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Query: UMLS:C0011854 (
type 1 diabetes
)
20,749
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Two hundred subjects with insulin-dependent (type I) diabetes mellitus (
IDDM
) were typed for HLA-B, HLA-DR, and properdin factor B (Bf). HLA and Bf antigen and haplotype frequencies in subjects were compared with control frequencies derived from the 8th HLA Workshop. Frequencies of extended haplotypes (defined by B-Bf-DR alleles on a chromosome) were also contrasted with control frequencies. Significant positive associations between
IDDM
and HLA-B8, DR3, DR4, BfS, and BfF1 were confirmed, as were significant negative associations between
IDDM
and HLA-B7, DR2, DR5,
DR7
, and BfF. One haplotype (B7-BfS-DR2) exhibited significant negative association, while five haplotypes (B8-BfS-DR3, B8-BfS-DR4, B15-BfS-DR4, B18-BfF1-DR3, and B40-BfS-DR4) exhibited significant positive associations with
IDDM
. In this sample, 64% of all probands carried at least one of the high-risk haplotypes. In conclusion, the occurrence of five "high-risk" haplotypes associated with
IDDM
provides evidence for previously undocumented genetic heterogeneity and suggests that possibly more than two HLA-region genes may be involved in
IDDM
susceptibility.
...
PMID:Genetic heterogeneity of insulin-dependent (type I) diabetes mellitus: evidence from a study of extended haplotypes. 659 40
The Basques were previously shown to present a high frequency of HLA-B18 and BfF1, which are known to be associated with
insulin dependent diabetes mellitus
(
IDDM
). During the VIII International Histocompatibility Workshop, we studied HLA-A, B, C, DR; Bf, C4 and GLO.I polymorphisms in 51 unrelated French Basque
IDDM
patients and in 50 controls. Haplotypes were established by family studies in all controls and some patients. Two haplotypes were frequently found in the controls: HLA-A1, Bw57, BfS, C4 F1S,
DR7
and HLA-Aw30, Cw5, B18, Bf F1, C4Fs degree, DR3. The first one was not found in the patients. All the components of the second haplotype had increased frequencies possibly as a consequence of linkage disequilibrium with HLA-DR3: a highly significant association between
IDDM
and HLA-DR3 was observed (90.2% vs 24.0%, relative risk (RR) = 29.1, P less than 10(-11)). The HLA-DR4 frequency was slightly increased (37.3% vs 16.0%), and HLA-DR2 was not found. The silent allele C4s degree was particularly associated with early diagnosed
IDDM
(86.7% in patients with age at onset under 20 years vs 57.1% in other patients, P less than 0.02). The high relative risk for HLA-DR3/DR4 heterozygous vs that of individuals, possibly HLA-DR3 homozygous, supported the hypothesis that two HLA-DR linked genetic factors could be involved in the inheritance of
IDDM
susceptibility.
...
PMID:HLA-A, B, C, DR antigens, Bf, C4 and glyoxalase I (GLO) polymorphisms in French Basques with insulin-dependent diabetes mellitus (IDDM). 695 94
IDDM
results from the immune-mediated destruction of pancreatic islet beta cells. Clinicopathologic heterogeneity in
IDDM
is reflected in part by the wide age range over which the onset of clinical symptoms can occur, after months to years of subclinical "insulitis." Because MHC genes play a critical role in immune function we studied their possible contribution to
IDDM
heterogeneity by analyzing HLA profiles of 194
IDDM
patients in relation to their age at diagnosis. Restriction of HLA-DR heterogeneity was observed in patients diagnosed before age 21 years. Frequencies of DR3 and DR3/4 were highest in the < or = 6-year-old age group and thereafter declined with increasing age at diagnosis. In contrast, the frequency of DR4 remained increased up to age 30 years at diagnosis.
