Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0751651 (mitochondrial disease)
 1,844 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We evaluated the effect of coenzyme Q10 supplementation to two patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) by using noninvasive tissue oximetry with near-infrared spectra of hemoglobin from the quadriceps muscle during bicycle ergometer exercise. Patients showed distinct oxygen consumption patterns reflecting the defect in oxidative phosphorylation and the impairment in oxygen utilization during exercise. Based on the oxygen consumption pattern, we considered one patient as having severe mitochondrial disorder and another patient as having mild one. After coenzyme Q10 supplementation, the oxygen consumption pattern of the patient with the severe form shifted to the mild one, while that of the patient with mild form remained unchanged. The shift of the pattern to the mild form correlated well with reduction of the sum of the serum lactate and pyruvate content during exercise. Noninvasive tissue oximetry may be useful to evaluate the effect of coenzyme Q10 supplementation to patients with mitochondrial encephalomyopathy including MELAS.
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PMID:Effect of coenzyme Q10 in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS): evaluation by noninvasive tissue oximetry. 1006 71

Mutations in SCO2, a cytochrome c oxidase (COX) assembly gene located on chromosome 22, have recently been reported in patients with fatal infantile cardio-encephalomyopathy and severe COX deficiency in heart and skeletal muscle. The Sco2 protein is thought to function as a copper chaperone. To investigate the extent to which mutations in SCO2 are responsible for this phenotype, a complete sequence analysis of the gene was performed on ten patients in nine families. Mutations in SCO2 were found in three patients in two unrelated families. We detected two missense mutations, one of which (G1541A) results in an E140K substitution adjacent to the highly conserved CxxxC metal-binding site. The other (C1634T) results in an R171W substitution more distant from the copper-binding site. A nonsense codon was found on one allele in two siblings presenting with a rapidly progressive fatal cardio-encephalomyopathy. Interestingly, all patients so far reported are compound heterozygotes for the G1541A mutation, suggesting that this is either an ancient allele or a mutational hotspot. The COX deficiency in patient fibroblasts (approximately 50%) did not result in a measurable decrease in the steady-state levels of COX complex polypeptide subunits and could be rescued by transferring chromosome 22, but not other chromosomes. These data indicate that mutations in SCO2 cause a fatal infantile mitochondrial disorder characterized by hypertrophic cardiomyopathy and encephalopathy, and point to the presence of one or more other genes, perhaps in the copper delivery pathway, in this clinical phenotype.
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PMID:Mutations in SCO2 are associated with a distinct form of hypertrophic cardiomyopathy and cytochrome c oxidase deficiency. 1074 87

Intestinal dysmotility and neurogenic bladder have been described as part of two autosomal-recessive mitochondrial disorders assumed to be due to a defect in communication between the nuclear and mitochondrial genomes: myoneurogastrointestinal encephalopathy (MNGIE) and diabetes insipidus, diabetes mellitus, optic atrophy, and deafness (Wolfram syndrome). Partial cytochrome c oxidase deficiency has been described in both. We describe three Ashkenazi Jewish siblings with progressive intestinal dysmotility, neurogenic bladder, and autonomic manifestations but no central nervous system involvement. Cytochrome c oxidase deficiency was demonstrated in peripheral and multiple intestinal muscle biopsies. Mitochondrial DNA analysis of an intestinal biopsy of patient 1 showed heteroplasmy consisting of a normal 16.5-kb band and an approximately 28-kb band, suggestive of a duplication. Mitochondrial DNA analysis of a muscle biopsy of patient 2 showed multiple deletions, mainly 10- and 11-kb bands. We suggest that this unique combination of intestinal pseudo-obstruction and neurogenic bladder could comprise a new autosomal-recessive mitochondrial disorder.
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PMID:Familial mitochondrial intestinal pseudo-obstruction and neurogenic bladder. 1086 81

We report the first case to our knowledge of chronic pancreatitis associated with mitochondrial encephalopathy with the A8344G mitochondrial DNA (mtDNA) mutation. This 10-year-old-girl had suffered from recurrent abdominal pain with elevated serum amylase and lipase since the age of 6, and easy fatigability, tremor and astatic seizures since the age of 8. A biopsy of quadriceps muscle revealed ragged-red-fibers and cytochrome c oxidase deficiency. Analysis of mtDNA in peripheral blood identified an A8344G mutation in the mitochondrial tRNA(Lys) gene. Taken together with physical signs of myoclonic seizures and cerebellar dysfunction, we diagnosed her as myoclonic epilepsy with ragged-red fibers associated with chronic pancreatitis. Although no association between mitochondrial disease and pancreatitis has yet been established, this case suggests it is necessary to consider the participation of mitochondrial abnormality in the pathogenesis of recurrent pancreatitis.
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PMID:A case of MERRF associated with chronic pancreatitis. 1129 46

MELAS is characterized by mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes, but cardiac involvement also frequently occurs. An 80-year-old female patient had been suffering from insulin-dependent diabetes mellitus and neurosensory hearing loss. At the age of 79 she suffered metabolic acidosis with persistent drowsiness and was subsequently found to have severe cardiac dysfunction. Muscle biopsy disclosed the presence of abnormal mitochondria, and the MELAS gene mutation (A3243G of the tRNA(Leu(UUR))) was demonstrated. It is noteworthy that this mitochondrial disease patient has survived until a great age, which shows the wide clinical spectrum of MELAS, especially in the age of onset.
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PMID:An 80-year-old mitochondrial disease patient with A3243G tRNA(Leu(UUR)) gene presenting cardiac dysfunction as the main symptom. 1139 11

