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.     

Association of vitamin D receptor gene polymorphisms with susceptibility to asthma in Tunisian children: A case control study

Background

Vitamin D and its nuclear receptor (VDR) are linked to asthma in a genetic and immunologic basis. Polymorphisms in the VDR gene may alter the actions of vitamin D and then influence the development and the severity of asthma.

Aims

We aimed at elucidating the genetic association of VDR gene polymorphisms with susceptibility to asthma in Tunisian children and with serum vitamin D levels.

Methods

The study included 155 patients recruited from Abderrahmen MAMI hospital in Tunisia and two hundred twenty five healthy individuals matched with patients in age and sex for comparison. VDR genotypes were determined by PCR-RFLP method using endonuclease FokI, BsmI, TaqI and ApaI and vitamin D was assessed with a radioimmunoassay kit.

Results

The distribution of genotype frequencies differed significantly between asthmatics and controls (FokI: P = 0.04; BsmI: P = 0.006; TaqI: P = 0.006). Haplotype analyses revealed a significant association between bAt and bat haplotypes and asthma (P = 0.00076, P = 0.016). When patients were stratified according to atopic status and stage of severity, no significant association was detected with VDR variants. No association was found between VDR SNPs and serum 25-hydroxyvitamin D levels.

Conclusion

Our study shows a relation between VDR gene polymorphisms and susceptibility to asthma in children.     

维生素D受体基因ApaⅠ和TaqⅠ位点多态性与帕金森病的相关性研究

目的 探讨维生素D受体(vitamin D receptor,VDR)基因ApaⅠ和Taq Ⅰ位点多态性与帕金森病(Parkinson's disease,PD)遗传易感性的相关性.方法 采用聚合酶链反应-限制性片段长度多态性技术和基因测序方法,检测285例中国北方汉族散发PD患者与285名正常对照VDR基因ApaⅠ和TaqⅠ位点多态性,并比较两组基因型和等位基因频率的差异.结果 ApaⅠ和Taq Ⅰ位点基因型和等位基因频率在PD组和对照组之间差异均无统计学意义(P＞0.05).将样本按性别及发病年龄分组后比较,ApaⅠ位点各亚组间基因型频率和等位基因频率差异亦无统计学意义(P＞0.05),而TaqⅠ位点的基因型分布在男性PD组(168例)与男性对照组(1 60名)之间差异有统计学意义(x2=4.187,P=0.032,OR=2.149,95％CI:1.011～4.567),男性PD组T等位基因频率较男性对照组显著增高(x2=3.867,P=0.036,OR=2.064,95％CI:0.989～4.307).结论 VDR基因ApaⅠ位点多态性与PD风险间无相关性,但TaqⅠ可能是男性PD的风险因素.     

EGLN1基因两个位点多态性与藏族人群高原低氧适应的关系

目的 探讨西藏藏族人群EGLN1基因2个SNP(单核苷酸多态性)位点rs479200（C/T）、rs480902（T/C）多态性与高原低氧适应的相关性。
方法 选取世居西藏拉萨藏族150人及辽宁汉族150人的血样,提取白细胞基因组DNA,应用限制性片段长度多态性-聚合酶链反应（PCR-RFLP）技
术检测EGLN1基因2个SNP位点,分析其多态性特征。结果 rs479200位点等位基因C等位基因频率在藏族人和汉族人分别为71.33%和38.17%,
rs480902位点等位基因T等位基因频率在藏族人和汉族人分别为66.67%和36.67%,两组比较差异显著（P<0.01）;rs479200位点TT、TC和CC基因
型频率在藏族人和汉族人分别为6.67%和56.67%、29.33%和33.33%、64%和10%,rs480902位点TT、TC和CC基因型频率在藏族人和汉族人分别为
60.67%和9.33%、30.66%和28.67%、8.67%和62%。两位点TC基因型两组比较差异无统计学意义;TT和CC基因型两组比较差异均显著（P<0.01）。
结论 EGLN1基因rs479200（C/T）和rs480902（T/C）SNP位点多态性与西藏藏族适应高原低氧环境存在相关性。rs479200位点的CC基因型和
rs480902位点的TT基因型可能更有利于适应低氧环境。     

