1/11. Progressive mitochondrial disease resulting from a novel missense mutation in the mitochondrial dna ND3 gene.We describe a 42-year-old man who presented with a progressive history of epilepsy, stroke-like episodes, bilateral optic atrophy, and cognitive decline. Investigation of his muscle biopsy revealed a specific defect in complex I activity. Subsequent analysis of the mitochondrial genome identified a novel heteroplasmic T10191C mutation in the ND3 gene. The mutation was present at lower levels in blood from the patient and unaffected maternal relatives and is the first pathogenic mitochondrial dna mutation in the ND3 gene to be described.- - - - - - - - - - ranking = 1keywords = optic atrophy, atrophy, optic (Clic here for more details about this article) |
2/11. autopsy case of autosomal recessive hereditary spastic paraplegia with reference to the muscular pathology.An autopsied case of autosomal recessive hereditary spastic paraplegia with severe neurogenic muscular atrophy is described herein. This patient, a 16-year-old woman, presented with gait disturbance. She developed progressive spastic paralysis of the upper and lower limbs and mental deterioration. She became bedridden at approximately 40years of age. dysarthria worsened at 45 years of age. She died of pneumonia at 50 years of age. Her younger sister has shown similar clinical symptoms and became bedridden at 37 years of age. Their parents were second cousins. autopsy revealed a severely atrophic brain, weighing 720 g. The cerebral cortex was thin, and the white matter was extremely reduced in volume. Microscopically, neuronal loss and variable astrogliosis with diffuse spongy changes were evident at the cerebral cortex, thalamic nuclei, basal ganglia and hippocampus. The remaining neurons were atrophied with heavy deposition of lipofuscin. In the spinal cord, the pyramidal tracts as well as the dorsal spinocerebellar tracts were degenerated. In addition, marked loss of the anterior horn cells was seen. Severe neuronal loss of the nucleus gracilis was also detected. In contrast, only mild degeneration of the ventral spinocerebellar tracts and fasciulus cuneatus in the spinal cord were observed. In the frozen sections of skeletal muscle, severe neurogenic atrophy and fatty infiltration were evident. In addition, several rimmed vacuoles were observed in the atrophic fibers, and cytochrome coxidase-deficient fibers were present in part. Reduced nicotinamide adenine dinucleotide (NADH)-tetrazolium reductase reaction revealed abnormal accumulation of mitochondria around the center of the non-atrophic muscle fibers. It is suggested that an analysis of mitochondrial function of Japanese autosomal recessive hereditary spastic hemiplegia may provide additional information to clarify the pathogenesis.- - - - - - - - - - ranking = 0.064245735629422keywords = atrophy (Clic here for more details about this article) |
3/11. Parkinson's disease associated with impaired oxidative phosphorylation.Parkinson's disease may be due to primary or secondary oxidative phosphorylation (OXPHOS) defects. In a 76-year-old man with Parkinson's disease since 1992, slightly but recurrently elevated creatine phosphokinase, recurrently elevated blood glucose, thickening of the left ventricular myocardium, bifascicular block and hypacusis were found. Cerebral MRI showed atrophy, periventricular demyelination, multiple, disseminated, supra- and infratentorial lacunas, and haemosiderin deposits in both posterior horns. Muscle biopsy showed typical features of an OXPHOS defect. Whether the association of Parkinson's disease and impaired OXPHOS was causative or coincidental remains unknown. Possibly, the mitochondrial defect acted as an additional risk factor for Parkinson's disease or the OXPHOS defect worsened the preexisting neurological impairments by a cumulative or synergistic mechanism. In conclusion, this case shows that Parkinson's disease may be associated with a mitochondrially or nuclearly encoded OXPHOS defect, manifesting as hypacusis, myopathy, axonal polyneuropathy, cardiomyopathy and recurrent subclinical ischaemic strokes and haemorrhages.- - - - - - - - - - ranking = 0.032122867814711keywords = atrophy (Clic here for more details about this article) |
4/11. Neuronal cell death in the visual cortex is a prominent feature of the X-linked recessive mitochondrial deafness-dystonia syndrome caused by mutations in the TIMM8a gene.The Mohr-Tranebjaerg syndrome (MIM 304700) and the Jensen syndrome (MIM 311150) were previously reported as separate X-linked recessive deafness syndromes associated with progressive visual deterioration, dystonia, dementia, and psychiatric abnormalities. In the most extensively studied Norwegian family, the Mohr-Tranebjaerg syndrome was reported to be caused by a one-basepair deletion (151delT) in the deafness/dystonia peptide (DDP) gene at Xq22. This gene has been renamed TIMM8a. We identified a stop mutation (E24X) in the TIMM8a gene segregating with the disease in the original Danish family with