Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: UMLS:C0011849 (diabetes)
277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The distribution of HLA class II alleles associated with insulin-dependent diabetes mellitus (Type 1) in the Algerian population is poorly known. We have typed 36 Algerian Type 1 diabetic probands and their families using DQA1 and DQB1 oligonucleotide probes. Fifty-nine parental haplotypes non transmitted to diabetic offspring served as controls. The frequencies of DQA1 and DQB1 alleles and haplotypes and their associations with Type 1 diabetes were, except minor differences, similar to those reported in French. Susceptibility DQA1 (Arg52+) and DQB1 (Asp57-) alleles were significantly increased among patients versus controls (90% vs 53%, RR = 8.4, p < 10(-6), and 94% vs 64%, RR = 9.4, p < 10(-5), respectively). 85% of Type 1 diabetics versus 34% of control haplotypes were either DR3DQw2 or DR4DQw8 susceptibility haplotypes (DQA1 Arg52+, DQB1 Asp57-) (RR = 10.8, p < 10(-7). 75% of the probands vs 14% of the controls (RR = 18, p < 10(-5)) and 73% of affected siblings versus 24% of unaffected siblings (RR = 8.4, p < 0.02) possessed a genotype composed of these two susceptibility haplotypes in the homozygous or heterozygous state. 42% of the probands were DR3DQw2/DR4DQw8, corresponding to Hardy-Weinberg expectations. The lack of excess of heterozygotes could be due to the consanguine families in this sample, as among the patients with consanguine parents the frequency of DR3, 4 heterozygotes was lower (27% vs 48% in non-consanguine patients, NS) and that of DR3 homozygotes increased (45% vs 12%, respectively, p < 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:HLA DQA1 and DQB1 study in Algerian type 1 diabetes families. 129 2

Insulin-dependent diabetic and control subjects of Japanese origin were HLA-DRB1, -DQB1, and -DQA1 typed using restriction fragment length polymorphism analysis and sequence-specific oligonucleotide gene probing. The DQA1 allele DQA1*0301 was positively associated with the disease [48/52 (92%) diabetic patients versus 44/64 (69%) control subjects, Pc less than 0.03, RR = 4.97]. Alleles of the DRB1 and DQB1 genes showed no significant association with the disease. The frequency of DQB1 genotypes encoding the amino acid aspartic acid at position 57 of the DQ beta chain did not differ significantly between subjects with insulin-dependent diabetes mellitus (IDDM) and controls. These findings suggest that a susceptibility allele for IDDM in the Japanese is more closely associated with the DQA1 gene than the DQB1 gene.
...
PMID:An investigation of Japanese subjects maps susceptibility to type 1 (insulin-dependent) diabetes mellitus close to the DQA1 gene. 134 65

In Caucasians the predisposition to Type 1 (insulin-dependent) diabetes mellitus has been shown to associate with HLA-DR3,DQw2 and DR4,DQw8 and with the presence of amino acids other than aspartic acid at position 57 on the HLA-DQ beta chain. In Finland the haplotype-specific absolute risk for developing Type 1 diabetes differs between various DR3 and DR4 positive haplotypes. The aim of our present analysis was to find out whether this variation is attributable to polymorphism at the DQ locus. As part of a nationwide prospective study including 757 serologically HLA genotyped families, we determined HLA-DQ alpha and DQ beta restriction fragment polymorphisms in 17 selected families with important susceptibility haplotypes. Additionally, the DQA1 alleles were determined from 19 haplotypes using sequence-specific oligonucleotide probes, and the DQB1 second exon was sequenced from nine haplotypes. The DR3 as well as DR4 positive haplotypes frequently found in Type 1 diabetic patients showed no variation at the HLA-DQ locus, and they were DQw2 and DQw8, respectively. The absolute risk for Type 1 diabetes for DR4,DQw8 positive haplotypes A2,Cw4,Bw35,DR4 A3,Cw3,Bw62,DR4, A24,Cw7,Bw39,DR4, A2,Cw3,Bw62, DR4, and A2,Cw1,Bw56,DR4 was 35/100,000, 130/100,000, 166/100,000, 196/100,000, and 218/100,000, respectively. The absolute risks for DR3,DQw2 positive haplotypes A1, Cw7,B8,DR3 and A2,Cw7,B8,DR3 were 68/100,000 and 103/100,000, respectively. These results provide further evidence that not only the polymorphism at the DQ locus but also other genes of the haplotypes contribute to susceptibility to Type 1 diabetes.
...
PMID:HLA haplotypes in type 1 (insulin-dependent) diabetes mellitus: molecular analysis of the HLA-DQ locus. The DIME Study Group. 134 11

