maple syrup urine disease

ma·​ple syr·​up urine disease | \ ˈmā-pəl-ˈsər-əp-, -ˈsir-əp- How to pronounce maple syrup urine disease (audio) \

Medical Definition of maple syrup urine disease

: an inherited disorder of amino acid metabolism that is characterized initially by an odor of maple syrup in the urine and in earwax and by vomiting, fatigue, irritability, and hypertonicity, and that unless treated with dietary measures leads to seizures, brain damage, coma, and death

Note: Maple syrup urine disease is caused by a deficiency of the enzyme decarboxylase, which leads to high concentrations of the amino acids valine, leucine, isoleucine, and alloisoleucine in the blood, urine, and cerebrospinal fluid. The disorder is inherited as an autosomal recessive trait requiring that both parents pass on a copy of the defective gene on a chromosome other than a sex chromosome.

Learn More about maple syrup urine disease

Cite this Entry

“Maple syrup urine disease.” Medical Dictionary, Merriam-Webster, Accessed 31 Oct. 2020.

Comments on maple syrup urine disease

What made you want to look up maple syrup urine disease? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Here Be Dragons: A Creature Identification Quiz

  • monster werewolf photo
  • Which is a synonym of werewolf?
Spell It

Can you spell these 10 commonly misspelled words?


Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!