eMedicine Specialties > Pediatrics: Genetics and Metabolic Disease > Metabolic Diseases

Maple Syrup Urine Disease: Differential Diagnoses & Workup

Author: Olaf A Bodamer, MD, PhD, FACMG, Professor, Department of Pediatrics, Biochemical Genetics and Neonatal Screening Laboratories, University of Vienna Children's Hospital, Austria
Coauthor(s): Brendan Lee, MD, PhD, Associate Professor, Department of Molecular and Human Genetics, Baylor College of Medicine
Contributor Information and Disclosures

Updated: Jul 7, 2008

Differential Diagnoses

Other Problems to Be Considered

Aminoacidopathies and organoacidopathies presenting during the first week of life

Workup

Laboratory Studies

  • Plasma amino acids should be evaluated to assess the elevation of branched-chain amino acids and to detect alloisoleucine. The detection of alloisoleucine is diagnostic for maple syrup urine disease (MSUD). Alloisoleucine may not appear until the sixth day of life, even when leucine levels are elevated. Transient elevations of branched-chain amino acids (without the presence of alloisoleucine) may develop in patients with ketotic hypoglycemia and in patients in the postabsorptive state.
  • Measure urine organic acids using gas chromatography-mass spectrometry (GC-MS) to detect alpha-hydroxyisovalerate, lactate, pyruvate, and alpha-ketoglutarate.
  • Newborn screening for MSUD is performed with tandem mass spectrometry using concentrations of leucine and isoleucine and the Fisher Ratio (branch-chain amino acids/phenylalanine and tyrosine) as diagnostic measures. Immediate treatment should follow the identification of affected newborn infants.
  • Enzyme activity can be measured in lymphocytes, cultured fibroblasts, or both, although this test is not necessary for diagnosis.
  • Prenatal diagnosis can be performed by measuring enzyme activity in cultured amniocytes or chorion villus cells, mutation analysis, or by measuring branch-chain amino acid concentrations in amniotic fluid.

More on Maple Syrup Urine Disease

Overview: Maple Syrup Urine Disease
Differential Diagnoses & Workup: Maple Syrup Urine Disease
Treatment & Medication: Maple Syrup Urine Disease
Follow-up: Maple Syrup Urine Disease
References
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References

  1. Menkes JH, Hurst PL, Craig JM. A new syndrome: progressive familial infantile cerebral dysfunction associated with an unusual urinary substance. Pediatrics. Nov 1954;14(5):462-7. [Medline].

  2. Chuang DT. Maple syrup urine disease: it has come a long way. J Pediatr. Mar 1998;132(3 Pt 2):S17-23. [Medline].

  3. Dancis J, Levits M, Westall RG. Maple syrup urine disease: branched-chain keto-aciduria. Pediatrics. Jan 1960;25:72-9. [Medline].

  4. Snyderman SE, Norton PM, Roitman E, Holt LE Jr. Maple syrup urine disease, with particular reference to dietotherapy. Pediatrics. Oct 1964;34:454-72. [Medline].

  5. Scriver CR, Mackenzie S, Clow CL, Delvin E. Thiamine-responsive maple-syrup-urine disease. Lancet. Feb 13 1971;1(7694):310-2. [Medline].

  6. Wendel U, Saudubray JM, Bodner A, Schadewaldt P. Liver transplantation in maple syrup urine disease. Eur J Pediatr. Dec 1999;158 Suppl 2:S60-4. [Medline].

  7. Chuang DT, Shih VE. Maple syrup urine disease. In: Scriver CR, Beaudet AL, Valle DL, Sly WS, eds. The Metabolic and Molecular Bases of Inherited Disease. 8th ed. New York, NY: McGraw-Hill Co; 2000.

  8. Fernstrom JD. Branched-chain amino acids and brain function. J Nutr. Jun 2005;135(6 Suppl):1539S-46S. [Medline].

  9. Hallam P, Lilburn M, Lee PJ. A new protein substitute for adolescents and adults with maple syrup urine disease (MSUD). J Inherit Metab Dis. 2005;28(5):665-72. [Medline].

  10. Harris RA, Joshi M, Jeoung NH, Obayashi M. Overview of the molecular and biochemical basis of branched-chain amino acid catabolism. J Nutr. Jun 2005;135(6 Suppl):1527S-30S. [Medline].

  11. Heldt K, Schwahn B, Marquardt I, et al. Diagnosis of MSUD by newborn screening allows early intervention without extraneous detoxification. Mol Genet Metab. Apr 2005;84(4):313-6. [Medline].

