Vitamin D Receptor TaqI Research Articles

Association of vitamin D receptor FokI and ApaI polymorphisms with lung cancer risk in Tunisian population.

Many studies reported that Vitamin D Receptor (VDR) gene polymorphisms might influence the cancer risk due to their antiproliferative, antiangiogenic, and apoptotic effects. The aim of this study was to explore the genetic association of VDR polymorphisms with lung cancer risk in Tunisian population. The genotype and haplotype frequencies of four VDR polymorphisms, FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232) and TaqI (rs731236) were studied using polymerase chain reaction and restriction fragment length polymorphism analysis in 240 patients with lung cancer and 280 healthy controls. The distribution of genotype frequencies differed significantly between lung cancer subjects and controls (FokI P adj = 0.002; ApaI P adj = 0.013). Haplotype analyses revealed a significant association between G-A-C and A-C-T haplotypes and lung cancer risk (P corr = 0.0128, P corr = 0.008). When patients were stratified according to gender, age, and smoking, significant associations were detected with FokI and TaqI polymorphisms. We found a lack of association between BsmI, TaqI polymorphisms and lung cancer risk (P > 0.05). Only, the attributable proportion due to interaction and the synergic index for interaction between ApaI polymorphism and smoking were statistically significant (P adj = 0.74, 95 % CI = 0.38-1.20) and (P adj = 0.63, 95 % CI = 0.05-1.21), respectively. Both the additive interaction measures suggested the existence of a biological interaction between SNP ApaI, but not FokI, and smoking. The multiplicative interaction measure was not statistically significant (P > 0.05). This is the first study in Tunisia, which suggested that VDR FokI and ApaI polymorphisms might be risk factors for lung cancer development.

Association of vitamin D receptor Fok1 (rs2228570), TaqI (rs731236) and ApaI (rs7975232) gene polymorphism with the risk of chronic kidney disease

Relationship between vitamin D receptor (VDR) gene polymorphism and the risk of chronic kidney disease (CKD) from the published reports are still conflicting. This study was conducted to evaluate the relationship between VDR Fok1 (rs2228570), TaqI (rs731236) and ApaI (rs7975232) gene polymorphism and the risk of CKD using meta-analysis method. The association studies were identified from PubMed and Cochrane Library on 1 March 2014, and eligible investigations were included and synthesized using meta-analysis method. Five reports were recruited into this meta-analysis for the association of VDR Fok1, TaqI and ApaI gene polymorphism with CKD susceptibility. In this meta-analysis, VDR Fok1, TaqI and ApaI gene polymorphism were not associated with CKD susceptibility for overall populations and in Caucasians. However, the Fok1 f allele, ff genotype and FF genotype were associated with the risk of CKD in Asians. In conclusion, VDR Fok1, TaqI and ApaI gene polymorphism were not associated with CKD risk in overall populations and in Caucasians. But, the Fok1 gene polymorphism was associated with the risk of CKD in Asians. However, more studies should be conducted to confirm it.

Melanoma risk is associated with vitamin D receptor gene polymorphisms

Previous studies have reported that vitamin D receptor (VDR) gene polymorphisms are associated with the occurrence of various cancers, including melanoma. The aim of the current study was to investigate the association of VDR gene polymorphisms with melanoma risk, clinicopathological characteristics, and vitamin D levels. The study group included 117 patients (84 patients with superficial spreading melanoma and 33 patients with nodular melanoma). The control group included 122 sex-matched and age-matched healthy-blood donors of the same ethnicity. VDR gene polymorphisms FokI, EcoRV, TaqI, and ApaI were genotyped by real-time PCR. In 60 patients, the total 25-hydroxyvitamin D levels were evaluated in serum samples by direct chemiluminescence. Associations among parameters were considered to be significant if the P value was less than 0.05. Significant differences in the frequencies of VDR genotypes were observed between cases and the control group for FokI and TaqI polymorphisms (P<0.0001; P=0.005, respectively). Heterozygous Ff as well as mutant FF genotypes of the FokI polymorphism were associated with increased melanoma risk compared with the wild-type form [odds ratio (OR)=3.035, P=0.003; OR=9.276, P<0.0001, respectively]. A significantly increased melanoma risk was observed for the heterozygous Tt (OR=2.302, P=0.011) and the mutated variant tt (OR=3.697, P=0.003) of the TaqI polymorphism in comparison with the wild-type genotype. None of the polymorphisms studied was associated with clinicopathological characteristics and vitamin D serum level. Our results suggest that FokI and TaqI polymorphisms in the VDR gene may be considered as potential biomarkers for melanoma susceptibility. Low vitamin D levels in melanoma patients indicate the need for vitamin D supplementation.

