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Galactose is a sugar that is part of the lactose found in milk and milk products. A galactosemia test is a blood or urine test that checks for enzymes that are needed to change galactose into glucose, a sugar that your body uses for energy. A person with galactosemia doesn't have one of these enzymes, so high levels of galactose build up in the blood or urine.
When galactose builds up in a baby's blood, it can cause liver damage, problems with eating, and intellectual disabilities. The damage caused by galactosemia can begin within weeks after the baby has started drinking breast milk or formula. Babies with galactosemia need foods low in galactose in order to gain weight and to prevent brain damage, liver problems, infection, and cataracts.
Galactosemia is a rare disease that is passed from parents to children (inherited genetic condition). A galactosemia screening test is usually done to find out if a newborn has an increased risk of the disease. The test is done in the first few days after birth, as early as 24 hours after birth. In a family with a member who has galactosemia, a genetic test can be done on adults to find out whether they have an increased chance of having a child with the disease.
A galactosemia test is done to:
You don't need to do anything to prepare for this test.
Tests for galactosemia are done on a blood or urine sample.
A heel stick is used to get a blood sample from a baby. The baby's heel is poked, and several drops of blood are collected. Your baby may have a tiny bruise where the heel was poked.
A health professional uses a needle to take a blood sample, usually from the arm.
To test for galactose in a urine sample from a baby, a health professional will tape a plastic collection bag to the baby's genital area. After the baby urinates, the collection bag is removed.
A quick sting or a pinch is usually felt when the lancet punctures the skin. Your baby may have a little discomfort with the skin puncture, but this doesn't last long.
Your baby may feel nothing at all from the needle, or he or she may feel a quick sting or pinch.
A baby will usually feel no discomfort from the use of a urine collection bag. But removing the tape that attaches the bag to the skin may cause discomfort for a short time.
There is very little risk of a problem from a heel stick. Your baby may get a small bruise at the puncture site.
There is very little chance of having a problem from this test. A small bruise may form at the site.
There are no risks linked with a urine test for galactosemia. Removing the tape that holds the bag in place may cause mild skin irritation.
The results from a galactosemia test may be negative (galactosemia is not present) or positive (galactosemia is present). Or the results may include specific lab values that mean the person has or does not have galactosemia or is a carrier for it.
A newborn screening test that shows that the baby has an increased risk of galactosemia will be confirmed by other tests.
Many conditions can change galactose levels. Your doctor will discuss any significant abnormal results with you in relation to your baby's symptoms and past health.
Adaptation Date: 2/25/2022
Adapted By: Alberta Health Services
Adaptation Reviewed By: Alberta Health Services
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