Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As part of an ongoing search for genes associated with type 1 diabetes (T1D), a common autoimmune disease, we tested the biological candidate gene IL2RA (CD25), which encodes a subunit (IL-2R alpha) of the high-affinity interleukin-2 (IL-2) receptor complex. We employed a tag single-nucleotide polymorphism (tag SNP) approach in large T1D sample collections consisting of 7,457 cases and controls and 725 multiplex families. Tag SNPs were analyzed using a multilocus test to provide a regional test for association. We found strong statistical evidence in the case-control collection (P=6.5x10(-8)) for a T1D locus in the CD25 region of chromosome 10p15 and replicated the association in the family collection (P=7.3x10(-3); combined P=1.3x10(-10)). These results illustrate the utility of tag SNPs in a chromosome-regional test of disease association and justify future fine mapping of the causal variant in the region.
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PMID:Localization of a type 1 diabetes locus in the IL2RA/CD25 region by use of tag single-nucleotide polymorphisms. 1577 95

Three very recent reports provide convincing statistical evidence (P < 10(-8)), at a genome-wide level, of the association of common polymorphisms with three different common diseases: systemic lupus erythematosus (IRF5), prostate cancer and type 1 diabetes (IFIH1 region). This adds to the trickle--soon to be a flood--of disease association results that are highly unlikely to be false positives. There are other convincing examples in the last 12 months: age-related macular degeneration (CFH), type 1 diabetes (IL2RA, also known as CD25) and type 2 diabetes (TCF7L2). Given 20 years of a literature full of irreproducible results, what has changed?
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PMID:Statistical false positive or true disease pathway? 1732 72

Interleukin-2 (IL-2) plays an established role in T-cell regulation through binding to the high-affinity IL-2 receptor (IL-2R). The alpha-chain encoded by the IL2RA (CD25) gene is a substantial component of the high-affinity receptor molecule highly expressed by activated T lymphocytes. Recently, a strong evidence was obtained for the involvement of IL-2RA in conferring susceptibility to type 1 diabetes (T1D). Significant association with T1D was also found in the region on chromosome 4q27 containing the IL2 gene and homologous to the susceptibility locus idd3 in non-obese diabetic (NOD) mice, an animal model for human T1D. Here we focus on the discussion of these new findings suggesting for a crucial role of IL-2/IL-2RA-mediated regulatory mechanisms in preventing T1D. The non-redundant role of IL-2 and its receptor in etiology of T1D could be particularly attributable to the regulation of CD4+ CD25+ regulatory T cells, whose function is critical in maintaining immune homeostasis.
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PMID:The crucial role of IL-2/IL-2RA-mediated immune regulation in the pathogenesis of type 1 diabetes, an evidence coming from genetic and animal model studies. 1841 24

Type 1 diabetes is a multifactorial disease caused by a complex interaction of genetic and environmental factors. The genetic factors involved consist of multiple susceptibility genes, at least five of which, HLA, INS, CTLA4, PTPN22 and IL2RA/CD25, have been shown to be associated with type 1 diabetes in Caucasian (Western) populations, as has recently been confirmed by genome-wide association studies. It has been proposed, however, that the contribution of these genes to type 1 diabetes susceptibility may be different in Asian (Eastern) populations. HLA and INS genes are consistently associated with type 1 diabetes in both Caucasian and Asian populations, but apparent differences in disease-associated alleles and haplotypes are observed between Japanese and Caucasian subjects. The association of CTLA4 with type 1 diabetes is concentrated in a subset of patients with autoimmune thyroid disease (AITD) in both Japanese and Caucasian populations, while the association of PTPN22 with type 1 diabetes in Japanese and most Asian populations is not as clear as in Caucasians. IL2RA/CD25 genes seem to be similarly distributed in type 1 diabetes patients in the two populations, whereas genetic heterogeneity may exist regarding SUMO4, with an association of the M55V variant with type 1 diabetes observed in Asians, but not in Caucasians. Genome-wide association studies (GWA) are largely outstanding for Asian populations but they are now underway in Japan. This review reports on the discovered similarities and differences in susceptibility genes for type 1 diabetes between East and West and discusses the most recent observations made by the involved investigators.
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PMID:Genetic Basis of Type 1 Diabetes: Similarities and Differences between East and West. 1879 9

