BB genotype of the vitamin D receptor gene polymorphism postpones parathyroidectomy in hemodialysis patients

BACKGROUND: Bsml vitamin D receptor (VDR) gene polymorphism has been reported to influence the progression of secondary hyperparathyroidism but it is not known how much the genetic background contributes to the need for parathyroidectomy (PTx). We investigated the influence of VDR gene polymorphism on PTx in patients with different dialysis vintage. METHODS: We studied 121 parathyroidectomized HD patients ("PTx " group). Patients who had required early parathyroidectomy ("early PTx" group) or late parathyroidectomy ("late PTx" group) were analyzed separately. The cut-off point between these two groups was 89 months (mean time on hemodialysis (HD) before parathyroidectomy). Serum intact parathyroid hormone, calcium, phosphorus and alkaline phosphatase were measured. Bsml genotypes were analyzed by polymerase chain reaction. Statistical analysis was done with univariant analysis of variance (ANOVA) to compare the genotype groups and general factorial ANOVA, entering time on HD as the dependent variable, with genotype, sex, age and chronic renal failure (CRF) etiology as factors. As a control group for the association studies we determined genotypic frequencies in 162 HD patients ("total HD" group), and in a healthy control population of 120 individuals ("healthy" group), tested by contingency table analysis and the chi-square test. RESULTS: No significant differences were found between the genotypes except for the time on HD. General factorial ANOVA showed that the adjusted means of the time on HD were significantly different for the various genotypes (p = 0.015). The BB genotype was significantly less frequent in the "early PTx " group than in the "total HD" and "late PTx" groups. CONCLUSIONS: Individuals with the BB genotype can remain longer on HD before they need parathyroidectomy.     

维生素D受体基因多态性对脊柱结核易感性的影响

目的：探讨维生素D受体（vitamin D receptor，VDR）基因多态性与中国湖南省汉族人群脊柱结核易感性的关系。方法：选取2004年10月至2006年2月我院收治的湖南省汉族新发脊柱结核患者42例（病例组）及志愿者64例（对照组），应用聚合酶链反应-限制性片断长度多态性分析技术检测两组对象VDR基因FokⅠ酶切位点多态性，并进行VDR基因分型。结果：VDR—FF、VDR—Ff与VDR—ff三种基因型在病例组和对照组中的分布频率分别为14．29％、35．71％、50％和23．45％、54．69％、21．86％；两组组间比较有显著性差异（P〈0．05）．其中VDR—ff基因型在病例组中的分布频率明显高于对照组，比值比（odds ratio，OR）为3．571（P〈0．05）．其95％可信区间（confidence interval，CI）为1．561～8.167。结论：VDR基因FokⅠ酶切值点多念性与湖南省汉族人群脊柱结核的易感性相关，VDR—ff基因型可能是其易感基因型。     

Association of vitamin D receptor gene polymorphism with urolithiasis

PURPOSE: Recent studies suggest that allelic variations of the vitamin D receptor (VDR) gene can influence calcium absorption and excretion. Therefore, we studied the association of VDR gene polymorphism with urolithiasis. SUBJECTS AND METHODS: We studied 83 patients with urinary stones and 83 controls. Patients were scored for certain clinical characteristics, including long axis diameter of the largest stone (1 point-less than 10 mm. and 2-10 mm. or greater), number of stones (1 point-1 and 2-multiple) and history of calcium stone disease (1 point-absent and 2-present). They were classified into 3 groups according to the total score, including low-3, intermediate-4 or 5 and high-6 points. The 2 VDR gene polymorphisms TaqI and ApaI were detected by polymerase chain reaction-restriction fragment length polymorphism and their relationships with the urinary calcium level were examined. RESULTS: The incidence of TaqI Tt and tt genotypes was significantly higher in the high score group than in controls. The TaqI t allele was associated with a 5.2-fold increase in the risk of severe stone disease. The urinary calcium level in patients with the Tt and tt genotypes was also higher than in those with the TT genotype. The rate of the ApaI genotype was not different in the high score group and controls. CONCLUSIONS: The TaqI t allele of the VDR gene may be a risk factor for severe stone disease and recurrent stones.     

Iron indices and vitamin D receptor polymorphisms in hemodialysis patients

Cardiovascular disease caused by accelerated atherosclerosis is the major determinant of morbidity and mortality in chronic kidney disease patients. Vitamin D and its analogs provide survival benefit for hemodialysis (HD) patients. Vitamin D exerts its effects through the vitamin D receptor (VDR) that is coded for by a gene showing several polymorphisms that, in turn, are associated with a variety of diseases and differential responses to vitamin D. In this study, we evaluated the association between 4 VDR polymorphisms (ie, those identified by the restriction enzymes BsmI, ApaI, TaqI, and FokI) and iron indices (serum iron, transferrin, transferrin saturation, and ferritin) in 88 hemodialysis patients routinely treated with vitamin D. The absence or presence of the BsmI, ApaI, TaqI, and FokI restriction sites were denominated B and b, A and a, T and t, F and f, respectively. Our results show that in HD patients with transferrin saturation <20%, the F allele was more frequent than in HD patients with transferrin saturation >20% (P = .03). This relationship may provide a link between VDR alleles and iron and nutritional markers, which are highly predictive variables of cardiovascular morbidity and mortality in hemodialysis patients.     