DR7
, normally considered to be a neutral allele, was like DR2 and DR5, significantly decreased in patients diagnosed before age 21 years. The A30-B18-DR3 haplotype was significantly increased in the < or = 6-year-old age group, A1-B8-DR3 was increased in the > or = 31-year-old group. B62-DR4 was increased only in the > 12-year-old age group. In DR4 patients the frequency of DQ8 was increased across all age groups. A sex difference was observed in those diagnosed at < or = 12 years of age, with an excess of females in the DR3+/DR4- group and males in the DR3-/DR4+ group. An association of DPB1 with
IDDM
was revealed by an increased frequency overall of DPB1*0301 and/or DPB1*0401, being more pronounced in patients diagnosed at > 20 years of age.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:HLA antigens and age at diagnosis of insulin-dependent diabetes mellitus. 774 14
Presence of autoimmune diseases and relationship of autoantibody expression with HLA association has been studied in 44 multicase rheumatoid arthritis (RA) families of Asian Indian origin. An increased prevalence of systemic lupus erythematosus (SLE) was observed in relatives (2.3%). Although HLA-DR4 segregated preferentially with seropositivity in general, no difference was observed among seropositive versus seronegative RA. On the other hand, no HLA association was observed with ANF positivity in these families. An increased frequency of
DR7
in the ANF negative and RF negative group of RA patients compared to positive groups suggests that it may act as protective element for the development of autoantibodies in RA. An increased occurrence of DR4 in relatives affected with SLE was observed. While RA segregated mostly with HLA-DR4 in these families, autoimmune thyroid disease and
insulin dependent diabetes mellitus
(
IDDM
) segregated with HLA-DR3 suggesting the involvement of at least two sets of HLA-linked autoimmunity favouring susceptibility genes in the Indian population.
...
PMID:Occurrence of autoimmune diseases and relationship of autoantibody expression with HLA phenotypes in multicase rheumatoid arthritis families. 835 6
The TNF region within the MHC includes a number of immunologically important genes. Microsatellites TNFa and TNFb adjacent to TNF exhibit extensive polymorphism. Employing a PCR-based technique, we identified TNFab haplotypes and defined their distribution in 97 controls and 48 diabetics of Caucasoid origin in a search for other genes within the MHC potentially associated with
IDDM
. Twenty-five different TNFab haplotypes were identified. A significant difference (p < 0.0005) in frequency between patients and controls was found for TNFa1b5 (relative risk 53). However, no other TNFab microsatellites demonstrated significantly different frequencies. Among diabetics TNFa1b5 was found to be in linkage disequilibrium with HLA-DR3-B18, a haplotype known to be associated with
IDDM
. Thus the increased frequency of TNFa1b5 among diabetics could reflect a linkage disequilibrium with a gene within the TNF region or with other genes, including the HLAs, which characterize this haplotype. In both controls and diabetics TNFa2b3 and TNFa7b4 were in linkage disequilibrium with DR3-B8 and
DR7
, respectively. Among diabetics, TNFa2b1 and TNFa6b5 were in linkage disequilibrium with DR4-B62 and DR4-B44, respectively. It is intriguing that TNFab haplotypes, represented by a short piece of about 200 nucleotides in the untranslated region upstream of TNF beta gene, maintain strong linkage disequilibria with different HLA haplotypes extending over 1 million base pairs. The identification of TNFab microsatellites exhibiting a high polymorphic index in a region lacking known polymorphic markers may provide potentially important information regarding the association of HLA haplotypes with autoimmune diseases, as they are in close proximity to other genes of immunologic importance.
...
PMID:Genetic polymorphism of the human tumor necrosis factor region in insulin-dependent diabetes mellitus. Linkage disequilibrium of TNFab microsatellite alleles with HLA haplotypes. 884 31
The prevalence of diabetes mellitus in the young is higher in Bangladesh like other Asian developing nations. Albeit, undernutrition has been shown to be associated with diabetes in the young, not all such individuals are diabetic. Diabetes Mellitus is a multigenic disease. In
IDDM
, DR3/4 heterozygotes were shown to have a greatly increased risk of developing the disease, suggesting the concept of genetic factor(s) being involved in the development of diabetes. Therefore, this study was undertaken to determine the distribution of HLA class II alleles (DRB) and to identify the HLA associated risk for developing diabetes mellitus in the young Bangladeshis. A total of fifty individuals were investigated. Half of them (n=25) were diabetic patients, registered in BIRDEM and half the participants were their non-diabetic sibs. A genomic DNA PCR and Enzyme Linked Probe Hybridization Assay (ELPHA, Bio-test, Germany) was used to determine HLA class II alleles (DRB1, DRB 3, 4, 5) by in vitro amplification of DRB gene. Among all the sero-equivalent antigens found in the study subjects, the prevalence of DR15 (DR2) was overrepresented, both in the diabetic subjects and in their non-diabetic sibs. Moreover, compared with the non-diabetic group the diabetic patients showed higher frequency of DR15 alleles (39 and 25%) though the difference was not significant (chisq. 1.7, p>0.05). Next to DR15, DR4 was the most prevalent HLA-DRB gene found in the study population. Interestingly, the frequency of DR4 was higher in the diabetic than in the non-diabetic group (20 vs. 14%). The study showed that the DR15 and DR4 were the most prevalent in the study population. Moreover,
DR7
though not very significant, was higher in non-diabetic compared to their diabetic sibs. Comparison between the diabetic and non-diabetic sibs could have been interesting and significant but we could not confirm our findings, possibly, due to small sample size. A study in a larger paired sample of unrelated population is also needed to substantiate our findings, and also to prove the susceptibility or resistant haplotype in the young diabetic subjects.