Type 1 diabetes mellitus (T1DM) is a widespread, severe disease which results from the immunologically mediated destruction of the beta-cells of pancreatic Langerhans islets. To date the several loci involved to the T1DM development have been reliably identified by means of a number of approaches: MHC locus, VNTR within 5'-nontranscibed region of insulin (INS) gene, CTLA4 gene, encoding surface receptor of T cells, PTPN22 and PTPN2 genes, encoding tyrosine phosphatases of T lymphocytes, interleukin 2 (IL2) gene and alpha-chain of its receptor gene (IL2RA), as well as KIAA0350 gene (unknown function) and IFIH1 gene, encoding receptor of double-stranded DNA generated during viral infections. The functional analysis of proteins encoded by the genes, which are involved to the T1DM development, performed to confirm the hypothesis that on the one hand the origin of T1DM development is founded on the some deregulation of mechanisms of the immune tolerance formation and on the other hand the cause is founded on the formation of destructive immune response against own proteins of organism after virus infection or some other immune stress. Thus the protein products of MHC, INS, PTPN22 and PTPN2 genes involve in the formation in thymus of T-lymphocyte repertoire, which provides the immune defense of organism. On the other hand the nonspecific activation of T cells, from that starts the autoimmune destruction of beta-cells of Langerhans islets of pancreas, in all probability, connects with the protein products of CTLA4, IL2, IL2RA genes, and, perhaps, PTPN22 and PTPN2 genes. The only exception, if not considering the genes with unknown function,--is the IFIH1 gene, but its association with T1DM confirms that fact, that the certain types of virus infection can lead to the activation of autoreactive T cells and T1DM development.
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PMID:[Molecular genetics of type 1 diabetes mellitus: achievements and future trends]. 1898 35

Multiple sclerosis (MS) and type 1 diabetes (T1D) are organ-specific autoimmune disorders with significant heritability, part of which is conferred by shared alleles. For decades, the Human Leukocyte Antigen (HLA) complex was the only known susceptibility locus for both T1D and MS, but loci outside the HLA complex harboring risk alleles have been discovered and fully replicated. A genome-wide association scan for MS risk genes and candidate gene association studies have previously described the IL2RA gene region as a shared autoimmune locus. In order to investigate whether autoimmunity risk at IL2RA was due to distinct or shared alleles, we performed a genetic association study of three IL2RA variants in a DNA collection of up to 9,407 healthy controls, 2,420 MS, and 6,425 T1D subjects as well as 1,303 MS parent/child trios. Here, we report "allelic heterogeneity" at the IL2RA region between MS and T1D. We observe an allele associated with susceptibility to one disease and risk to the other, an allele that confers susceptibility to both diseases, and an allele that may only confer susceptibility to T1D. In addition, we tested the levels of soluble interleukin-2 receptor (sIL-2RA) in the serum from up to 69 healthy control subjects, 285 MS, and 1,317 T1D subjects. We demonstrate that multiple variants independently correlate with sIL-2RA levels.
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PMID:IL2RA genetic heterogeneity in multiple sclerosis and type 1 diabetes susceptibility and soluble interleukin-2 receptor production. 1911 14

Multiple sclerosis (MS) is an organ-specific autoimmune disorder that is in part genetically determined. The gene encoding the alpha-chain of the IL-2 receptor, IL2RA, harbors alleles associated with risk to MS and other autoimmune diseases. In addition, IL2RA genetic variants correlate with the levels of a soluble form of the IL-2 receptor in subjects with type 1 diabetes and multiple sclerosis. Here, we show that the IL2RA genotypes differentially affects soluble IL-2RA (sIL-2RA) levels in MS cases vs healthy controls; the two variants associated with MS (rs12722489 and rs2104286) account for 15 and 18% of the total variance in log(10)-transformed sIL-2RA concentration in control subjects but less so in subjects with MS (2 and 5%), suggesting that perturbations associated with disease or treatment may influence sIL-2RA levels in subjects with MS. Whereas analyses demonstrate that sIL-2RA serum concentrations are a remarkably stable phenotype in both healthy controls and untreated MS subjects, a difference is observed between benign and malignant MS. These data indicate that, in addition to specific allelic variants at IL2RA, immunological perturbations associated with aggressive forms of the disease can influence sIL-2RA levels in serum of MS subjects. We also demonstrate, functionally, that sIL-2RA can inhibit IL-2 signaling, yet enhance T cell proliferation and expansion. In summary, we propose that before disease onset, strong genetic factors associated with disease risk dictate sIL-2RA levels that may be further modulated with onset of chronic systemic inflammation associated with MS.
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PMID:Soluble IL-2RA levels in multiple sclerosis subjects and the effect of soluble IL-2RA on immune responses. 1915 2