Association of vitamin D receptor gene polymorphism with the risk of lung cancer: a meta-analysis

Relationship between vitamin D receptor (VDR) gene polymorphism and the risk of lung cancer from the published reports are still conflicting. This study was conducted to evaluate the relationship between VDR TaqI (rs731236), BsmI (rs1544410) and ApaI (rs7975232) gene polymorphism and the risk of lung cancer using meta-analysis method. The association studies were identified from PubMed and Cochrane Library on 1 December 2013, and eligible investigations were included and synthesized using meta-analysis method. Six reports were recruited into this meta-analysis for the association of VDR gene polymorphism with lung cancer susceptibility. In the meta-analysis for ApaI gene polymorphism, AA genotype was associated with the risk of lung cancer in Asians. In the meta-analysis for BsmI gene polymorphism, B allele, BB genotype and bb genotype were associated with lung cancer in Asians, and B allele bb genotype were associated with lung cancer risk in overall populations; furthermore, bb genotype was associated with lung cancer risk in Caucasians. In the meta-analysis for TaqI gene polymorphism, t allele and TT genotype were associated with lung cancer in overall populations and in Caucasians. In conclusion, B allele bb genotype t allele and TT genotype were associated with lung cancer risk in overall populations. AA genotype, B allele, BB genotype and bb genotype were associated with the risk of lung cancer in Asians. Furthermore, bb genotype t allele and TT genotype was associated with lung cancer risk in Caucasians. However, more studies should be conducted to confirm it.

Association of vitamin D receptor gene polymorphism with the risk of systemic lupus erythematosus

Relationship between vitamin D receptor (VDR) gene polymorphism and the risk of systemic lupus erythematosus (SLE) from the published reports are still conflicting. This study was conducted to evaluate the relationship between VDR BsmI (rs1544410), Fok1 (rs2228570), ApaI (rs7975232) and TaqI (rs731236) gene polymorphism and the risk of SLE using meta-analysis method. The association studies were identified from PubMed and Cochrane Library on 1 March 2014, and eligible investigations were included and synthesized using meta-analysis method. Thirteen reports were recruited into this meta-analysis for the association of VDR gene polymorphism with SLE susceptibility. In this meta-analysis for overall populations, the BsmI B allele and bb genotype, Fok1 f allele and ff genotype, and ApaI aa genotype, were associated with the risk of SLE. In Asians, the BsmI B allele, BB genotype and bb genotype, Fok1 f allele and ff genotype were associated with the risk of SLE. In Africans, the BsmI B allele, BB genotype and bb genotype, Fok1 f allele and ff genotype, ApaI A allele, AA genotype and aa genotype were associated with the risk of SLE. However, VDR BsmI, Fok1, ApaI and TaqI gene polymorphism were not associated with the risk of SLE in Caucasians. In conclusion, the BsmI B allele and bb genotype, Fok1 f allele and ff genotype were associated with the risk of SLE in overall populations, and in Asians, but these associations were not found in Caucasians. However, more studies should be conducted to confirm it.

