Vitamin D receptor allele combinations influence genetic susceptibility to type 1 diabetes in Germans

Vitamin D has been shown to exert manifold immunomodulatory effects. Because type 1 diabetes is regarded to be immune-mediated and vitamin D prevents the development of diabetes in the NOD mouse, we investigated the role of the vitamin D receptor (VDR) gene as a candidate for type 1 diabetes susceptibility. A total of 152 Caucasian families with at least one affected offspring were genotyped for four VDR restriction-site polymorphisms (FokI, BsmI, ApaI, and TaqI). Whereas the BsmI, ApaI, and TaqI polymorphisms are in strong linkage disequilibrium with each other, no significant linkage disequilibrium with the FokI site was observed. Extended transmission disequilibrium testing (ETDT) was used to detect preferential transmission of allelic combinations to affected offspring. We found significant haplotype-wise ETDT results for the BsmI/ApaI/TaqI (chi2 = 18.886, df = 7, P = 0.0086), the BsmI/TaqI (chi2 = 8.373, df = 3, P = 0.0389), and theApaI/TaqI (chi2 = 17.182, df = 3, P = 0.0006) haplotypes. The "At" and "Bt" alleles confer an increased risk, whereas "AT" and "at" are protective. The combination with the strongest susceptibility was the "BAt" haplotype (64% transmitted, P = 0.0106). Analysis of the FokI site does not provide more information on susceptibility (FokI/BsmI/ApaI/TaqI [chi2 = 24.702, df = 15, P = 0.0541]). These findings suggest a linkage of VDR itself or a nearby gene with type 1 diabetes susceptibility in Germans, confirming respective observations previously made in Indian Asians.     

维生素D受体基因多态性与白癜风的相关性研究

目的：探讨维生素D受体基因多态性与白癜风的相关性。方法：采用聚合酶链反应和限制性片段长度多态性方法，对749例白癜风患者和763例健康人的维生素D受体基因型进行分析。结果：白癜风患者维生素D受体BsmI、ApaI、TaqI位点基因型的分布与正常对照组相比有显著性差异，bb、aa、tt基因型在白癜风患者中频率较高，FokI位点基因型的分布与对照组无明显差异。单倍体型分析表明FokI位点和BsmI位点，BsmI位点和ApaI位点，BsmI和TaqI位点，ApaI位点和TaqI位点之间存在较强的连锁不平衡，白癜风患者中fbAT、FbAT和FbaT单倍体型的频率显著高于对照组。结论：维生素D受体基因多态性与白癜风有明显的相关性。携带维生素D受体基因纯合子bb、aa或tt基因型可能会增加对白癜风的易感性。     

Association analysis of the polymorphisms of the <Emphasis Type="Italic">VDR</Emphasis> gene with bone mineral density and the occurrence of fractures

Associations of the FokI, BsmI, ApaI, and TaqI polymorphisms of the vitamin D receptor (VDR) gene with the bone mineral density (BMD) of the lumbar part of the spinal column (BMD LS) and the neck of the femur (BMD FN), and with the occurrence of fractures, were studied using the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis on DNA isolated from peripheral blood of 239 women and 40 men from the region of western Poland. Three polymorphisms of the 3′ end of the VDR gene (BsmI, ApaI, TaqI) indicated a strong linkage disequilibrium. Association analysis of the VDR gene FokI polymorphism with BMD LS showed a dose effect of allele f. The association of the bAT haplotype of the BsmI, ApaI, and TaqI polymorphisms of the VDR gene with BMD FN was statistically significant. The association of the ApaI polymorphism with the occurrence of fractures was observed. Associations were also observed between the occurrence of fractures and the baT haplotypes of the VDR gene.     

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

BackgroundOur objective was to evaluate the association between vitamin D receptor (VDR) BsmI, FokI, TaqI, and ApaI gene polymorphisms and the risk of renal disease. A meta?analysis was conducted to determine the correlation between these VDR gene polymorphisms and the renal disease.MethodsMeta-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).ResultsThe 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.ConclusionsThis meta-analysis identifies BsmI, FokI, TaqI and ApaI polymorphisms of the VDR gene as risk factors for renal diseases.     