  12. Henneke M, Flaschker N, Helbling C, et al. Identification of twelve novel mutations in patients with classic and variant forms of maple syrup urine disease. Hum Mutat. Nov 2003;22(5):417. [Medline].

  13. Hoffmann B, Helbling C, Schadewaldt P, Wendel U. Impact of longitudinal plasma leucine levels on the intellectual outcome in patients with classic MSUD. Pediatr Res. Jan 2006;59(1):17-20. [Medline].

  14. Hoffmann GF, von Kries R, Klose D, et al. Frequencies of inherited organic acidurias and disorders of mitochondrial fatty acid transport and oxidation in Germany. Eur J Pediatr. Feb 2004;163(2):76-80. [Medline].

  15. Mitsubuchi H, Owada M, Endo F. Markers associated with inborn errors of metabolism of branched-chain amino acids and their relevance to upper levels of intake in healthy people: an implication from clinical and molecular investigations on maple syrup urine disease. J Nutr. Jun 2005;135(6 Suppl):1565S-70S. [Medline].

  16. Morton DH, Strauss KA, Robinson DL, et al. Diagnosis and treatment of maple syrup disease: a study of 36 patients. Pediatrics. Jun 2002;109(6):999-1008. [Medline].

  17. Righini A, Ramenghi LA, Parini R, et al. Water apparent diffusion coefficient and T2 changes in the acute stage of maple syrup urine disease: evidence of intramyelinic and vasogenic-interstitial edema. J Neuroimaging. Apr 2003;13(2):162-5. [Medline].

  18. Yudkoff M, Daikhin Y, Nissim I, et al. Brain amino acid requirements and toxicity: the example of leucine. J Nutr. Jun 2005;135(6 Suppl):1531S-8S. [Medline].

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Further Reading

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Keywords

maple syrup urine disease, MSUD, maple sugar urine disease, branched-chain ketonuria, branched chain ketonuria, branched-chain ketoaciduria, branched chain ketoaciduria, muscular hypotonia, muscular hypertonia, dystonia, seizures, encephalopathy, pseudotumor cerebri, pancreatitis, ketosis, otitis media, thiamine-responsive MSUD, ketotic hypoglycemia

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Contributor Information and Disclosures

Author

Olaf A Bodamer, MD, PhD, FACMG, Professor, Department of Pediatrics, Biochemical Genetics and Neonatal Screening Laboratories, University of Vienna Children's Hospital, Austria
Olaf A Bodamer, MD, PhD, FACMG is a member of the following medical societies: American Society of Human Genetics
Disclosure: Nothing to disclose.

Coauthor(s)

Brendan Lee, MD, PhD, Associate Professor, Department of Molecular and Human Genetics, Baylor College of Medicine
Brendan Lee, MD, PhD is a member of the following medical societies: American Academy of Pediatrics, American College of Medical Genetics, and Society for Pediatric Research
Disclosure: Hyperion Grant/research funds clinical research

Medical Editor

Christian J Renner, MD, Consulting Staff, Department of Pediatrics, University Hospital for Children and Adolescents, Erlangen, Germany
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc
Disclosure: Pfizer Inc Stock Investment from broker recommendation; Avanir Pharma Stock Investment from broker recommendation

Managing Editor

Leonard G Feld, MD, PhD, MMM, Chairman of Pediatrics, Carolinas Medical Center; Chief Medical Officer, Levine Children's Hospital, Carolinas Healthcare System
Leonard G Feld, MD, PhD, MMM is a member of the following medical societies: American Academy of Pediatrics, American College of Physician Executives, American Society of Nephrology, American Society of Pediatric Nephrology, International Society of Nephrology, and Juvenile Diabetes Foundation International
Disclosure: Nothing to disclose.

CME Editor

Paul D Petry, DO, FACOP, FAAP, Consulting Staff, Freeman Pediatric Care, Freeman Health System
Paul D Petry, DO, FACOP, FAAP is a member of the following medical societies: American Academy of Osteopathy, American Academy of Pediatrics, American College of Osteopathic Pediatricians, and American Osteopathic Association
Disclosure: Nothing to disclose.

Chief Editor

Bruce Buehler, MD, Professor, Department of Pediatrics, Pathology and Microbiology, Executive Director, Hattie B Munroe Center for Human Genetics and Rehabilitation, University of Nebraska Medical Center
Bruce Buehler, MD is a member of the following medical societies: American Academy for Cerebral Palsy and Developmental Medicine, American Academy of Pediatrics, American Association on Mental Retardation, American College of Medical Genetics, American College of Physician Executives, American Medical Association, and Nebraska Medical Association
Disclosure: Nothing to disclose.

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