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)

Clinical and biochemical classifications of mitochondrial disorders have given way to an as yet incomplete genetic classification system based on alterations of the mitochondrial genome, the nuclear genome, or both. The first group includes mitochondrial disorders due to specific mutations of mitochondrial DNA such as the MELAS, MERRF or NARP encephalomyopathies, various conditions involving deafness (non-syndromic or associated with diabetes), Leber's optic neuropathy and a small group of cases of maternally transmitted Leigh's syndrome. All these diseases are transmitted through maternal line. conditions which are usually sporadic are due to deletion or duplication of mitochondrial DNA, and give rise to myopathies, with or without ophthalmoplegia, and to more complex disorders such as Kearns Sayre syndrome are also included. The second group is composed of all the mitochondrial disorders in which the nuclear genes which codify sub-units of mitochondrial DNA contain a genetic defect. This includes most cases of Leigh's syndrome, Alpers polydystrophies, the myoneurogastrointestinal syndrome, Barth's syndrome and Friedreich's disease. Amongst the disorders secondary to defects in communication between the nuclear and mitochondrial genomes is a progressive external ophthalmoplegic form with autosomal dominance which arises secondary to mutations on chromosomes 3 and 10. Further mitochondrial disorders due to faults in the relationship between the two genomes will probably be found in the near future.
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PMID:[Classification of mitochondrial diseases]. 981 May 85

We compared clinical pictures of a case of mitochondrial encephalomyopathy with tRNA(Leu(UUR)) point mutation at nucleotide position 3254 of mitochondrial DNA with those at position 3243. The mutation 3254 was a 19-year-old male patient with cardiomyopathy accompanied with muscle atrophy. The first mutant 3243 was a 31-year-old female patient showing clinical features of MELAS and endocrinological abnormalities. The second 3243 mutant was a 27-year-old male patient who had an external ophthalmoplegia and slight mental decline. In all cases, muscle biopsy specimen showed ragged red fibers and strongly SDH-reactive blood vessels, but their limb weakness were unremarkable. These results suggest that tRNA(Leu(UUR)) point mutation 3254 exhibits similar clinical phenotypes as those observed in 3243 mutant.
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PMID:[Comparison of clinical pictures of mitochondrial encephalomyopathy with tRNA(Leu(UUR)) mutation in 3243 with that in 3254]. 998 53

Mitochondrial cytopathy is a heterogeneous group of disorders with a wide range of clinical features. To evaluate the incidence and clinical heterogeneity of A3243G mitochondrial tRNA mutation in the Korean population, we evaluated patients who were clinically suggestive of having mitochondrial encephalomyopathy. Eighty-five patients were included in this study. All showed clinical features of mitochondrial encephalomyopathy and had three or more of the following clinical manifestations: (1) psychomotor regression, (2) hyperlacticacidemia, (3) recurrent stoke-like episodes, (4) idiopathic cardiomyopathy, (5) sensoryneural hearing loss, (6) diabetes mellitus, (7) myopathy, (8) renal disease and (9) relatives with known mitochondrial disease. The patients were clinically classified as MELAS, MERRF, Leigh syndrome, Kearns-Sayre syndrome, chronic progressive external ophthalmoplegia and uncertain. Of the 85 patients, 19 had the A3243G mutation (22.3%). Thirty-one patients showed typical clinical characteristics of MELAS. Fourteen of those 31 patients had A3243G mutation (45.1%). Four patients harboring A3243G mutations showed atypical and heterogeneous clinical features, unlike MELAS. This study revealed the frequent occurrence of A3243G mutation in Korean patients with mitochondrial disorders and their clinical features can be heterogeneous. It will be helpful to screen the presence of A3243G mutation for the genetic diagnosis of mitochondrial encephalomyopathy in Korea.
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PMID:Clinical features of A3243G mitochondrial tRNA mutation. 1535 Oct 82

