Diagnosis of MSUD by newborn screening allows early intervention without extraneous detoxification

Mol Genet Metab. 2005 Apr;84(4):313-6. doi: 10.1016/j.ymgme.2004.11.010. Epub 2005 Jan 24.


Maple syrup urine disease (MSUD) is a genetic metabolic disorder resulting from the defective activity of branched-chain 2-ketoacid dehydrogenase complex. Due to the metabolic block, high concentrations of the branched-chain amino acids (BCAA) leucine, valine, isoleucine, and allo-isoleucine as well as their corresponding branched-chain 2-keto acids accumulate in patients on a BCAA-unrestricted diet or during episodes with increased protein catabolism. Early diagnosis and management are essential to prevent permanent brain damage. Newborn screening by tandem MS allows for detection of elevated BCAA concentrations in blood in patients with classical MSUD before they show severe encephalopathic symptoms. Here, we report that newborn screening by expanded tandem MS enables for reversing the intoxication in newborns with MSUD within 24-48 h without any need for extraneous detoxification and thus decreasing the risk of brain damage during a particularly vulnerable period.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids, Branched-Chain / blood
  • Diet, Fat-Restricted
  • Early Diagnosis
  • Female
  • Humans
  • Infant Nutritional Physiological Phenomena
  • Infant, Newborn
  • Male
  • Maple Syrup Urine Disease / blood
  • Maple Syrup Urine Disease / diagnosis*
  • Maple Syrup Urine Disease / diet therapy
  • Mass Spectrometry / methods
  • Neonatal Screening / methods*
  • Pregnancy


  • Amino Acids, Branched-Chain