Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029089 (ophthalmoplegia)
 3,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We performed a comparative analysis of the clinical, morphological and molecular characteristics of 62 patients affected with progressive external ophthalmoplegia with ragged-red fibres in muscle. Twenty-seven patients had only muscular disease, and 35 had a multisystemic disease with neurological, cardiac, sensory, or endocrine symptoms. Quantitation of mitochondrial accumulation and numbering of cytochrome c oxidase deficient muscle fibres were done in 43 patients. Muscle mitochondrial DNA deletions were detected, quantitated and localised by Southern Blot analysis. Point mutations were screened in five mitochondrial DNA transfer RNA genes by denaturing gradient gel electrophoresis technique. This study further emphasized the relationships between progressive external ophthalmoplegia and mitochondrial DNA mutations that were present in 46/62 patients (40 deletions, 4 h point mutations in the tRNA leucine gene and 2 further families with maternal inheritance but no mutation identified to-date). Family history was positive in 12 patients: 4 with a maternally inherited disease (2 of whom had an identified mitochondrial DNA mutation), and 4 with an autosomal dominant inherited disease, none of which was associated with multiple mitochondrial DNA deletions. Interestingly, 2 of our patients with an identified mitochondrial DNA mutation appeared as sporadic cases. No morphological or molecular parameters was correlated with the tissular extension of the disease. However, mitochondrial DNA deletions were significantly associated with ocular symptoms which had an earlier onset and were more severe. Clinical features of the patients with a multisystemic disease and a mitochondrial DNA deletion were essentially related to Kearns-Sayre syndrome. In particular, a cardiac conduction defect was present in 12 patients out of 18 with a multisystemic disease associated with a mitochondrial DNA deletion; it was never encountered in 17 patients with a multisystemic disease but no mitochondrial DNA deletion.
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PMID:[Progressive external ophthalmoplegia of mitochondrial origin: contribution of morphological and molecular studies]. 929 56

We report a sporadic case of chronic progressive external ophthalmoplegia that developed during childhood and was associated with ragged-red and cytochrome c oxidase (COX)-negative fibers in skeletal muscle. Sequencing of all the mitochondrial transfer RNA (tRNA) genes identified a single potentially pathogenic mutation--a T to C transition at position 4274 in the tRNA(Ile) gene. This mutation was not present in skeletal muscle from 79 controls, and the level of the mutation in COX-negative fibers was significantly greater than the level in COX-positive fibers.
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PMID:A novel mitochondrial tRNA isoleucine gene mutation causing chronic progressive external ophthalmoplegia. 933 12

Inclusion body myositis (IBM) is a sporadic progressive myopathy, which is morphologically characterized by inflammatory cell infiltrates and rimmed vacuoles in muscle fibers. Mitochondrial changes are regularly present with ragged-red fibers showing deficiency of cytochrome c oxidase. In these muscle fiber segments, there is accumulation of mitochondria with mitochondrial DNA (mtDNA) deletions. There are different deletions in different muscle fibers. In this study, we have sequenced for the first time the multiple mtDNA deletions in muscle from four patients with IBM. The deletion breakpoints were sequenced from cloned polymerase chain reaction (PCR)-amplified mtDNA fragments. The sequencing was performed directly from the bacterial colonies used for cloning. Of 122 analyzed clones, 33 different deletions were identified. The majority of these have not previously been described. There was a marked predominance of deletion breakpoints in certain regions of mtDNA. These predominant breakpoint regions are similar to those described in other conditions with multiple deletions, such as autosomal dominant progressive external ophthalmoplegia (adPEO) and normal aging, but different from those described in diseases due to single deletions such as Kearns-Sayre syndrome and sporadic PEO. These findings indicate that common factors are involved in the development of multiple mtDNA deletions in IBM, adPEO, and aging.
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PMID:Analysis of multiple mitochondrial DNA deletions in inclusion body myositis. 937 54

