Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

HLA-DQ alpha and HLA-DX alpha gene polymorphisms were analyzed by Southern blot techniques in 78 Caucasoid insulin-dependent diabetes mellitus (IDDM) subjects and 55 control subjects. Five restriction fragment length polymorphisms of the HLA-DQ alpha gene correlated with HLA-DR typing. Two allelic DX alpha-related gene fragments, of 2.1 kb (U) and 1.9 kb (L) in size were identified. Genotype frequencies in the IDDM group for UU, UL, and LL were 54%, 38.5%, and 7.5%, respectively, whereas the corresponding frequencies in the control group were 24%, 40%, and 36% (P less than 0.00005 for differences in genotype frequencies). The U allele was associated particularly with IDDM patients who were DR3, with healthy controls who were DR3, as well as with IDDM patients who were not DR3. Thus, if this DX alpha U allele is not the DR3-associated IDDM susceptibility gene, it is the closest marker hitherto studied.
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PMID:A DR3-related DX alpha gene polymorphism strongly associates with insulin-dependent diabetes mellitus. 300 76

One hundred seventy-two members from 27 randomly selected multiple case Caucasian families of patients with insulin-dependent diabetes mellitus (IDDM) were studied at the DNA level to ascertain the reliability of codon 57 of the HLA-DQ beta-chain gene as a disease protection/susceptibility marker. The analysis was carried out by polymerase chain reaction amplification of DNA encoding the first domain of the DQ beta chain and by dot blot analysis of the amplified material with allele-specific oligonucleotide probes. One hundred twenty-three randomly selected healthy Caucasian donors were also tested. The results demonstrated that haplotypes carrying an aspartic acid in position 57 (Asp-57) of their DQ beta chain were significantly increased in frequency among nondiabetic haplotypes (23/38), while non-Asp-57 haplotypes were significantly increased in frequency among diabetic haplotypes (65/69). Ninety-six percent of the diabetic probands in our study were homozygous non-Asp/non-Asp as compared to 19.5% of healthy unrelated controls. This conferred a relative risk of 107 (chi 2 = 54.97; P = 0.00003) for non-Asp-57 homozygous individuals. Even though the inheritance and genetic features of IDDM are complex and are not necessarily fully explained by DQ beta chain polymorphism, this approach is much more sensitive than HLA serolog in assessing risk for IDDM.
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PMID:Aspartic acid at position 57 of the HLA-DQ beta chain protects against type I diabetes: a family study. 318 14

Over half of the inherited predisposition to insulin-dependent diabetes mellitus maps to the region of chromosome 6 that contains the highly polymorphic HLA class II genes which determine immune responsiveness. Analysis of DNA sequences from diabetics indicates that alleles of HLA-DQ beta determine both disease susceptibility and resistance, and that the structure of the DQ molecule, in particular residue 57 of the beta-chain, specifies the autoimmune response against the insulin-producing islet cells.
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PMID:HLA-DQ beta gene contributes to susceptibility and resistance to insulin-dependent diabetes mellitus. 330 80

To examine the nature of HLA-linked genetic susceptibility to insulin-dependent diabetes mellitus (IDDM), we compared HLA class II gene sequences from IDDM patients and control individuals. Genomic libraries were constructed from two siblings with IDDM, typed serologically as DR3,w6 and DR3,4. These libraries represent the HLA haplotypes (DR3, DR4) most frequently associated with IDDM, as well as one haplotype found less often. Individual genomic clones were identified and assigned to specific loci and haplotypes. The nucleotide sequence was then determined from the variable second exon from the HLA-DQ alpha, DQ beta, and DR beta genes from all three haplotypes. Sequence variation within the DQ alpha genes could not be correlated with the disease. For all three haplotypes, the DQ alpha sequence from the IDDM patient was identical to the DR-matched control sequence. Similarly, for the DR3 haplotype, the DQ beta sequences matched all control DR3 alleles. The DQ beta sequence from the DR4 haplotype was identical to the predominant DR4 allele (DQ beta 3.2) but differed at four amino acid residues from the other major DR4 DQ beta sequence (DQ beta 3.1) found rarely among IDDM patients. Sequence analysis of the DQ beta gene from the DRw6 haplotype revealed a new allele that differed from the DQ beta allele from a control DR6 allele at two residues. The DR beta genes from these three haplotypes also did not show any sequence features uniquely associated with IDDM, although the frequency of certain allelic variants in all three of these haplotypes may be altered in the IDDM population. A particular group of amino acids was found to be shared between the DR beta-1 alleles from the DR4 and DRw6 haplotypes and may be involved in genetic susceptibility to IDDM.
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PMID:Sequence analysis of HLA class II genes from insulin-dependent diabetic individuals. 337 63