PRKCI基因单核苷酸多态性与神经管畸形的相关性研究

目的探讨PRKCI基因单核苷酸多态性（SNP）与中国山西省神经管畸形（NTDs）发生的相关性。方法采用病例对照研究,利用MassARRAY分子量阵列分析平台,检测133例NTDs标本和135例非病理性胎儿标本PRKCI基因中17个标签SNPs的基因分型,分析其与NTDs发生的相关性。结果 17个SNPs位点中,16个的微效等位基因频率（MAF）与HapMap或dbSNP数据库的结果基本一致。除rs9876082外,其余SNPs位点的基因型分布和等位基因频率在病例组和对照组均无明显差异。rs9876082位点为纯合的微效等位基因A时,NTDs的发病率增加（P=0.035,比值比=2.135,95%可信区间=1.846-2.471）,但是调整其它变量后进行logistic回归分析,这种相关性不再明显（P=0.057）。结论 PRKCI基因rs9876082位点与NTDs的发生有弱的相关性,这种相关性需进一步加大样本进行验证,PRKCI基因可能不是通过其SNPs影响NTDs的易感性。     

Vitamin D receptor gene polymorphism and its association with Parkinson's disease in Chinese Han population

Vitamin D plays an important role in neurodegenerative disorders as a crucial neuro-immunomodulator, and accumulating data have provided evidence for that vitamin D receptor (VDR) gene is a candidate gene for susceptibility to Parkinson's disease (PD). In this study, we performed a case-control study to demonstrate whether the risk for the development of onset of sporadic PD might be influenced by VDR gene polymorphisms in a Chinese cohort. Two hundred and sixty PD patients and 282 matched-healthy controls were genotyped for two representative single nucleotide polymorphisms (SNPs) in VDR gene (FokI C/T and BsmI G/A) by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis in. Results from our study revealed that FokI C allele carriers were likely to associate with an increased risk of PD (P = 0.004) as well as early-onset PD (EOPD) (P = 0.010). Moreover, the frequency of FokI C allele was significantly increased in PD group and late-onset PD (LOPD) group relative to the control groups respectively (P = 0.023 and P = 0.033, respectively). For BsmI polymorphisms, no significant difference in genotype or allele distribution was found between PD patients and the controls, as well as gender- and age-related differences between PD patients and the controls subgroup. This study demonstrated a possible association between the VDR FokI T/C polymorphism and PD, indicating that VDR polymorphisms may well change genetic susceptibility to sporadic PD in a Han Chinese population.     

Association between promoter polymorphisms of the nicastrin gene and sporadic Alzheimer's disease in North Chinese Han population

Increasing evidences have shown that nicastrin (NCSTN) plays a crucial role in γ-cleavage of the amyloid precursor protein (APP). Inhibition of NCSTN demonstrated an altered γ-cleavage activity, suggesting its potential implication in developing Alzheimer's disease (AD). We detected the NCSTN gene promoter region in 359 sporadic AD (SAD) patients and 331 controls and found three promoter single nucleotide polymorphisms (SNPs): −1216C/A (rs2147471), −796T/G (rs10752637) and −436C/T (rs1324738). For −1216C/A, there were significant differences in the allele and genotype frequency between AD and control subjects (allele P = 0.031, genotype P = 0.017). The allele and genotype frequencies remained significant before and after APOE?4 stratification. The −1216CC carriers increased 2-fold risk for the development of SAD compared to the carriers with −1216CA and AA genotypes (OR = 2.049, 95%CI = 1.410–2.976, P = 0.000). For −796T/G, there were significant differences in the genotype frequency between SAD and control subjects (P = 0.009). This trend is still obvious in the subjects without APOE?4 allele. The −796GG carriers might decrease the risk compared to the carriers with −796TG and TT genotypes (OR = 0.602, 95%CI = 0.393–0.932, P = 0.022). No significant difference was detected either in genotype or in allele frequencies between SAD and control for −436C/T, even after APOE?4 stratification. The haplotype −1216A/−796G may be a protective factor for SAD (OR = 0.795, 95%CI = 0.636–0.995, P = 0.045). Our investigation suggests that −1216C/A and −796T/G are probably related to the development of SAD.     