...
PMID:Genetic background of diabetic and nondiabetic sibs in young Bangladeshis. 1176 1
MMDM patients are typically young at onset with low body mass index, require insulin treatment for glycemic control, have insulin resistance, and do not develop ketosis on withdrawal of insulin. WHO's revised classification in 1999, based on the etiopathogenesis of the disease, identifies only two categories:
type 1 diabetes
and type 2 diabetes. MMDM could be considered as type 1b diabetes. Genetic and immunological studies were done on MDDM patients (n = 72) from Cuttack and healthy controls to understand and to justify its inclusion in the category of type 1b diabetes. Antibodies (Abs) to tyrosine pyrophosphatase (IA2-Abs), glutamate decarboxylase 65 (GAD65-Abs), and other minor markers like ICA12 Abs and tissue transglutaminase Abs (TTG-Abs) were studied. HLA-DR and DQ were studied for the genetic markers. Of the MMDM patients 30% were positive for either GAD65 or IA-2 antibodies, and 14% were positive for ICA12 antibodies. All three antibody markers together accounted for 39% of PDDM patients, as some patients were positive for more than one autoantibody. TTG antibodies (specific for Celiac disease) were present in 14/71 (20%) of MMDM patients compared to 3/122 (2%) controls. All four autoantibodies accounted for 53% of PDDM patients, leaving 47% of patients free of known autoantibodies. The autoantibody-negative PDDM patients were analyzed for HLA and MICA markers, showing that
DR7
-DQ9 and MICA allele 9 are increased in this group compared to healthy controls, which suggests an autoimmune response to an unknown dietary autoantigen. We conclude from our data that an autoimmune mechanism is involved in the etiology of MMDM. In addition, the presence of silent celiac disease seen with MMDM patients, which has not yet been reported, is significant. It is important to note that subclinical celiac disease exists with diabetes mellitus and must be considered in the diagnosis of MMDM.
...
PMID:Molecular mechanisms involved in the etiopathogenesis of malnutrition-modulated diabetes mellitus. 1202 Oct 93
Genetic studies of malnutrition-related diabetes are few. We have analyzed the HLA class II gene polymorphism in malnutrition-modulated diabetes mellitus (MMDM), which was previously referred to as protein-deficient diabetes mellitus (PDDM) in the 1985 WHO classification.
Insulin-dependent diabetes mellitus
(
IDDM
) is a polygenic disorder with an autoimmune basis for disease development. In addition to HLA, a second susceptibility locus for
IDDM
has been identified to lie in the major histocompatibility class III region. Both
IDDM
and MMDM in eastern Indians are associated with DR3-DQ2 but not DR4-DQ8. The presence of autoantibodies to
IDDM
autoantigens in clinical MMDM either identifies the slow-onset form of
IDDM
or suggests autoimmunity different from that in
IDDM
. Our study demonstrates that the presence of GAD65 antibody and DR3-DQ2 positivity in MMDM patients identifies the underlying autoimmune mechanism in the etiology in eastern India. In autoantibody-negative MMDM patients an association with
DR7
-DQ2 is identified. The date obtained also indicate the possibility that MMDM can coexist with
IDDM
in these patients and that malnutrition could be one of the reasons for the slower onset in
IDDM
-prone individuals. The association of
DR7
-DQ2 suggests that there is a different immunogenetic background to MMDM than to
IDDM
. MICA is located in the MHC class I region and is expressed by monocytes, keratinocytes, and endothelial cells. Sequence determination of MICA gene identifies trinucleotide repeat (GCT) microsatellite polymorphism in exon 5. Five alleles with 4, 5, 6, and 9 repetitions of GCT or 5 repetitions of GCT with 1 additional nucleotide insertion (GGCT) are identified. The alleles are A4, A5, A5.1, A6, and A9. We studied the association of MICA alleles with
IDDM
(n = 52) and MMDM (n = 41) patients and healthy controls (n = 73) from Cuttack, eastern India. MICA was typed by PCR amplification, and fragment sizes were determined in an ABI prism DNA sequencer. Allele 9 of MICA is positively and allele 4 negatively associated with MMDM patients compared to controls. Allele 5 is positively associated with
IDDM
(OR 2.64, P < 0.05) when compared to controls. Our findings suggest that MMDM is immunogenetically different from
IDDM
in eastern India and that MIC-A is important in the pathogenesis of MMDM patients from Cuttack in eastern India.
