Heterogeneity of vitamin D receptor gene association with celiac disease and type 1 diabetes mellitus

Objective: Vitamin D has been shown to exert multiple immunomodulatory effects and is known to suppress T-cell activation by binding to the vitamin D receptor (VDR). To determine whether VDR gene polymorphisms are related to the susceptibility to celiac disease, we investigated its implication as a candidate gene in the Basque population. Because celiac disease and type 1 diabetes share common susceptibility loci, we also analyzed families with type 1 diabetes mellitus.

Methods: A total of 37 families with celiac disease and 64 type 1 diabetic families of Basque origin with at least one affected offspring were genotyped for four VDR restriction-site polymorphisms (Fok I, Bsm I, Apa I and Taq I). The AFBAC approach was used to test for association.

Results: Comparison of VDR genotypes of the patients with those of 88 healthy individuals identified “ff” as a risk genotype for celiac disease [p = 0.01; OR = 3.45 (1.12–10.79)]. On the other hand, a significantly higher frequency of haplotype “fBAt” was observed in the type 1 diabetic group [p_c = 0.02; OR = 4.4 (1.5–15.3)].

Conclusion: Our findings suggest that polymorphisms within the vitamin D receptor gene are markers of susceptibility to or protection from autoimmune diseases, although, at least in the Basque population, association of VDR variants with celiac disease and type 1 diabetes seems to be heterogeneous.     

Lack of association of vitamin D receptor gene polymorphisms with susceptibility to type 1 diabetes mellitus in the Portuguese population

The vitamin D receptor (VDR) gene is a candidate gene for susceptibility to autoimmune disorders. Association studies of VDR polymorphisms and risk of type 1 diabetes often produced conflicting results in different ethnic backgrounds. The aim of this study was to test for association between common VDR polymorphisms and the genetic susceptibility to type 1 diabetes in the Portuguese population. We genotyped 207 patients with type 1 diabetes and 249 controls for the FokI T>C (rs10735810), BsmI A>G (rs1544410), ApaI G>T (rs7975232), and TaqI C>T (rs731236) single nucleotide polymorphisms by polymerase chain reaction and restriction fragment length polymorphism analysis. The distribution of VDR genotype, allele, and haplotype frequencies did not differ significantly between patients and controls. These data suggest that the single nucleotide polymorphisms of the VDR gene are unlikely to contribute significantly to type 1 diabetes susceptibility in the Portuguese population.     

Vitamin D receptor (VDR) gene polymorphisms and age onset in type 1 diabetes mellitus

Abstract

Vitamin D receptor is a mediator of immune responses through the action of vitamin D, which is capable of regulate the insulin secretion by the pancreas. Since polymorphisms in the vitamin D receptor (VDR) gene might modulate vitamin D function, and thus immunologic response, VDR is possibly able to influence the predisposition to type 1 diabetes mellitus (T1DM). The aim of this work was to perform an association study among VDR polymorphisms and T1DM susceptibility, as well as the correlation with the disease onset. Two hundred and four T1DM patients and 217 controls, from Northeast Brazil, were genotyped for five tagSNPs, covering the whole VDR gene. Our results indicated an association between rs1540339 and rs4760648 SNPs (p?=?0.02 and p?=?0.03, respectively) and T1DM. No association was found with T1DM onset and age at diagnose. To our knowledge, this is the first association study in T1DM where the whole VDR gene was analyzed, and our results indicate that VDR polymorphisms could be important for T1DM susceptibility, but do not seem to be associated to age at disease onset.     