Association of vitamin D receptor gene polymorphism with the risk of renal cell carcinoma: a meta-analysis

Relationship between vitamin D receptor (VDR) gene polymorphism and the risk of renal cell carcinoma from the published reports are still conflicting. This study was conducted to evaluate the relationship between VDR ApaI (rs7975232), BsmI (rs1544410), TaqI (rs731236), and Fok1 (rs2228570) gene polymorphism and the risk of renal cell carcinoma using meta-analysis method. The association studies were identified from PubMed, and Cochrane Library on 1 March 2014, and eligible investigations were included and synthesized using meta-analysis method. Five reports were recruited into this meta-analysis for the association of VDR gene polymorphism with renal cell carcinoma susceptibility. In this meta-analysis, the ApaI AA genotype, BsmI BB genotype, Fok1 f allele, and Fok1 FF genotype were associated with the risk of renal cell carcinoma in Asians. However, VDR ApaI, BsmI, TaqI, and Fok1 gene polymorphism were not associated with the risk of renal cell carcinoma in overall populations and in Caucasians. In conclusion, the ApaI AA genotype, BsmI BB genotype, Fok1 f allele, and Fok1 FF genotype were associated with the risk of renal cell carcinoma in Asians. However, more studies should be conducted to confirm it.

Vitamin D receptor TaqI and ApaI polymorphisms: A comparative study in patients with Behçet’s disease and Rheumatoid arthritis in Tunisian population

Recent genetic surveys have identified vitamin D receptor (VDR) as a susceptibility gene for several autoimmune diseases. This study was designed to investigate the association of VDR gene polymorphisms with Behçet’s disease (BD) and Rheumatoid arthritis (RA). A case–control study including 151 BD, 106 RA patients and an appropriate number of healthy control subjects were performed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques. Association between TaqI polymorphism and BD was marginal under codominant and recessive models (P=0.078 and P=0.058, respectively). After stratification, we found evidence for a significant association between TaqI polymorphism and BD in the elderly subjects (P=0.037). The minor ApaI a allele tended to confer an increased risk for BD susceptibility (P=0.087). BD patients with VDR homozygous AA or aa genotypes were at increased risk for development of erythema nodosum (EN) skin manifestation (P=0.038). No significant association was observed for VDR ApaI and TaqI polymorphisms with RA risk (P>0.05). TaqI and ApaI polymorphisms might be modestly implicated in BD pathogenesis. They could be considered as potential biomarkers in BD rather than susceptibility genes. However, TaqI and ApaI seemed not to be implicated in RA pathogenesis.

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.

Vitamin D receptor polymorphisms predict greater decrease in calcium absorption (373.1)

Genetic variation may account for more than 70% of the variance in Ca absorption, and several studies suggest that vitamin D receptor (VDR) gene polymorphisms influence absorption. Estrogen is also known to affect Ca absorption, yet only one study has examined the influence of estrogen‐α (ESR1) gene polymorphisms. Ca absorption is attenuated during caloric restriction (CR) and is increased by vitamin D supplementation (VitD). We therefore studied whether the ESR1 and VDR polymorphisms influence the Ca absorption response 6 weeks after either CR or VitD supplementation. True fractional calcium absorption (TFCA) was measured in 180 pre‐ and post‐menopausal women. Genotypes for the VDR (BsmI, ApaI, TaqI, and FokI) and the ESR1 (XbaI, PvuII) polymorphisms were determined through PCR‐RFLP analysis and the haplotypes were reconstructed using PHASE v2.1.1. Multiple linear regression and two‐way ANOVA analyses using dietary interventions and the dominant/recessive models as predictors showed that in the absence and presence of a dietary intervention, the BB genotype and the 2 copies of BAt allele predicted a greater decrease in TFCA. We found no association with the ESR1 polymorphisms. Our findings suggest that the VDR polymorphism improves the ability to predict Ca absorption under a variety of conditions and may influence dietary Ca requirements.Grant Funding Source: NIH‐AG12161

The association between VDR polymorphisms and renal cell carcinoma susceptibility: a meta-analysis

