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)

HLA Class II polymorphisms were analysed in 27 families with at least one Type I diabetic proband using Southern blotting technique according to 10th Histocompatibility Workshop Standards. The probes used were DRB, DQA1, DQB1 and DOB. We have studied 108 haplotypes and performed segregation analysis with HLA serology and restriction fragment length polymorphism (RFLP) data and compared "affected" with "non-affected" haplotypes (not inherited by IDDM patients). RFLPs correlated well with DR and DQ serology and detected additional polymorphisms. In particular, DQB polymorphism analysis showed segregation of the DQw3 splits with 88.5% of the DR4 affected haplotypes bearing the DQw3.2 split (now DQw8) and 11.5% the DQw3.1 split (now DQw7) while in the non-affected DR4 haplotypes 33.3% were DQw3.2 and 66.6% were DQw3.1. Haplotype analysis showed that DR4-DQw3.2 was in strong linkage with the U fragment (2.1 kb Taq I) of DQA2 (DX alpha) and with the L fragment (5.4 kb BamH I) of DOB. This study confirms previous observations of DQB polymorphisms in heterozygous IDDM patients, supports the protective effect of DQw3.1 (DQw7) against the development of the disease and demonstrates the importance of DQw3.2 (DQw8) for susceptibility to Type I diabetes.
 ...
PMID:Restriction fragment length polymorphism analysis of HLA haplotypes in families with type I diabetes mellitus. 196 92

Restriction fragment length polymorphisms (RFLPs) of the HLA-DR beta, -DQ alpha, -DQ beta, and -DX alpha genes have been examined in South Indian diabetic patients and controls. The DR. DQ linkage arrangements in South Indians were shown to be different for DR2, DR4, and DRw6 from those commonly seen in Europeans, so that localization of the primary disease-promoting gene in IDDM could be attempted. This study clearly implicates at least one DQ beta allele in the pathogenesis of IDDM.
 ...
PMID:HLA-DR and -DQ DNA genotyping in insulin-dependent diabetes patients in South India. 290 31

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.
 ...
PMID:Insulin-dependent diabetes mellitus: HLA-DR and -DQ genotyping in three ethnic groups. 290 33

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.
 ...
PMID:Molecular biology of the HLA system in insulin-dependent diabetes mellitus. 330 Dec 40

We have investigated DNA polymorphism of the class II alpha chain genes in HLA typed patients with insulin dependent diabetes mellitus (IDDM; n = 79), celiac disease (CD; n = 46), dermatitis herpetiformis (DH; n = 53), and controls (n = 86). Preferential allelic associations of HLA genes and gene products have thus been constructed for susceptibility to these diseases. DR alpha and DQ alpha gene polymorphisms indicated heterogeneity of HLA DR3, DRw6, and DR7, and HLA DR2 and DRw6, respectively. In DR7 positive CD patients a 3.8-kilobase (kb) DR alpha fragment, which correlated with DQw3, was found in only 11% of patients compared with 45% of corresponding controls (P less than 0.05). An increased frequency of a DX alpha genotype UU in all three diseases was found (IDDM 59%, DH 45%, CD 48%, compared to 21% in controls, P less than 0.001), which is not explained solely by the increased frequencies of DR3-DX alpha U. We therefore conclude part of the genetic susceptibility for these three conditions is encoded by genes within the DQ-DX subregion.
 ...
PMID:HLA class II alpha chain gene polymorphisms in patients with insulin-dependent diabetes mellitus, dermatitis herpetiformis, and celiac disease. 380 83