the Jensen syndrome, which confirms that the two disorders are allelic conditions. We also report abnormal VEP examinations and neuropathological abnormalities in affected males from the two unrelated families with different mutations. The findings included neuronal cell loss in the optic nerve, retina, striate cortex, basal ganglia, and dorsal roots of the spinal cord. The demonstration of mitochondrial abnormalities in skeletal muscle biopsies in some patients is compatible with the suggestion from recent research that the TIMM8a protein is the human counterpart of an intermembrane mitochondrial transport protein, Tim8p, recently characterized in yeast. The clinical and neuropathological abnormalities associated with mutations in the TIMM8a gene support that this X-linked deafness-dystonia-optic neuropathy syndrome is an example of progressive neurodegeneration due to mutations in a nuclear gene necessary for some, yet unknown mitochondrial transport function. We recommend sequencing the TIMM8a gene, thorough ophthalmological examination, and measuring visual evoked potentials in clinically suspected male patients with either progressive hearing impairment, dystonia, or visual disability in order to establish an early diagnosis and provide appropriate genetic counselling.- - - - - - - - - - ranking = 0.033665357774819keywords = optic (Clic here for more details about this article) |
5/11. Clinical features and neuroradiological findings of mitochondrial pathology in six neonates.OBJECTS: We hoped to itemize the clinical and neuroradiological features of six neonates with mitochondrial disorders. methods: We examined a case series of six neonates. The diagnosis of mitochondrial cytopathy was made on the basis of spectrophotometric measurements of respiratory chain enzyme activities in skeletal muscle biopsy specimens. Magnetic resonance (MR) imaging was performed in all cases. CONCLUSIONS: The antenatal onset in five cases and the lack of any symptom-free interval are suggestive of fetal expression of the disease. No specific symptoms were found: arthrogryposis congenita multiplex in one, progressive hepatocellular dysfunction in three, encephalomyelopathy and cardiomyopathy in four. Complex I deficiency was found in three patients, while one patients had a defect of complex IV and the last a combined defect of complexes I and IV. Neuroradiological findings were either cerebral atrophy or white matter abnormalities of the brain stem in all cases but one and gave additional information, because clinical symptoms are not quite specific. The combination of clinical and MRI findings in neonatal cases can rule out hypoxic ischemic encephalopathy, which suggests an additional screening method to look for mitochondrial disorder.- - - - - - - - - - ranking = 0.032122867814711keywords = atrophy (Clic here for more details about this article) |
6/11. Neonatal liver failure and Leigh syndrome possibly due to CoQ-responsive OXPHOS deficiency.CoQ transfers electrons from complexes I and II of the mitochondrial respiratory chain to complex III. There are very few reports on human CoQ deficiency. The clinical presentation is usually characterized by: epilepsy, muscle weakness, ataxia, cerebellar atrophy, migraine, myogloblinuria and developmental delay. We describe a patient who presented with neonatal liver and pancreatic insufficiency, tyrosinemia and hyperammonemia and later developed sensorineural hearing loss and Leigh syndrome. Liver biopsy revealed markedly reduced complex I III and II III. Addition of CoQ to the liver homogenate restored the activities, suggesting CoQ depletion. Histological staining showed prominent bridging; septal fibrosis and widening of portal spaces with prominent mixed inflammatory infiltrate, associated with interface hepatitis, bile duct proliferation with numerous bile plugs. Electron microscopy revealed a large number of mitochondria, which were altered in shape and size, widened and disordered intercristal spaces. This may be the first case of Leigh syndrome with liver and pancreas insufficiency, possibly caused by CoQ responsive oxphos deficiency.- - - - - - - - - - ranking = 0.032122867814711keywords = atrophy (Clic here for more details about this article) |
7/11. A boy with mitochondrial disease: asymptomatic proteinuria without neuromyopathy.Mitochondrial disorder is a relatively rare disease during childhood. Previous studies concluded that renal complications in this disease most often occur in patients with mitochondrial encephalomyopathies. We describe a boy with mitochondrial disease who presented with proteinuria while lacking neuromyopathy. proteinuria was detected at the age of 6 years, including large amounts of low-molecular-weight proteins such as beta(2)- and alpha1-microglobulin. Renal functions were normal. Proximal tubular dysfunction and other renal manifestations were absent. Episodic neurologic problems such as migraine and nervous system diseases including epilepsy, depression, schizophrenia and amytrophic lateral sclerosis (ALS) were found in the boy's family members. Renal tubular basement membrane atrophy and interstitial fibrosis with mononuclear cell infiltration were observed. Ultrastructural examination showed mitochondria, mainly in the proximal tubules, which varied in size and had disoriented cristae. Mutation analysis using mitochondrial dna (mtDNA) extracted from renal tissues demonstrated a A-->G point mutation at nucleotide position 3243 in the tRNA(Leu(UUR)) gene, while there was no mutation found in mtDNA extracted from peripheral leukocytes. awareness among pediatricians of mitochondrial disorders, detection of low-molecular-weight proteinuria, renal ultrastructural examination and mutation analysis of mtDNA obtained from renal tissues could be important for early diagnosis of this disease.- - - - - - - - - - ranking = 0.032122867814711keywords = atrophy (Clic here for more details about this article) |
8/11. A case of CPT deficiency, homoplasmic mtDNA mutation and ragged red fibers at muscle biopsy.A 45-year-old male patient had an episode of acute renal failure with myoglobinuria, myalgias, weakness, and markedly increased serum CK levels. Similar episodes had occurred in the past. carnitine palmitoyl-transferase II (CPT II) deficiency was documented both biochemically and genetically. Interestingly, muscle biopsy also showed some ragged red fibers (RRF) and complete mitochondrial dna (mtDNA) sequence disclosed a homoplasmic T3394C point mutation. This mutation is described in Leber's hereditary optic neuropathy (LHON) or in patients with diabetes mellitus.- - - - - - - - - - ranking = 0.016832678887409keywords = optic (Clic here for more details about this article) |
9/11. Developmental regression and mitochondrial dysfunction in a child with autism.Autistic spectrum disorders can be associated with mitochondrial dysfunction. We present a singleton case of developmental regression and oxidative phosphorylation disorder in a 19-month-old girl. Subtle abnormalities in the serum creatine kinase level, aspartate aminotransferase, and serum bicarbonate led us to perform a muscle biopsy, which showed type I myofiber atrophy, increased lipid content, and reduced cytochrome c oxidase activity. There were marked reductions in enzymatic activities for complex I and III. Complex IV (cytochrome c oxidase) activity was near the 5% confidence level. To determine the frequency of routine laboratory abnormalities in similar patients, we performed a retrospective study including 159 patients with autism (diagnostic and statistical manual of mental disorders-IV and Childhood Autism Rating Scale) not previously diagnosed with metabolic disorders and 94 age-matched controls with other neurologic disorders. Aspartate aminotransferase was elevated in 38% of patients with autism compared with 15% of controls (P <.0001). The serum creatine kinase level also was abnormally elevated in 22 (47%) of 47 patients with autism. These data suggest that further metabolic evaluation is indicated in autistic patients and that defects of oxidative phosphorylation might be prevalent.- - - - - - - - - - ranking = 0.032122867814711keywords = atrophy (Clic here for more details about this article) |
10/11. Clinical spectrum of mitochondrial dna depletion due to mutations in the thymidine kinase 2 gene.BACKGROUND: Mitochondrial dna depletion syndrome is an autosomal recessive disorder characterized by decreased mitochondrial dna copy numbers in affected tissues. It has been linked to 4 genes involved in deoxyribonucleotide triphosphate metabolism: thymidine kinase 2 (TK2), deoxyguanosine kinase (DGUOK), polymerase gamma (POLG), and SUCLA2, the gene encoding the beta-subunit of the adenosine diphosphate-forming succinyl coenzyme a synthetase ligase. OBJECTIVE: To highlight the variability in the clinical spectrum of TK2-related mitochondrial dna depletion syndrome. DESIGN: review of patients and the literature. SETTING: Tertiary care university. patients: Four patients with mitochondrial dna depletion syndrome and mutations in the TK2 gene. MAIN OUTCOME MEASURES: Definition of clinical variability. RESULTS: Patient 1 had evidence of lower motoneuron disease and was initially diagnosed as having spinal muscular atrophy type 3. Patient 2, who is alive and ambulatory at age 9 years, presented at age 2 years with a slowly progressive mitochondrial myopathy. Patient 3 had a more severe myopathy, with onset in infancy and death at age 6 years of respiratory failure. Patient 4 had a rapidly progressive congenital myopathy with rigid spine syndrome and he died at age 19 months. CONCLUSION: The clinical spectrum of TK2 mutations is not limited to severe infantile myopathy with motor regression and early death but includes spinal muscular atrophy type 3-like presentation, rigid spine syndrome, and subacute myopathy without motor regression and with longer survival.- - - - - - - - - - ranking = 0.064245735629422keywords = atrophy (Clic here for more details about this article) |
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