Vitamin D receptor (VDR) gene polymorphisms have previously been associated with susceptibility to renal cell carcinoma, although the findings are inconsistent. This study therefore evaluated the association of three single nucleotide polymorphisms (SNPs) in VDR (FokI, BsmI, and TaqI) with the risk of renal cell carcinoma in five previous studies of a total of 1,510 cases and 2,101 controls identified from PubMed, Web of Science, Embase, and Wanfang databases. Pooled odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were calculated, and stratified analysis by ethnicity was conducted for further estimation. All statistical analyses were conducted using STATA software. Obvious heterogeneity was noted among the five studies. The VDR BsmI polymorphism was not found to be associated with renal cell carcinoma risk, although subgroup analysis revealed a significant association with renal cell carcinoma risk in Asians (b vs B OR=1.479, 95 % CI=1.171-1.869, P OR=0.001 and bb vs BB OR=2.608, 95 % CI=1.529-4.449, P OR=0.001). No significant association was found between renal cell carcinoma risk and either FokI or TaqI polymorphisms in different models and populations. Further large-scale studies are required to confirm these conclusions.

Vitamin D receptor gene polymorphisms and risk of osteoarthritis: A meta-analysis

The vitamin D receptor (VDR) gene polymorphisms have been reported to be involved in the development of many musculoskeletal disorders, including osteoarthritis (OA). However, results were inconsistent and there is no definite conclusion regarding the association between any VDR polymorphism and the risk of OA. In this study, we conducted a meta-analysis to determine whether BsmI, TaqI, and ApaI polymorphisms in the VDR gene are associated with OA susceptibility. Literature research was performed using PubMed and EMBASE databases. Studies illustrating the association between the three VDR polymorphisms and OA were included, and their qualities were assessed using Newcastle-Ottawa scale. Eight eligible studies, recruiting 1626 cases and 2024 controls were identified. Their methodological qualities were generally good, with scores ranging from 6 to 8 points. However, throughout all summary analyses, which were performed for multiple categories and on four contrasts (allele contrast, contrast of homozygotes, recessive and dominant models), none of the VDR BsmI, TaqI, and ApaI gene polymorphisms were found to be significantly associated with the risk of OA. On the other hand, there was no significant publication bias. Results from this meta-analysis suggested that the VDR BsmI, TaqI, and ApaI gene polymorphisms might not be important predictors of OA. More studies further investigating these associations, especially taking into account of gene-gene, gene-environment interactions, and other confounding factors are warranted.

Vitamin D receptor FokI gene polymorphisms may be associated with colorectal cancer among African American and Hispanic participants

Vitamin D plays a role in cancer tumorogenesis and acts through the vitamin D receptor (VDR). Although African Americans have the lowest serum vitamin D levels, supplementation has not yielded a significant improvement in cancer. Gene polymorphisms in VDR may play a role. There is a dearth of information on VDR gene polymorphisms and colorectal cancer (CRC) among under-represented ethnic groups. In this study, the authors examined whether VDR gene single nucleotide polymorphisms (SNPs) were associated with CRC in predominately African American and Hispanic study participants. Blood samples were collected from 378 participants, including a group of 78 patients with CRC (cases), a group of 230 noncancer participants without polyps (controls without polyps), and a group of 70 noncancer participants with polyps (controls with polyps). The 4 polymorphic SNPs in VDR (FokI, BsmI, TaqI, and ApaI) were assessed using the polymerase chain reaction-restriction fragment length polymorphism method. There was a significant association of the VDR-FokI FF genotype with CRC cases (odds ratio, 2.9; P= .036) compared with the controls without polyps. The most common VDR-FokI genotype in the overall study population was the FF genotype (46%). However, upon breakdown by ethnicity, the FF genotype was the most common in African American participants (61%), and the Ff genotype was the most common in Hispanic/Latino participants (49%). When the association was assessed in a multivariate model, there was no significant association with any VDR polymorphism and CRC cases (P> .05). The other 3 polymorphic variants of VDR (BsmI, TaqI, and ApaI) were not associated with CRC. The results from this study suggest that genetic variation of the VDR-FokI SNPs may influence CRC risk, particularly in African American cohorts.