We report herein on eleven Brazilian patients with mitochondrial DNA (mtDNA) deletions, found among thirteen patients with chronic progressive external ophthalmoplegia (CPEO) and ragged-red fibers (RRF). The molecular data was correlated with the morphological and clinical findings. The muscle biopsies were studied by histochemistry, immunohistochemistry and DNA analysis. Muscle mtDNA deletions were mapped and quantitated by Southern blot analysis, polymerase chain reaction and sequencing. Of the eleven patients, ten had CPEO without multisystemic involvement and one had Kearns-Sayre syndrome. Three patients had multiple deletions, two of them with no apparent family history. Eight patients showed heteroplasmic single deletions, ranging in length from 2309 to 7566 bp; three of them had the same 'common deletion' of 4977 bp. The proportion of deleted mtDNA ranged from 14 to 89%. Immunohistochemical studies revealed decreased reactivity with the mtDNA-encoded subunit II of cytochrome c oxidase (COX) in all patients, but preserved activity with the nuclear-encoded COX subunit IV in COX-deficient fibers. Two cases presented a few COX-negative fibers with reduced COX IV immunostaining. We found a high frequency of mtDNA deletions in Brazilian patients with CPEO. There was no correlation between clinical severity, morphological findings and the size or amount of the mutated mtDNA in muscle, suggesting that there are still unknown factors influencing the disease phenotype.
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PMID:Mitochondrial DNA defects in Brazilian patients with chronic progressive external ophthalmoplegia. 941 37

Multiple mitochondrial DNA (mtDNA) deletions have been described in patients with autosomal dominant progressive external ophthalmoplegia (AD-PEO) and in autosomal recessive disorders including mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) and autosomal recessive cardiomyopathy ophthalmoplegia (ARCO). The pathogenic bases of these disorders are unknown. We studied three patients with AD-PEO and three patients with autosomal recessive (AR)-PEO (two patients with MNGIE and one patient with ARCO). Histochemistry and Southern blot analyses of DNA were performed in skeletal muscle from the patients. Muscle mtDNA was used to characterize the pattern and amounts of the multiple mtDNA rearrangements; PCR analysis was performed to obtain finer maps of the deleted regions in both conditions. The patients with AD-PEO had myopathic features; the patients with AR-PEO had multisystem disorders. The percentage of ragged-red and cytochrome c oxidase-negative fibers tended to be higher in muscle from the patients with AD-PEO (19% +/- 13.9, 29.7 +/- 26.3) than in muscle from the patients with AR-PEO (1.4% +/- 1.4, 3.3% +/- 3.2; p < 0.10). The sizes of the multiple mtDNA deletions ranged from approximately 4.0 to 10.0 kilobases in muscle from both groups of patients, and in both groups, we identified only deleted and no duplicated mtDNA molecules. Patients with AD-PEO harbored a greater proportion of deleted mtDNA species in muscle (31% +/- 5.3) than did patients with AR-PEO (9.7% +/- 9.1; p < 0.05). In the patients with AD-PEO, we identified a deletion that included the mtDNA heavy strand promoter (HSP) region, which had been previously described as the HSP deletion. The HSP deletion was not present in the patients with AR-PEO. Our findings show the clinical, histologic, and molecular genetic heterogeneity of these complex disorders. In particular, the proportions of multiple mtDNA deletions were higher in muscle samples from patients with AD-PEO than in those from patients with AR-PEO.
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PMID:Multiple mtDNA deletions features in autosomal dominant and recessive diseases suggest distinct pathogeneses. 944 65

We report a new mutation, a G to A transition at nucleotide position 4298 within the mitochondrial tRNA(Ile) gene in a patient with chronic progressive external ophthalmoplegia and multiple sclerosis. The mutation, which alters an evolutionary conserved nucleotide within the anticodon stem, was heteroplasmic in skeletal muscle but was not present in the patient's blood. Single fibre PCR analysis revealed significantly higher levels of the G4298A mutation in cytochrome c oxidase (COX) negative fibres than in COX-positive fibres. This mutation represents the seventh pathogenic nucleotide substitution to be found in this gene and as such confirms the tRNA(Ile) gene as a susceptible "hot spot" for mitochondrial DNA point mutations. Of particular interest is that this patient has the clinical features of both multiple sclerosis and a mitochondrial DNA disorder.
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PMID:A novel mitochondrial DNA point mutation in the tRNA(Ile) gene: studies in a patient presenting with chronic progressive external ophthalmoplegia and multiple sclerosis. 947 77

