1/28. Congenital hydranencephalic-hydrocephalic syndrome with proliferative vasculopathy: a possible relation with mitochondrial dysfunction.We report the case of a fetus aborted at gestation week 20 because of hydranencephalic-hydrocephalic syndrome. The fetus was the third pregnancy of a nonconsanguineous couple whose first child exhibited congenital hydranencephalic-hydrocephalic syndrome associated with muscle histology findings consistent with mitochondrial cytopathy and deficiency of complexes III and IV of the respiratory chain and whose second pregnancy had terminated in an elective abortion on detection of progressive hydrocephalus at gestation week 19. The third pregnancy had a normal course according to obstetric and ultrasonography examinations performed at gestation weeks 5, 10, and 15, and negative results were obtained in standard serologic and polymerase chain reaction (PCR) tests for prenatal infections of the mother. However, the ultrasonography examination at gestation week 18 revealed hydrocephalus, in response to which the parents requested an abortion, which was performed at gestation week 20; the fetus was male and with no evident external malformations. Histopathologic studies of the brain and medulla oblongata revealed proliferative vasculopathy (glomeruloid vessels, intracytoplasmic inclusions, and microcalcifications) and intracytoplasmic inclusions in the voluntary muscle. Microbiologic and PCR tests of hepatic and spleen tissue were negative for prenatal infections. In view of the precedent of a sister with mitochondrial dysfunction, these findings raise the pos sibility that at least some cases of familial syndrome of congenital hydranencephalic-hydrocephalic syndrome with proliferative vasculopathy can be attributed to alterations in the mitochondrial respiratory chain.- - - - - - - - - - ranking = 1keywords = life (Clic here for more details about this article) |
2/28. Multiple neonatal deaths due to a homoplasmic mitochondrial dna mutation.Mutations of mitochondrial dna (mtDNA) are an important cause of genetic disease. We describe a family with an unusual homoplasmic mutation that resulted in six neonatal deaths and one surviving child with Leigh syndrome. The mother is clinically normal, but a severe biochemical and molecular genetic defect was present in both a fatally affected child and the mother. This family highlights the role of homoplasmic mt-tRNA mutations in genetic disease.- - - - - - - - - - ranking = 124.23482510288keywords = family (Clic here for more details about this article) |
3/28. 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 = 124.23482510288keywords = family (Clic here for more details about this article) |
4/28. Detection of dna mutations associated with mitochondrial diseases by Agilent 2100 bioanalyzer.BACKGROUND: Molecular analysis of mitochondrial dna (mtDNA) has provided a final diagnosis for many of the mitochondrial diseases. We evaluated the Agilent 2100 bioanalyzer (Agilent Technologies, Palo Alto, CA) to determine whether the system could replace the conventional restriction fragment length polymorphism (RFLP) analysis by the agarose gel electrophoresis for the detection of the mtDNA mutation. methods: Three members of a family with melas syndrome and four members of a family with merrf syndrome were recruited for this study. After PCR and restriction enzyme digestion, dna fragments were separated on the Agilent 2100 bioanalyzer in conjunction with the dna 500 and dna 1000 Labchip kits and by electrophoresis on precast 3% agarose gels. RESULTS: The data generated by the dna 500 and dna 1000 assays using the Agilent 2100 bioanalyzer showed a lower percentage error and a better reproducibility as compared to those obtained by the conventional method. CONCLUSION: Based on the performance of the bioanalyzer, we suggest that this novel Labchip is adequate to replace the current RFLP analysis by the agarose gel electrophoresis for mtDNA mutation detection.- - - - - - - - - - ranking = 125.44608812371keywords = family, member (Clic here for more details about this article) |
5/28. Mitochondrial disorders: a clinician's primer.Mitochondrial disorders represent an extremely challenging set of conditions, partly due to the complexities of the mitochondrial genetic system. nurses must be prepared with knowledge about genetic conditions so that they can participate fully in early identification of affected individuals and assist them in accessing the most current genetic diagnostic and treatment therapeutics. This knowledge will be critical as nurses collect family history data, provide current and accurate genetic information and support to individuals and families, and refer to and collaborate with genetic specialists in their communities.- - - - - - - - - - ranking = 62.11741255144keywords = family (Clic here for more details about this article) |
6/28. MEHMO (Mental retardation, Epileptic seizures, Hypogenitalism, microcephaly, obesity): a new X-linked mitochondrial disorder.MEHMO (Mental retardation, Epileptic seizures, Hypogenitalism, microcephaly and obesity) is an X-linked disorder characterised by mental retardation, epileptic seizures, hypogenitalism, microcephaly and obesity. It was recently assigned to the locus Xp21.1-p22.13. We describe a child with MEHMO and lactic acidosis whose muscle biopsy revealed markedly reduced activities of complexes 1,3 and 4 of the mitochondrial electron transport chain. Histological staining showed mitochondrial proliferation and lipid storage. Electron microscopy revealed abnormal and enlarged mitochondria with concentric cristae and electron dense bodies. This is the first identification of MEHMO as a mitochondrial disorder and one of the very few X-linked mitochondrial syndromes.- - - - - - - - - - ranking = 0.16666666666667keywords = life (Clic here for more details about this article) |
