1/34. Neuroradiologic findings in glutaric aciduria type II.The authors report a 3-year-old male with glutaric aciduria type II, whose magnetic resonance imaging studies revealed agenesis of the cerebellar vermis and hypoplastic temporal lobes. Proton magnetic resonance spectroscopy in the parietal white matter revealed a markedly increased choline/creatine ratio, suggesting a demyelinating process. Gas chromatographic analysis of urinary organic acids should be studied in any patient with agenesis of the cerebellar vermis and cystic renal disease to exclude glutaric aciduria type II.- - - - - - - - - - ranking = 1keywords = spectroscopy (Clic here for more details about this article) |
2/34. [13C]valine metabolism in methylmalonicacidemia using nuclear magnetic resonance: propinonate as an obligate intermediate.[Alpha-13C]- and [alpha,beta-13C]valine were administered sequentially to a patient with methylmalonicacidemia to clarify the metabolic pathway of valine from methylmalonic acid semialdehyde to methylmalonyl-CoA. methylmalonic acid was isolated from multiple urine samples, purified, and analyzed by 13C nuclear magnetic resonance spectroscopy. Contrary to the widely accepted view, the results show unequivocally that methylmalonic acid semialdehyde is decarboxylated to propionate before conversion to methylmalonyl CoA.- - - - - - - - - - ranking = 1keywords = spectroscopy (Clic here for more details about this article) |
3/34. Localized proton MR spectroscopy in infants with urea cycle defect.SUMMARY: urea cycle defect is an inborn error of ammonium metabolism caused by a deficient activity of the enzymes involved in urea synthesis. Localized short-TE proton MR spectroscopy, performed in two infants who had citrullinemia and ornithine transcarbamylase deficiency, respectively, showed a prominent increase of glutamine/glutamate and lipid/lactate complex in both cases. N-acetylaspartate, total creatine, and myo-inositol were decreased in the infant with citrullinemia. Proton MR spectroscopy provided useful information for the diagnosis and understanding of the pathophysiology of urea cycle enzyme defect.- - - - - - - - - - ranking = 6keywords = spectroscopy (Clic here for more details about this article) |
4/34. magnetic resonance spectroscopy in a 9-day-old heterozygous female child with creatine transporter deficiency.An X-linked creatine deficiency syndrome caused by mutations in the creatine transporter gene SLC6A8/CRTR mapped to Xq28 has recently been described. Essential in the recognition of this disorder is the absence of creatine on proton magnetic resonance spectroscopy (MRS) examination. A 9-day-old heterozygous female child with this syndrome demonstrated a significant reduction of creatine on proton MRS. She is a carrier of the R514X nonsense mutation.- - - - - - - - - - ranking = 5keywords = spectroscopy (Clic here for more details about this article) |
5/34. Proton NMR spectroscopy of Canavan's disease.Proton Nuclear Magnetic Resonance (NMR) spectroscopy was used to quantitatively determine cerebral N-Acetyl Aspartate (NAA) concentrations in four patients with Canavan's disease and in four age-matched control subjects. Macroscopic NAA concentrations (mumol/gm wet weight) were not found to be significantly different from controls. Reduced levels of choline and creatine were observed in all patients, and increased levels of lactate and inositol in the eldest three patients.- - - - - - - - - - ranking = 5keywords = spectroscopy (Clic here for more details about this article) |
6/34. Proton MR spectroscopy in succinic semialdehyde dehydrogenase deficiency.Succinic semialdehyde dehydrogenase (SSADH) deficiency is a rare hereditary disorder of the CNS catabolism of gamma-aminobutyric acid (GABA), leading to accumulation of the metabolite 4-hydroxybutyrate (GHB). Here the authors report on 1.5 and 3.0 T proton MR spectroscopy in a patient with SSADH deficiency. A characteristic pattern with clearly elevated GABA levels and traces of GHB was found in both the white and the gray matter of the brain. In vivo spectroscopy may be useful for diagnosis and monitoring SSADH deficiency.- - - - - - - - - - ranking = 6keywords = spectroscopy (Clic here for more details about this article) |
7/34. Aromatic L-amino acid decarboxylase deficiency: clinical features, treatment, and prognosis.BACKGROUND: Deficiency of aromatic L-amino acid decarboxylase (AADC) is associated with severe developmental delay, oculogyric crises (OGC), and autonomic dysfunction. Treatment with dopamine agonists and MAO inhibitors is beneficial, yet long-term prognosis is unclear. OBJECTIVE: To delineate the clinical and molecular spectrum of AADC deficiency, its management, and long-term follow-up. RESULTS: The authors present six patients with AADC deficiency and review seven cases from the literature. All patients showed reduced catecholamine metabolites and elevation of 3-O-methyldopa in CSF. Residual plasma AADC activity ranged from undetectable to 8% of normal. Mutational spectrum was heterogeneous. All patients presented with hypotonia, hypokinesia, OGC, and signs of autonomic dysfunction since early life. Diurnal fluctuation or improvement of symptoms after sleep were noted in half of the patients. Treatment response was variable. Two groups of patients were detected: Group I (five males) responded to treatment and made developmental progress. Group II (one male, five females) responded poorly to treatment, and often developed drug-induced dyskinesias. CONCLUSIONS: The molecular and clinical spectrum of AADC deficiency is heterogeneous. Two groups, one with predominant male sex and favorable response to treatment, and the other with predominant female sex and poor response to treatment, can be discerned.- - - - - - - - - - ranking = 0.0011208671672736keywords = spectrum (Clic here for more details about this article) |
