Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0016719 (Friedreich's ataxia)
 2,098 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A patient with Friedreich's disease and chronic progressive external ophthalmoplegia is descirbed. An investigation was performed into the nature of the ocular motor disorders, which appeared clinically to be supranuclear. The EMG of the ocular muscles suggested myopathy. A specimen of ocular muscle was obtained by biopsy and examined with the light microscope and-for the first time-under the electron microscope. Signs of mitochondrial myopathy were found alongside neurogenic features. Postmortem examination of the central nervous system confirmed the diagnosis of Friedreich's disease with lesions of the motor cells in the anterior horn of the spinal cord. No evidence was found for a supranuclear or inernuclear origin of the ocular palsies, but 20-30 per cent of the neutrons in the nuclei III and IV were atrophic. Lesions of the non-medullated motor nerve fibres were also visible under the electron microscope. That the origin of the c. p. e. o. in this heredo-ataxia is neurogenic-nuclear is postulated on the grounds of the neuropathological and electronmicroscopic findings. Resemblances to the microscopic and submicroscopic and submicroscopic appearance of many types of "ocular myopathy" and "ophthalmoplegia-plus" throw doubt upon the myogenic character of these conditions. Possibly chronic, slowly progressive atrophy in the nuclear areas of the ocular motor nerves must in these cases also be held responsible for the c. p. e. o. Perhaps Moebius's Kern-Schwund theory may be revived after 85 years.
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PMID:Chronic progressive external ophthalmoplegia in a heredo-ataxia: neurogenic or myogenic? A clinical, neuropathological and submicroscopic study. 60 73

The post-mortem findings are reported of two patients with myoclonus epilepsy associated with ragged-red fibers (MERRF, Fukuhara's disease), whose clinical findings have been described in detail previously. In addition to the mitochondrial myopathy, both patients had consistent lesions in the central and peripheral nervous systems: (1) degeneration of the dentatorubral and pallidoluysian systems, (2) spinal cord lesions resembling Friedreich's ataxia, and (3) degeneration of the substantia nigra, cerebellar cortex, inferior olivary nucleus, locus ceruleus, gracile and cuneate nuclei, and the pontine tegmentum. The nature and distribution of the lesions are different not only from the other mitochondrial encephalomyopathies but also from other known diseases. It is concluded that MERRF is a disease entity.
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PMID:Neuropathology of myoclonus epilepsy associated with ragged-red fibers (Fukuhara's disease). 313 27

A report is given of an association of dyssynergia cerebellaris myoclonica associated with Friedreich's ataxia and mitochondrial myopathy in 2 patients. They had suffered from gradually increasing bursts of myoclonus since the wage of 14 and childhood, respectively. The other striking clinical features included generalized convulsions, mental deterioration, intention tremor, ataxia, muscular atrophy and deformity of feet. Muscle biopsies revealed ragged-red fibres in both cases. On electron microscopy these fibres contained subsarcolemnal aggregations of abundant abnormal mitochondria with proliferation of inner membranes or paracrystalline inclusions. One of these patients showed elevated blood lactate and pyruvate with an increased lactate/pyruvate ration, apparently of primary origin. These 2 cases resemble those reported briefly by Tsairis et al. (1974). An association of dyssynergia cerebellaris myoclonica associated with Friedreich's ataxia and mitochondrial myopathy in these 2 patients is unlikely to be coincidental but may represent one nosological entity. This myoclonus epilepsy syndrome associated with ragged-red fibres is compared with other possibly related mitochondrial encephalomyopathies.
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PMID:Myoclonus epilepsy associated with ragged-red fibres (mitochondrial abnormalities ): disease entity or a syndrome? Light-and electron-microscopic studies of two cases and review of literature. 677 61