7/28. Treatment of cardiomyopathy and rhabdomyolysis in long-chain fat oxidation disorders using an anaplerotic odd-chain triglyceride.The current dietary treatment of long-chain fatty acid oxidation defects (high carbohydrate with medium-even-chain triglycerides and reduced amounts of long-chain fats) fails, in many cases, to prevent cardiomyopathy, rhabdomyolysis, and muscle weakness. We hypothesized that the apparent defect in energy production results from a depletion of the catalytic intermediates of the citric acid cycle via leakage through cell membranes (cataplerosis). We further hypothesized that replacing dietary medium-even-chain fatty acids (precursors of acetyl-CoA) by medium-odd-chain fatty acids (precursors of acetyl-CoA and anaplerotic propionyl-CoA) would restore energy production and improve cardiac and skeletal muscle function. We fed subjects with long-chain defects a controlled diet in which the fat component was switched from medium-even-chain triglycerides to triheptanoin. In three patients with very-long-chain acyl-coa dehydrogenase deficiency, this treatment led rapidly to clinical improvement that included the permanent disappearance of chronic cardiomyopathy, rhabdomyolysis, and muscle weakness (for more than 2 years in one child), and of rhabdomyolysis and weakness in the others. There was no evidence of propionyl overload in these patients. The treatment has been well tolerated for up to 26 months and opens new avenues for the management of patients with mitochondrial fat oxidation disorders.- - - - - - - - - - ranking = 0.47852366255144keywords = cycle (Clic here for more details about this article) |
8/28. Impaired mitochondrial pyruvate importation in a patient and a fetus at risk.The patient was the first child of healthy consanguineous parents. She presented at birth with hypotonia, mild facial dysmorphism, periventricular cysts, marked metabolic acidosis, hyperlactacidemia with normal lactate/pyruvate molar ratios, normoglycemia, and normal ammonia. Hyperlactacidemia was severe (5-14 mmol/l) and not corrected with bicarbonate, thiamine (10 mg/d), 2-chloropropionate (100 mg/kg/d) and a ketogenic diet. Pyruvate dehydrogenase (PDHC) activity was normal in lymphocytes and fibroblasts. Functional assays were performed in digitonin-permeabilized fibroblasts to measure oxidation rates from radiolabeled pyruvate and malate. The production of [14C]acetylcarnitine or [14C]citric cycle intermediates derived from [2-14C]pyruvate as well as the release of 14CO(2) from [1-14C]pyruvate was severely impaired, whereas decarboxylation of [U-14C]malate was normal. With increasing concentrations of [1-14C]pyruvate, the patient's fibroblasts behave like control fibroblasts incubated in the presence of alpha-cyano-4-hydroxycinnamate, a specific inhibitor of mitochondrial pyruvate uptake: a progressive increase in 14CO(2) production was observed, likely due to passive diffusion of [1-14C]pyruvate through the mitochondrial membranes. Our results are consistent with a defect of mitochondrial pyruvate transport in the patient. Mutational analysis was precluded as the cDNA sequence of the pyruvate carrier has not been identified as yet in any organism. An affected fetus was recognized in a subsequent dichorionic twin pregnancy using the coupled assay measuring [2-14C]pyruvate oxidation rates on digitonin-permeabilized trophoblasts. After selective feticide, the pregnancy was uncomplicated with delivery at 37w of a healthy female, who is currently 2-month old.- - - - - - - - - - ranking = 0.47852366255144keywords = cycle (Clic here for more details about this article) |
9/28. Autosomal dominant acute necrotizing encephalopathy.OBJECTIVE: To define the clinical and biochemical abnormalities of an autosomal dominant form of acute encephalopathy. methods: The clinical details of 11 affected family members in comparison with 63 unaffected relatives were analyzed. RESULTS: Affected children become comatose after onset of a febrile illness. Outcomes include full recovery, permanent neurologic impairment, and death. Recurrences produce more severe impairments. Lesions of necrotizing encephalopathy of the thalamus and brainstem are present on autopsy and MRI. oxidative phosphorylation of intact mitochondria from a muscle biopsy shows loose coupling. Unaffected family members, including obligate carriers, share no clinical characteristics, demonstrating incomplete penetrance. CONCLUSIONS: Characteristic pathology and MRI findings define this disorder of autosomal dominant acute encephalopathy. Leigh syndrome and sporadic acute necrotizing encephalopathy share similarities but are distinct.- - - - - - - - - - ranking = 140.43114229681keywords = family, family member, member (Clic here for more details about this article) |
10/28. New pattern of brain MRI lesions in isolated complex I deficiency.We describe a boy presenting at the end of the first year of life with severely delayed motor development and only mild mental retardation. Neurological examination revealed axial hypotonia, mild ataxia and pyramidal signs. Elevated lactate and protein in cerebrospinal fluid were the most prominent laboratory abnormalities. brain MRI showed severe supratentorial white matter changes. Cerebellar white matter appeared normal whereas the signal of the atrophic cerebellar cortex was markedly increased. In vivo 1H-magnetic resonance spectroscopy of the parietooccipital white matter region showed a distinct resonance of lactate. By means of biochemical analysis of respiratory chain enzymes in fibroblasts, the diagnosis of an isolated complex I deficiency could be established in our patient.- - - - - - - - - - ranking = 0.16666666666667keywords = life (Clic here for more details about this article) |
| | Next -> |