Associations between vitamin D receptor gene polymorphisms and osteoarthritis: an updated meta-analysis

Vitamin D receptor (VDR) gene polymorphisms may be associated with the risk of OA, however, evidence for this is controversial. This meta-analysis aims to confirm whether VDR gene polymorphisms are associated with OA. Meta-analyses on the association between OA and VDR ApaI, BsmI, TaqI and FokI polymorphisms were conducted using allele and homozygote contrast and contrasts in the recessive and dominant models. Stratification analyses by different demographic regions (Europe vs Asian) were also performed and pooled odds ratios (ORs) were obtained using the random effects model if the results were heterogeneous. A total of 13 relevant studies involving OA patients (n = 2104) and controls (n = 2939) were included in the analysis. There were significant associations between VDR ApaI polymorphisms and OA in the Asian population (A vs a: OR= 1.16, 95% CI 1.02, 1.32, P = 0.025; AA vs Aa/aa: OR= 1.36, 95% CI 1.04, 1.77, P = 0.025; AA vs aa: OR= 1.35, 95% CI 1.00, 1.80, P = 0.047), but not in the whole population. There was also a statistically significant association between FokI polymorphism and OA (FF vs Ff/ff: OR= 0.65, 95% CI 0.44, 0.95, P = 0.024); however, this result was derived from only two studies. No significant associations were found between VDR TaqI and BsmI polymorphisms and OA. There are modest but statistically significant associations between VDR ApaI polymorphisms and the susceptibility of OA in the Asian population.

Juvenile idiopathic arthritis patients and their skeletal status: possible role of vitamin D receptor gene polymorphism

We evaluated bone mineralization and metabolism changes related to vitamin D receptor (VDR) polymorphic genotypes in children with juvenile idiopathic arthritis. One hundred and ninety eight children (82 boys and 116 girls) were included in our study. Bone mineral density (BMD) was measured by lumbar spine DXA. Osteocalcin, CTX, parathyroid hormone, total and ionized calcium, inorganic phosphate, total alkaline phosphatase activity was utilized for assessment of bone metabolism. Molecular testing: TaqI (rs731236) and Cdx2 (rs11568820) polymorphisms of VDR were detected by RFLP. No differences in TaqI and Cdx2 haplotypes, genotypes and alleles distribution related with normal and low BMD (Zscore <-2SD) were found. Children with low linear growth (<10th percentile) had more allele T-contained genotypes of TagI VDR (p = 0.037), compare with medium or high linear growth children. Children with high linear growth (>90th percentile) had the highest frequency of allele A-contained genotypes (GA+AA) of Cdx2 VDR (p = 0.009). Girls with TT TaqI VDR, who never been treated by glucocorticoides had lower BMD-Zscore than C allele carriers (TT = -0.94SD [IQR: -2.1;-0.5], TC+CC = -0.62SD [IQR: -1.26;0.39], p = 0.03). Girls with Tanner I with TT had higher total and ionized Ca level than carriers of C allele (Ca: TT = 2.43 ± 0.15 mmol/l, TC+CC = 2.28 ± 0.2 mmol/l, p = 0.024; Ca(2+): TT = 1.15 ± 0.08 mmol/l, TC+CC = 1.06 ± 0.13 mmol/l, p = 0.026). Presence of TT genotype negatively correlated with BMD-Zscore (r = -0.28, p = 0.04), and positively with frequency of LBMD (r = 0.3, p = 0.037). Boy with GG Cdx2 genotype had lower total Ca (GG = 2.3 ± 0.17 mmol/l, GA+AA = 2.43 ± 0.17 mmol/l, p = 0.004) compare with carriers of A allele. Pubertal boys (Tanner IV-V) with GG had higher CTX (GG = 1.75 ± 0.11 ng/ml, GA+AA = 1.06 ± 0.07 ng/ml, p = 0.04. TT genotype of TaqI and GG genotype of Cdx2 VDR is a negative factor impact bone mineralization metabolism and linear growth.

Evaluating the Association between TaqI Variant of Vitamin D Receptor Gene and Susceptibility to Tuberculosis: A Meta-analysis.