Brain single photon emission computed tomography (SPECT) studies were conducted in three patients with A3243G mutation of the mitochondrial (mt) DNA tRNA. All were born to mothers suffering from chronic progressive external ophthalmoplegia (CPEO) with the same A3243G point mutation of the mtDNA tRNA. The first case manifested clinically with MELAS, the second case manifested with CPEO, and third case was characterized by recurrent migraine-like headache, tremor, and epilepsy. Brain SPECT of all patients, regardless of whether they had or had not suffered from stroke-like episodes, showed multiple areas of asymmetrical decreased perfusion, particularly in the posterior and lateral head regions, especially the temporal lobes. Crossed-cerebellar diaschisis may occur. Conventional brain magnetic resonance images failed to show some of the lesions. Decreased regional cerebral blood flow, rather than previously proposed hyperemia, is likely to be the cause. We conclude that mitochondrial vasculopathy with regional cerebral hypoperfusion may be seen on brain SPECT in patients with mitochondrial disorders and A3243G mutations, regardless of whether they have or have not suffered from stroke-like episodes.
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PMID:Brain single photon emission computed tomography in patients with A3243G mutation in mitochondrial DNA tRNA. 1596 44

Although linked with cardiac dysfunction, the association of MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) and pulmonary artery hypertension (PAH) has not been previously described. PAH and right ventricular heart failure were identified by echocardiography in a 3-year-old boy with a history of hypotonia, microcephaly and developmental delay. He initially presented with a 10-day history of dyspnoea, dependent oedema and reduced oral intake. Lactic acidosis was noted on serial arterial blood sampling and cerebrospinal fluid. Muscle biopsy demonstrated cytochrome-c oxidase-positive 'ragged-red' fibres consistent with MELAS; subsequent analyses revealed the m.3243A>G point mutation most commonly associated with MELAS. The mutation was heteroplasmic, representing 92% of the total mtDNA from a lung sample. Nitric oxide and epoprostenol were administered without significant clinical or echocardiographic improvement of his PAH. A 'mitochondrial cocktail' including biotin, riboflavin, carnitine and coenzyme Q10 also was provided. Five months after presentation, he developed seizures; MRI imaging of his brain demonstrated multiple focal lesions. His clinical status worsened with increasing cardiopulmonary failure. He died two months later. Although therapy for both MELAS and PAH remains limited, recent investigations suggest a beneficial role for l-arginine in both conditions, implying a possible common pathophysiology. Mitochondrial diseases such as MELAS should be considered in cases of idiopathic PAH, particularly when associated with multisystem involvement including short stature, hearing loss, renal dysfunction, retinopathy, diabetes mellitus, migraines, seizures, ophthalmoplegia, fatigability and weakness.
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PMID:Pulmonary artery hypertension in a child with MELAS due to a point mutation of the mitochondrial tRNA((Leu)) gene (m.3243A>G). 1818 Oct 29

We sequenced all mitochondrial tRNA genes in a 61-year-old man with chronic progressive external ophthalmoplegia and mitochondrial myopathy but without mtDNA rearrangements, and identified a heteroplasmic m.3244G>A mutation in the tRNA(Leu(UUR)) gene. This mutation had been previously associated with the MELAS phenotype, but not described in any detail. The mutation load in muscle was 84% and COX-negative fibers harbored greater levels of mutant genomes than COX-positive fibers. The m.3244G>A mutation affects a highly conserved nucleotide in the dihydrouridine loop and has been associated with a wobble modification deficiency of the mutant tRNA.
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PMID:The m.3244G>A mutation in mtDNA is another cause of progressive external ophthalmoplegia. 1928 65

The term chronic progressive external ophthalmoplegia (CPEO) is not only a symptom but is also used as a syndrome within the group of mitochondrial diseases. However, the symptom CPEO might also occur in other well defined mitochondrial syndromes such as MELAS, MNGIE, SANDO. The molecular bases of the syndrome CPEO are mostly single or multiple deletions of the mtDNA, less frequently point mutations. Multiple deletions are caused by defects of nuclear encoded proteins. In this case, the mode of inheritance might be autosomal dominant or recessive. However, all these types of mtDNA mutations are not only associated with the symptom or syndrome of CPEO but might also cause other well defined mitochondrial syndromes. Thus, the diagnosis of CPEO either as a symptom or as a syndrome requires the subtle characterisation of the complete clinical phenotype as well as the precise genotype. Only on this basis a valid prognosis and information about the mode of inheritance are possible.
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PMID:[Chronic progressive external ophthalmoplegia--symptom or syndrome?]. 1983 Jun 38