Impact of vitamin D receptor gene polymorphisms on clinical outcomes of HLA-matched sibling hematopoietic stem cell transplantation

We hypothesized that polymorphisms of the vitamin D receptor (VDR) gene might affect clinical outcomes of allogeneic hematopoietic stem cell transplantation (HSCT). Three VDR gene polymorphisms (BsmI G>A, ApaI G>T, and TaqI T>C) were genotyped in 147 patients who underwent HLA-matched sibling allogeneic HSCT. Frequencies of infection, graft-vs.-host disease (GVHD), overall survival (OS), and disease-free survival (DFS) were compared according to genotypes and haplotypes. Infection and acute GVHD had trends to be less frequent in patients with ApaI TT genotype than non-TT genotypes (p = 0.061 and p = 0.059, respectively). For TaqI genotypes, there were no statistical differences in frequency of infection and acute GVHD (p = 0.84 and p = 0.30, respectively), but TC genotype was associated with longer OS and DFS than TT genotype (p = 0.022 and p = 0.038, respectively). In the ApaI-TaqI haplotype analysis, patients with TC haplotype had significantly longer OS and DFS than those without TC haplotype (p = 0.022 and p = 0.038, respectively). In multivariable analysis, TaqI genotype and ApaI-TaqI haplotype of recipients were independent prognostic factors for both OS and DFS. This study suggests that the genotype and haplotype of VDR in recipient might be associated with clinical outcome of sibling HLA-matched HSCT.     

Associations between vitamin D receptor gene polymorphisms and ankylosing spondylitis in Chinese Han population: a case–control study

Summary

We assessed whether the vitamin D receptor gene polymorphisms (FokI, BsmI, ApaI, and TaqI) were associated with ankylosing spondylitis (AS) in a Chinese Han population. The TaqI polymorphism G allele was a risk factor in AS susceptibility.

Introduction

Previous studies have found that serum vitamin D levels are declined in patients with AS. The present study aims to evaluate the role of vitamin D receptor (VDR) gene polymorphisms in AS susceptibility in a Chinese Han population.

Methods

Four single nucleotide polymorphisms (SNPs) in the VDR gene (FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232), and TaqI (rs731236)) were genotyped by the improved multiplex ligase detection reaction (iMLDR) method in 620 AS patients and 620 geographically and ethnically matched healthy controls. Haplotypes were constructed after linkage disequilibrium (LD) analysis.

Results

Statistically significant difference was only found in the TaqI polymorphism between AS patients and controls. The TaqI polymorphism G allele was higher in AS group than that in controls (OR [95 % CI]?=?1.624 [1.122–2.352], χ ²?=?6.705, P?=?0.006). Linkage disequilibrium has been detected in TaqI and BsmI polymorphisms (D′?=?0.87, r ²?=?0.70). Two novel haplotypes (H1: AC and H2: GT) were significantly associated with the risk of AS, and they play protective and risk roles in AS morbidity, respectively.

Conclusions

The VDR gene TaqI polymorphism G allele may be a risk factor in AS susceptibility.

     

Vitamin D receptor gene polymorphism is related to bone density, circulating osteocalcin, and parathyroid hormone in healthy adolescent girls

Bone mineral density (BMD) in adolescence is under strong genetic control and may influence the risk of future osteoporosis and resulting fracture. We investigated the vitamin D receptor (VDR) gene polymorphisms ApaI, BsmI, FokI, and TaqI, in relation to BMD, circulating calcium, osteocalcin, and parathyroid hormone (PTH) concentrations in healthy Caucasian girls (n = 99; mean (+/- SD) age 16.9 +/- 1.2 years). BMD of the total body, femoral neck, and lumbar spine, and bone area of the femur, lumbar spine, and total body were measured using dual energy X-ray absorptiometry. BMD values were adjusted for age, body height, body weight, and physical activity. Using ANOVA, the ApaI genotype Aa had lower circulating levels of osteocalcin (P < 0.01), higher levels of PTH (P = 0.04), and there was a strong tendency toward a significantly higher lumbar spine BMD (P = 0.08) compared with aa subjects. BMD of the lumbar spine (P = 0.02), but not femoral neck or total body, was higher in Bb subjects compared with their bb counterparts. There was no difference in BMD at any measured site of the FokI alleles. There was a strong tendency for a higher BMD at the lumbar spine of Tt subjects compared with TT subjects (P = 0.05). Neither of the different VDR polymorphisms was related to BMD before adjustment for age, body weight, body height, and physical activity. In conclusion, VDR gene polymorphism, defined by ApaI, is related to differences in circulating osteocalcin and PTH, and BsmI is related to lumbar spine BMD in healthy adolescent girls. The results stress the importance of adjusting BMD for confounding factors, such as body weight and physical activity, in order to be able to find any genotype effect on BMD.     