8/34. Follow-up of a child with hypoacetylaspartia.We provide a 5-year follow-up of a patient previously reported to have no NAA signal on neurospectroscopy. At 8 years this boy was found to have profound neurological dysfunction: he had truncal ataxia, no expressive speech, behaviour abnormalities, secondary microcephaly and cognitive achievements corresponding to less than 12 months of age. He started to have generalized seizures at 5 years 9 months. Although not directly proven we assume an inborn error of NAA metabolism, possibly a defect of the anabolic enzyme L-aspartate N-acetyltransferase (EC 2.3.1.17).- - - - - - - - - - ranking = 1keywords = spectroscopy (Clic here for more details about this article) |
9/34. Nuclear magnetic resonance spectroscopy in glutaryl-coa dehydrogenase deficiency.Nuclear magnetic resonance (NMR) spectroscopy is a safe, noninvasive method that is the preferred technique for in vivo analysis of specific chemical compounds in localized brain regions. Besides quantification of compounds, NMR spectroscopy allows the detailed analysis of neurotransmitter, glucose and lactate metabolism following peripheral infusions of stable isotopically labelled precursors. The latter has been successfully applied to patients with different neurological disease states not including glutaryl-coa dehydrogenase (GCDH) deficiency. In contrast, single patients with GCDH deficiency who were neurologically unremarkable have been studied with conflicting results. One patient was shown to have an increase in intracerebral creatine and phosphocreatine concentrations, while the second studied had unremarkable levels. In a 15-year-old patient, we were able to demonstrate elevated levels of intracerebral lactate and elevated choline/N -acetylaspartate ratios, indicating potentially increased myelin turnover and reduced neuronal integrity in periventricular white matter. Interestingly, spectra in basal ganglia were within normal limits. Systematic studies to address well-defined questions in GCDH deficiency are urgently needed. In particular, analysis of in vivo neurotransmitter metabolism following administration of isotopically labelled precursors in patients with GCDH deficiency, both when metabolically stable and when unstable, may help to advance our understanding of the pathophysiology of GCDH deficiency.- - - - - - - - - - ranking = 6keywords = spectroscopy (Clic here for more details about this article) |
10/34. Guanidinoacetate methyltransferase deficiency identified in adults and a child with mental retardation.Our study describes the adult clinical and biochemical spectrum of guanidinoacetate methyltransferase (GAMT) deficiency, a recently discovered inborn error of metabolism. The majority of the previous reports dealt with pediatric patients, in contrast to the present study. A total of 180 institutionalized patients with a severe mental handicap were investigated for urine and plasma uric acid and creatinine. patients with an increased urinary uric acid/creatinine ratio and/or decreased creatinine were subjected to the analysis of guanidinoacetate (GAA). Four patients (three related and one from an unrelated family) were identified with GAMT-deficiency. A fifth patient had died before a biochemical diagnosis could be made. They all had shown a normal psychomotor development for the first year of life, after which they developed a profound mental retardation. Three out of four had convulsions and all four totally lacked the development of speech. Their GAMT activity in lymphoblasts was impaired and two novel mutations were identified: the 59 G > C and 506 G > A missense mutations. Urinary GAA was increased, but highly variable 347-1,624 mmol/mol creat (Controls <150 mmol/mol creat). In plasma and CSF the GAA levels were fairly constant at 17.3-27.0 mumol/L (Controls 1.33-3.33) and 11.0-12.4 mumol/L, respectively (Controls 0.068-0.114). GAMT deficiency in adults is associated with severe mental retardation and absence or limited speech development. Convulsions may be prominent. The nonspecific nature of the clinical findings as well as the limited availability of GAA assays and/or in vivo magnetic resonance spectroscopy of the brain may mean that many more patients remain undiagnosed in institutions for persons with mental handicaps.- - - - - - - - - - ranking = 1.0003736223891keywords = spectroscopy, spectrum (Clic here for more details about this article) |
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