Objectives:Vitamin D has been shown to hamper the growth of Mycobacterium tuberculosis in macrophages. The actions of vitamin D are exerted through a vitamin D receptor (VDR). The genetic variant TaqI of VDR has been implicated in tuberculosis (TB) risk in several case-control studies. However, these studies have shown inconsistent results. Hence, a meta-analysis was conducted to investigate the potential relationship between VDR TaqI polymorphism and risk of developing TB.Materials and Methods:We performed a quantitative synthesis for published studies based upon the relationship between TaqI polymorphism and TB risk from PubMed (Medline) and Embase databases. The meta-analysis was performed and pooled odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for all genetic models.Results:A total of 21 studies including 2,960 TB cases and 3,894 controls were included in this study. The pooled analysis demonstrated no evidence of association between VDR TaqI genotypes and risk of TB in any of the genetic models; variant (t vs T: P = 0.618; OR = 1.051, 95% CI = 0.864–1.278), homozygous (tt vs TT: P = 0.120; OR = 1.336, 95% CI = 0.927–1.924), heterozygous (Tt vs TT: P = 0.925; OR = 0.988, 95% CI = 0.774–1.262), dominant model (tt + Tt vs TT: P = 0.805; OR = 1.032, 95% CI = 0.805–1.322), and recessive model (tt vs TT + Tt: P = 0.180; OR = 1.229, 95% CI = 0.909–1.660). No publication bias was detected during the analysis.Conclusions:Overall findings of this meta-analysis suggest that genetic polymorphism TaqI of VDR gene may not contribute to the risk of TB. However, future larger studies with group of populations are warranted to analyze this relationship.

Vitamin D receptor FokI, BsmI, ApaI, and TaqI polymorphisms and the susceptibility to breast cancer: a meta-analysis.

The goal of this study is to examine whether vitamin D receptor (VDR) polymorphisms are associated with the susceptibility to breast cancer. Meta-analysis was employed to investigate the association between the VDR FokI, BsmI, ApaI, and TaqI polymorphisms and the incidence of breast cancer.A total of 32 comparative studies were evaluated in this meta-analysis, which included 17,067 patients and 20,843 controls. Meta-analysis of the VDR FokI polymorphism indicated an association between the incidence of breast cancer and the ff genotype in Europeans (OR = 1.126, 95% CI = 1.026-1.243, p = 0.019). Furthermore, an association between the incidence of breast cancer and the VDR FokI polymorphism was found in the Europeans using the allele contrast, as well as the homozygote contrast. However, the meta-analysis indicated no association between breast cancer and the BsmI polymorphism in all study subjects, including the Europeans (OR for the B allele = 0.996, 95% CI = 0.964-1.097, p = 0.930, 1.026, 95% CI = 0.929-1.134, p = 0.610). Moreover, breast cancer incidence was not associated with the ApaI and Taq polymorphisms (OR for the A allele = 0.908, 95% CI = 0.763-1.041, p = 0.167, OR for the T allele = 0.972, 95% CI = 0.929-1.017, p = 0.221).This meta-analysis suggests that the VDR FokI polymorphism is associated with susceptibility to breast cancer in the European population.

The influence of BsmI and TaqI vitamin D receptor gene polymorphisms on the intensity of hyperparathyroidism in Iranian hemodialysis patients

Background:The influence of vitamin D receptor (VDR) gene polymorphisms on the regulation of the parathyroid hormone is important in end-stage renal disease (ESRD) patients. We analyzed rs1544410 (BsmI) and rs731236 (TaqI) polymorphisms of VDR gene in hemodialysis patients to determine their relationship with serum intact parathyroid hormone (iPTH).Materials and Methods:Ninety hemodialysis patients were included in this study. Patients were classified into four groups according to their serum iPTH level. Polymorphisms of VDR gene were surveyed using polymerase chain reaction-restriction fragment length polymorphism method with BsmI and TaqI enzymes in all the patients.Results:Patients age ranged between 30 and 60 years (mean ± SD: 36.0 ± 11.4) and period undergoing hemodialysis 80 ± 71 months. Patients were divided into four groups based on the serum concentration of iPTH. The distribution of VDR gene allelic variation for BsmI and TaqI polymorphisms was different between the four groups of uremic patients. Analysis of data revealed a significant correlation between the TaqI variants and serum iPTH level. There was also a correlation between the BsmI variants and serum iPTH level in that patients with the BB genotype were more likely to have a higher serum iPTH level. However, the latter was not statistically significant.Conclusions:Genotype of the TaqI and BsmI VDR gene polymorphisms is reported in Iranian patients with ESRD. Those with tt or BB genotypes may develop more severe secondary hyperparathyroidism.

