Maple syrup disease

Menkes, J. (1959) Maple syrup disease isolation and identification of organic acids in the urine. 

Maple syrup disease Branched chain a-ketoacid dehydrogenase... 

Dancis, J., Levitz, M., Westall, R. (1960) Maple syrup urine disease branched-chain keto-aciduria. Pediatrics 25, 72-79. Menkes, J.H. (1959) Maple syrup disease isolation and identification of organic acids in the urine. Pediatrics 23, 348-353. 

Snyderman, S. E., Maple syrup disease. In Amino Acid Metabolism and Genetic Variation (W. L. Nyhan, ed.), pp. 171-183. McGraw-Hill, New York, 1967. 

Determination of active substances and their metabohtes in biological matrices, diagnosis of metabolic disorders such as PKU (phenylketomuia), cystimuia and maple syrup disease in babies. 

Specific amino acids Analysis of a few or specific amino acids is useful and easy to perform. This often requested in the detection of inborn errors of metabolism (phenylketonuria or maple syrup disease). In these cases, the abnormal amino acids are present in high concentration that makes the analysis simple. Several amino acids have been determined by CE for this purpose, such as tyrosine, proline, and phenylalanine. 

Morton DH, et al. Diagnosis and treatment of maple syrup disease a study of 36 patients. Pediatrics. 2002 109(6) 999 1008. 

The branched fatty acids the oxidation of which will be considered now are carbon compounds derived from amino acid metabolism. Isovalerate, methylbu-tyrate, and isobutyrate are related to the metabolism of leucine, isoleucine, and valine, respectively. The interest in the metabolism of branched fatty acids stems partly from the fact that the branched amino acids from which they are derived are precisely those that accumulate in maple syrup disease. 

Several metabolic blocks could account for the biochemical distortion observed in maple syrup disease. A deficiency in amino oxidase could lead to accumulation of amino acids. Because the enzyme has such a broad specificity, whenever it is completely deleted a more complex aminoaciduria can be expected to develop. The deletion of a specific transaminase could hardly explain the keto acid accumulation. Therefore, it seems more likely that the metabolic block involves a step between the keto acid and the simple acids, possibly the oxidative decarboxylation of the keto acid. This reaction requires coenzyme A, NAD, lipoic acid, and thiamine pyrophosphate, and it was described in some detail in the chapter devoted to the bioenergetic pathways. Leukocytes of at least some patients with maple syrup disease have been shown to contain normal transaminase activity but are defective in the oxidative decarboxylase. 

Fructose intolerance Phenylketonuria Maple syrup disease Cretinism ... 

Miscellaneous Hereditary Disease Galactosemia Glycogen storage disease Maple syrup disease Fructosuria... 

Gas Chromatographic and Mass Spectrometric Identification of Alloiso-leucine in Maple Syrup Disease Hanguk Non wa Hakhoe Chi 21(1) 11-15 (1978) CA 90 83073h... 

Indole acetic acid normal carcinoid hepatolenticular degeneration pellagra phenylketonuria idiopathic sprue infantile toxicosis neuromuscular diseases Hartnup s disease maple syrup disease ... 

The inborn errors of L-leucine catabolism present biochemically with branched-chain amino and/or organic aciduria [1]. These disorders include maple syrup disease (MSD branched-chain a-ketoacid dehydrogenase (BCKD) deficiency), isovaleric acidemia (isovaleryl-coenzyme A (CoA) dehydrogenase deficiency), isolated 3-methylcrotonyl-CoA carboxylase deficiency, the 3-methylglutaconic acidurias (3-methylglutaconyl-CoA hydratase deficiency, Barth syndrome, and other disorders in which the primary defect has not been demonstrated), and 3-hydroxy-3-methylglutaric aciduria (3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) lyase deficiency). 

Signs and Symptoms Table 6.1. Maple syrup disease (all forms) ... 

Maple syrup disease (MSD) Yellow precipitate Greenish-gray color Leucine >2 mg/dl (>153 pmol/1)... 

Maple syrup disease Molecular analysis, CV sampling, cultured AFC 1.11... 

Maple syrup disease F, WBC RT-PCR genomic amplification and sequencing... 

Support endogenous protein synthesis with enteral or intravenous amino acid mixtures devoid of leucine. Supplement as needed to prevent isoleucine and valine deficiencies, including in maple syrup disease, wherein isoleucine and valine rapidly become depleted and 40-80 mg/kg per day of each of these two essential amino acids are needed to support high rates of protein synthesis and maximum rates of leucine decrease. 

Decreased brain 5HT and DA in rats on a high dietary leucine intake is probably due to inhibition of amine precursor transport to the brain [411, 412]. Similar biochemical changes might be responsible for the mental retardation associated with maple syrup disease in which keto acids derived from leucine and other branched chain amino acids accumulate [413]. Decreased brain 5HT might also be involved in the mental... 

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