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Newborn Screening Ontario
Screening Results

Tyrosinemia Type 1Download version for offline viewing or printing

At a Glance

Approximate Incidence in Ontario

1 in 100, 000

Marker Measured

Tyrosine and succinylacetone

Screening can Prevent

Liver and kidney damage and sequelae, failure to thrive, coagulopathy


Special diet, medication

  • Screening is Important
    • In Ontario, a heel prick is used to take a few drops of blood from each baby shortly after birth. The blood is tested for more than 25 treatable diseases, including Tyrosinemia Type 1.
    • A screen positive result means that more tests are needed to know whether or not a baby has tyrosinemia. It does not mean that a baby has Tyrosinemia. Babies identified at a young age through screening can be treated early to help prevent health problems.
  • What is Tyrosinemia Type 1?

    Tyrosinemia Type 1 is a rare, inherited (genetic) disease.

    • Babies with Tyrosinemia cannot break down tyrosine.
    • Tyrosine is a building block of protein (also called an amino acid). It is found in many foods, including breast milk and infant formula.
    • There are other rare forms of tyrosinemia (types II and III), which can sometimes be picked up by newborn screening.
  • Screening Positive for Tyrosinemia Type 1
    • It is normal for parents and guardians to feel worried when their baby has a screen positive result. A ‘screen positive’ result does not mean that a baby has Tyrosinemia. It means that there is a chance that the baby may have Tyrosinemia.
    • Follow-up testing is important to find out whether the baby truly has Tyrosinemia.
    • The baby’s health care provider or a health care provider at a newborn screening Regional Treatment Centre will discuss the results with the baby’s family.
    • Follow-up testing is arranged as soon as possible and involves blood and urine tests.
    • It can take a few days to weeks to find out if a baby truly has tyrosinemia or not. This waiting period can be hard for families.
  • Possible Follow-up Test Results
    • Normal – the baby does not have Tyrosinemia.
    • Abnormal – the baby does have Tyrosinemia and will need treatment. The family will be supported by a team of caring specialists.
    • Inconclusive – more testing is required. The baby will be followed closely by a specialist to ensure that he/she receives optimal care.
  • Signs and Symptoms

    While most babies with Tyrosinemia appear normal at birth, early signs of the disease can include:

    • poor weight gain (failure to thrive)
    • feeding problems
    • irritability
    • extreme sleepiness (lethargy)
    • yellowing of the whites of the eyes and skin (jaundice)
    • fever
    • vomiting
    • diarrhea
    • distinctive cabbage-like odor of the skin and urine

    Early treatment helps to prevent serious and life threatening health problems such as:

    • developmental delay
    • liver and kidney disease
    • neurological problems
  • Treatment

    Treatment for Tyrosinemia Type 1 begins as early as possible and is life long.

    • Treatment may include medication and a special diet that is low in protein (low in tyrosine).
    • A team, including a metabolic doctor and a dietitian, cares for babies with tyrosinemia.
    • Babies with Tyrosinemia have their health and development checked regularly.
    • Regular follow-up tests are used to monitor and adjust treatments.
  • Living with Tyrosinemia Type 1
    • Children with Tyrosinemia can be as healthy and intelligent as other children their age if tyrosine levels are well managed with diet and medication.
    • If liver damage has already occurred, or if it occurs, a small number of children with tyrosinemia will require a liver transplant.