Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We identified two patients with pathogenic single nucleotide changes in two different mitochondrial tRNA genes: the first mutation in the tRNA(Asn) gene, and the ninth known mutation in the tRNA(Leu(UUR)) gene. The mutation in tRNA(Asn) was associated with isolated ophthalmoplegia, whereas the mutation in tRNA(Leu(UUR)) caused a neurological syndrome resembling MERRF (myoclonus epilepsy and ragged-red fibers) plus optic neuropathy, retinopathy, and diabetes. Both mutations were heteroplasmic, with higher percentages of mutant mtDNA in affected tissues, and undetectable levels in maternal relatives. Analysis of single muscle fibers indicated that morphological and biochemical alterations appeared only when the proportions of mutant mtDNA exceeded 90% of the total cellular mtDNA pool. The high incidence of mutations in the tRNA(Leu(UUR)) gene suggests that this region is an "etiologic hot spot" in mitochondrial disease.
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PMID:Two novel pathogenic mitochondrial DNA mutations affecting organelle number and protein synthesis. Is the tRNA(Leu(UUR)) gene an etiologic hot spot? 825 46

It has been clarified at the molecular and genetic levels that mitochondrial DNA (mt DNA) and/or nuclear DNA mutations are the cause of a group of diseases called mitochondrial cytopathies or mitochondrial myopathies. We review: (1) the characteristics of mtDNA and its inheritance, (2) the mtDNA deletions in Kearns-Sayre syndrome and chronic progressive external ophthalmoplegia, (3) the point mutations in mtDNA tRNA(Leu(UUR)) gene at positions 3,243 and 3,271 in mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), (4) the mtDNA deletions and point mutations in patients with dilated or hypertrophic cardiomyopathy, and (5) the mtDNA deletions or point mutation in three pedigrees with maternally transmitted non-insulin-dependent diabetes mellitus.
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PMID:[Molecular biology of mitochondrial DNA and mutations in mitochondrial cytopathy]. 832 Aug 24

A family with maternally-transmitted deafness and diabetes mellitus is described. Although the proband clinically exhibited MELAS-like symptoms such as sudden-onset cerebellar ataxia and weakness of the proximal portion of the limbs in addition to deafness and diabetes mellitus, the other three members of the family had only deafness and diabetes mellitus and no neurological manifestations. The analysis of mitochondrial DNA of the two members revealed an A-->G mutation of tRNA(leu(UUR)), a mutation commonly seen in patients with MELAS. According to the clinical histories and endocrinological investigations, the type of the diabetes mellitus in this family was considered to be IDDM, which may be attributed to the dysfunction of mitochondrial of the pancreas islet cells, resulting from the mutation of the mitochondrial DNA.
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PMID:[A family with MELAS whose main manifestations are maternally-transmitted deafness and diabetes mellitus]. 840 88

Inhibition of protein synthesis in perfused rat liver deprived of either methionine or tryptophan results from a defect in peptide-chain initiation. Similarly, the decreased rate of protein synthesis in liver from rats deprived of food for 24 h and in skeletal muscle after 2 days of diabetes results from a defect in initiation. In the present study, the tissue content of tRNA(iMet) and its level of aminoacylation were measured in these conditions to determine whether methionyl-tRNA(iMet) formation is a mechanism involved in the regulation of initiation. The extent of aminoacylation of tRNA(iMet) in livers perfused with supplemented medium or medium deficient in either methionine or tryptophan was 64 +/- 2, 61 +/- 3, and 66 +/- 2% of the total accepting activity, respectively. The total tissue content of tRNA(iMet), expressed as a percentage of total RNA, was 1.7 +/- 0.1, 1.6 +/- 0.1, and 1.6 +/- 0.1 for the three conditions, respectively. In livers from starved rats, the extent of aminoacylation of tRNA(iMet) was 80 +/- 7% and the total tissue content of tRNA(iMet) was 1.9 +/- 0.1% compared with control values of 82 +/- 6 and 2.0 +/- 0.1%, respectively. In skeletal muscle from diabetic rats, the extent of aminoacylation of tRNA(iMet) was 79 +/- 4% and the total tissue content of tRNA(iMet) was 2.0 +/- 0.3% compared with values of 79 +/- 5 and 2.0 +/- 0.2% for control animals.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Aminoacylation of initiator methionyl-tRNA(i) under conditions inhibitory to initiation of protein synthesis. 844 93