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.     

Vitamin D receptor gene polymorphism in familial prostate cancer in a Japanese population

AIM: Vitamin D acts as an antiproliferative agent against prostate cells. Epidemiological study has shown that a low level of serum vitamin D concentration is a risk factor for prostate cancer. Vitamin D acts via vitamin D receptor (VDR), and an association of genetic polymorphisms of the VDR gene has been reported. In the current study, we examined the association of VDR gene polymorphisms with familial prostate cancer in a Japanese population. METHODS: We performed a case-control study consisting of 81 familial prostate cancer cases and 105 normal control subjects. Three genetic polymorphisms (BsmI, ApaI and TaqI) in the VDR gene were examined by the restriction fragment restriction length polymorphism method. RESULTS: Overall, there was no significant association of the VDR gene polymorphisms with familial prostate cancer risk in the cases and control subjects. However, a weak association between BsmI or TaqI genotypes and cancer risk was observed in subjects under 70 years of age. Stratification of cases by clinical stage or pathological grade did not show significant association between the VDR gene polymorphisms and prostate cancer risk. CONCLUSION: In the present study, we could not confirm any significant association between VDR gene polymorphisms with familial prostate cancer risk in a Japanese population. Further large-scale case-control studies are warranted to confirm the importance of VDR gene polymorphisms in familial prostate cancer.     

Vitamin D receptor (VDR) mRNA and VDR protein levels in relation to vitamin D status,insulin secretory capacity,and VDR genotype in Bangladeshi Asians

Associations have been reported between vitamin D receptor (VDR) gene polymorphisms, type 1 diabetes, insulin secretion, and the insulin resistance syndrome. As VDR polymorphisms have no known functional significance, these findings may implicate a variant of the VDR gene or a locus in linkage disequilibrium with the VDR. We have examined VDR mRNA and VDR protein levels in relation to VDR polymorphisms (41 Bangladeshi subjects) and analyzed insulin secretory capacity (143 Bangladeshi subjects), allowing for other known determinants. Peripheral blood mononuclear cells (PBMCs) from subjects who had been genotyped for BsmI, ApaI, TaqI, and FokI VDR restriction fragment length polymorphisms were used for both total VDR mRNA quantitation (using TaqMan) and measurement of VDR protein levels (using a specific micro-immunoassay). Stepwise multiple regression analyses were used (to P < 0.05) to analyze the data. For the insulin secretion index, the best-fit model (n = 143, P < 0.0001) gave age (P = 0.002), TaqI (P < 0.0001), and BMI (P = 0.001) as independent determinants; with the inclusion of VDR mRNA and VDR protein levels, VDR mRNA was the sole independent determinant (n = 41, P = 0.024). However, the best-fit model for VDR mRNA (P = 0.004) gave FokI (P = 0.044) and TaqI (P = 0.04) genotypes and insulin secretory capacity (P = 0.042) as independent determinants. For VDR protein levels, the best-fit model (P = 0.006) gave TaqI genotype (P = 0.005) and circulating 1,25-dihydroxyvitamin-D levels (P = 0.03) as independent determinants. In conclusion, these studies confirm an association between VDR polymorphisms and insulin secretory capacity and demonstrate the VDR genotype to be a significant determinant of VDR mRNA and VDR protein levels in PBMCs, providing functional support to previously described genetic associations with the VDR gene. Furthermore, VDR expression has been shown to be a determinant of insulin secretory capacity.     