A new HLA-DQ-related genetic system with two alleles, 2B3 and TA10, defined serologically by MAbs and alloantisera, showed an almost perfect correlation with charge differences on DQ beta molecules, as well as with two polymorphic DNA fragments hybridizing with a DQ beta probe and various restriction enzymes on a panel of 14 DR4+ homozygous typing cells. It was therefore concluded that the serologically defined alleles 2B3 and TA10 are coded by the DQ beta gene and situated on the HLA-DQ beta chain. This 2B3/TA10 polymorphism is independent of HLA-D and segregates with HLA in families. The TA10 allele appears to be a new marker for resistance to type I diabetes, which is independent from the known resistance marker DR2, whereas no association was observed between this DQ beta polymorphism and rheumatoid arthritis.
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PMID:HLA-DO polymorphism associated with resistance to type I diabetes detected with monoclonal antibodies, isoelectric point differences, and restriction fragment length polymorphism. 346 3

The HLA association with insulin-dependent diabetes mellitus is highest among individuals heterozygous for DR3 and DR4. To investigate potential mechanisms to account for this association, we performed two-dimensional gel-electrophoretic analysis of HLA molecules from DR3/4 heterozygous patients. These studies demonstrated hybrid molecular dimers corresponding to products of HLA-DQ genes linked to DR3 and DR4, i.e., the DQw2 and DQw3 genes, respectively. Two types of DQ molecules were found: immunoprecipitation by DQw3-specific monoclonal antibody 17.15 identified a DQw3 beta-chain associating with a DQw3 alpha-chain and a DQw3 beta-chain associating with a DQw2 alpha-chain. The identity of alpha- and beta-chains comprising these hybrid molecules was confirmed by HPLC peptide-map analysis. Several characteristic peptide peaks identified both DQw2 and DQw3 alpha-chains associated with DQw3 beta-chains. The formation of such DQ alpha (DQw2)-Dq beta (DQw3) dimers potentially contributes a direct molecular mechanism for HLA-associated contributions to disease in DR3/DR4 heterozygotes.
Diabetes 1987 Jan
PMID:Transcomplementation of HLA genes in IDDM. HLA-DQ alpha- and beta-chains produce hybrid molecules in DR3/4 heterozygotes. 349 69

Type 1 (insulin-dependent) diabetes is less common in Asian Indians than in white Caucasoids. Forty-five Punjabi Asians with Type 1 diabetes and 96 racially matched control subjects were HLA-DR typed. DR3 was increased in diabetic patients vs control subjects (82% vs 38%, p less than 10(-5)) with relative risk 7.7 and etiological fraction 0.72. DR4 was increased in diabetic patients vs control subjects (31% vs 7%, p less than 0.003) with relative risk 5.7 and etiological fraction 0.26. DR2 showed a negative association (relative risk 0.19, etiological fraction -0.28), as did DR7 (relative risk 0.21, etiological fraction -0.33). HLA-DQ beta-chain gene probing using restriction enzyme BamHI in 43 diabetic patients and 90 control subjects showed that the DR1-associated 6.2 and 3.2 kb fragments were less common in diabetic patients than in the control subjects (12% vs 36%, p less than 0.02). A 12 kb fragment was associated with DR4 in both diabetic patients and control subjects. DR3 is the major susceptibility factor for Type 1 diabetes in Punjabi Asians and DR4 is a second marker. Gene probing indicates that the same DR4 subset is associated with the condition as in white Caucasoids. DR1 and its associated DQ beta restriction fragments are reduced in Asian Type 1 diabetic patients making it unlikely that DR1 haplotypes carry a predisposing factor in this racial group. We conclude that the genetic component of Type 1 diabetes in Punjabis shows differences from that of the white Caucasoid population and that the lower frequency of DR4 in this population may contribute to the lower prevalence of Type 1 diabetes.
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PMID:The HLA-D associations of type 1 (insulin-dependent) diabetes in Punjabi Asians in the United Kingdom. 365 60

