| amino acids analysis were made on serum and cerebrospinal fluid samples of a Japanese 5-month-old infant suffering from irritability and mental retardation noticed at 2 months of age. Excessive amounts of branched-chain amino acids and of keto acids were detected in those samples and the large quantity of keto acids was found in urine with a qualitative 2,4-dinitro-phenyl-hydrazin test and with quantitative estimation. When thiamine hydrochloride (100 mg/day) was administered orally for 7 days to the patient fed with the cow's milk formula containing 2.1 gm/dl milk protein, there was no improvement of the branched-chain amino acidemia. Urinary keto acids, however, showed a marked decrease 7 days after the administration of thiamine hydrochloride. An overnight fast for 13 h resulted in normoglycemia. There was found no difference of blood L-lencine level between both parents and normal infants to whom L-leucine was loaded. The relation between decarboxylase activity for keto acids of branched-chain amino acids and thiamine hydrochloride was studied clinically, in the present communication. ( info) |
| A 25-year-old woman with maple syrup urine disease (MSUD) developed generalized weakness over 1 week. She had severe leg and moderate arm weakness, areflexia, and distal sensory loss. plasma branched-chain amino acid concentrations were elevated, reflecting an acute exacerbation of the disease. Electrodiagnostic studies indicated an acute axonal polyneuropathy and sural nerve biopsy revealed acute wallerian degeneration without inflammation. Peripheral neuropathy, although not identified previously as a clinical feature of MSUD, may become more common as chronic dietary restrictions and improved management of the disease allow survival into adulthood. ( info) |
| We characterized the effect of orthotopic liver transplantation on the catabolism of branched-chain L-amino acids in a female patient with classical form of maple syrup urine disease. Transplantation was performed at the age of 7.4 years due to a terminal liver failure triggered by a hepatitis a infection. Since then, the patient is on an unrestricted diet and plasma concentrations of branched-chain L-amino and 2-oxo acids are stable, yet at moderately increased levels (2- to 3-fold of control). L-Alloisoleucine concentrations, however, remained remarkably elevated (> 5-fold of control). In vivo catabolism was investigated by measuring the metabolic L-alloisoleucine clearance and whole-body leucine oxidation in the postabsorptive state. In an oral loading test with 580 micromol alloisoleucine per kg body wt, the L-alloisoleucine elimination rate constant (0.067 h(-1)) was in the normal range (0.069 /-0.012 h(-1), n = 4). In an oral L-[1-13C]leucine load (38 micromol/kg body wt), 19.5% of the tracer dose applied was recovered in exhaled 13CO2 versus 18.9 /-3.6% in healthy subjects (n = 10). Thus, the patient exhibited obviously normal whole-body catabolic rates although branched-chain L-amino acid oxidation was confined to the liver transplant. Most likely, the enhanced substrate supply from extrahepatic sources led to an elevation of the plasma concentrations and thus induced a compensatory enhancement of the metabolic flux through the branched-chain 2-oxo acid dehydrogenase complex in the intact liver tissue. ( info) |
| maple syrup urine disease is a rare inborn error of metabolism, characterized by elevated plasma levels of branched chain amino acids and urinary excretion of branched chain keto acids. plasma amino acid levels in two subjects were followed by deproteinizing plasma, derivatizing the free amino acids with phenylisothiocyanate, and analysis by HPLC. The results indicate that valine, leucine and isoleucine are elevated in maple syrup urine disease, and that leucine remains high even after dietary treatment. ( info) |
5/80. Detection of inherited metabolic disorders via tandem mass spectrometry in Thai infants. From a retrospective study in Medical genetics Unit, Department of pediatrics, Siriraj Hospital faculty of medicine, Mahidol University in Bangkok (1983-1988), the estimated pediatric patients with clinically suspected IEM are approximately 2-4% of total annual pediatrics admission of 5,000 or more. This is, a low estimation since survey from all teaching hospitals in the country including the largest Children's Hospital in Bangkok indicated the presence of numerous IEM. However, most IEM were clinically diagnosed with limited laboratory facilities. We started a collaboration with Magee Womens Hospital of Pittsburgh and NeoGen Screening, USA; using tandem mass spectrometry to diagnose high risk infants and children for IEM from July 1993 to March 1998. Of total 146 samples sent, we detected numerous metabolic disorders (11.2%) eg phenylketonuria, organic acidemia, maple syrup urine disease, isovaleric acidemia, methylmalonic acidemia, albinism, translocase/carnitine palmitoyltransferase type II, G6PD deficiency and lysinuric protein intolerance. ( info) |