Genome-wide association studies (GWAS) have identified over 300 regions associated with more than 70 common diseases. However, identifying causal genes within an associated region remains a major challenge. One approach to resolving causal genes is through the dissection of gene-phenotype correlations. Here we use polychromatic flow cytometry to show that differences in surface expression of the human interleukin-2 (IL-2) receptor alpha (IL2RA, or CD25) protein are restricted to particular immune cell types and correlate with several haplotypes in the IL2RA region that have previously been associated with two autoimmune diseases, type 1 diabetes (T1D) and multiple sclerosis. We confirm our strongest gene-phenotype correlation at the RNA level by allele-specific expression (ASE). We also define key parameters for the design and implementation of post-GWAS gene-phenotype investigations and demonstrate the usefulness of a large bioresource of genotype-selectable normal donors from whom fresh, primary cells can be analyzed.
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PMID:Cell-specific protein phenotypes for the autoimmune locus IL2RA using a genotype-selectable human bioresource. 1970 Nov 92

The mechanism for the association of type 1 diabetes (T1D) with IL2RA remains to be clarified. Neither of the two distinct, transmission-disequilibrium confirmed loci mapping to this gene can be explained by a coding variant. An effect on the levels of the soluble protein product sIL-2RA has been reported but its cause and relationship to disease risk is not clear. To look for an allelic effect on IL2RA transcription in cis, we examined RNA from 48 heterozygous lymphocyte samples for differential allele expression. Of the 48 samples, 32 showed statistically significant allelic imbalance. No known single nucleotide polymorphism (SNP) had perfect correlation with this transcriptional effect but the one that showed the most significant (p = 1.6 x 10(-5)) linkage disequilibrium with it was the SNP rs3118470. We had previously shown rs3118470 to confer T1D susceptibility in a Canadian dataset, independently of rs41295061 as the major reported locus (p = 5 x 10(-3), after accounting for rs41295061 by conditional regression). Lower IL2RA levels consistently originated from the T1D predisposing allele. We conclude that an as yet unidentified variant or haplotype, best marked by rs3118470, is responsible for this independent effect and increases T1D risk through diminished expression of the IL-2R, likely by interfering with the proper development of regulatory T cells.
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PMID:A cis-acting regulatory variant in the IL2RA locus. 1979 70

To confirm and fine map previous reports of association, the Type I Diabetes (T1D) Genetics Consortium (T1DGC) assembled a large collection of DNA samples from affected sib-pair (ASP) families with T1D (5003 affected individuals) and genotyped polymorphic markers. One of these loci, involving the IL2RA gene, had been reported to be due to three independent effects. The T1DGC genotyped 69 single-nucleotide polymorphisms (SNPs) that span approximately 88 kb from the 5' flanking to 3' flanking region of the IL2RA locus. The most highly associated SNP reported earlier (ss52580101) was not included in the genotyping list; however, a 5-SNP (rs3134883, rs3118470, rs7072793, rs4749955 and rs12251307) haplotype (H5) was identified that strongly tagged its minor allele with r(2)=0.869 (95% CI, 0.850-0.885). This haplotype was significantly protective (P=3.2 x 10(-5)) in the T1D ASP families, with an odds ratio virtually identical to that reported for ss52580101. The SNP marking the second independent locus, (rs11594656) showed no association in the T1DGC set and the third (rs2104286) could not be distinguished, by conditional regression, from H5. Instead, the most significant independent effect was detected from the 5' flanking IL2RA SNP rs4749955, which remained significant after regression for H5. Thus, we confirm independent effects at the IL2RA locus.
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PMID:The type I diabetes association of the IL2RA locus. 1995 99


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