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

Human genomic DNA samples from Caucasoids, Chinese, and Koreans of known serological DR antigen specificity were studied for IDDM-associated variation in HLA-DR and -DQ RFLPs (restriction fragment length polymorphisms). Genotyping allowed for accurate assignment of HLA-DR types and in Caucasoids DRw6 as well as DR2 was unequivocally decreased in IDDM. Further, the universality of certain DR2-associated DQ beta subtypes in protection against IDDM was established. HLA-DR3 was found to be increased in IDDM irrespective of whether carried on the B8. DR3 or B18. DR3 haplotype in Caucasoids or on the Bw58. DR3 haplotype in Chinese. These haplotypes have different DR alpha and DX alpha arrangements, so the region of susceptibility is confined to DQ alpha, DQ beta. For HLA-DR4, a 12kb/DQ beta/Bam HI fragment was increased in Caucasoid IDDM, but since this fragment is haplotype specific in Caucasoids and occurs in most healthy DR4- and w9-positive Asians, the 12 kb fragment may be a marker for a DR beta subtype of DR4 associated with IDDM in Caucasoids only. This study has shown the value of ethnic comparisons of HLA-associated diseases, where different linkage disequilibrium relationships have permitted identification of common susceptibility determinants and have provided evidence for some heterogeneity between Caucasoid and Asian populations, in the genetics of IDDM.
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PMID:Insulin-dependent diabetes mellitus: HLA-DR and -DQ genotyping in three ethnic groups. 290 33

HLA-DR4, Dw4-associated haplotypes associated with IDDM and JRA were compared using genomic DNA restriction fragment analysis to distinguish among DQ beta and alpha alleles linked to DR4. DQ beta polymorphisms that subdivide the HLA-DQw3 specificity into DQ3.1 and 3.2 alleles were identified. More than 90% of DR4+ IDDM patients express one of these alleles, DQ3.2; restriction enzyme mapping indicates that the presence of this allele also accounts for the genomic fragment patterns previously reported in IDDM. Furthermore, haplo-identical siblings of DQ3.2 IDDM patients also carry the DQ3.2 allele, regardless of clinical presentation. In contrast, DR4+ JRA patients show no allelic preference at DQ beta, implicating different HLA genetic contributions in these two DR4-associated diseases.
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PMID:Specific genomic markers for the HLA-DQ subregion discriminate between DR4+ insulin-dependent diabetes mellitus and DR4+ seropositive juvenile rheumatoid arthritis. 301 39

The development of IDDM correlates with the presence of biologic markers pointing to the involvement of the immune system in the disease process. In addition to clinical observations of association of IDDM with other autoimmune disease and morphologic evidence of a mononuclear cell infiltration of the islets of Langerhans at the onset of the disease, anti-islet cell antibodies are detected in the serum of IDDM patients. Moreover, a strong genetic association with HL-A DR3 and DR4 identifies a genetic background compatible with autoimmune phenomena. Whether autoimmune phenomena are primary or secondary to an initial damage of the islets by infectious agents or other environmental factors is unknown. Whether or not the autoimmune response participates in the selective destruction of insulin-secreting cells has been a major issue in the past five years. The presence of T lymphocytes and anti-islet cell antibodies, which selectively inhibit or lyse insulin-secreting cells in vitro, strongly suggests that it may be the case. A definitive demonstration is difficult to provide in human IDDM. The development of animal models for IDDM has allowed useful insight into the pathogenetic mechanisms responsible for IDDM. In both the BB rat and the low-dose streptozotocin mouse model, the role of the immune system in the destruction of the islets of Langerhans is supported by the prevention of the disease by treatments interfering with the immune system. The BB rat develops a spontaneous autoimmune disease on a genetic background defined by the association with a major histocompatibility complex allele without any evidence for a role in initial damage of islets of a triggering infectious or chemical process. The low-dose streptozotocin model is an autoimmune IDDM secondary to the selective damage of islet cells by a toxin. The present scheme of an islet cell target and specific autoreactive T and B lymphocyte clones raises two major issues: what is the target antigen on islet cells and what is the role at the molecular level of class II major histocompatibility complex genes in susceptibility for IDDM? The first issue is presently being addressed in several laboratories using the hybridoma technology. The second issue is addressed at the biochemical level by studying restriction site polymorphism of major histocompatibility genes in susceptible individuals and IDDM patients, and at the functional level by studying the action of monoclonal antibodies to class II antigen on the development of IDDM in animal models. These steps are likely to be a prerequisite to antigen-specific immunotherapy in IDDM.
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PMID:Autoimmune disorders in diabetes. 308 14