HLA-DRB1 and MHC class 1 chain-related A haplotypes in Basque families with celiac disease

The contribution of HLA genes to the genetic risk for celiac disease (CD) has been known for a long time. Recent publications have pointed to the possibility that a second, independent susceptibility locus could be located in the same genomic region, and a triplet repeat polymorphism in exon 5 of the gene MHC class I chain-related protein A (MICA; located between TNFA and HLA-B) has been associated with several autoimmune disorders, including type 1 diabetes mellitus (DM1) and Addison's disease. On the other hand, a single amino acid change in exon 3 of MICA (M129V) has been shown to strongly reduce MICA binding to NKG2D, an activating natural killer receptor expressed also on T cells, and this could have significant effects on autoimmune reactions. In this study, we have analyzed the contribution of these polymorphisms to CD in 37 Basque families, and have constructed MICA-HLA-DRB1 haplotypes to determine whether MICA has an effect independent from the HLA class II conferred risk. In our population, HLA-DRB1*0301 was associated with an increased risk for CD, while HLA-DRB1*1501 conferred protection from the disease (OR: 7.38 and 0.06, respectively). On the other hand, MICA allele A4 was positively associated with the disease (OR: 4.69) whereas allele A9 showed a trend towards protection (OR: 0.18), although significance did not hold after correction. No association of the exon 3 biallelic polymorphism was observed. A positive allelic association was found for haplotypes A5.1-DRB1*0301 (associated with risk for disease), A4-DRB1*0301 and A6-DRB1*07. In view of our results, both HLA-DRB1 and MICA are associated with CD, but stratification analysis did not show any independent contribution of the MICA polymorphisms analyzed to CD risk. Besides, MICA allele A4 (also A5.1 was associated with risk for CD and other diseases) is in strong linkage disequilibrium with HLA-DRB1*0301. Finally, the major histocompatibility complex region's conferred susceptibility to CD, at least in Basque, is very similar to that observed for DM1, with shared risk and protective haplotypes.     

Association analysis of vitamin D receptor gene polymorphisms in North England population with Type 2 diabetes mellitus

BackgroundNumerous diabetes susceptibility loci, include a region consisting vitamin D receptor gene found in chromosome 12q, have been known using genome wide screens.AimThe aim of present study is to probe the relationship between polymorphism of vitamin D receptor gene (single nucleotide polymorphisms) and type 2 diabetes mellitus (T2DM). Five hundred T2DM patients and 200 healthy subjects with normal HbA1c (≤ 5.0 %), fasting blood sugar (≤ 120 mg/dL) and random blood sugar (≤ 140 mg/dL) were enrolled.MetholodgyThe genotypes were found by polymerase chain reaction restriction fragment length polymorphism and DNA sequencing.Resultsrevealed that no considerable differences in frequencies of genotype and allele of the Bsm I and Fok I polymorphisms between healthy and patients in the North England (For Fok I: OR = 1.11, 95% CI: 0.72–1.12; for Bsm I: OR = 1.35, 95% CI: 0.79–1.98).ConclusionIt is recommended that both following polymorphisms of vitamin D receptor gene may not considerably add to the progression of T2DM in the North England.     

维生素D受体基因多态性与乙型肝炎病毒感染的关联研究

目的探讨中国汉族人群维生素D受体（vitamin D receptor，VDR）基因多态性是否与乙型肝炎病毒（hepatitis B virus，HBV）感染结局相关联。方法以184例慢性乙肝患者和205名无症状HBV携带者为研究对象，收集外周血，提取基因组DNA，应用聚合酶链反应．限制性片段长度多态性（polymerase chain reaction-restriction fragmentlength polymorphism，PCIR-RFLP）方法，分析VDR基因第2外显子Fok Ⅰ位点、第9外显子Taq Ⅰ位点的多态性分布。结果单因素分析结果显示Fok Ⅰ位点FF基因型在慢性乙肝组的频率44．6％显著高于无症状HBV携带组的31．7％（P〈0．05）。经多因素非条件Logistic回归分析调整混杂作用后，结果仍然显示FF基因型在慢性乙肝组与无症状HBV携带组之间的差异存在统计学意义（OR=1．95，P〈0．05）。FokⅠ位点与TapⅠ位点组成的FT单倍型在慢性乙肝组的分布频率显著高于无症状HBV携带组（OR=1．45，P〈0．05），fT单倍型在慢性乙肝组的分布频率显著低于无症状HBV携带组（OR=0．72，P〈0．05）。结论维生素D受体基因多态性可能影响HBV感染的遗传易感性。     