Polymorphisms in the vitamin D receptor gene and the risk of calcium nephrolithiasis in children

OBJECTIVE: Polymorphism in the Vitamin D Receptor (VDR) gene has recently been reported to be associated with calcium metabolism disorders. This study was conducted to investigate the association of VDR gene polymorphism with the risk of calcium nephrolithiasis. METHODS: We investigated the VDR ApaI, BsmI and TaqI polymorphisms, in relation to serum calcium, phosphate, intact parathyroid hormone and 1.25(OH)(2)D(3) in 64 hypercalciuric stone-forming children and 90 healthy children. DNA was isolated from peripheral blood, and genotyping was performed with PCR-based methods. RESULTS: The frequency of ApaI AA genotype was significantly higher in the children with calcium nephrolithiasis than the controls (chi(2)=9.5; p=0.008). The distribution of BsmI and TaqI genotypes in stone-forming patients was similar to those in the control group. There was a significant association between TaqI TT genotype and the strength of the family history. The patients with TT genotype were observed to have a 8 times more risk than patients with Tt/tt genotype for recurrent stone episodes (OR 8, 95%CI 1.61-39.6). CONCLUSION: VDR genotype determination may provide a tool to identify individuals who are at a risk for calcium nephrolithiasis.     

Vitamin D receptor gene BsmI and TaqI polymorphisms and fracture risk: a meta-analysis

INTRODUCTION: Fracture is the major clinical outcome of osteoporosis. The vitamin D receptor (VDR) gene is thought to be a candidate gene for osteoporosis. Many genetic studies have suggested an association of VDR polymorphisms and osteoporosis, but evidence remains conflicting. MATERIALS AND METHODS: We searched published studies from 1996 to September 2005 through PubMed and evaluated the genetic effect of the BsmI and TaqI polymorphism of VDR on fracture risk in a meta-analysis. Thirteen studies with a total of 20 eligible comparisons (1632 fracture cases and 5203 controls) were analyzed with fixed and random effects models. RESULT: No evidence of relationship between the VDR BsmI or TaqI polymorphism and fracture risk was observed with any genetic model. The odds ratio (95% confidence interval) of b-allele versus B-allele was 0.98 (0.86-1.12) with random effects calculations. There was significant between-study heterogeneity. Small studies did not differ significantly from larger ones. CONCLUSION: No relationship of the VDR BsmI or TaqI polymorphism and fracture risk was found in the meta-analysis of published data.     

Vitamin D receptor gene polymorphisms are associated with increased risk and progression of renal cell carcinoma in a Japanese population

AIM: Biological and epidemiologic data suggest that 1 alpha, 25 dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) levels may influence development of renal cell carcinoma. The vitamin D receptor (VDR) is a crucial mediator for the cellular effects of 1,25(OH)(2)D(3) and additionally interacts with other cell signaling pathways that influence cancer progression. VDR gene polymorphisms may play an important role in risk of incidence for various malignant tumors. This study investigated whether VDR gene polymorphisms were associated with increased risk and prognosis of renal cell carcinoma (RCC) in a Japanese population. METHODS: To analyze risk of RCC depending on VDR polymorphism, a case-control association study was performed. The VDR gene polymorphisms at three locations, BsmI, ApaI and TaqI, were genotyped in 135 RCC patients and 150 controls in a Japanese population. Logistic regression models were used to assess the genetic effects on prognosis. RESULTS: Significant differences in the ApaI genotype were observed between RCC patients and controls (chi(2) = 6.90, P = 0.032). No statistical significant difference was found in the BsmI and TaqI polymorphisms. The frequency of the AA genotype in the ApaI polymorphism was significantly higher in the RCC patients than in the controls (odds ratio, 2.59; 95% confidence intervals, 1.21-5.55; P = 0.012). Multivariate regression analysis showed that the AA genotype was an independent prognostic factor for cause-specific survival (relative risk 3.3; P = 0.038). CONCLUSION: The AA genotype at the ApaI site of the VDR gene may be a risk of incidence and poor prognosis factor for RCC in the Japanese population. Additional studies with a large sample size and investigation of the functional significance of the ApaI polymorphism in RCC cells are warranted.     