Thirty-one Ethiopian insulin-dependent (or type I) diabetes mellitus (IDDM) patients and thirty-three healthy controls from the same ethnic background were typed for HLA-A, B, C, DR and DQ specificities. The frequencies of both DR3 and DR4 were significantly increased among IDDM patients (resp. p = 0.02, p = 0.01), confirming results in other populations. In contrast to observations in Caucasians, no significant negative association was found with TA10, a newly recognized DQ specificity, at least in the population studied here, whereas DQwl was more frequently observed among healthy controls (p = 0.01). Although this latter difference does not retain statistical significance after correction for the number of comparisons made, these findings may support previous results suggesting the existence of IDDM susceptibility genes associated with DR3 and DR4 and of IDDM resistance genes associated with DQ antigens.
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PMID:HLA-DR and DQ antigens in insulin-dependent diabetics in Ethiopia. 312 28

Associations of insulin dependent diabetes mellitus exist with the HLA-DR antigens DR3 and DR4 in both British Caucasoid and Dravidian subjects. However, it is only in British Caucasoids that an increased relative risk is found in those subjects who co-inherit both of these antigens. The nature of these HLA associations has been explored using Southern blot techniques and radioactive HLA-D region probes. In both populations the same DR4 related polymorphism was found in IDDM subjects whereas different HLA-DR3 preferential allelic associations were observed between British Caucasoid and Dravidian subjects. The best differentiation between diabetics and controls was found by a combination of HLA-DQ region alpha and beta polymorphisms which were totally different for the two populations. These data indicate that at least one gene involved in the susceptibility to IDDM is located within the HLA-DQ region and this may be related to HLA-DR4. The location of a DR3 related gene remains elusive and may be the DR beta gene encoding DR3 itself. In both populations it is a combination of two HLA-D region haplotypes which is strongly associated with IDDM leading to the possibility of trans complementation leading to the formation of mixed isotypic dimers.
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PMID:The genetic susceptibility to IDDM in British and south Indian subjects. 314 91

We studied HLA-A, -B, -C, and -DR antigens in 45 patients (from among 34 families), aged 10.2-60 yr, with polyglandular autoimmune disease type I (APG I) and in other family members. HLA-A28 was more frequent in the patients (25%) than in unaffected siblings (16%; P less than 0.05) or in normal Finnish subjects (8.8%; P less than 0.005, corrected P less than 0.2). Compared with the normal subjects, HLA-A28 was more frequent in the patients with hypoparathyroidism (31%; P less than 0.001, corrected P less than 0.04), adrenocortical failure (27%; P less than 0.01), insulin-dependent diabetes mellitus (IDDM; 66%; P less than 0.01), keratopathy (53%; P less than 0.001, corrected P less than 0.04), and alopecia (40%; P less than 0.001, corrected P less than 0.04), but not in the patients with ovarian failure (9%; P = NS). HLA-A28 was more frequent in the patients with hypoparathyroidism (31%) than in APG I patients without it (13%; P less than 0.005, corrected P less than 0.2). It was also more frequent in the patients with IDDM (66%) than in those without it (21%; P less than 0.05). HLA-A3 was more frequent in the patients with ovarian failure (82%) than in APG I patients with normal ovarian function (22%; P less than 0.025) and in normal subjects (45.5%; P less than 0.05). HLA-A9 was less frequent in the patients with ovarian failure (0%) than in those with normal ovarian function (55%; P less than 0.005, corrected P less than 0.2), and it was less frequent (P less than 0.025) in the patients with adrenocortical failure than in those with normal adrenal function. No association was found with any single DR antigen, but of 4 DR-typed IDDM patients, 3 were DR3 or DR4 positive (P = NS). The occurrence of adrenocortical failure, but not hypoparathyroidism, was familial and associated with HLA haploidentity among sets of affected siblings.
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PMID:The expression of autoimmune polyglandular disease type I appears associated with several HLA-A antigens but not with HLA-DR. 316 97

HLA-A,B,C, and DR frequencies have been determined in 34 Coloured Martinican IDDM patients to establish the HLA and IDDM associations. HLA A3, B15, B18, Cw3 and DR4 antigens associations with IDDM are confirmed by this study. We found an increase of B21 similar to that found in Asiatic Indians. As in some African Black populations and in Cape coloured people, A1, B8, and DR3 are not increased in our population. We should point out that our patients' ages of onset were low, and that some studies have found DR4 association in young patients and DR3 in older ones. The protective role of DR2 is confirmed here. B35 and Cw4 negative associations have been found. We have observed that the antigens associated with IDDM are decreased in our control population, except DR4, and that the negative associated DR/ and Cw4 antigens are increased compared to the Continental French population. This corresponds with the low IDDM incidence in Blacks and Coloured people.
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PMID:HLA A,B,C and DR association with insulin-dependent diabetes in Martinique. 318 90