Association of MYO9B haplotype with type 1 diabetes

MYO9B (myosin IXB) polymorphisms were associated with celiac disease and ulcerative colitis susceptibility, presumably through alteration of the intestinal permeability. Recently this gene was also associated with several diseases with an autoimmune component, such as rheumatoid arthritis and systemic lupus erythematosus. We aimed to test, for the first time, the potential role of MYO9B polymorphisms in type 1 diabetes (T1D), an autoimmune condition preceded by changes in intestinal barrier integrity. Three previously associated MYO9B polymorphisms (rs962917, rs2279003, and rs2305764) were studied in 316 T1D patients and 706 ethnically matched controls. Minor alleles of those polymorphisms were more frequent in diabetic patients than in controls and the haplotype carrying major alleles in those positions, rs962917*G/rs2279003*C/rs2305764*G, significantly reduced the risk of T1D in the Spanish population (p = 0.004; OR [95% confidence interval] = 0.68 [0.52-0.90]). Our data suggest an involvement of this MYO9B chromosomal region in T1D predisposition, indicating extensive influence on autoimmune diseases.     

Association of polymorphisms in the vitamin D receptor gene with susceptibility to and severity of hand,foot, and mouth disease caused by coxsackievirus A16

Coxsackievirus A16 (CA16) remains the most common causative agent of hand, foot, and mouth disease (HFMD), and is related to high incidence and critical complications. Vitamin D receptor (VDR) activity might affect the outcome of CA16 infection. Our case-control research aims to evaluate the relationship between VDR polymorphisms in the gene encoding and susceptibility to and severity of HFMD due to CA16. Three single-nucleotide polymorphisms (SNPs) of VDR gene were selected according to functional prediction and linkage disequilibrium, and were examined utilizing the SNPscan method to identify possible associations with HFMD caused by CA16. A significant relationship was found in the HFMD cases of polymorphism rs11574129 (GA vs GG: odds ratio (OR) = 0.068, 95% confidence interval (CI) = 0.007-0.693, P = .023; GA + AA vs GG: OR = 0.322, 95%CI = 0.106-0.984, P = .047), and vitamin D levels in genotype AA were significantly higher than those in genotype GG (P < .05). These results suggest that VDR rs11574129 may influence genetic susceptibility to CA16-associated HFMD.     

Association study of VDR gene with rheumatoid arthritis in the French population

Vitamin D is a potent regulator of calcium homeostasis and may have immunomodulatory effects. The influence of vitamin D on human autoimmune disease is controversial. The aim of this study was to investigate the role of vitamin D receptor gene (VDR) in rheumatoid arthritis (RA). Three polymorphisms for VDR gene FokI T>C (rs 10735810), BsmI A>G (rs 1544410) and TaqI C>T (rs 731236) were genotyped in 100 RA French nuclear families (set 1) and 100 additional French nuclear families for replication (set 2). The association analysis was performed using comparison of alleles frequencies (AFBAC), transmission disequilibrium test and genotype relative risk. Our results revealed a significant difference of F allele of FokI polymorphism between transmitted and nontransmitted frequencies (P=0.01) in set 1. Furthermore, the F/F genotype was more frequent in RA patients compared to controls (P=0.01) in set 1. The replication in set 2 showed similar patterns of transmission with a nonsignificant association. Association with FokI was found to be significant when the two sets were combined (P=0.006). These data suggest that the F allele and F/F VDR genotype are associated with RA. The mechanisms by which distinct receptor variants might confer disease susceptibility remain to be elucidated.     