Association between vitamin D receptor genetic polymorphisms and acute cellular rejection in liver-transplanted patients

Vitamin D receptor (VDR) polymorphisms may confer susceptibility to immunologically mediated liver diseases. We aimed to verify whether recipient VDR polymorphisms might affect the incidence of acute cellular rejection (ACR) of the graft after liver transplantation (LT). Two hundred and fifty-one liver-transplanted patients surviving at least 1month were studied. ACR in the first post-LT year was graded according to the Banff score. Recipients genotyping for VDR polymorphic sites (FokI C>T, BsmI G>A, ApaI T>G, TaqI T>C) was performed. A significant difference was found between patients with and without ACR episodes in allele frequencies of BsmI (G: 0.660 vs. 0.545, P=0.017) and TaqI (T: 0.667 vs. 0.543, P=0.010). Patients carrying the G-*-T/G-*-T diplotypes of the BsmI G>A, ApaI T>G and TaqI T>C experienced more frequently ACR: 33/79 Vs 42/172, P=0.005. Carriage of G-*-T/G-*-T diplotypes was an independent predictor of ACR (OR 2.41, P=0.006), with CMV reactivation (OR 2.34, P=0.033) and HCV aetiology (OR 1.86, P=0.036). In conclusion, recipient VDR polymorphic loci are strongly associated with ACR occurrence during the first year after LT. The knowledge of VDR genetic polymorphisms may be helpful in identifying recipients at higher risk of ACR and in selecting them for a more aggressive immunosuppressive therapy.     

Polymorphisms and haplotypes of integrinalpha1 (ITGA1) are associated with bone mineral density and fracture risk in postmenopausal Koreans

INTRODUCTION: ITGA1 is involved in the early remodeling of osteoarthritic cartilage and plays an essential role in the regulation of mesenchymal stem cell proliferation and cartilage production. We investigated the association between bone parameters and ITGA1 polymorphisms and their haplotype linkage disequilibrium (LD) blocks (BL_hts). Genetic susceptibility to osteoporosis was studied in 946 postmenopausal Korean women. METHODS: We identified 67 genetic polymorphisms in ITGA1 region by direct sequencing (n = 114). Eight SNPs were genotyped to further investigate their potential involvement in osteoporosis in postmenopausal women (n = 946). Areal BMD of the lumbar spine and proximal femur was measured using dual-energy X-ray absorptiometry. RESULTS: The SNPs, +73187C>T (exon 3) and +76969T>G (intron 5), and their BL_hts were associated with bone mineral density (BMD) at various femur sites (p = 0.009-0.05). Moreover, +159174A>C (intron 28) and its haplotype BL3_ht1 showed a highly significant association with risk of non-vertebral fracture (p = 0.002-0.005) and the minor allele of +159174A>C showed a protective effect. CONCLUSIONS: These results are suggestive of the association of ITGA1 with osteoporosis and related risk in postmenopausal women.     

Vitamin D receptor gene allelic variants,bone density,and bone turnover in community-dwelling men

The role of vitamin D receptor (VDR) gene polymorphisms in the determination of bone mass and bone turnover is controversial in women. The aim of the study was to determine whether VDR polymorphisms are associated with indices of bone mineral density (BMD) (by dual-energy X-ray absorptiometry and by ultrasound) and/or with bone turnover and muscle strength, factors related to both BMD and fracture risk. For this purpose, we investigated a cohort of community-dwelling men >70 years (n = 271) and a group of healthy control subjects between the ages of 20 and 50 years (n = 137). VDR TaqI, ApaI, and FokI genotypes were determined using enzymatic restriction digestion of polymerase chain reaction (PCR) fragments. In the elderly group, the lowest BMD value at the femoral neck and at the calcaneus was observed in subjects with the "At-At" haplotype genotype, with differences between extreme haplotype groups ("At-At" vs. noncarriers of the "At" allele) ranging from 5.8% to 34.3% (p < or = 0.05). Moreover, at the different subregions of the distal forearm and the tibia, the lowest BMD estimates were consistently associated in both elderly and younger men with the "At" haplotype allele, although this did not approach statistical significance. Elderly subjects with the "At-At" genotype had a significantly higher serum osteocalcin level. BMD was not significantly related to the FokI VDR polymorphism at any of the assessed skeletal sites, nor were any of the biochemical markers associated with the FokI VDR genotype. There were no differences between genotype groups for any of the indices of muscle strength. The present study indicates that the VDR genotype is associated with BMD in healthy community-dwelling elderly men and tends to be associated with biochemical markers, particularly of bone formation, in elderly men.     