We describe a family with three cases of "clinically incomplete mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes (MELAS) syndrome" in which heteroplasmic tRNA(Leu(UUR)) mutation at nucleotide 3243 of the mitochondrial DNA was present in three generations. The amount of mutant genome varied among tissues: it was 60% in the kidney, 72% in the cardiac muscle, and 91% in the liver of the female proband's affected brother and 63% in the kidney, 71% in the cardiac muscle, and 71% in the liver of the female proband's perinatally deceased son. The tRNA(Leu(UUR)) mutation was also carried by the siblings of the proband's affected mother. None of them had any clinical signs of MELAS syndrome. This syndrome has the new feature of being associated with adult-onset diabetes mellitus, neurosensory hearing loss, and short stature.
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PMID:Adult-onset diabetes mellitus and neurosensory hearing loss in maternal relatives of MELAS patients in a family with the tRNA(Leu(UUR)) mutation. 849 19

A 44-year-old woman with diabetes mellitus, cardiomyopathy, and a mitochondrial gene mutation, was reported. She was diagnosed as having diabetes at 33 years of age and was treated with insulin. However, she stopped treatment 6 months later and had no medical care until she developed diabetic ketoacidosis at 41 years of age. She had diabetic foot, diabetic retinopathy, and nephropathy with low insulin secretory capacity, leading to insulin treatment. A point mutation of the mitochondrial tRNA(Leu(UUR)) gene was identified in peripheral leukocytes at 43 years of age, and sensorineural hearing impairment was detected at the same time. Her mother also suffered from diabetes mellitus with deafness and her son, who was not diabetic at age 19, had the same mitochondrial DNA (mtDNA) mutation. At 44 years of age, she developed congestive heart failure due to cardiomyopathy, and the same mtDNA mutation was identified in the cardiac muscle. Thus, it is very likely that in this patient, diabetes and cardiomyopathy was caused by the same abnormality, the point mutation of mitochondrial tRNA(Leu(UUR)) gene.
Diabetes Res Clin Pract 1995 Jun
PMID:A patient with diabetes mellitus, cardiomyopathy, and a mitochondrial gene mutation: confirmation of a gene mutation in cardiac muscle. 852

Left ventricular function and morphology were assessed using M-mode echocardiography in 3 patients with diabetes mellitus associated with mitochondrial tRNA(Leu)(UUR) gene mutation, who were free of clinical, electrocardiographic, or thallium scan evidence of ischemic heart disease. Echocardiograms revealed hypertrophic cardiomyopathy in all 3 patients. Hypertrophy of the interventricular septum was mild in Cases 1 and 3 (12 and 13 mm, respectively) and severe in Case 2 (22 mm) (normal 7-10 mm). When they had neither signs nor symptoms suggestive of congestive heart failure, percentage fractional shortening (%FS), an index of wall motion of the left ventricle (normal > 28%), was normal in Cases 2 and 3 (28 and 32%, respectively) whereas it was slightly decreased in Case 1 (22%). In Case 1 with mild hypertrophy, the development of congestive heart failure was associated with a marked decrease in %FS to 13%; this patient responded well to diuretics and captopril and %FS rose to 22%. However, a mild decrease in %FS to 21% caused congestive heart failure in Case 2 with severe hypertrophy. His response to treatment was marginal. The present study indicates that mitochondrial DNA analysis should be done in patients with diabetic cardiomyopathy, and that sequential echocardiography is invaluable for the detection of hypertrophic cardiomyopathy and the management of subsequent myocardial dysfunction in patients with mitochondrial diabetes mellitus and cardiomyopathy.
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PMID:Hypertrophic cardiomyopathy in patients with diabetes mellitus associated with mitochondrial tRNA(Leu)(UUR) gene mutation. 856 88

