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

An account is given of the present conception of asymptomatic (chemical) diabetes in the pediatric age group, which also has been named MODY (maturity-onset type of diabetes of young people). Long-term studies show that about 10% will eventually decompensate to overt diabetes. In contrast to classical juvenile-onset type of diabetes the inheritance of MODY seems to be autosomal dominant in many cases. Some authors have suggested that insulin resistance exists in non-obese patients with asymptomatic diabetes, but this view is not supported by observations of the author. Obese patients should reduce their body fat, but other therapeutic approaches are difficult to evaluate because of the normal fluctuation of the disease. There is no general agreement in the literature concerning the value of insulin treatment. The author supports the view that insulin treatment should be started in the late stages of chemical diabetes just before symptomatic disease emerges. In the long run this approach may ameliorate the condition due to the preservation of some beta-cell function for long periods. An unsettled question is whether early insulin treatment in asymptomatic diabetes will delay diabetic vascular complications.
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PMID:Asymptomatic diabetes in childhood and adolescence. A review. 35 15

In a family with maturity-onset type of diabetes mellitus inherited as a dominant, autosomal trait (MODY), the HLA genotypes were compared with the glucose tolerance and the plasma insulin response to oral glucose. In the members with impaired glucose tolerance, the plasma insulin response was of the insulino-tardic type, while those with normal or borderline glucose tolerance had a normal plasma insulin response. HLA tissue typing for A, B, C and D series antigens carried out in 19 of the members showed no association between specific HLA antigens and imparied glucose tolerance. Moreover, when analysing the segregation of the disease and the HLA characters, several recombinants between MODY and HLA would have to be postulated if the gene(s) for this form of diabetes mellitus should be closely linked to the HLA locus.
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PMID:HLA antigens in a family with maturity-onset type diabetes mellitus. 58 Aug 33

Glucokinase, the major enzyme that phosphorylates glucose upon entry into liver and islet beta-cells, has been considered a prime candidate for inherited defects predisposing to NIDDM. Now that the human gene has been isolated, this question has been addressed directly. Polymorphic markers flanking the gene were identified. These markers (microsatellites) are composed of variable numbers of dinucleotide repeats that vary in size, resulting in different alleles. Variably sized alleles can be typed rapidly from genomic DNA of individuals by the PCR. Studies of inheritance of glucokinase genes have revealed significant linkage in families with early-onset NIDDM, or MODY, and mutations have been identified within the coding region of the gene in some families. These studies are extremely encouraging, as they indicate that genes can be identified even in this heterogeneous genetic disorder. This study considers the phenotypes that result from glucokinase defects and the relationship of MODY to NIDDM, and it estimates the role of glucokinase defects in NIDDM in general.
Diabetes 1992 Nov
PMID:Glucokinase and NIDDM. A candidate gene that paid off. 139 13

NIDDM has a strong genetic component, as evidenced by the high level of concordance between identical twins. The nature of the genetic predisposition has remained largely unknown. Recently, the glucokinase gene locus on chromosome 7p has been shown to be linked to a subtype of NIDDM known as MODY in French and British pedigrees, and glucokinase mutations have been identified. To study the relationship between the glucokinase gene and NIDDM, we performed a linkage analysis in 12 Caucasian pedigrees ascertained through a proband with classical NIDDM. The LINKAGE program was used under four models, including autosomal dominant and recessive, with individuals with glucose intolerance counted as either affected or of unknown status. Linkage was significantly rejected with the dominant models (LOD scores -4.65, -4.25), and was unlikely with the recessive model when glucose intolerance was considered as affected (LOD score -1.38). These findings suggest that mutations in or near the glucokinase gene are unlikely to be the major cause of the inherited predisposition to NIDDM in Caucasian pedigrees, but do not exclude a role for this locus with a polygenic model, or a major role in some pedigrees.
Diabetes 1992 Nov
PMID:Linkage analysis of glucokinase gene with NIDDM in Caucasian pedigrees. 139 24

Recently, linkage between the ADA gene locus and MODY, a subtype of NIDDM, has been reported. The possibility that the region of chromosome 20q containing the ADA locus also may play a role in susceptibility to NIDDM needs to be investigated. Therefore, we examined the linkage between the ADA locus and NIDDM in affected siblings of 50 European white diabetic pedigrees--21 Italian and 29 British. Departure from independent segregation of the disease and an Alu VpA polymorphism within the 5' flanking region of the ADA locus was tested in the affected sib-pairs with the APM statistical method. After DNA amplification by the PCR and PAGE, five alleles were identified in the ALU VpA tract at the ADA locus in the two populations. Allele frequencies did not differ significantly between the two populations (chi 2 = 2.426, P > 0.05 [NS]). Analysis of the 50 diabetic sib sets, and independently of the Italian and British groups of affected sib pairs, revealed no segregation distortion between the marker locus and NIDDM. We conclude that mutations within or around the ADA locus are unlikely to play a major role in the etiology of NIDDM.
Diabetes 1992 Dec
PMID:Sib-pair analysis of adenosine deaminase locus in NIDDM. 144 5