A single nucleotide polymorphism under the reverse primer binding site may lead to BsmI mis-genotyping in the vitamin D receptor gene.

The BsmI polymorphism in the VDR gene has been extensively investigated by PCR and restriction digestion in bone genetics. A SNP within the corresponding region for the previously published reverse primer was observed and confirmed by DNA sequencing. BsmI mis-genotyping caused by this SNP could confound genetic findings. INTRODUCTION: By analyzing the FokI, BsmI, ApaI, and TaqI polymorphisms in the vitamin D receptor (VDR) gene, we observed a significantly different genotype distribution in the BsmI polymorphic locus with a deviation from Hardy-Weinberg equilibrium. One of the reasons for polymerase chain reaction (PCR) non-amplification may be a mismatched base at the primer binding region. Therefore, the aim of this study was to analyse whether a single nucleotide polymorphism (SNP), which has been recently described as TruI, is responsible for the discrepancy between expected and observed genotype frequencies. MATERIALS AND METHODS: The VDR genotypes were identified in a cohort of 165 peri- and postmenopausal women of white origin. PCR amplification was carried out using the originally published primers and followed by restriction cleavage. The BsmI genotypes were further verified with a reverse primer external to the original binding site. The presence of the TruI polymorphism under the previously published reverse primer was confirmed by a restriction digestion and DNA sequencing. In Bb subjects, the colocalization of b allele with the TruI restriction site on the same chromosome was confirmed by a simultaneous digestion of the PCR product with both BsmI and TruI restriction enzymes. RESULTS: The BsmI reanalysis with an external primer provided a higher number of heterozygous subjects with a proportionally smaller number of BB subjects, and the changed genotype distribution was under Hardy-Weinberg equilibrium (BB, 31; Bb, 80; bb, 54; r = 0.0203; p = 0.90). In our primary analysis, the presence of the TruI polymorphism led to a drop out of b allele during PCR amplification and thus to the false prevalence of BB genotypes (BB, 50; Bb, 61; bb, 54; r = 11.17; p = 0.01). CONCLUSION: The SNP in the region corresponding to the reverse primer may lead to BsmI mis-genotyping, which may have confounded some previous genetic studies.     

Vitamin D receptor gene polymorphisms modulate the skeletal response to vitamin D supplementation in healthy girls

ObjectivesVitamin D receptor (VDR) gene plays an important role in bone mass regulation. We have previously shown a beneficial effect of vitamin D supplementation on bone mass in girls. This study investigated whether the musculo-skeletal response to Vitamin D was modulated by polymorphisms in VDR gene.DesignRandomized placebo-controlled trial.Methods179 girls (10–17 years), were randomly assigned to placebo or Vitamin D3 for one year. VDR genotypes were determined in 167 girls using BsmI, TaqI and ApaI restriction enzymes. Bone mass at the spine, hip, forearm and total body, and lean mass were measured by DXA at baseline and at one year.ResultsAfter one year, VDR gene polymorphisms using Bsm1 and TaqI restriction enzymes were associated with percent changes in bone area, BMC and BMD at multiple skeletal sites in the Vitamin D3 group but not in the placebo group. The least increments were observed in the BB and tt genotypes. No similar effect was observed with ApaI enzyme. This relationship between VDR genotypes and changes in BMD and BMC remained significant after adjustment for puberty, changes in lean mass, height and bone area.ConclusionVDR gene polymorphisms influence the skeletal response to vitamin D supplementation in healthy adolescent girls.     

Possible involvement of vitamin D receptor gene polymorphism in male patients with ossification of spinal ligaments