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.     

Test of linkage and/or association between the estrogen receptor alpha gene with bone mineral density in Caucasian nuclear families

Extensive studies have been performed on the association between the estrogen receptor alpha (ER-alpha) gene and bone mineral density (BMD). Despite considerable efforts, the studies using limited markers and relatively small sample size have yielded largely inconsistent results. In this study, 1873 Caucasian subjects from 405 nuclear families containing 1512 sib pairs were recruited. BMD at the lumbar spine (LS) and femoral neck (FN) was measured by dual-energy X-ray absorptiometry (DXA). Seven single-nucleotide polymorphisms (SNPs) spanning from exon 1 to 8 in the ER-alpha gene were genotyped. The program QTDT (quantitative transmission disequilibrium test) was applied to test linkage and/or association of the ER-alpha gene and BMD variation using individual SNP markers and reconstructed haplotypes. Linkage disequilibrium (LD) was generally detected for SNPs in the ER-a gene (P < 0.05). Associations were observed between SNP rs932477 and FN BMD (P = 0.028), and between the most predominant three-marker haplotype (GCG) containing SNP rs932477 and FN BMD (P = 0.010). Within-family association (present only with both linkage and association) between SNP rs2228480 (G2014A) and FN BMD (P = 0.015) was observed. The most predominant seven-SNP haplotype (TCGCGGG) was associated with higher LS BMD (P = 0.015). However, after correction for multiple testing, these associations did not reach statistical significance. Denser markers may be necessary to better define the relationship between the ER-alpha gene and BMD variation in our sample.     

Common Polymorphism of the Vitamin D Receptor Gene is Associated with Variation of Peak Bone Mass in Young Finns

Previous studies suggested a relation between polymorphism of the vitamin D receptor (VDR) gene and bone mineral density (BMD) at perimenopausal age. To enlighten the possible association of the VDR gene polymorphism and BMD, we studied young (20–29 years) adults whose BMD provides a measure of their maximal bone mass. After sequencing the DNA regions flanking the polymorphic BsmI site, we set up a specific solid-phase minisequencing technique to assay this allelic variation. BMD values were adjusted for age, sex, weight, physical activity, smoking, and calcium intake. Young subjects homozygous for the b allele (BsmI site present) had a significantly higher BMD in lumbar spine and femoral neck than those homozygous for the B allele (BsmI site absent). This data shows that the BsmI polymorphism of the VDR gene is associated with peak bone mass. The implication of this result regarding the prevention of osteoporosis deserves further attention. Received: 3 July 1995 / Accepted: 13 February 1996     

Influence of polymorphisms in VDR and COLIA1 genes on the risk of osteoporotic fractures in aged men

BACKGROUND: Osteoporosis in chronic renal failure is a common finding caused by several factors, including age. In the last decade, the likely effect of genetic markers related with the appearance and evolution of osteoporosis has been mainly studied in women, with no categorical results. The aim of this study was to assess the influence of polymorphisms of the vitamin D receptor (VDR) and COLIA1 genes on the risk of osteoporotic fractures in men older than 50 years. METHODS: The study population comprised 156 men, aged 64 +/- 9 (50-86), randomly selected from the population list of Oviedo, Spain. Prevalent vertebral fractures and incident non-vertebral fractures were identified, as well as several genetic polymorphisms. Prevalent vertebral fractures were considered according to the Genant grade 2 classifications. The analyzed genetic polymorphisms were located on restriction sites BsmI (B,b), ApaI (A,a), and TaqI (T,t) in the VDR and on Sp1 (S,s) in COLIA1. RESULTS: Although none of the VDR gene polymorphisms separately analyzed showed any differences between fractured and non-fractured men, the utilization of haplotypes could be employed in order to find osteoporotic fractures in men. By contrast, the COLIA1 polymorphism was associated with osteoporotic fractures. The percentage of prevalent vertebral fractures was significantly higher in the "ss" genotype with respect to the other genotypes. These results show that in men, the "ss" genotype of COLIA1 polymorphism could be the best osteoporotic fracture risk genetic predictor, independent of bone mass values.