Urine Maple syrup

E. Podehrad, M. Heil, S. Leih, B. Geier, T. Beck, A. Mosandl, A. C. Sewell and H. Bohles, Analytical approach in diagnosis of inherited metabolic diseases maple syrup urine disease (MSUD)-simultaneous analysis of metabolites in urine by enantioselective multidimensional capillary gas chromatography-mass specti ometiy (enantio-MDGC-MS) , 7. High Resolut. Chromatogr. 20 355-362(1997). 

As the name implies, the odor of urine in maple syrup urine disease (brancbed-chain ketonuria) suggests maple symp or burnt sugar. The biochemical defect involves the a-keto acid decarboxylase complex (reaction 2, Figure 30-19). Plasma and urinary levels of leucine, isoleucine, valine, a-keto acids, and a-hydroxy acids (reduced a-keto acids) are elevated. The mechanism of toxicity is unknown. Early diagnosis, especially prior to 1 week of age, employs enzymatic analysis. Prompt replacement of dietary protein by an amino acid mixture that lacks leucine, isoleucine, and valine averts brain damage and early mortality. 

The catabolism of leucine, valine, and isoleucine presents many analogies to fatty acid catabolism. Metabolic disorders of branched-chain amino acid catabolism include hypervalinemia, maple syrup urine disease, intermittent branched-chain ketonuria, isovaleric acidemia, and methylmalonic aciduria. 

Dancis, J. "Maple Syrup Urine Disease", in "Antenatal Diagnosis", ed. A. Dorfmn, University of Chicago Press, Chicago, 1972, 123-125. 

DISORDERS OF BRANCHED-CHAIN AMINO ACIDS MAPLE SYRUP URINE DISEASE 671... 

Maple syrup urine disease involves a congenital failure to oxidize the three branched-chain amino acids 671... 

Effective treatment of maple syrup urine disease involves the restriction of dietary branched-chain amino acids 672... 

Imbalances of brain amino acids may hinder the synthesis of brain lipids, leading to a diminution in the rate of myelin formation. Decreases of lipids, proteolipids and cerebrosides (Ch. 3) have been noted in several of these syndromes, e.g. maple syrup urine disease, when intra-myelinic edema is a prominent finding, particularly during the acute phase of metabolic decompensation [9]. Pathological changes in brain myelin are common, especially in infants who die early in life. The fundamental... 

Effective treatment of maple syrup urine disease involves the restriction of dietary branched-chain amino acids. Long-term treatment entails the dietary restriction of the BCAAs. This is accomplished by administration of a special formula from which these amino acids are removed. The outlook for intellectual development is favorable in youngsters in whom diagnosis is made early and who do not suffer recurrent, severe episodes of metabolic decompensation [17]. 

Jan,W., Zimmerman, R. A.,Wang, Z. J., Berry, G. T., Kaplan, P. B. and Kaye, E. M. MR diffusion imaging and MR spectroscopy of maple syrup urine disease during acute metabolic decompensation. Neuroradiology 45 393-399,2003. 

Wagner, M., Coelho, D. M., Barschak, A. G. et al. Reduction of large neutral amino acid concentrations in plasma and CSF of patients with maple syrup urine disease. J. Inker. Metab. Dis. 23 505-512,2000. 

Kaplan, P., Mazur, A., Field, M., Berlin, J.A., Berry, G.T., Heidenreich, R., Yudkoff, M. and Segal, S (1991). Intellectual outcome in children with maple syrup urine disease. /. Pediatr. 119 46-50. 

Mueller, G. M., McKenzie, L. R., Homanics, G. E., Watkins, S. C., Robbins, P. D. and Paul, H. S. Complementation of defective leucine decarboxylation in fibroblasts from a maple syrup urine disease patient by retrovirus-mediated gene transfer. Gene Ther. 2 461-468,1995. 

LC locus ceruleus MSUD maple syrup urine disease... 

Podebrad, F., Heil, M., Reichert, S., Mosandl, A., Sewell, A.C. and Bohles, H. (1999) 4,5-dimethyl-3-hydroxy-2[5H]-furanone (sotolone) - The odour of maple syrup urine disease. J. Inher. Metabol. Dis.22, 107-114. 

Yalcin, S.S., Tekinalp, G. and Ozalp, I. (1999) Peculiar odor of traditional food and maple syrup urine disease. Pediatr. Int. 41, 108-109. 

Valine, leucine, and isoleucine are branched-chain amino adds whose metabolism is abnormal in maple syrup urine disease (discussed in Chapter 17). 

Branched-Chain Ketoacid Dehydrogenase Deficiency (Maple Syrup Urine Disease)... 

Maple syrup urine disease (branched-chain ketoacid dehydrogenase)... 

Answer C. Maple syrup urine disease substrates are branched chain a-ketoacids derived from the branched chain amino acids. 

Patients snffering from metabolic disorders such as phenylketonuria (PKU), branched-chain ketoaciduria (maple syrup urine disease, MSUD), nrea and ammonia disorders or glycogen storage disease reqnire formulations manufactured specifically for each disease (Elsas Acosta, 2006). (Appendix 15.1). 

Infants suffering from maple syrup urine disease exhibit failure to thrive, feeding problems, vomiting, dehydration, and severe metabolic acidosis, with mental retardation as a major sequela. 

As discussed above, in the case of phenylketonuria, early intervention can make the difference between mental retardation and a near normal life course for a newborn. Congenital adrenal hyperplasia and maple syrup urine disease are two examples of neonatal hereditary disorders where early diagnosis and medical intervention can make the difference between life and death for the newborn. In addition, in a number of genetic diseases, early diagnosis and treatment can help ameliorate symptoms these include fragile X syndrome, homocystinuria, sickle cell anemia, cystic fibrosis, and many /1-thalassemias. 

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