Inborn Errors of Metabolism

Also known as: Phenylketonuria, fructose intolerance, galactosemia, maple sugar urine disease.

What are inborn errors of metabolism?

If a baby is having trouble digesting certain foods and turning them into energy, these are known as inborn errors of metabolism. There are a variety of different medical conditions that fit into this category, and they can cause different symptoms depending on their nature and severity.

What causes inborn errors of metabolism?

Inborn errors of metabolism are genetic disorders that are inherited from one or both parents.

What are the symptoms of inborn errors of metabolism?

A variety of symptoms can occur due to inborn errors of metabolism. These can include:

  • Poor feeding
  • Irritability
  • Jaundice
  • Sleepiness
  • Vomiting
  • Convulsions
  • Poor weight gain
  • Low tone
  • Coma

What are inborn errors of metabolism care options?

Inborn errors of metabolism are typically treated with dietary changes. This may start with a special infant formula and then transition to a unique diet as the child grows older. In some instances, medication may also be taken to help with symptoms related to the condition.

Reviewed by: Parul B Jayakar, MD

This page was last updated on: 1/2/2026 11:01:13 AM

Genetic and Metabolic Disorders

Our clinical geneticists and genetic counselors at Nicklaus Children's Hospital evaluate children with developmental delays, unusual facial features, metabolic disorders, seizures, craniofacial anomalies and failure to thrive.

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Hyperbilirubinemia and jaundice Bilirubin is a yellow compound that forms when red blood cells are broken down. A newborn/premature baby breaks down their red cells faster and with a liver that's immature, cannot get rid of all the bilirubin produced. When this normally builds up, the baby's eyes and skin become yellow - this is called hyperbilirubinemia or jaundice.
Malnutrition When children are not getting the necessary nutrients and calories from the diet that they need for daily functioning and growth, this is known as malnutrition.
Amino Acid Quantitation (CSF) Patients born with inborn errors of amino acid metabolism may have a variety of different medical conditions related to metabolism. These diseases typically become evident in infancy or early childhood. An amino acid quantitation test of cerebral spinal fluid is useful in diagnosing these disorders.