A 6-year-old boy with a rare mitochondrial disease (MELAS: mitochondrial encephalopathy, lactic acidosis, stroke-like episodes) was presented to undergo adenoid resection and bilateral paracentesis. ENT surgery was performed without complications under general anaesthesia using propofol, fentanyl, and ventilation with nitrous oxide and oxygen. Routine intraoperative monitoring (ECG, noninvasive blood pressure, oxymetry and capnometry) was supplemented by frequent body temperature measurements and repeated laboratory analysis of venous blood gases, lactate, and glucose. Clinically, the postoperative course was uneventful and the boy was discharged from hospital on the first postoperative day. Signs or symptoms of malignant hyperthermia never occurred. Laboratory analysis only showed a remarkable serum lactate elevation postoperatively (6 mmol/l) which decreased on the first postoperative day (3.7 mmol/l). The present anaesthesiologic experiences with MELAS-syndrome are limited, and recommendations are mainly based on case reports. Careful preoperative physical examination with special regard to all available medical records, and anaesthetic management comparable with that in malignant hyperthermia susceptible resulted in an uneventful course in our patient. Pathogenetic aspects of mitochondrial diseases focussing on anaesthetic considerations are briefly discussed.
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PMID:[Anesthesia in mitochondrial encephalomyopathies]. 1149 20

Congenital disorders of glycosylation (CDG) and mitochondrial diseases are multisystem disorders with clinical characteristics that may overlap. We present four patients with CDG whose phenotypes suggested the diagnosis of a mitochondrial disease. Patients 1 and 2 are siblings with hemiplegic headache, stroke-like episodes, lactic acidaemia and history of maternal migraine; their initial clinical diagnosis was MELAS syndrome (mitochondrial encephalopathy, lactic acidosis and stroke-like episodes). Patient 3 suffers from ataxia, neuropathy, ophtalmoplegia and retinitis pigmentosa suggestive of NARP (neuropathy, ataxia, and retinitis pigmentosa) syndrome. Patient 4 presented with neurological regression mimicking Leigh disease, with ptosis, myoclonus, ataxia and brainstem and cerebellar atrophy. Screening for mitochondrial disease including enzyme and mtDNA investigations on muscle biopsy were performed on Patients 1, 2 and 4 with normal results. However, evidence for a glycosylation disorder was substantiated by an increased carbohydrate deficient transferrin (CDT). The isoelectric focussing pattern of serum sialotransferrin was typical of CDG type I in Patients 1, 2 and 3 and was shifted towards the less sialylated bands in case 4. A deficiency of phosphomanomutase (PMM) confirmed the diagnosis of CDG-Ia in Patients 1, 2 and 3, who are compound heterozygous for mutations R141H/T237M (Patients 1 and 2) and R141H/P113L (Patient 3). In Patient 4, PMM activity was normal, and further enzymatic and molecular studies are underway. As the search for the primary defect in mitochondrial diseases is often unsuccessful, the pool of mitochondrial patients that remain without definite diagnosis might include CDG cases. Routine screening for CDG may avoid precocious invasive investigations.
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PMID:Congenital disorders of glycosylation (CDG) may be underdiagnosed when mimicking mitochondrial disease. 1158 67

Mitochondrial diseases are a clinically heterogeneous group of disorders related to dysfunction of various components of oxidative metabolism. Common manifestations of these diseases include encephalopathy, skeletal myopathy, and cardiomyopathy, but essentially any tissue can be affected. To understand better the pathogenesis of mitochondrial disease and to potentially evaluate novel therapies, several mouse models have been reported in the literature over the past few years. In assessing genetically altered mice as potential models of human mitochondrial disease, careful behavioral and physiologic analyses are essential components of the overall phenotypic characterization. Noninvasive, in vivo approaches are useful because they assess end-organ and multiorgan function in a whole-organism context, as well as permit serial measurements of individual animals over time. This review presents various behavioral and exercise physiology protocols that can be used for the evaluation of potential mouse models of human mitochondrial disorders.
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PMID:Noninvasive, in vivo approaches to evaluating behavior and exercise physiology in mouse models of mitochondrial disease. 1205 28

Leber's hereditary optic neuropathy is a mitochondrial disease caused by point mutations in mitochondrial DNA. It usually presents as severe bilateral visual loss in young adults. We report on a neurological disorder resembling Leigh syndrome, which complicated Leber's hereditary optic neuropathy in three unrelated male patients harboring mitochondrial DNA mutations at nucleotide positions 3460, 14459, and 14484, respectively. This Leigh-like encephalopathy appears to be associated with a much more severe outcome than isolated Leber's hereditary optic neuropathy.
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PMID:Leigh-like encephalopathy complicating Leber's hereditary optic neuropathy. 1220 55

Alpers-Huttenlocher syndrome (AHS) is a rare mitochondrial disorder of childhood onset that is characterized by progressive encephalopathy and hepatopathy. MRI studies are rare and have not added substantial information to the pathogenesis of the encephalopathy. Diffusion-weighted MRI (DWI) and MR spectroscopy (MRS) were used in a patient with AHS during acute clinical deterioration and after improvement. DWI detected signal hyperintensity in several brain areas not restricted to any vascular territory. MRS revealed an unequivocal lactate peak and a reduced N-acetyl-aspartate-creatinine (NAA/Crea) ratio. DWI signal hyperintensity was correlated with neurologic symptoms and decreased after clinical improvement. Potentially reversible neuronal cytotoxic edema resulting from acute impairment of mitochondrial function is strongly suggested to be an important pathogenetic mechanism in AHS encephalopathy.
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PMID:Detection of acute cytotoxic changes in progressive neuronal degeneration of childhood with liver disease (Alpers-Huttenlocher syndrome) using diffusion-weighted MRI and MR spectroscopy. 1221 35


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