In a group of 10 children (ranging from 5 months to 15 years old) affected by diseases with mitochondrial dysfunction, 4 suffered from mitochondrial myopathy, 4 from mitochondrial encephalopathy and 2 from Friedreich's ataxia. The clinically detectable visual impairment consisted of 3 grey ocular fundi (the other 7 were normal) associated, in 2 subjects, with a mild nystagmus. Electrophysiological assessment, consisting of ERGs and flash VEPs, was systematically performed. The normal ERGs in all subjects confirmed the normal functioning of retinal electrogenesis. In contrast, the VEPs of 6 out of 10 subjects were modified: in 2 of the 4 subjects with mitochondrial myopathy, the VEPs had a hyperamplitude; in the 2 subjects with Friedreich's ataxia, the implicit time of the principal VEP peaks was increased, together with a hyperamplitude in 1 case; lastly, in 2 of the 4 subjects with mitochondrial encephalopathy, the VEPs were altered. These modifications reflected visual pathway conduction disorders with no clinical expression. Various underlying pathophysiological mechanisms possibly responsible for these modifications are discussed.
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PMID:Electrophysiological exploration of visual function in mitochondrial diseases. 748 70

Oxidative stress has been implicated in many diseases. The chief source of reactive oxygen species within the cell is the mitochondrion. We have characterized a variety of the biochemical and metabolic effects of inactivation of the mouse gene for the mitochondrial superoxide dismutase (CD1-Sod2(tm1Cje)). The Sod2 mutant mice exhibit a tissue-specific inhibition of the respiratory chain enzymes NADH-dehydrogenase (complex I) and succinate dehydrogenase (complex II), inactivation of the tricarboxylic acid cycle enzyme aconitase, development of a urine organic aciduria in conjunction with a partial defect in 3-hydroxy-3-methylglutaryl-CoA lyase, and accumulation of oxidative DNA damage. These results indicate that the increase in mitochondrial reactive oxygen species can result in biochemical aberrations with features reminiscent of mitochondrial myopathy, Friedreich ataxia, and 3-hydroxy-3-methylglutaryl-CoA lyase deficiency.
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PMID:Mitochondrial disease in superoxide dismutase 2 mutant mice. 992 56

A 13-year-old boy with clinical and electrophysiologic findings of Friedreich's ataxia developed unusually prominent myopathy. Skeletal muscle biopsy showed mitochondrial proliferation and structural abnormalities. No mutation was found in skeletal muscle mitochondrial DNA to explain this finding. Molecular genetic and pathologic studies confirmed a diagnosis of Friedreich's ataxia in the proband and affected relatives. Although the Friedreich's ataxia phenotype results from decreased expression of a mitochondrially targeted protein, frataxin, mitochondrial myopathy has not been described as a feature of the disease. The association between the frataxin gene mutation and mitochondrial myopathy in this case suggests that severe or cumulative insults to mitochondrial function may produce myopathic changes in some cases of Friedreich's ataxia. The patient also responded clinically to carnitine supplementation, suggesting a potential palliative therapy for the disease.
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PMID:Friedreich's ataxia associated with mitochondrial myopathy: clinicopathologic report. 1217 69

At onset mitochondrial disorders (MID) frequently manifest as a mono-organic problem but turn into multisystem disease during the disease course in most of the cases. Organs/tissues most frequently affected in MID are the cerebrum, peripheral nerves, and the skeletal muscle. Additionally, most of the inner organs may be affected alone or in combination. Hematological manifestations of MID include aplastic, megaloblastic, or sideroblastic anemia, leukopenia, neutropenia, thrombocytopenia, or pancytopenia. In single cases either permanent or recurrent eosinophilia has been observed. Hematological abnormalities may occur together with syndromic or nonsyndromic MIDs. Syndromic MIDs, in which hematological manifestations predominate, are the Pearson syndrome (pancytopenia), Kearns-Sayre syndrome (anemia), Barth syndrome (neutropenia), and the autosomal recessive mitochondrial myopathy, lactic acidosis and sideroblastic anemia syndrome. In single cases with Leigh's syndrome, MERRF (myoclonic epilepsy and ragged-red fiber) syndrome, Leber's hereditary optic neuropathy, and Friedreich's ataxia anemia has been described. Anemia, leukopenia, thrombocytopenia, eosinophilia, or pancytopenia can frequently also be found in nonsyndromic MIDs with or without involvement of other tissues. Therapy of blood cell involvement in MID comprises application of antioxidants, vitamins, iron, bone marrow-stimulating factors, or substitution of cells.
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PMID:Hematological manifestations of primary mitochondrial disorders. 1763 11