Family-based analysis of vitamin D receptor gene polymorphisms and type 1 diabetes in the population of South Croatia

Type 1 diabetes mellitus (T1DM) is a disease characterised by the autoimmune destruction of insulin-producing pancreatic β cells. Vitamin D is a known immune system modulator and its effects are exerted via the vitamin D receptor (VDR). Several VDR gene single nucleotide polymorphisms (SNPs) have been commonly studied in relation to T1DM. The aim of this study was to evaluate the role of VDR gene variation in T1DM susceptibility by genotyping four SNPs (FokI-rs10735810, TaqI-rs731236, BsmI-rs1544410, and Tru9I-rs757343) in 160 case–parent trio samples from the population of South Croatia. We observed overtransmission of Tru9I allele G and undertransmission of the Tru9I-BsmI A-A haplotype from parents to affected children (P = 0.032, P = 0.002, respectively). These results indicate a possible role of the VDR gene in T1DM aetiology. In conclusion, this family-based study presents some evidence of association of specific VDR gene variants with T1DM in the population of South Croatia.     

The association study between CYP24A1 gene polymorphisms and risk of liver,lung and gastric cancer in a Chinese population

Recently, four single nucleotide polymorphisms (rs2585428, rs4809960, rs6022999 and rs6068816) in CYP24A1 gene were extensively studied for their associations with cancer risk. However, these studies included only a few types of cancer, which calls for further investigations. In view of this, we here conducted a case-control study to explore the associations between these four CYP24A1 gene polymorphisms and risk of liver, lung and gastric cancer in a Chinese population. A total of 480 liver cancer patients, 550 lung cancer patients, 460 gastric cancer patients and 800 normal controls were recruited in this study. The genotyping of CYP24A1 gene polymorphisms was applied with Sanger sequencing assay. Single-locus analysis demonstrated that rs6022999 was significantly associated with risk of liver and lung cancer, while rs6068816 was significantly associated with the risk of gastric cancer. Haplotype analysis revealed that haplotype GTAT was associated with an increased risk of liver cancer and a decreased risk of lung cancer, and haplotype ATGC was associated with a decreased risk of lung cancer. The further meta-analysis of rs6068816 and lung cancer risk showed that rs6068816 was not associated with lung cancer risk in Chinese population, which confirmed our present finding. Conclusively, rs6022999 may be a genetic biomarker for liver and lung cancer susceptibility in Chinese population, and rs6068816 may be used to predict gastric cancer risk in Chinese population.     

Evaluation of beta-thalassemia in the fetus through cffDNA with multiple polymorphisms as a haplotype in the beta-globin gene

ObjectiveInvasive biopsy during the pregnancy is associated with an abortion risk of approximately 1% for the fetus. Free fetal DNA in maternal plasma is an excellent source of genetic material for prenatal molecular diagnoses. This study was conducted to investigate beta-thalassemia mutation in the fetus through maternal blood with multiple polymorphisms as haplotypes in the beta-globin gene.MethodsIn this study, a total of 33 beta-thalassemia carrier (minor) couples were genotyped by ARMS-PCR for IVSII-IG>A mutation. During pregnancy, 10 mL of blood was collected from pregnant women, and DNA was extracted by the magnetic bead-based extraction, and fetal DNA was enriched with AMPure XP kit. Five polymorphisms in 4 haplotype groups were evaluated by the Sanger Sequencing method. Finally, results were compared with those of the invasion method.ResultsParticipants in study were 33 couples, mean age of the men was 26 ± 5 years, and mean age of women was 23 ± 4 years, and mean MCV, MCH, HbA2 blood parameters were 62.4 ± 5.3, 19.6 ± 3.1, 4.2 ± 2.1 respectively. A total of 33 fetuses were genotyped for IVSII-IG>A mutation. Nine fetuses were affected, 10 fetuses were normal and 14 fetuses were carrier of beta-thalassemia. Sensitivity and specificity of Sanger Sequencing were equal to 88.8% and 91.6% respectively. Positive and negative predictive values were obtained as 80% and 95.6%, respectively.ConclusionMutational status of the fetus can be assessed by determining inheritance of paternally-derived alleles based on detection of haplotype-associated SNP in maternal plasma. Magnetic-based DNA extraction and fetal DNA enrichment are very simple and easy to perform and have satisfactory accuracy.     