We encountered a patient with diabetes mellitus due to the 3243 mitochondrial tRNA mutation(DM-Mt3243), who developed insulin edema and hepatic dysfunction after starting insulin. Such a rare phenomenon was unlikely to be a fortuitous coincidence in mitochondrial diabetes, as none in 197 non-mutant NIDDM patients had same episode. Moreover, similar leg edema was noticed in another DM-Mt3243 patient, and other two DM-Mt3243 patients had leg edema which responded to coenzyme Q10. These observations suggest further a role of mitochondrial function on leg edema. The mechanism of his insulin edema may involve vasomotor changes induced by the rapidly glycemic control, because our case of insulin edema had a prominent increase of strong succinate dehydrogenase reactive vessels. Alternatively, myocardial dysfunction might have produced leg edema and hepatic dysfunction, because he had subclinical myocardial dysfunction, judged by imaging with beta-methyl-p-(123I)-iodophenyl-pentadecanoic acid. The third explanation is that a rapid improvement of glycemic control might have induced hepatic reoxygenation and the production of reactive oxygen species in the liver that contributed to cell damage. Thus, although we cannot draw definite conclusion, our experiences here suggest that mitochondrial dysfunction is important in the etiology of insulin edema.
Diabetes Res Clin Pract 1995 Aug
PMID:Insulin edema in diabetes mellitus associated with the 3243 mitochondrial tRNA(Leu(UUR)) mutation; case reports. 859 1

We identified three families having a mutation in the mitochondrial tRNA(LEU(UUR)) gene at bp 3243 in 300 patients with non-insulin dependent diabetes mellitus (NIDDM), who had first degree relatives of patients with NIDDM. We found six individuals with diabetes, one with impaired glucose tolerance (IGT), and five with normal glucose tolerance (NGT) among three families. Insulin secretory response to oral glucose load was impaired in six diabetics, but was normal in IGT and NGT, and the proportion of mutant DNA in the blood did not always associate with the severity of glucose intolerance. Furthermore, both gender and obesity may influence the clinical expression of diabetes in three pairs with an age-matched brother-sister relationship with similar high mutation rate in blood samples. Thus, although patients with mitochondrial gene mutation had a high frequency of diabetes, the proportion of mutant DNA evaluated by blood samples may not necessarily indicate glucose intolerance in the members with the mutation. Unidentified factors including gender, aging, and obesity may alter the clinical manifestation of diabetes.
Diabetes Res Clin Pract 1995 Aug
PMID:Clinical and laboratory characteristics in the families with diabetes and a mitochondrial tRNA(LEU(UUR)) gene mutation. 859 2

A 35-year-old woman with features of Kearns-Sayre syndrome consisting of progressive ptosis, ophthalmoparesis, mitochondrial myopathy, and pigmentary retinopathy also had autoimmune polyglandular syndrome type 11 (Addison's disease, autoimmune insulin-dependent diabetes mellitus, Hashimoto's thyroiditis, and primary ovarian failure). There was no history of similarly affected relatives. Analysis of muscle mitochondrial DNA (mtDNA) revealed a 2,532-bp deletion of the type seen in Kearns-Sayre syndrome as well as a heteroplasmic A3243G mutation in the tRNA-Leu(UUR) gene of the type seen in mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS). The patient's blood and her mother's blood harbored the A3243G mutation but not the deletion, and the maternal grandmother's blood had neither mutation. In muscle, the species of mtDNA harboring the deletion was exclusively associated with the species harboring the A3243G mutation, suggesting that the point mutation predisposed to the large-scale deletion. The mtDNA species with both mutations accounted for 88% of total muscle mtDNA. Other and as yet unrecognized point mutations in mtDNA might also be associated with, and possible causally related to, large-scale mtDNA deletions.
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PMID:MELAS- and Kearns-Sayre-type co-mutation [corrected] with myopathy and autoimmune polyendocrinopathy. 865 48


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