Still, there are a lot of questions about the pathogenesis of neonatal diabetes mellitus. In the author's opinion neonatal diabetes mellitus is a distinct entity which differs from the well-known types of diabetes in children (type 1 diabetes, MODY-diabetes) and transient neonatal hyperglycemia regarding pathogenesis, pathophysiology and prognosis. Casuistics of three children two of whom were sibs are reported in detail to demonstrate the characteristics of neonatal diabetes mellitus. Regarding the reported sibs we suppose genetic origin of the disease. Autosomal-recessive mode of inheritance must be assumed.
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PMID:[Neonatal diabetes mellitus and microcephaly. Indications for autosomal recessive inheritance]. 147 Jan 85

MODY is a form of NIDDM inherited as an autosomal dominant condition. We studied the linkage of MODY to two loci: ADA and GLUT2 in two large pedigrees with nonradioactive microsatellite polymorphic systems. A positive linkage of ADA to MODY was recently demonstrated in the large RW pedigree. Formal linkage analysis excluded a tight linkage between ADA and MODY with a LOD score of -5.82 and -2.24 at a recombination fraction of 0.01 in the two families. This result suggests genetic heterogeneity in the molecular basis of MODY. GLUT2 is a candidate gene that is expressed in the liver and beta-cells of pancreatic islets. In the two families studied, the disease did not cosegregate with GLUT2 alleles. The LOD scores for GLUT2 were -7.79 and -1.9 at a recombination fraction of 0.001 in the two families, thus providing evidence against the involvement of GLUT2 in MODY.
Diabetes 1992 Aug
PMID:Linkage analysis of maturity-onset diabetes of the young with microsatellite polymorphisms. No linkage to ADA or GLUT2 genes in two families. 162 71

Polymorphisms occur on the average of one out of every 500 base pairs of DNA, and these polymorphisms provide useful markers for genetic analysis. Hundreds of RFLP markers have been mapped at regular intervals throughout the human genome. Diabetes genes have not been mapped with these markers, however, only one MODY family has been partially evaluated. This type of analysis is further complicated if NIDDM is multigenic and/or polygenic. RFLPs have been used to evaluate specific candidate loci for NIDDM, e.g. the insulin, insulin receptor and glucose transporter genes. For these analyses, population and family studies (limited in number) have suggested that none of these loci are major contributors to the genetic susceptibility to NIDDM. In no case, however, could a contribution of 10% or less of these loci be confidently excluded, because of variable penetrance, different degrees of linkage disequilibrium between RFLPs and putative mutations, the frequencies of the RFLPs in non-diabetic populations, and inadequate sample size. The conclusions are clear: either (1) the correct candidate gene(s) has not been found, or (2) sample sizes need to be increased by at least an order of magnitude, or (3) newer methods of analysis must be adopted (e.g. use of extended haplotypes and associations with subphenotypes, or screening with allele specific oligonucleotide probes, denaturing gradient gel electrophoresis or direct genomic sequencing of polymerase chain reaction amplified DNA).
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PMID:Use of DNA polymorphisms for genetic analysis of non-insulin dependent diabetes mellitus. 167 85

In Madras city (India) 10,513 school students between 3 and 20 yr of age were investigated for glycosuria and its causes. While no previously known cases of diabetes mellitus of any type were encountered, four students (0.038%) in the survey population were found to have glycosuria. One (0.009%) had renal glycosuria, two (0.019%) were possibly NIDDY (MODY) and one (0.009%) had transient glycosuria while receiving anti-tuberculous chemotherapy. It is therefore concluded that neither diabetes mellitus nor glycosuria of non-diabetic causes is a crucial health problem in Indian children and adolescents. While the reasons for this are not known, further research in this field could be of global interest.
Diabetes Res Clin Pract 1991 Aug
PMID:Glycosuria and diabetes mellitus in children and adolescents in south India. 177 10

There are two approaches to identify diabetes-susceptibility genes. One approach is to isolate and characterize genes expressed in the beta-cell and in insulin target tissues whose mutation or altered expression may contribute to the development of diabetes mellitus. Another approach is to clone a diabetes-susceptibility gene by a reverse genetic strategy. The first step for this strategy is to identify a DNA polymorphism that is linked to the disease locus. Using the strategy of the first approach, several candidate genes were examined. Among these genes, the mutation of insulin genes and insulin receptor genes was found in the patient with diabetes. By cDNA cloning or PCR-direct sequencing methods, we identified several mutations in the insulin receptor genes of four insulin-resistant diabetic patients. At least two mutants of insulin receptor genes were expressed in Chinese hamster ovary cells and these mutated receptors showed impaired ability to transduce insulin action in these cultured cells. The expression of these mutant genes in animals such as transgenic mice will be indispensable to establish the relationship between the gene mutation and the abnormality found in the patient. Using the strategy of the second approach, Bell et al. recently reported that the gene responsible for MODY (maturity-onset diabetes of the young) is tightly linked to the adenosine deaminase gene on chromosome 20q. However, this strategy will not be applicable for identification of diabetes-susceptibility genes of NIDDM, since this disorder is likely to be genetically heterogenous, with mutations in several different genes able to cause hyperglycemia, and this heterogeneity could confound the linkage analysis.
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PMID:[Diabetes mellitus and molecular biology]. 177 65


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