To gain insight into the HLA subregions involved in protection against insulin-dependent diabetes mellitus (IDDM) we investigated the polymorphism of HLA-DR and -DQ genes in 23 DR2 IDDM patients. Results show the following. (1) Fourteen patients (61%) possess the DRB1, DRB5, and DQB1 alleles found in DRw16/DQw5 healthy people. These data contrast with the 5% of DRw16 normally found in DR2 populations and are in agreement with former observations supporting that the DRw16 haplotype is not protective. (2) Nine DR2 patients, i.e., 39% versus 95% in published DR2 controls, possess the DRB alleles found in DRw15 unaffected people. Among them, six patients have also DQA1 and DQB1 alleles identical to those found in DRw15/DQw6 healthy individuals. These data confirm that the DRw15/DQw6 haplotype is protective but indicate that none of the DR or DQ alleles, alone or in association, confers an absolute protection. (3) Our most striking results concern the very high frequency of recombinant haplotypes among the DRw15 patients: 3 of 9. In these three patients recombinations led to the elimination of both DQB1 and DQA1 alleles usually associated with DRw15. This strongly suggests that the occurrence of IDDM in these DRw15 patients is due to the absence of the usual DQ product and thus reinforces the assumption that DQ rather than DR region is involved in the protection conferred by the DRw15/DQw6 haplotype. Finally, analysis of the non-DRw15 haplotypes in heterozygous patients showed that IDDM can occur in the absence of any DQ alpha beta heterodimer of susceptibility.
...
PMID:Extensive study of DRB, DQA, and DQB gene polymorphism in 23 DR2-positive, insulin-dependent diabetes mellitus patients. 134 43

The question of HLA susceptibility to Type 1 (insulin-dependent) diabetes mellitus remains unresolved. In the present study, 127 diabetic patients and 177 unrelated control subjects have been analysed for their class I and class II serological antigens, class II (DR, DQ) DNA restriction fragment length polymorphisms and DQA1 and B1 exon-2 nucleotide sequences and their corresponding amino acid residues. By using the aetiologic fraction (delta) as an almost absolute measure of the strongest linkage disequilibrium of an HLA marker to the putative Type 1 diabetes susceptibility locus, it has been found that the strength of association of the HLA markers may be quantified as follows: DR4 less than DR3 less than DR3 or DR4 less than non-Aspartate 57 beta DQ and Arginine 52 alpha DQ less than Arginine 52 alpha DQ. Thus, molecular HLA-DQ markers appear to be more accurate as susceptibility markers than the classic serologically defined ones (DR3 and DR4); however, any effect of DQ markers disappears when non-DR3/DR4 individuals are considered, suggesting that DR factors (or others in between DQ and DR) are also important. In addition, a dominant non-Aspartate 57 beta DQ susceptibility theory does not hold (but a recessive one does) in our diabetic population (probably due to the high frequency of the protective DR7-non-Aspartate 57 beta DQ haplotypes); Arginine 52 alpha DQ is the best single HLA marker found in our population, both as a recessive or as a dominant one. Also there are 13 patients in our sample who bear neither Arginine 52 alpha DQ nor non-Aspartate 57 beta DQ susceptibility factors.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Comparison between HLA-DRB and DQ DNA sequences and classic serological markers as type 1 (insulin-dependent) diabetes mellitus predictive risk markers in the Spanish population. 135 47