汉族人群脂联素基因-11377C/G多态性与子痫前期的相关性研究

目的探讨福建莆田地区汉族人群脂联素基因（APN）单核苷酸多态性（SNP）和子痫前期（pre-eclampsi-a）及其血脂水平的关联性。方法研究对象516例,包括对照组260例,子痫前期病例组256例。采用聚合酶链反应一限制性片段长度多态性（PCR-RFLP）法鉴定APN基因启动子-11377C/G单核苷酸多态性并测定血脂水平。结果 APN基因启动子-11377C/G位点G等位基因频率和GG＋CG基因型频率在子痫前期病例组明显升高,差异有统计学意义（P〈0.05）。子痫前期病例组内GG＋CG基因型患者血清甘油三酯（TG）、血浆总胆固醇（TC）和低密度脂蛋白（LDL）值均高于CC基因型（P〈0.05）。结论 APN基因启动子-11377C/G位点GG＋CG基因型与子痫前期及其血浆TG、TC和LDL水平升高关联,C-G多态性提高了子痫前期合并血脂代谢紊乱的风险性。     

Association study of polymorphisms in miRNAs with T2DM in Chinese population

Accumulated evidence indicates that microRNA (miRNA or miR) is involved in the development of type 2 diabetes (T2DM). Several studies have shown that single nucleotide polymorphisms (SNPs) located in miRNAs are associated with T2DM in Caucasian populations. The association studies of miRNA''s SNPs with T2DM in Asian are rarely reported, and there are distinct genetic differences between Caucasian and Asian populations. The focus of this study, therefore, is the association of T2DM with five SNPs (rs895819 in miR-27a, rs531564 in miR-124a, rs11888095 in miR-128a, rs3820455 in miR-194a and rs2910164 in miR-146a) located in five miRNAs in a Han Chinese population. A total of 738 subjects with T2DM and 610 non-diabetic subjects were genotyped using the TaqMan method. Next, the associations between the five SNPs with T2DM and individual metabolic traits were evaluated. Our data showed that the C allele of rs531564 in miR-124a may protect against T2DM (P=0.009, OR=0.758; 95%CI: 0.616-0.933). Conversely, the C allele of rs2910164 in miR-146a may increase the risk of developing T2DM (P<0.001, OR=1.459; 95%CI: 1.244-1.712). However, these five SNPs did not exhibit significant associations with individual metabolic traits in either the T2DM or non-diabetic groups. Our results revealed that genetic variations in miRNAs were associated with T2DM susceptibility in a Han Chinese population, and these results highlight the need to study the functional effects of these variants in miRNAs on the risk of developing T2DM.     

