Maple Syrup Urine Disease (MSUD)


Maple Syrup Urine Disease (MSUD) is an inborn error of metabolism, an inherited condition in which an enzyme complex, branched-chain alpha-ketoacid dehydrogenase, in the body is either missing or not working well. The job of this enzyme is to help break down the amino acids leucine, isoleucine and valine (parts of protein). MSUD is considered an amino acid condition because people with this condition are unable to break down these amino acids (parts of protein). When this enzyme complex does not work properly, these parts of protein and other substances build up in the body. There are different forms of MSUD. Signs of MSUD can include maple syrup odor, poor feeding, poor growth, irritability, breathing problems, extreme tiredness/lethargy, stereotyped body movements, changes in muscle tone, developmental delay and/or other potential symptoms. If MSUD is untreated, it can lead to seizures, coma, and other symptoms. MSUD can be a life-threatening condition. Illnesses, infections or going too long without food are some examples of circumstances that could also trigger symptoms of MSUD. Early detection along with prompt and ongoing management can benefit children living with MSUD. Support groups are available to help connect families living with MSUD with others who have experience or expertise with this condition.

For more information about Maple Syrup Urine Disease, visit Screening, Technology, and Research in Genetics (STAR-G): Maple Syrup Urine Disease and Baby's First Test: Maple Syrup Urine Disease. Please see Medically Prescribed Formula for information about medically prescribed formula and pharmacologic interventions for inborn errors of metabolism. A listing of contact information for Minnesota inborn errors of metabolism medical specialty providers/clinics serving children affected with or undergoing evaluation for conditions that can be detected through Minnesota Newborn Screening is available upon request.