...
PMID:Immunogenetic studies on malnutrition-modulated diabetes mellitus. 1202 Oct 94
The genetic susceptibility for gestational diabetes (GDM) was estimated by comparisons of genotypes within human leukocyte antigen (HLA) and major histocompatibility complex class I chain-related gene A (MICA) in 199 women with GDM and 213 healthy women. At least one of ICA, glutamic acid decarboxylase antibodies, or islet cell antigen-2 antibodies/tyrosine phosphatase antibodies was found in 6.0% (12/199) of women with GDM and were considered as autoimmune GDM, whereas the remaining 187 were considered as nonautoimmune GDM. HLA genotyping was done with polymerase chain reaction and sequence-specific oligonucleotides. MICA polymorphism was determined with polymerase chain reaction and fragment size determination. HLA-DR3-DQ2/x or DR4-DQ8/x and MICA5.0/5.1 were more frequent in autoimmune GDM compared with controls; 92% versus 46% and 42% versus 13% and conferred increased risk (odds ratio [OR] = 13; 95% confidence interval [CI] 1.7-104) and (OR = 4.7; 95%CI 1.4-16). Four other genotypes were more frequent in nonautoimmune GDM compared with controls: HLA-
DR7
-DQ2/y, 24% versus 14%; DR9-DQ9/y, 9.6% versus 1.9%; DR14-DQ5/y, 7.5% versus 0.94%; and MICA5.0/z, 24% versus 13% and gave increased risk: OR = 2.0; 95%CI 1.2-3.4, OR = 5.6; 95%CI 1.8-17, OR = 8.5; 95%CI 1.9-38, and OR = 2.0; 95%CI 1.2-3.4, respectively. We concluded that autoimmune diabetes with onset during pregnancy is associated with the
type 1 diabetes
-associated genotypes and also with MICA5.0/5.1, whereas
DR7
-DQ2/y, DR9-DQ9/y, DR14-DQ5/y, and MICA5.0/z are risk factors for nonautoimmune GDM.
...
PMID:Different HLA-DR-DQ and MHC class I chain-related gene A (MICA) genotypes in autoimmune and nonautoimmune gestational diabetes in a Swedish population. 1560 71
The genetic predisposition to
type 1 diabetes
(DM1) is associated with genes of the human leukocyte antigen (HLA) system, specially the HLA-DR and -DQ. In Caucasians, the HLA-DR3 and -DR4 antigens are associated with susceptibility and the -DR2, with protection. In Brazil, a country with a large miscegenation of European Caucasians, Native Amerindians and African Blacks, the genetic basis of DM1 has not been adequately studied. The aim of this paper is to present a critical review of articles indexed in the MEDLINE and LILACS-BIREME data basis about the association of HLA with DM1 in Brazilians. Eight papers, all of them from the Southeast region, were found. Immunogenetic susceptibility to DM1 in Brazilians was associated with HLA-DRB1*03, -DRB*04, -DQB1*0201, -DQB1*0302 alleles, and protection against DM1 was associated with HLA-DQB1*0602, -DQB1*0301 alleles and -DR2 and -
DR7
antigens. Since the Brazilian population is not racially homogeneous, it is not possible to extrapolate studies from a single region to the remainder of the country. It is necessary to study populations from different regions to identify new associations or to strengthen associations with the ones already identified. This knowledge will contribute to future prophylactic or therapeutic interventions in the group of Brazilians at risk of developing DM1.
...
PMID:[Distribution and frequency of HLA alleles and haplotypes in Brazilians with type 1 diabetes mellitus]. 1693 83
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