Ossification of spinal ligaments (OSL) is a common form of myelopathy characterized by heterotopic bone formation in the spinal ligaments, predominantly in men. Although the etiology of OSL is not fully understood, previous studies have strongly suggested the involvement of genetic factors in this disease. To investigate the possible involvement of vitamin D receptor (VDR) gene polymorphism in Japanese male patients with OSL, we analyzed: (a) the VDR genotype defined by BsmI polymorphism in patients with obvious OSL and controls; and (b) the effect of 1,25-dihydroxyvitamin D3 on alkaline phosphatase (ALP) activity of spinal ligament cells derived from patients without OSL. With regard to the VDR genotype, of the patients with OSL (n = 27), none had the BB genotype (0%), one had the Bb genotype (4%), and 26 had the bb genotype (96%). In the control group (n = 97) three had the BB genotype (3%), 18 had the Bb genotype (19%), and 76 had the bb genotype (78%). As a result, the B allele frequency in patients with OSL (2%) was significantly lower than in controls (12%). 1,25-Dihydroxyvitamin D3, at concentrations of 10-9 and 10-8 M, significantly increased ALP activity of the ligament cells (n = 8), suggesting that 1,25-dihydroxyvitamin D3 is able to promote osteogenic differentiation of normal ligament cells. Among the Japanese, sensitivity to vitamin D has been reported to vary between the alleles of the VDR; i.e., bone mineral density (BMD) in patients without the B allele is increased by vitamin D treatment, whereas patients with the B allele do not show such an increase in BMD. The present investigation is a small preliminary study, but the findings suggest, for the first time, that the B allele of the VDR acts as an inhibitor in the pathogenesis of human male OSL.     

维生素D受体基因TaqⅠ和ApaⅠ位点单核苷酸多态性与特发性低枸橼酸尿症关系的研究

目的：探讨维生素D受体（VDR）基因TaqⅠ和ApaⅠ位点单核苷酸多态性与特发性低枸橼酸尿症的关系及其临床意义。方法：实验筛选出无特发性低枸橼酸尿症者50名及特发性低枸橼酸尿症患者21名．通过PCR—RFLP技术检测VDR基因TaqⅠ及ApaⅠ位点单核苷酸多态性，并分析其与特发性低枸橼酸尿症之间的相关性。结果：两组间VDR基因ApaⅠ位点各基因型频率差异无统计学意义（P〉0．05）；而TaqⅠ各基因型频牢差异有统计学意义（P〈0．05）．在特发性低枸橼酸尿症患者组中TT型较为多见。且两组人群中基因型为TT者21h尿枸橼酸含量明显低于同组的其他基因型（P〈0．05）。结论1特发性低枸橼酸尿症与VDR—TaqⅠ单核降酸多态性间存在遗传相关性，而与VDR ApaⅠ单核苷酸多态性关系不明显。VDR基因TaqⅠ位点的TT型基因有望成为特发性低枸橼酸尿症的遗传标志基因。     

维生素D受体基因多态性与冠心病的相关性

近年来国内外研究均证实维生素D能够抑制炎症反应程度,从而具有延缓冠状动脉粥样硬化的作用,而维生素D的作用通过维生素D受体来实现,现已知维生素D受体基因存在变异,而这些变异可能影响维生素D的作用。本文拟就维生素D 及其受体基因变异与动脉硬化相关心血管疾病的关系进行综述。     

哈尔滨地区部分汉族人群维生素D受体Bsm I基因多态性与骨质疏松性骨折关系的研究

目的旨在了解哈尔滨地区部分汉族人群维生素D受体(VDR)BsmⅠ基因多态性与骨质疏松性骨折患者骨密度(BMD)的相关关系。方法98例研究对象按骨质疏松性骨折诊断标准分2组,骨量正常组:48人;骨质疏松性骨折组:50人。聚合酶链反应限制性片断长度多态性(PCR-RFLP)技术检测98例受试者VDRBsmⅠ基因型。测试受试者腰椎2～4(L2-4),股骨颈(Neck)、大转子(Troch)、Wards三角、桡骨远端(Radius)5个部位骨密度(BMD)。结果骨折组各部位骨密度均显著低于对照组各部位骨密度,差异具有显著性(P<0.01)。受试者VDR基因型未发现BB型,检出Bb型16人,占16.3%,bb型82人,占83.7%。b和B等位基因频率分别为91.8%、8.2%,Bb、bb两基因型在两组之间的分布无差异;VDR两基因型与各部位BMD之间,虽然在腰椎2～4、股骨颈、大转子和桡骨远端等4个部位Bb基因型比bb基因型的BMD高,但结果没有统计学意义。结论这组哈尔滨地区人群VDR基因型分布以bb型、Bb型为主,VDR基因BsmⅠ多态性与骨密度之间没有相关关系。     

维生素D受体基因BsmI多态性与发育性髋关节发育不良的相关性研究

[目的]明确我国北方汉族人维生素D受体基因(vitamin dreceptor gene,VDR)Bsml位点多态性分布及与发育性髋关节发育不良(developmental dysplasia op the hip,DDH)的相关性.[方法]采用PCR-测序的方法,对54个DDH患儿及55个正常儿的VDR基因BsmI位点进行分型.采用精确概率的x2检验,比较病例组及对照组中等位基因及基因型频率分布的差异.并把正常组与文献报道的不同人群该位点的多态性分布情况相比较,以了解VDR基因BsmI位点多态性在不同种族人群中的差异.[结果]VDR基因Bsml位点的基因型及等位基因频率分布,在DDH组与对照组之间均无明显的统计学差异(P值分别为0.527和0.428);我国北方汉族人该位点的基因型以GG为主,与美国人、澳洲人及法国人均存在明显的统计学差异(P<0.01).[结论]VDR基因Bsnfl位点基因型分布存在人群差异;该位点多态性与我国北方汉族人DDH的发生可能无关.     