Staphylococcus aureus nasal carriage might be associated with vitamin D receptor polymorphisms in type 2 diabetes

Vitamin D receptor (VDR) gene polymorphisms have been associated with susceptibility to several diseases, including type 1 diabetes (T1D), type 2 diabetes (T2D), and various infections. The study investigated whether VDR gene polymorphisms influence nasal carriage of Staphylococcus aureus in individuals with T2D, an important source for bloodstream, surgical site and other nosocomial infections. In 173 patients with T2D genotyped for the VDR gene polymorphisms on FokI (rs10735810) F>f, BsmI (rs1544410) B>b, ApaI (rs7975232) A>a, and TaqI (rs731236) T>t, a nasal swab was obtained to detect colonization by S. aureus. A repeat swab was obtained in 162/173 subjects for the estimation of persistent S. aureus carriage. The prevalence of S. aureus nasal colonization was 19.7% and of persistent carriage was 8.6%. Nasal colonization by S. aureus was more common in individuals with FokI f allele than F allele (p 0.05; OR 1.69, 95% CI 1.00–2.89) and individuals with FokI ff genotypes were more frequently colonized than those with FokI FF and Ff genotypes combined (p 0.03; OR 2.61, 95% CI 1.14–5.99). The presence of the FokI f allele was related to higher rates of S. aureus persistent nasal colonization (p 0.002; OR 3.53, 95% CI 1.56–7.98), and individuals with a FokI ff genotype were more often persistent carriers than those with FokI FF and Ff genotypes combined (p <0.001; OR 7.32, 95% CI 2.39–22.41). This study is the first, to our knowledge, to show an association between FokI polymorphism in the VDR gene and nasal carriage of S. aureus in individuals with T2D.     

Multiple independent variants in 6q21-22 associated with susceptibility to celiac disease in the Dutch, Finnish and Hungarian populations

Celiac disease is an inflammatory enteropathy caused by intolerance to gluten. Previous linkage studies in the Dutch, Finnish and Hungarian populations have revealed a locus on chromosome 6q21-22 conferring susceptibility to celiac disease. This locus has previously been implicated in susceptibility to other autoimmune diseases such as Crohn's disease and type 1 diabetes. We performed fine mapping on 446 independent individuals with celiac disease and 641 controls of Dutch origin, testing 872 tagging SNPs in a 22 Mb region of chromosome 6. The 12 most promising SNPs were followed up in 2071 individuals from 284 Finnish and 357 Hungarian celiac disease families to identify risk variants in this region. Multiple markers in the region were significantly associated with celiac disease in the Dutch material. Two SNPs, rs9391227 and rs4946111, were significantly associated with celiac disease in the Finnish population. The association to rs9391227 represents the strongest association signal found in the Finnish (P = 0.003, OR 0.66) as well as the combined Dutch, Finnish and Hungarian populations (P = 3.6 × 10(-5), OR 0.76). The rs9391227 is situated downstream of the HECT domain and ankyrin repeat containing, E3 ubiquitin protein ligase 1 (HACE1) gene and is contained within a region of strong linkage disequilibrium enclosing HACE1. Two additional, independent, susceptibility variants in the 6q21-22 region were also found in a meta-analysis of the three populations. The 6q21-22 region was confirmed as a celiac disease susceptibility locus and harbors multiple independent associations, some of which may implicate ubiquitin-pathways in celiac disease susceptibility.     

DC-SIGN (CD209), pentraxin 3 and vitamin D receptor gene variants associate with pulmonary tuberculosis risk in West Africans

We investigated the role of DC-SIGN (CD209), long pentraxin 3 (PTX3) and vitamin D receptor (VDR) gene single nucleotide polymorphisms (SNPs) in susceptibility to pulmonary tuberculosis (TB) in 321 TB cases and 347 healthy controls from Guinea-Bissau. Five additional, functionally relevant SNPs within toll-like receptors (TLRs) 2, 4 and 9 were typed but found, when polymorphic, not to affect host vulnerability to pulmonary TB. We did not replicate an association between SNPs in the DC-SIGN promoter and TB. However, we found that two polymorphisms, one in DC-SIGN and one in VDR, were associated in a nonadditive model with disease risk when analyzed in combination with ethnicity (P=0.03 for DC-SIGN and P=0.003 for VDR). In addition, PTX3 haplotype frequencies significantly differed in cases compared to controls and a protective effect was found in association with a specific haplotype (OR 0.78, 95% CI 0.63-0.98). Our findings support previous data showing that VDR SNPs modulate the risk for TB in West Africans and suggest that variation within DC-SIGN and PTX3 also affect the disease outcome.     