We report a 56-year old female with mitochondrial neurogastrointestinal encephalomyopathy (MNGIE), presenting with protein-losing gastroenteropathy and serum copper deficiency. There was no neuromuscular disease in her family members. Three years prior to admission, she developed severe gastrointestinal symptoms including diarrhea, nausea, vomiting and ascites, and was diagnosed as having protein-losing gastroenteropathy based on alpha(1)-antitrypsin clearance and other tests. She was referred to our department when neurological symptoms were apparent. Neurological examinations revealed bilateral ptosis, ophthalmoplegia, hearing loss, facial and limb muscle weakness, mild sensory deficit of vibration on her feet and hypoactive deep tendon reflexes. Pigmentary retinopathy, cerebellar ataxia and heart block were not seen. Serum copper level was decreased to 45 micrograms/dl (normal: 83-155). Chronic intestinal pseudo-obstruction was proven by X-ray studies, and diffuse leukoencephalopathy demonstrated on brain MRI. On EMG, motor nerve conduction velocities were prolonged with temporal dispersion. Her muscle biopsy from biceps brachii muscle showed both neuropathic and myopathic changes, scattered ragged-red fibers and focal cytochrome c oxidase deficiency. Southern blot and polymerase chain reaction analysis on mitochondrial DNA showed no deletions nor point mutations. The clinical and pathologic findings of the present patient fulfilled the diagnostic criteria of mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) proposed by Hirano et al. There are few reported patients with MNGIE in Japan, but none presented with protein-losing gastroenteropathy and serum copper deficiency. Since the copper is a cofactor of cytochrome c oxidase, decreased serum copper level may aggravate the respiratory chain enzyme metabolism in mitochondria. Therefore, treatment for gastrointestinal tract disturbance and copper administration may be necessary to prevent disease progression.
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PMID:[Mitochondrial neurogastrointestinal encephalomyopathy presenting with protein-losing gastroenteropathy and serum copper deficiency: a case report]. 949 Sep 4

A 64-year-old female had slowly progressive bilateral external ophthalmoplegia, blepharoptosis and muscle weakness of the extremities since age 30. Laboratory examination showed an elevation of serum CK level. Biopsied specimens from the left biceps and the left orbicularis oculi muscles revealed myopathic change with infiltration of mononuclear cells. In addition, some ragged-red fibers and a few cytochrome c oxidase-negative fibers, which are characteristic of mitochondrial myopathy, were observed. Polymerase chain reaction analysis of mtDNA in the muscles showed multiple mtDNA deletions. On administration of prednisolone (initial dose, 60 mg/day), blepharoptosis and muscular strength improved transiently and serum CK level was normalized but external ophthalmoplegia was not improved. We diagnosed our case as chronic progressive external ophthalmoplegia (CPEO). This is the first report of CPEO presenting as inflammatory myopathy.
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PMID:[A case of chronic progressive external ophthalmoplegia presenting as inflammatory myopathy]. 971 Nov 19

We compared the distribution of deleted mitochondrial DNA (Delta-mtDNA) in skeletal muscle of a patient with autosomal recessive (AR) and another with autosomal dominant (AD) progressive external ophthalmoplegia (PEO) by in situ hybridization (ISH). The patients studied had similar numbers of fibers deficient in cytochrome c oxidase (COX) activity (13.6% and 12.8%) and fibers with mitochondrial proliferation (5.5% and 5.3%). ISH suggested that each COX-deficient fiber contained a single species of Delta-mtDNA. Most deletions ablated the region between the genes encoding adenosine triphosphate (ATP) synthase subunit 8 and cytochrome b. Fibers that appeared to be depleted of mtDNA were also present. We conclude that muscle from patients with autosomally inherited PEO contains not only Delta-mtDNA but also focal depletion of mtDNA and that the distribution of these mtDNA defects appears to be similar. These changes most likely represent the common consequence of whatever genetic factors are responsible for the generation of Delta-mtDNA.
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PMID:Analysis of mtDNA deletions in muscle by in situ hybridization. 1059 Apr 9

In the present work, by titrating cytochrome c oxidase (COX) with the specific inhibitor KCN, the flux control coefficient and the metabolic reserve capacity of COX have been determined in human saponin-permeabilized muscle fibers. In the presence of the substrates glutamate and malate, a 2.3 +/- 0.2-fold excess capacity of COX was observed in ADP-stimulated human skeletal muscle fibers. This value was found to be dependent on the mitochondrial substrate supply. In the combined presence of glutamate, malate, and succinate, which supported an approximately 1.4-fold higher rate of respiration, only a 1.4 +/- 0.2-fold excess capacity of COX was determined. In agreement with these findings, the flux control of COX increased, in the presence of the three substrates, from 0.27 +/- 0.03 to 0.36 +/- 0.08. These results indicate a tight in vivo control of respiration by COX in human skeletal muscle. This tight control may have significant implications for mitochondrial myopathies. In support of this conclusion, the analysis of skeletal muscle fibers from two patients with chronic progressive external ophthalmoplegia, which carried deletions in 11 and 49% of their mitochondrial DNA, revealed a substantially lowered reserve capacity and increased flux control coefficient of COX, indicating severe rate limitations of oxidative phosphorylation by this enzyme.
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PMID:Flux control of cytochrome c oxidase in human skeletal muscle. 1086 62


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