DNA sequence analysis of class II HLA from Caucasian and black patients with type 1 (insulin-dependent) diabetes mellitus has suggested that aspartic acid at position 57 (Asp 57) of the DQ beta chain provides protection against insulin-dependent diabetes mellitus (IDDM). In contrast, most Japanese patients with IDDM have Asp 57-positive alleles. To determine the reason for the differences and to localize the HLA-linked diabetogenic gene in Japanese, we studied the DQA1 and DQB1 genes of Japanese patients with IDDM and control subjects by the polymerase chain reaction in combination with restriction fragment length polymorphism analysis. Associations of DQA1*0301 and DQB1*0303 with IDDM were observed. DQA1*01 was associated negatively with IDDM. The HLA-DR9 haplotype, which is associated positively with IDDM in Japanese, was associated with DQA1*0301 and DQB1*0303, indicating that the Japanese DR9 haplotype is the same as that in caucasians but different from that in blacks. Of the loci on Japanese DR9 haplotypes, the DQA1*0301 allele showed the highest association with IDDM. DQB1*0303 was also positively associated with IDDM. Since DQB1*0303 is identical to DQB1*0302 except that it contains Asp 57, the data suggests that an Asp 57-positive allele confers susceptibility to IDDM when the whole molecule of the DQ beta chain is similar to other susceptible DQ beta chains. DQA1*0301 appears to be a marker of IDDM in all these populations: Japanese, caucasian, and black.
...
PMID:Analysis by the polymerase chain reaction of histocompatibility leucocyte antigen-DR9-linked susceptibility to insulin-dependent diabetes mellitus. 135 11

In the Sardinian population a very high incidence of insulin-dependent diabetes mellitus (IDDM) and the lack of HLA-DR2 protective effect due to the high frequency of the A2, Cw7, B17, 3F31, DR2, DQw1 extended haplotype has been reported. This haplotype, carrying a Serine at position 57 of the DQB1*0502 allele, has been previously reported to be underrepresented in patients when compared to controls. In order to provide an explanation for this finding, we defined by RFLP analysis the HLA haplotype of 45 Sardinian IDDM patients and 49 controls. All DR-2DQw1 subjects were molecularly characterized at the HLA DQA and DQB loci. All DR2-positive patients and the vast majority of the DR2-positive controls had the DQB1*0502 allele at the DR2-linked DQB1 locus, with no statistically significant difference between the two groups. All DQA1 genes were the ones expected, with only two exceptions. Nine out of 10 of the DR2-positive patients were compound heterozygotes for DQB1*0201/DQB1*0502 alleles; only this allele combination was significantly increased (p less than 0.0003). Our data suggests that a) the DQB1*0502 allele is neutral for IDDM development and b) the susceptibility to IDDM in our DR2-positive patients is related to the compound heterozygous state between the neutral DQA1*0102/DQB1*0502 and the susceptibility DQA1*0501/DQB1*0201 alleles.
...
PMID:The HLA DQB1*0502 allele is neutrally associated with insulin-dependent diabetes mellitus in the Sardinian population. 141 11

The risk for insulin-dependent diabetes mellitus (IDDM) associated with genetic susceptibility markers at the human leukocyte antigen (HLA) DQA1 and DQB1 loci was evaluated among individuals with and those without islet cell antibodies. A total of 108 antibody-positive parents and siblings of IDDM patients from the Pittsburgh registry were identified among 1,592 who were screened. HLA-DQ molecular typing was performed on 79 of these individuals and on 78 antibody-negative relatives. There were similar proportions of homozygotes for both of the diabetogenic alleles DQA1 arginine-52 (R/R) and DQB1 non-aspartate-57 (nD/nD) among the antibody-positive and antibody-negative relatives (19.0 and 15.4%, respectively). However, subsequent development of IDDM was restricted to individuals who were both antibody positive and carried the potential to make at least one diabetogenic DQ heterodimer. A dose-response effect was observed among the antibody-positive relatives, in which two of 18 capable of generating one diabetogenic heterodimer and six of 29 generating two heterodimers became insulin requiring. Nine of 15 who were homozygous for both R/R and nD/nD, coding exclusively for diabetogenic variants, became diabetic over the course of the follow-up. With a multivariate model, the relative risk for IDDM among those with islet cell antibodies who were also R/R and nD/nD was estimated to be 229.3 compared with those lacking both, after age and sex were controlled for. The data suggest that while autoimmunity, indicated by the presence of cytoplasmic islet cell antibodies may be relatively common, it progresses only in those with variant HLA-DQ molecules.
...
PMID:Autoimmunity and genetics contribute to the risk of insulin-dependent diabetes mellitus in families: islet cell antibodies and HLA DQ heterodimers. 823 77