Vitamin D status and vitamin D receptor gene polymorphisms and susceptibility to type 1 diabetes in Egyptian children

BackgroundType 1 diabetes mellitus (T1DM) is recognized as a T-cell-mediated autoimmune disease. Vitamin D compounds are known to suppress T-cell activation by binding to vitamin D receptor (VDR); and thus, VDR gene polymorphisms may be related to T-cell-mediated autoimmune diseases. The aim of this study was to investigate the association between vitamin D status and VDR gene polymorphisms and T1DM. Materials and methodsOne hundred and twenty patients with T1DM and one hundred and twenty controls were enrolled in the study. VDR gene BsmI, FokI, ApaI and TaqI polymorphisms were determined using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Serum 25-hydroxyvitamin D (25(OH)D) was determined using ELISA. ResultSerum 25(OH)D levels revealed a vitamin D deficiency or insufficiency in 75% of the patients. The mean levels of vitamin D were significantly lower in patients as compared to their controls (P=<0.001). VDR BsmI Bb and bb genotypes and VDR FokI Ff and ff genotypes were associated with increased risk of T1DM (OR=2.3, 95% CI=1.3–4.2, P=0.005; OR=2.2, 95% CI=1.1–4.7, P=0.04; OR=1.8, 95% CI=1.03–3.04, P=0.04; OR=4.03, 95% CI=1.2–13.1, P=0.01 respectively), while the VDR ApaI and TaqI polymorphisms were not. ConclusionOur study indicated that vitamin D deficiency and VDR BsmI and FokI polymorphisms were associated with T1DM in Egyptian children.

Vitamin D receptor gene polymorphisms and the risk of rickets among Asians: a meta-analysis

AimsTo evaluate the association between vitamin D receptor (VDR) gene polymorphisms and the risk of rickets among Asians.MethodsEligible studies were included in our meta-analysis by searching PubMed, Embase, Cochrane and...

Association between vitamin D receptor gene BsmI, FokI, ApaI and TaqI polymorphisms and the risk of systemic lupus erythematosus: a meta-analysis

Association studies of vitamin D receptor (VDR) gene polymorphisms and the risk of systemic lupus erythematosus (SLE) have yielded conflicting results in different backgrounds. We aimed to evaluate the association between VDR gene polymorphisms and SLE risk. A predefined electronic databases search was performed to identify eligible studies that were related to the association of VDR gene BsmI, FokI, ApaI or TaqI polymorphism with SLE risk. Either a fixed-effects model, or in the presence of heterogeneity, a random-effects model was used to calculate the pooled odds ratios (ORs) and its corresponding 95% confidence interval (CI). A total of 11 studies with 1,621 cases and 1,883 controls were included in this meta-analysis. BsmI B allele was associated with the onset of SLE for overall populations (OR 1.726, 95% CI 1.214-2.455) and Asians (OR 1.952, 95% CI 1.135-3.355). FokI FF genotype was correlated with the susceptibility of SLE for Asians (OR 1.469, 95% CI 1.005-2.148). FokI T/C and TaqI polymorphisms were not associated with SLE risk for Caucasians. There was no significant association between ApaI polymorphism and SLE risk for overall populations, Asians and Caucasians. No evidence of publication bias was observed. In conclusion, BsmI B allele may be a risk factor for SLE onset among overall populations and Asians, and FokI FF genotype is a risk factor for SLE susceptibility in Asians. However, more studies should be performed in the future.