Maple Syrup Urine Disease

• ● MSUD is a rare disorder, inherited as an autosomal recessive trait.

  ● In this disease, there is a defect in the metabolism of the amino acids leucine, isoleucine, and valine because of a lack of liver enzymes needed to convert them

  ○ Leads to cerebral degeneration similar to that observed in children with PKU.

  ● As a result, there is no normal breakdown of leucine, isoleucine and valine as shown in the photo. So, these amino acids and their by-products build up in the body. Like PKU, it is toxic to the brain.
• ASSESSMENT

  ● Unlike PKU, MSUD can be detected prenatally through amniocentesis

  1. By 1st or 2nd day of life, urine develops the characteristic odor of maple syrup.

  ● Ketoacidosis: produce a sweet smelling urine

  2. Feeding difficulty, loss of the Moro reflex, and irregular respirations quickly begin at birth

  ● They appear well at birth but quickly, they begin to show these signs.

  3. Progress rapidly to opisthotonos, generalized muscular rigidity, and seizures.

  ● These shows CNS involvement.
• MANAGEMENT

  ● If conditions remain untreated, an infant may die as early as 2-4 weeks of age

  1. Placed on a well-controlled diet that is high in thiamine and low in the amino acids leucine, isoleucine, and valine.

  ● If done on the early 1st or 2nd day of life, cerebral degeneration can be prevented just like in PKU.

  ● This diet is extremely difficult to maintain so parents need intensive nutritional counseling.
• 2. Hemodialysis or peritoneal dialysis can be used to temporarily reduce abnormal serum levels at birth or during a childhood infection.

  ● At birth, because high levels are evident

  ● During infection when catabolism of cells release, increase amino acids into the blood.

  3. Undergo liver transplant

  ● Last resort. Since problem is a liver enzyme necessary for conversion of a branch-chained amino acids.