determined. Eighty-three percent of subjects had vitamin D deficiency, and 40.7% of the whole group had severe deficiency. Median 25 (OH)D level was 11.97 ng/ml. Vitamin D levels were not related to inflammatory markers, disease severity, admission to intensive care unit (ICU), and mortality. While disease severity was related to Fok I Ff genotype, it was Taq TT genotype for ICU admission. Moreover, the ApaI aa genotype was common among the patients who were died. None of the deceased subjects had the Fok I FF genotype. 25 (OH)D levels were not related to the severity and mortality of COVID-19. VDR gene polymorphisms are independently associated with the severity of COVID-19 and the survival of patients.

Assessment the effect of vitamin D supplementation on plasma vitamin D levels, inflammation, and oxidative stress biomarkers based on vitamin D receptor genetic variation in breast cancer survivors: a protocol for clinical trial

BackgroundBoth human genes and environmental exposures, due to complex interplay, play important role in the cancer etiology. Vitamin D is associated with a reduced risk of incidence and mortality of several human cancers. This study will aim to investigate the possible effects of individual polymorphisms in vitamin D receptor (VDR) as well as effects of VDR haplotypes on response to vitamin D supplementation in breast cancer survivors.MethodsThis is an interventional study in which the effects of vitamin D supplementation on plasma vitamin D levels, inflammatory and antioxidant biomarkers and factors associated with cell proliferation, differentiation, damage, and apoptosis will be investigated stratified by variations in VDR genotype. The present study will be conducted on breast cancer survivors referred to the Shohadaye Tajrish hospital and its associated clinics. One hundred ninety-eight breast cancer survivors will receive 4000 IU of vitamin D3 daily for 12 weeks. VDR Fok1, ApaI, TaqI, BsmI, and Cdx-2 genotype will be determined at the end of the study and responses to vitamin D supplements (inflammatory, antioxidant, cell proliferation, differentiation, damage, and apoptosis biomarkers) will be compared between the three subgroups of each VDR polymorphism as well as different VDR haplotype categories.DiscussionGenetic variation is a fundamental factor influencing individuals’ divergent responses to diet, nutritional status, metabolic response, and diet-related health disorders. Furthermore, studies of gene and environment interactions will provide a precise and accurate assessments of individuals’ dietary requirements by considering both the genetic and environmental aspects simultaneously. The results of the current study, to some extent, will highlight the discrepancies existing in the findings of different studies regarding vitamin D, VDR, and cancer by considering both the genetic and environmental aspects simultaneously. If responses to vitamin D supplementation could be modified by VDR SNPs, determining the distribution of VDR polymorphisms in both breast cancer survivors and healthy populations will provide a new insight into the vitamin D requirements of individuals to prevent cancer and its related mortality based on their genotypes.Trial registration This trial has been registered on Iranian Registry of Clinical Trials (IRCT) under the identification code: IRCT2017091736244N1, registration date: 2017-11-10, http://www.irct.ir/trial/27153