Association between vitamin D receptor gene haplotypes and chronic periodontitis among Japanese men

BACKGROUND: The vitamin D receptor (VDR) is involved in a variety of biological processes, such as bone metabolism and modulation of the immune response. Recent findings suggest that the pathway involving bone mineral density-mediated effects is important for the development of periodontitis, but their effects of combined VDR gene polymorphisms have not been confirmed on periodontitis. We assessed the relationship between ApaI, BsmI, and FokI VDR polymorphisms and the risk of severe chronic periodontitis among Japanese adult men. MATERIALS AND METHODS: In a cross-sectional study, we examined 97 unrelated healthy Japanese men (mean age: 45.6 years, range: 22-59). A clinical examination was performed at a worksite health checkup, and information was obtained using a self-reported questionnaire. DNA was extracted from whole blood, and the VDR ApaI, BsmI, and FokI polymorphisms were genotyped using polymerase chain reaction. RESULTS: F-carriers of FokI VDR polymorphisms were less likely to develop severe chronic periodontitis than non-F-carriers (p = 0.09). The ApaI and BsmI VDR polymorphisms did not show significant differences in the alleles or genotypes between the subjects with or without severe chronic periodontitis. The haplotype analysis of the three combined VDR polymorphisms revealed that the Abf homozygote had a notably higher prevalence of severe chronic periodontitis than the others, and adjustments for age, smoking status, number of teeth present, and prevalence of diabetes did not change this association (OR = 7.5; 95% CI = 1.6-34.4; p = 0.01). CONCLUSION: The VDR haplotype constructed from the ApaI, BsmI, and FokI polymorphisms is related to the risk of severe chronic periodontitis in Japanese men.     

Vitamin D binding protein alleles and susceptibility for type 1 diabetes in Germans

Vitamin D has been shown to modulate the immune system thereby preventing the development of diabetes in NOD mice. Since the vitamin D binding protein (DBP) is the main transporter for vitamin D and DBP has immunomodulatory properties itself, we investigated three polymorphic sites within the DBP gene as candidates for type 1 diabetes susceptibility for the first time. 152 Caucasian families with at least one affected offspring were genotyped for intron 8 [(TAAA)n repeat] and exon 11 (HaeIII, StyI) polymorphisms. Transmission disequilibrium testing was used to detect preferential transmission to affected offspring. We found no significant transmission disequilibrium for DBP alleles. The strongest deviation from expected values was observed for the "10" allele (relative risk = 0.57, transmitted 13 of 36 times (corrected p = 0.249)). Although we cannot exclude an association of the studied DBP alleles with type 1 diabetes at present, these data do not suggest their contribution to this disease in Germans.     

Polymorphisms within exon 9 but not intron 8 of the vitamin D receptor are associated with the nephropathic complication of type-2 diabetes