Insulin-dependent (type 1) diabetes mellitus (IDDM) is a multifactorial disease with a strong genetic component. The majority of the genetic component can be explained by associations between IDDM and genes in the major histocompatibility complex (MHC). The best single marker for IDDM is based on amino acid polymorphism of the HLA-DQ gene. Current evidence, however, indicates that the MHC susceptibility to IDDM is determined by a combination of HLA class I, II and III genes contained on HLA haplotypes. A non-MHC genetic component to IDDM also exists. To date, the most consistent association is between IDDM and markers of the insulin gene locus.
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PMID:The immunogenetics of insulin-dependent diabetes. 760 36

Whether genetic susceptibility for insulin-dependent diabetes mellitus (IDDM) at the 5' insulin gene polymorphic region (5' INS) interacts with human leukocyte antigen (HLA)-DQ-linked disease risk and whether it is associated with autoantibody formation is presently controversial. Diabetes registries allow more systematic reassessment of these questions. Two hundred and ninety-six Caucasian IDDM patients were recruited by the Belgian Diabetes Registry and sampled at disease onset, together with 195 ethnically matched control subjects. 5'INS genotypes were determined by Southern blotting, HLA-DQ by allele-specific oligotyping, and autoantibodies by validated immunoassays. The 5' INS 1/1 genotype was more prevalent in patients than in controls [relative risk (RR) = 2.3; P < 10(-4)]. Regardless of age at onset, the 5' INS 1/1 genotype occurred less frequently in patients with the high-risk genotype DQA1*0301-DQB1*0302/DQA1*0501-DQB1*0201 than in patients without it (P < 0.04). The RR associated with this high-risk HLA-DQ genotype (24.9; P < 10(-6)) was not affected by the presence or absence of the 5' INS 1/1 genotype. Combined positivity for the 5' INS 1/1 genotype and for one of three other HLA-DQ genotypes associated with an intermediate risk for IDDM conferred an age-independent RR of 12.1 (P < 10(-4)). In the absence of the 5' INS 1/1 genotype, intermediate-risk HLA-DQ genotypes no longer conferred a significant risk (2.9; not significantly different from 1). In subjects carrying neutral, protective, or infrequent HLA-DQ genotypes, the overall RR for IDDM was significantly lower than 1 (0.2; P < 10(-6)) in the absence of the 5' INS 1/1 genotype but not in its presence (0.8; not significantly different from 1). The 5' INS 1/1 genotype was not preferentially associated with immune markers for IDDM. In conclusion, regardless of age at onset and the presence of autoantibodies, 5' INS polymorphisms contribute preferentially to IDDM susceptibility in subjects without the highest HLA-DQ-associated risk.
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PMID:Genetic susceptibility for insulin-dependent diabetes mellitus in Caucasians revisited: the importance of diabetes registries in disclosing interactions between HLA-DQ- and insulin gene-linked risk. Belgian Diabetes Registry. 767 95

Most autoimmune diabetes occurs in those without a diabetic relative, but few cases are identifiable prospectively. To model general population prediction, 491 consecutive newly diabetic children from all of Sweden were tested for autoantibodies to glutamate decarboxylase (GAD65ab), insulin (IAA), and islet cells (ICA), and for HLA-DQ genotypes by PCR; 415 matched control children were tested in parallel. GAD65ab sensitivity/specificity was 70/96%, versus 84/96% for ICA, 56/97% for IAA, 93/93% (any positive), 39/99.7% (all positive), and 41/99.7% (GAD65ab plus IAA). The latter's 25% predictive value was not improved by requiring concomitant high-risk HLA genotypes. GAD65ab were associated with DQA1*0501/B1*0201 (DQ2; P = 0.007) but not DQA1*0301/B1*0302 (DQ8), and IAA with DQA1*0301/B1*0302 (DQ8; P = 0.03) but not DQA1*0501/B1*0201 (DQ2). GAD65ab were more prevalent in females than males (79 vs. 63%; P < 0.0001) but did not vary with onset age nor season. Combining the three antibody assays yielded sufficient sensitivity for screening. GADab were relatively sensitive/specific for diabetes, but even with HLA marker combinations yielded predictive values insufficient for early immunointervention in the low-prevalence general population.
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PMID:Glutamate decarboxylase-, insulin-, and islet cell-antibodies and HLA typing to detect diabetes in a general population-based study of Swedish children. 770 55


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