6/80. Pseudo-maple syrup urine disease due to maternal prenatal ingestion of fenugreek. Fenugreek, maple syrup and the urine of maple syrup urine disease (MSUD) patients all share a characteristic odour originating from a common component, sotolone. Ingestion of fenugreek by mothers during labour resulted in a maple syrup-like odour in their newborn infants, leading to a false suspicion of MSUD. ( info) |
| The first two patients in israel in whom the diagnosis of maple syrup urine disease was confirmed are reported. The clinical course of the disease and therapeutic procedures during the first months of life are described. The age on onset and the severity of neurological symptomatology were different in the two patients. In the first, blood leucine levels were extremely high, and drastic procedures, such as peritoneal dialysis, were employed in addition to dietary treatment to lower the leucine levels to normal and to improve the patient's clinical condition. In the second infant, blood leucine levels were moderately elevated and the disease was controlled by dietary treatment alone. Neither of the patients responded to thiamine hydrochloride treatment. The two infants probably represent examples of different genotypes of the classic form of maple syrup urine disease. ( info) |
| maple syrup urine disease (MSUD) is an inborn error of metabolism stemming from a deficiency in 2-ketoacid dehydrogenase and resulting in the systemic accumulation of branched chain amino acids (BCAAs). Affected children may suffer profound developmental and cognitive impairment from exposure to high levels of BCAA and their associated neurotoxic metabolites. Endogenous renal clearance of BCAA is limited and several therapeutic modalities including intensive nutritional regimens, exchange transfusions, peritoneal dialysis, and continuous hemofiltration have been utilized in neonates with MSUD, all of which have had varying success in reducing systemic BCAA levels. In this report, a symptomatic 7-day-old 3-kg neonate with MSUD underwent treatment with a combination of early hemodialysis and aggressive enteral feedings of a metabolically appropriate formula. This approach results in a 75% reduction of systemic toxin levels within 3 h. When compared to other reported modalities of therapy for symptomatic neonates with MSUD, this approach appears to be most efficacious. Moreover, by minimizing the amount of time that an affected neonate is exposed to neurotoxic levels of BCAAs, long-term developmental and cognitive capabilities may be preserved. ( info) |
| We report the case of a newborn child with maple syrup urine disease (MSUD), diagnosed at 10 days of life. Diffusion-weighted echoplanar MRI showed marked hyperintensity of the cerebellar white matter, the brainstem, the cerebral peduncles, the thalami, the dorsal limb of the internal capsule and the centrum semiovale, while conventional dual-echo sequence evidenced only a weak diffuse T2 hyperintensity in the cerebellar white matter and in the dorsal brainstem. The apparent diffusion coefficient (ADC) of these regions was markedly (>80%) decreased. Therefore, in agreement with current hypotheses on MSUD pathogenesis, MSUD oedema proves to be a cytotoxic oedema. Diffusion-weighted MRI may be a valuable tool, more sensitive than conventional spin-echo techniques, to assess the extent and progression of cytotoxicity in MSUD, as well as the effectiveness of the therapeutic interventions. ( info) |
| An 8-year-old boy with the intermediate variant of maple syrup urine disease is reported. On b = 1000 s/mm2 (heavily diffusion weighted) images of diffusion magnetic resonance imaging, there was symmetric high signal in the globus pallidus, mesencephalon, dorsal pons, and nucleus dentatus, consistent with restriction of the mobility of water molecules. Apparent diffusion coefficient (ADC) maps revealed low ADC values ranging from 0.42 to 0.56 x 10(-3) mm2/s in these regions, compared to those of apparently unaffected regions in the brain parenchyma ranging from 0.63 to 0.97 x 10(-3) mm2/s. It is suggested that the areas of increased signal (and low ADC values) are the result of dysmyelination as a reflection of disorganized tissue integrity. ( info) |