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Newborn Screening Ontario
Screening Results

Glutaric Acidemia Type 1 (GA1)Download version for offline viewing or printing

At a Glance

Approximate Incidence in Ontario

Unknown as so rare

Marker Measured


Screening can Prevent

Developmental delay, spasticity, encephalopathy, coma, death


Avoid fasting, low protein 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 GA1.
    • A screen positive result means that more tests are needed to know whether or not a baby has GA1. It does not mean that a baby has GA1. Babies identified at a young age through screening can be treated early to help prevent health problems.
  • What is GA1?

    Glutaric Acidemia, Type 1 (GA1) is a rare, inherited (genetic) disease.

    • Glutaric acid is naturally produced when the body digests proteins from the foods we eat, including breast milk and infant formula.
    • Babies with GA1 cannot break glutaric acid down into energy for the body.
  • Screening Positive for GA1
    • 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 glutaric acidemia. It means that there is a chance that the baby may have GA1.
    • Follow-up testing is important to find out whether the baby truly has GA1.
    • 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 GA1 or not. This waiting period can be hard for families.
  • Possible Follow-up Test Results
    • Normal – the baby does not have GA1.
    • Abnormal – the baby does have GA1 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

    Most babies with GA1 are normal at birth. Many will be born with larger heads than average. Some babies with GA1 never develop any health problems, while others do.

    Early signs of GA1 include:

    • low muscle tone
    • irritability

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

    • learning delays
    • speech delays
    • co-ordination problems
    • enlarged liver
    • metabolic crisis

    A metabolic crisis is a life-threatening episode caused by low blood sugar and/or the build-up of harmful substances in the blood.

    Symptoms of a metabolic crisis include:

    • poor feeding
    • vomiting
    • extreme fatigue
    • excessive sleepiness
    • irritability
    • muscle spasms

    If a metabolic crisis is not treated, breathing problems, seizures, coma, brain damage and sometimes death can occur. Screening and treatment aim to prevent metabolic crises and help children with GA1 live healthier lives.

  • Treatment

    Treatment for GA1 is started as early as possible and is usually life long.

    Treatment may include:

    • frequent feeding, especially when ill (to prevent a metabolic crisis, babies with GA1 must not go a long time without eating)
    • a low protein diet and special medical foods
    • vitamins and supplements prescribed by a metabolic doctor

    A team, including a metabolic doctor and a dietitian, cares for babies with GA1. Babies with GA1 have their health and development checked regularly. Regular follow-up tests are used to monitor and adjust treatments.

    If signs of a metabolic crisis are present, urgent medical care is very important.


  • Living with GA1
    • For most children with GA1, treatment allows them to lead healthy lives with normal growth and intelligence.
    • A few children may develop some symptoms despite treatment, even when metabolic crises are avoided.