Haplotypes including HLA, Bf and C4 loci were analyzed in a material comprising 55 families with diabetic children. One hundred and ten haplotypes found in IDDM patients were compared with 101 haplotypes present only in healthy family members. Two complotypes, BfSC4A3B3 and SC4A0B1, were significantly more common (P less than 0.05) in the diabetic haplotypes, and these were in most cases found in haplotypic combinations with HLA-B15,Dw4,DR4 and HLA-B8,Dw3,DR3 genes, respectively. The B8/DR3 haplotype was better conserved, as 72% included the BfSC4A0B1 complotype as compared with only 35% of the B15/DR4 haplotypes with "high risk" C4A3B3 complement alleles (p less than 0.05). DR3 was found in 26% of the diabetic haplotypes and DR4 in 43%. DR4 associated with the Dw4 in 69% of cases and with Dw14 in 26% of the diabetic haplotypes. Our results confirm that the two phenotypes found earlier to be associated with IDDM in Northern Finland, e.g. "B15,BfS,C4A3B3,Dw4,DR4" and "B8,Bfs,C4A0B1,Dw3,DR3" are inherited as haplotypes.
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PMID:Extended HLA haplotypes in families with insulin-dependent diabetes mellitus in northern Finland. 321 30

The Wolfram, or DIDMOAD, syndrome is a rare congenital disease that is associated with diabetes insipidus, insulin dependent diabetes mellitus of an early onset, bilateral optic atrophy and deafness. Urological disorders are usually present as well. We have studied nine patients belonging to five different families. All of the family members were HLA typed (including DR), and islet cell as well as antinuclear antibody determinations were carried out. Although individuals with insulin dependent diabetes mellitus are very prone to have either HLA-DR3 or -DR4 antigens, none of our patients had DR3 antigens and only one was DR4 positive. On the other hand, three of our patients were typed as HLA-DR2 positive. This antigen is uncommon in classical insulin dependent diabetes. In one of the families, the affected siblings did not share the same HLA haplotype. Islet cell and antinuclear antibodies were not found in any of the cases and six of the patients had a small, but significant, insulin secretory reserve. On the basis of some of the clinical features it was also possible to further distinguish between the DIDMOAD syndrome and the classical insulin dependent diabetes mellitus. The differences encountered between classical and DIDMOAD insulin dependent diabetes mellitus--the presence/absence of HLA linkage, HLA-DR2, -DR3 and -DR4 associations, islet cell or antinuclear antibodies, the tendency to ketosis and diabetic retinopathy--indicate that their etiopathogenies are triggered by distinct mechanisms.
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PMID:Contrasting features of insulin dependent diabetes mellitus associated with neuroectodermal defects and classical insulin dependent diabetes mellitus. 329 50

Genetic studies indicate that the IDDM susceptibility genes in the HLA region are closely linked to the DR3 and DR4 specificities; however, these specificities do not define the actual susceptibility genes. Molecular studies confirm this hypothesis by demonstrating restriction fragment length polymorphism between DNA's of identical DR specificities and thereby separating the DR haplotypes into those strongly or weakly associated with IDDM. Further studies at the nucleotide sequence level demonstrate further heterogeneity, with DR4 being associated with at least three different DQ beta genes and five different genes of the DR beta-1 locus. However, the majority of these subtypes are now recognized either serologically or by T-cell responses in mixed lymphocyte cultures. Furthermore, the sequences associated with IDDM are those most commonly found in DR4 individuals, ie, Dw4 and DQw3.2. Clearly, these and other class II genes must be studied for additional DNA polymorphism and their relevance for IDDM. For example, the DX alpha, 2.1-kb Taql polymorphism shows a stronger correlation with IDDM than DR3. However, it is not even known if the DX alpha genes are expressed. In addition, little is known of the DQ beta and DR beta genes associated with different DR3-associated haplotypes. Furthermore, an IDDM susceptibility gene may contain important differences in flanking or intron sequences controlling expression of these genes. The methods of recombinant DNA technology are enabling these unanswered questions to be addressed.
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PMID:Molecular biology of the HLA system in insulin-dependent diabetes mellitus. 330 Dec 40


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