Association of vitamin D receptor gene polymorphism and calcium urolithiasis in the Chinese Han population

To investigate the effect of the vitamin D receptor (VDR) Fok I Bsm I Dde I Apa I Taq I polymorphism on the clinical presentation of calcium urolithiasis, 464 patients with urolithiasis and 450 age- and sex-matched healthy controls were recruited from The First Affiliated Hospital of Zhejiang University between January 2010 and March 2011. Five SNPs of VDR polymorphism were detected using polymerase chain reaction-based restriction analysis. The frequency of VDR Apa I genotypes between the patients and the healthy controls was significantly different (P = 0.006). Apa I a allele was found to be associated with increased risk of stone recurrence (P = 0.028). We also found Fok I Dde I Apa I showed a significant difference between male and female in the patients group (P < 0.05). Haplotype analysis of the five VDR polymorphisms showed a significant association with urolithiasis (global-P value = 0.0001). Genetic polymorphisms of VDR are important in the clinical presentation of patients with calcium urolithiasis in the Han population of southern China.     

Vitamin D receptor gene polymorphism,bone mass,body size,and vitamin D receptor density

We determined vitamin D receptor (VDR) gene alleles (based on the BsmI restriction site polymorphism), duodenal mucosal receptor density, bone mass at spine and total body, and body size in 32 healthy premenopausal females. While we found no relationship between allele and receptor density in duodenal mucosa, bone mineral content (BMC) at both spine and total body was significantly associated with VDR gene alleles. BMC was highest for the bb allele, lowest for BB, and intermediate for Bb. A similar association was noted between allele and body size variables, particularly weight. When BMC was adjusted for body weight, the association with VDR polymorphism disappeared. The VDR gene polymorphism may be affecting bone mass not through classical nutritional mechanisms (e.g., intestinal calcium absorption), but through an influence on body size.     

Association of vitamin D receptor gene polymorphism and risk of prostate cancer in India

INTRODUCTION: Vitamin D plays an important role in the proliferation and differentiation of normal and malignant cells. In several studies polymorphism in the vitamin D receptor (VDR) gene has been reported to be associated with prostate cancer (CaP). The rationale of this study was to determine the association between the VDR (Fok-I) polymorphism and the risk of developing CaP. MATERIALS AND METHODS: Polymorphism was detected by the polymerase chain reaction (PCR)-restriction fragment length polymorphism method in 128 CaP patients (age range 43-89 years) and 147 age-matched controls (age range 42-91 years). PCR products were designated as F or f allele according to the absence or presence of a restriction site. RESULTS AND CONCLUSIONS: The frequencies of the FF, Ff and ff genotypes were 60.9, 35.2 and 3.9% in CaP patients and 42.2, 46.9 and 10.9% in healthy controls, respectively. The genotype frequency distribution between CaP and the control group was statistically significant (p = 0.003). However, the distribution of genotypes was not significantly associated with the Gleason score. The present study thus demonstrates that the FF genotype (or F allele) of the VDR gene plays an important role in determining the risk of CaP and could be postulated as a good candidate genetic marker.     

宁夏回、汉老年女性原发性骨质疏松症的维生素D受体基因多态性研究

目的 探讨宁夏地区回、汉老年女性原发性骨质疏松症（primary osteoporosis,PO）维生素D受体基因（vitamin D receptor, VDR）基因多态性分布。方法 应用聚合酶链反应限制性片段长度多肽性技术（polymerase chain reaction-restrictive fragment length polymorphism, PCR-RFLP）,从2015年至 2018年筛选宁夏医科大学总医院门诊及住院患者,收集119例汉族和111例回族原发性骨质疏松症妇女的血液样本并进行VDR基因型的分型检测,探讨宁夏回、汉VDR基因多态性是否存在差异。结果 111例患者的VDR受体基因型频率分布均符合Hardy-Weinberg定律,汉族和回族的女性骨质疏松症的bb 型占89.20%,68.21%。Bb基因型频率分别为8.79%和27.16%,BB基因型频率为0.00%和3.80%。宁夏回、汉女性原发性骨质疏松症中VDR基因型频率分布差异具有统计学意义（P<0.001）。结论 宁夏回、汉女性原发性骨质疏松症患者VDR基因多态性存在民族差异性,这种民族差异性与骨质疏松症的相关性有待于进一步研究。