The impact of several environmental and genetic factors on diabetes and its complications is well documented but there is an urgent need to understand more about genetic risk factors associated with this disease. The present study was aimed at examining the two single nucleotide polymorphisms (SNP) in intron 8 and exon 9 of the vitamin D receptor (VDR) gene in nephropathic and non-nephropathic type-2 diabetic patients. In this clinical study, peripheral blood samples were obtained from 100 type-2 diabetic patients, 100 nephropathic type-2 diabetic patients and 100 healthy controls. DNA was extracted and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed to examine two SNP polymorphisms within the VDR gene. Our results showed a significant difference in the Taq-1 evaluated genotypes of exon 9 in the VDR gene of diabetic individuals with (P = 0.012) and without (P ≤ 0.001) nephropathy. Analysis of the Taq-1 evaluated alleles of nephropathic (P = 0.917) and non-nephropathic (P = 1.000) did not show a significant difference. We also evaluated the intron 8 Apa-1 alleles in patients with (P = 0.480) and without nephropathy (P = 0.543) and determined there were no differences between these groups. Our results also showed that the frequency of Apa-1 genotypes did not differ in nephropathic (P = 0.224) and non-nephropathic (P = 0.236) diabetic patients. Based on our results, it can be concluded that VDR and its functional polymorphism in exon 9 may play an important role in pathogenesis of type-2 diabetes and more investigations are required to clarify their role in nephropathy.     

Serum Vitamin D Levels and VDR Polymorphisms (BsmI and FokI) in Patients and their Household Contacts Susceptible to Tuberculosis

Vitamin D, an immunomodulator of macrophage function, can activate human antimycobacterial activity. Vitamin D deficiency (VDD) is associated with an impaired mycobacterial immunity and susceptibility to tuberculosis. It has been found that vitamin D and its receptor may be essential for immune function. In this study, we examined the serum 25(OH) vitamin D levels and its receptor (VDR) polymorphisms with susceptibility to tuberculosis in patients, household contacts and healthy controls. Serum 25(OH) vitamin D levels were measured in 75 cases (25 patients, 25 household contacts and 25 healthy controls), and polymorphisms (BsmI and FokI) were carried out in 335 cases (110 patients, 110 household contacts and 115 healthy controls). The proportion of serum 25(OH) vitamin D deficiency and insufficiency was high in patients (44, 58%) and household contacts (40, 48%) compared to controls (48%). The BB and Bb genotypes of BsmI were significantly associated in patients (P < 0.014; OR: 0.509; CI: 0.265–0.876) (P < 0.001; OR: 2.351; CI: 1.368–4.041) and household contacts (P < 0.04; OR: 0.575; CI: 0.336–0.985); (P < 0.002; OR: ?2.267; CI: 1.32–3.895) when compared to healthy controls. The diplotype and MDR analysis showed the high‐risk genotypes of BsmI and FokI polymorphisms. Vitamin D deficiency and its association with VDR gene polymorphisms may be useful to identify the high‐risk group individuals.     

Association of vitamin D receptor genotypes with early onset rheumatoid arthritis

The presence of certain vitamin D receptor (VDR) genotypes has been associated with low bone mineral density (BMD) in elderly populations as well as with accelerated bone loss in patients with rheumatoid arthritis (RA). In the present study, VDR genotypes from 120 Spanish patients with RA were investigated. Three VDR gene polymorphisms (BsmI, ApaI and TaqI) were investigated using polymerase chain reaction followed by enzymatic digestion. The distributions of VDR allelic frequencies were similar in patients and controls and therefore no influence of VDR polymorphisms on rheumatoid arthritis susceptibility could be demonstrated. However, in an analysis of the clinical features of the different VDR‐related genetic subgroups, the BB/tt genotype, defined by the BsmI and TaqI restriction site polymorphisms, was identified to be weakly associated with an early onset RA in female patients. This VDR genotype has been associated with a low BMD level in various studies. When patients were stratified according to the presence of the shared HLA epitope SE, it was found that SE + female patients bearing the BB/tt genotype showed the earliest disease onset. The mechanisms by which the VDR polymorphism is associated with RA is unknown, but they could be related to the immunoregulatory properties of vitamin D.     

5Apal,Taql, Fokl,and Bsml polymorphisms and the susceptibility of Behcet’s disease: an updated meta-analysis

Immunologic Research - The aim of this study was to investigate whether the gene polymorphisms of vitamin D receptor (VDR) had a genetic effect on the susceptibility of Behcet’s disease (BD)....