2型糖尿病合并甲状腺功能减退的影响因素分析研究

目的：探究2型糖尿病(type 2 diabetes mellitus,T2DM)合并甲状腺功能减退的影响因素。方法：选择2013年1月至2015年6月在我院接受治疗的2型糖尿病患者784例。将2型糖尿病合并甲状腺功能减退的71例患者作为甲减组,甲状腺功能正常的713例患者作为T2DM组。比较甲减组和T2DM组患者的临床资料,用单因素分析和Logistic回归分析其影响因素。结果：2型糖尿病合并甲状腺功能减退的发病率为9.06%,其中临床甲减16例,为2.04%,亚临床甲减55例,为7.02%。比较甲减组与T2DM组患者的一般临床资料,发现2型糖尿病合并甲状腺功能减退与年龄、糖尿病病程、ABI、FCP、E/A、TC、TG、LDL-C、Lp(a)、S-CRP、UAER、TPO-Ab、性别、吸烟、冠心病、DN、DNP、DR、DF、PAD、DM治疗方式有关(P<0.05)。将2型糖尿病患者是否合并甲状腺功能减退作为因变量,将上述因素纳入Logistic多元回归分析,结果显示年龄、吸烟、胰岛素治疗、TPO-Ab是2型糖尿病患者合并甲状腺功能减退的独立危险因素。结论：年龄、吸烟、胰岛素治疗、TPO-Ab是2型糖尿病患者合并甲状腺功能减退的独立危险因素,2型糖尿病患者应定期进行甲状腺功能检查,以便及早诊断和干预甲状腺功能减退。     

2型糖尿病及其肾病与血管生成素2基因多态性的关联分析

目的 研究2型糖尿病(type 2 diabetes mellitus,T2DM)及其肾病(diabetic nephropathy,DN)发生、发展与血管生成素2(angiopoietin-2,Ang-2)基因多态性的关联性.方法 应用等位基因特异聚合酶链反应检验无亲缘关系汉族人群的2型糖尿病及其肾病患者221例、正常对照104名Ang-2基因单核苷酸多态性(single nucleotide polymorphism,SNP)759T/G、1078A/G、1233A/G在病例组中的频率,并用尿白蛋白排泄率、炎症标志物单核细胞趋化蛋白浓度变化探讨上述SNP与T2DM、DN发生发展的关联.结果 (1) Ang-2 759 T/G、1078 A/G基因型频率和等位基因频率在各组中的差异无统计学意义,而1233 A/G基因型频率和等位基因频率的差异有统计学意义(P＜0.05);(2)在校正年龄和性别等因素后,1233A/GSNP G等位基因患T2DM和DN的风险分别是A等位基因的2.265倍(95％ CI:1.223～1.402,P=0.031)和1.789倍(95％ CI:0.889～1.021,P=0.012);(3) Ang-2 1233A/G G等位基因与DN发生相关(r=1.321,OR=1.427,95％ CI:2.324～4.177,P=0.034).结论 Ang-2 1233A/G SNP与2型糖尿病的发生有关;AG+ GG基因型和等位基因G可能是DN发生、发展的风险因素.     

Candidate gene analysis of SPARCL1 gene in patients with multiple sclerosis

Recently, proteomic analysis in cerebrospinal fluid (CSF) from patients with MS identified four proteins which are present in MS but not in normal human CSF, including SPARCL1, an extracellular matrix-associated protein member of the SPARC family. One hundred eighty-six patients with MS and 185 age-matched controls were genotyped for A/G single nucleotide polymorphism (SNP) in exon 1 (rs1049539), C/G SNP in exon 4 (rs1049544), resulting in a substitution of an aspartate with an histidine, and A/G substitution in the exon 5 (rs1130643), leading to the substitution of alanine with threonine. No significant differences in either allelic or genotypic frequency of the three SNPs were found (P>0.05), even in stratifying MS patients according to the course of the disease. Stratifying according to gender, a trend towards a decreased frequency of the C/C genotype of the rs1049544 was observed in male patients as compared with male controls (30.2% versus 44.0%; P=0.217). Despite proteomic studies in CSF from MS patients suggested an important role for SPARCL1 in the development of the disease, SPARCL1 gene does not appear to act as susceptibility factor for MS in the population investigated here. However, the frequency of the C/C genotype of rs1049544 was decreased in male patients, possibly conferring a lower risk of developing MS in male population. Further studies are needed to clarify this issue.