Some insulin-dependent diabetic patients present with auto-immune diseases involving extra pancreatic tissues (type 1b diabetes mellitus). The genetic specificity of this syndrome, as opposed to insulin dependent diabetes mellitus (IDDM) free of such associations (Type 1a IDDM) is not clearly established. We have analyzed the HLA-DQB1 and DQA1, loci, after PCR amplification of genomic DNA, in 44 Type 1b IDDM patients, 78 Type 1a IDDM patients and 105 control subjects. No essential difference in HLA-DQ profiles appeared between Type 1b and Type 1a IDDM patients. Both diabetic groups displayed a significant enrichment in DQB1 alleles negative for aspartate at position 57 (Type 1b: 83%; Type 1a: 89%; controls 48%; p < 0.001 vs both patient groups) and in DQB1 Asp 57 negative homozygosity: 71% of Type 1b; 80% of Type 1a; 25% of controls (p < 0.01). This enrichment in DQB1 Asp 57 negative alleles was accounted for by DQB1* 0201 in the Type 1b group, and by DQB1 % 0201 and 0302 in the Type 1a patients. Conversely, alleles DQB1* 0602 and 0301 (DQB1 Asp 57 positive) were protective. Both diabetic groups also displayed a significant enrichment in DQA1 alleles positives for arginine at position 52 (65% of Type 1b; 76% of Type 1a; 50% of control subjects; p < 0.01 and 0.001, respectively, vs controls), and in DQA1 Arg 52 positive homozygotes (48% of Type 1b, 58% of Type 1a, 22% of control subjects; p < 0.01). All differences between diabetic groups and the control group were more pronounced in the case of Type 1a than of Type 1b patients. The HLA-DQ genes shared by Type 1a and Type 1b patients must therefore be closely associated with islet autoimmunity. Genetic differences between Type 1a and Type 1b syndromes, if any, must be investigated in other MHC and non-MHC regions of the genome.
...
PMID:Similarity of HLA-DQ profiles in adult-onset type 1 insulin-dependent diabetic patients with and without extra-pancreatic auto-immune disease. 145 19

Genetic susceptibility alleles have been identified at the DQ HLA region. The aim of the present study was to confirm the value of these markers, and to evaluate the respective weight in the risk of the different alleles at the DQA1 and DQB1 levels, identified by restriction mapping after polymerase chain reaction on exon 2. A significant enrichment in DQB1 alleles encoding for an aminoacid different from Aspartic acid at position 57 (NA) was observed in diabetic (n = 213) in comparison to control (n = 93) children (94% vs 52%; p < 10(-8)). Not all the given NA/NA allelic combinations were equally and positively associated to the disease. Homozygous "Ala/Ala" combinations carried the highest relative risk (OR = 12.3; p < 10(-8)), and among them, the *0201/*0302 genotype was more positively associated to type 1 diabetes (OR = 66; p < 10(-8)). A significant enrichment in DQA1 alleles encoding for Arginine at position 52 in diabetic children was also observed (82% vs 40%; p < 10(-8)). The *0301/*0501 (Arg/Arg) genotype was significantly associated to Type 1 diabetes (OR = 16.2; p < 10(-4)). The highest risk was carried by the whole genotype, a result which could be expected from the known linkage desequilibrium between HLA-DQA1 and DQB1, DRB1 loci. The frequency of Ala DQB1 alleles was low in the background non-at-risk population, although the incidence of the disease is low in our country.
...
PMID:[Respective weight of genotypes DQA1 and DQB1 associated with insulin-dependent diabetes in French children]. 145 18


1 2 3 4 5 6 7 8 9 10 Next >>

---