Involvement of peripheral nerves is frequent in mitochondrial disorders but with variable severity. Mitochondrial diseases causing peripheral neuropathies (PN) may be due to mutations of mitochondrial DNA (mtDNA), as is the case in MERRF and MELAS syndromes, or to mutations of nuclear genes. Secondary abnormalities of mtDNA (such as multiple deletions of muscle mtDNA) may result from mitochondrial disorders due to mutations in nuclear genes involved in mtDNA maintenance. This is the case in several syndromes caused by impaired mtDNA maintenance, such as Sensory Ataxic Neuropathy, Dysarthria and Ophthalmoplegia (SANDO) due to recessive mutations in the POLG gene, which encodes the catalytic subunit of mtDNA polymerase (DNA polymerase gamma), or Mitochondrial Neuro-Gastro-Intestinal Encephalomyopathy (MNGIE), due to recessive mutations in the TYMP gene, which encodes thymidine phosphorylase. Genetically-determined PN due to mutations of mitofusin 2, a GTPase involved in the fusion of external mitochondrial membranes, were identified during the last few years. Characteristic ultrastructural lesions (abnormalities of axonal mitochondria) are observed on longitudinal sections of nerve biopsies in patients with PN due to mitofusin 2 mutations.
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PMID:[Peripheral neuropathies due to mitochondrial disorders]. 1994 42

Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is a clinical syndrome associated with mitochondrial abnormalities. In approximately 80% of patients, the syndrome is associated with the A3243G mutation. However, it has been realized that the A3243G mutation is not uncommon in the general population and is found in many patients with clinical presentations other than MELAS. We present four patients who presented with rhabdomyolysis, muscle fatigue, external ophthalmoplegia and myoclonic jerks respectively. These patients were all found to have the A3243G mutation on muscle biopsy. These patients illustrate the variety of presentations associated with A3243G mutation.
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PMID:Atypical clinical presentations of the A3243G mutation, usually associated with MELAS. 2274 55

Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is a maternally inherited disease due to mitochondrial DNA (mtDNA) point mutations. The clinical phenotype varies in relation to the systems affected, age at onset and disease severity. The characteristic signs of MELAS are nausea and vomiting due to acidosis, headache, epilepsy, ataxia or generalized weakness, ophthalmoplegia, motor and sensory focal neurological deficits. The clinical course may improve due to partial regression of the typical lesions, but the prognosis is usually adverse. A 19-year-old man with a diagnosis of benign occipital epilepsy and resumption of seizure activity with focal occipital attacks since the age of 14 years came to our attention for the recent onset of drug-resistant electroclinical seizures of long duration with complex symptoms, where the dominant clinical feature was an intense, persistent bilateral periorbital migraine with nausea and vomiting, scintillation scotomata and blurring of vision. MR studies were performed at our institution in the immediate post-seizure phase and then at one week, three and six months. The acute-phase morphological scans showed a right cortical-subcortical area with altered signal in the occipitopolar region that was hypointense on T1 and hyperintense on T2 and FLAIR, with cortical thickening and effacement of the sulci. Contrast-enhanced scans did not demonstrate BBB alterations. The DWI scans showed a right temporo-occipital cortical area with higher signal intensity. In the subsequent examinations the area with altered signal shrank gradually and significantly in parallel with improvement in clinical conditions. The diagnostic hypothesis of benign occipital epilepsy was consistent neither with the clinical course, characterized by persistent headache, visual disturbance and refractoriness to antiepileptic drugs, nor with the temporal-occipital cortical MR findings, which resembled ischemic lesions but displayed a non-territorial pattern as well as reversibility over time. These elements guided in the diagnosis of MELAS, which was subsequently confirmed by identification of the typical gene mutation. On DWI the stroke-like lesions of MELAS are seen more frequently as focal hyperintense areas compared with healthy parenchyma. Such high signal intensity likely corresponds to T2 shine-through rather than cytotoxic edema. Indeed, several studies have demonstrated that in acute-phase scans of MELAS stroke-like lesions DWI hyperintensity is associated with increased ADC values that are not associated with restricted water diffusivity, reflecting the metabolic rather than anoxic-ischemic nature of these changes. In the present case, morphological MR associated with DWI was very helpful in guiding the diagnosis by demonstrating some pathognomonic features of MELAS stroke-like lesions such as cortical-subcortical involvement of the posterior hemispheres, the non-territorial pattern, lesion reversibility and the pathophysiological role of vasogenic edema in inducing an increase in extracellular water and thus in diffusion values.
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PMID:Atypical Clinical Picture in a Patient with Benign Occipital Epilepsy: Diagnostic Contribution of Morpho-Functional MR. A Case Report. 2429 88


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