A galactosemia test is a blood test given to newborns to check for a rare genetic disorder called galactosemia. This disorder prevents the body from breaking down a simple sugar called galactose. Galactose is found in many foods and all dairy products. This includes breast milk and milk-based baby formulas.
Normally, certain enzymes break down galactose. Galactosemia happens when a genetic change affects the function of these enzymes. There are three types of galactosemia. The type depends on which enzyme is affected:
- GALT (galactose-1 phosphate uridyl transferase) deficiency. This is also known as classic galactosemia. It is the most common and severe form of the disorder.
- GALK (galactose kinase) deficiency
- GALE (galactose epimerase) deficiency
If a baby with a GALT, GALK, or GALE deficiency eats food with galactose, high levels of sugar build up in the blood. This can lead to serious health problems. These include liver disease, kidney failure, brain damage, and even death. But with early diagnosis and treatment, children with galactosemia can live healthy lives.
Other names: galactosemia newborn screening test, GALT test
What is it used for?
A galactosemia test is used to help diagnose galactosemia in a baby. It may also help identify whether it is a GALT, GALK, or GALE deficiency.
Why does my baby need a galactosemia test?
Newborns in the United States are required to get this test as part of a newborn screening. A newborn screening is a simple blood test that checks for a variety of serious diseases.
Some older infants may need testing if they were adopted from another country and have symptoms of galactosemia. These include:
- Poor weight gain
- Refusal to eat
- Jaundice, a condition that causes the skin and eyes to turn yellow
What happens during a galactosemia test?
A health care provider will clean your baby’s heel with alcohol and poke the heel with a small needle. The provider will collect a few drops of blood and put a bandage on the site.
Will I need to do anything to prepare for this test?
There are no special preparations needed for a galactosemia test.
Are there any risks to this test?
Your baby may feel a little pinch when the heel is poked, and a small bruise may form at the site. This should go away quickly.
What do the results mean?
Your baby’s results will be either positive or negative for galactosemia. If the results are negative, your child doesn’t have the disorder. If the results are positive, your baby will probably need more testing to confirm the diagnosis. These may include other blood tests, urine tests, and genetic tests.
Is there anything else I need to know about a galactosemia test?
There is no cure for galactosemia. Infants diagnosed with the disorder can be fed soy formula or certain other lactose-free formulas. Children with classic galactosemia (GALT) must keep a special diet that avoids all milk and products that contain milk. Children with GALK and GALE deficiencies may be able to include a limited amount of dairy in their diets.
If your child has one of these deficiencies, talk to your child’s provider about how to plan a safe and healthy diet, both in infancy and as your child grows up. Children with these deficiencies will probably need to stay on special diets for the rest of their lives.
Courtesy of MedlinePlus from the National Library of Medicine.