Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0162671 (MELAS)
 587 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied 40 MELAS patients (21 male and 19 female) to characterize the clinical features and biochemical and muscle biopsy findings related to the mtDNA mutation at the nucleotide position of 3,243, the most common genetic defect in MELAS. The most frequent symptom was episodic sudden headache with vomiting and convulsions, which commonly affected patients aged 5 to 15 years (80%). Biochemical defects in the muscle were variable; 13 patients had complex I, seven complex IV, and four complexes I + IV deficiencies. In four muscle biopsies without ragged-red fibers or any enzyme defect, we based the diagnosis on the identification of strongly SDH-reactive blood vessels, which occurred in 87.5% of the biopsies. The mtDNA mutation was present in 32 of 40 patients (80%). We conclude that there are no clinical and pathologic differences between the patients with and without this mtDNA mutation.
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PMID:Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS): a correlative study of the clinical features and mitochondrial DNA mutation. 154 15

A 37-year-old male with an 8-year-history of schizophrenic psychosis and dementia developed hyperpyrexia and cataleptic rigidity during haloperidol administration. He was transferred to our hospital where he was noticed to have generalized muscle weakness and atrophy. In his muscle biopsy, there were numerous ragged-red fibers and focal cytochrome c oxidase deficiency. In addition, the presence of strongly SDH-reactive blood vessels (SSV) in his muscle biopsy suggests that the similar systemic vascular abnormality as seen in MELAS plays a certain role for inducing the central nervous system symptoms. He discontinued haloperidol, and was placed on coenzyme Q and idebenone which were effective for his psychic problems. Several months later, his schizophrenic symptom disappeared and mental status improved from IQ of 60 to 68. We would emphasize that mitochondrial encephalomyopathies must be taken into account for differential diagnosis for psychiatric patients with mental deterioration.
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PMID:[A case of mitochondrial encephalomyopathy with schizophrenic psychosis, dementia and neuroleptic malignant syndrome]. 181 91

A 25-year-old man developed nausea, vomiting, severe headache, and confusion. He had a past history of hyperuricemia and mild renal dysfunction. On admission he had somatic growth retardation, hypertrichosis, and bilateral auditory impairment. A cranial CT scan showed a small area of low density in the left temporal lobe and cerebellar atrophy. Five days later, he developed right homonymous hemianopia, sensory aphasia, and sensory inattention, and a new, large area of low density in the left occipital lobe on a cranial CT scan. On laboratory examination, lactate, pyruvate, and the lactate-to-pyruvate ratio were elevated in both the serum and cerebrospinal fluid. The biopsied muscle showed ragged red fibers and strongly SDH-reactive blood vessels. Gene analysis revealed the presence of the A 3243 G point mutation of the mitochondrial tRNA(Leu) gene in his blood leucocytes and muscle. Serum concentrations of BUN and creatinine were elevated to 46 mg/dl and 2.2 mg/dl, respectively. Creatinine clearance was 14.1 ml/min. An abdominal CT scan disclosed atrophy of his left kidney with subcapsular calcification and the findings of his abdominal ultrasonography were compatible with chronic renal failure. His mother, who suffered from renal failure and became dialysis dependent in her late forties also bore the A 3243 G mutation of the mitochondrial tRNA(Leu) gene in her circulating leucocytes. Though the association between MELAS and renal dysfunction still remains obscure, we speculate that renal failure can be a manifestation of MELAS.
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PMID:[Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) with chronic renal failure: report of mother-child cases]. 897 30

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

A patient of MELAS is reported. A 28-year-old woman was admitted to Shimada Municipal Hospital because of nausea, vomiting, and right homonymous hemianopsia. She had past history of dizziness and convulsion. A brain magnetic resonance imaging showed an ischemic lesion in the left occipital lobe, which disappeared in the follow-up study. Laboratory examination indicated elevated lactate and pyruvate levels in both blood and cerebrospinal fluid. The muscle biopsy demonstrated ragged-red fibers and strongly SDH-reactive blood vessels. PCR-RFLP analysis of DNA extracted from her muscle and blood as well as her mother's blood revealed a T to C mutation at nucleophile position of 3271 in mitochondrial DNA. She was diagnosed as having MELAS and discharged. One year after the first admission, she re-visited our hospital because of three days' duration of fatigability and generalized muscle pain after alcohol intake. She had severe lactic acidosis, rhabdomyolysis and acute renal failure. Despite a continuous hemodialysis and other intensive efforts, the patient died 20 hours later. Alcohol intake has been reported to induce rhabdomyolysis in myopathy with mitochondrial DNA deletions. The course of this patient suggests that alcohol intake can be an aggravating factor also in MELAS.
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PMID:[A patient of MELAS with 3271 mutation with fatal outcome after alcohol intake]. 1108 93

Skin and muscles biopsy specimens of a patient harboring A3243G mutation in mitochondrial DNA, with dissection of internal carotid and vertebral arteries, associated with MELAS were studied using histochemical and electron-microscopy techniques. Ragged red fibers, regional variability of SDH histochemical reaction, two types of morphologically atypical mitochondria and their aggregation were found in muscle. There was correlation between SDH histochemical staining and number of mitochondria revealed by electron microscopy in muscle tissue. Similar mitochondrial abnormality, their distribution and cell lesions followed by extra-cellular matrix mineralization were found in the blood vessel walls. In line with generalization of cytopathy process caused by gene mutation it can be supposed that changes found in skin and muscle microvessels also exist in large cerebral vessels causing the vessel wall "weakness", predisposing them to dissection.
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PMID:[Morphological signs of mitochondrial cytopathy in skeletal muscles and micro-vessel walls in a patient with cerebral artery dissection associated with MELAS syndrome]. 2288 Apr 19