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URL of this page: https://medlineplus.gov/lab-tests/galactosemia-tests/

Galactosemia Tests

What is a galactosemia test?

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:

  • Vomiting
  • Poor weight gain
  • Refusal to eat
  • Irritability
  • 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.

Learn more about laboratory tests, references ranges, understanding results.

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.

References

  1. Baby's First Test [Internet]. Expecting Health; c2020. Classic Galactosemia; [cited 2021 Apr 29]; [about 4 screens]. Available from: https://www.babysfirsttest.org/newborn-screening/conditions/classic-galactosemia
  2. Baby's First Test [Internet]. Expecting Health; c2020. Galactoepimerase Deficiency; [cited 2021 Apr 29]; [about 4 screens]. Available from: https://www.babysfirsttest.org/newborn-screening/conditions/galactoepimerase-deficiency
  3. Baby's First Test [Internet]. Expecting Health; c2020. Galactokinase Deficiency; [cited 2021 Apr 29]; [about 4 screens]. Available from: https://www.babysfirsttest.org/newborn-screening/conditions/galactokinase-deficiency
  4. Kids Health from Nemours [Internet]. Jacksonville (FL): The Nemours Foundation; c1995–2021. Galactosemia; [cited 2021 Apr 29]; [about 3 screens]. Available from: https://kidshealth.org/en/parents/galactosemia.html
  5. Kids Health from Nemours [Internet]. Jacksonville (FL): The Nemours Foundation; c1995–2021. Newborn Screening Tests; [cited 2021 Apr 29]; [about 3 screens]. Available from: https://kidshealth.org/en/parents/newborn-screening-tests.html
  6. March of Dimes [Internet]. Arlington (VA): March of Dimes; c2021. Newborn Screening Tests for Your Baby; [cited 2021 Apr 29]; [about 3 screens]. Available from: https://www.marchofdimes.org/baby/newborn-screening-tests-for-your-baby.aspx
  7. Michigan Medicine: University of Michigan [Internet]. Ann Arbor (MI): Regents of the University of Michigan; c1995–2021. Galactosemia Test: How to Prepare; [cited 2021 Apr 29]; [about 5 screens]. Available from: https://www.uofmhealth.org/health-library/hw7694#hw7713
  8. Michigan Medicine: University of Michigan [Internet]. Ann Arbor (MI): Regents of the University of Michigan; c1995–2021. Galactosemia Test: Results; [cited 2021 Apr 29]; [about 9 screens]. Available from: https://www.uofmhealth.org/health-library/hw7694#hw7728
  9. Michigan Medicine: University of Michigan [Internet]. Ann Arbor (MI): Regents of the University of Michigan; c1995–2021. Galactosemia Test: Risks; [cited 2021 Apr 29]; [about 8 screens]. Available from: https://www.uofmhealth.org/health-library/hw7694#hw7724
  10. Michigan Medicine: University of Michigan [Internet]. Ann Arbor (MI): Regents of the University of Michigan; c1995–2021. Galactosemia Test: Test Overview; [cited 2021 Apr 29]; [about 3 screens]. Available from: https://www.uofmhealth.org/health-library/hw7694#hw7697
  11. Michigan Medicine: University of Michigan [Internet]. Ann Arbor (MI): Regents of the University of Michigan; c1995–2021. Galactosemia Test: Why It Is Done; [cited 2021 Apr 29]; [about 4 screens]. Available from: https://www.uofmhealth.org/health-library/hw7694#hw7707
  12. National Center for Advancing Translational Sciences [Internet]. Gaithersburg (MD): U.S. Department of Health and Human Services; Galactosemia; [updated 2018 Oct 11; cited 2021 Apr 29]; [about 3 screens]. Available from: https://rarediseases.info.nih.gov/diseases/2424/galactosemia
  13. Perkin Elmer: Solutions for Newborn Screening [Internet]. Perkin Elmer Inc; 1998–2021. Galactosemia; [cited 2021 April 29]; [about 3 screens]. Available from: https://newbornscreening.perkinelmer.com/disorders/primary_newborn_screening_disorders/galactosemia
  14. UF Health: University of Florida Health [Internet]. Gainesville (FL): University of Florida Health; c2021. Galactose-1-phosphate uridyltransferase blood test; [updated 2021 Apr 29; cited 2021 Apr 29]; [about 2 screens]. Available from: https://ufhealth.org/galactose-1-phosphate-uridyltransferase-blood-test
  15. UF Health: University of Florida Health [Internet]. Gainesville (FL): University of Florida Health; c2021. Galactosemia; [updated 2021 Apr 29; cited 2021 Apr 29]; [about 2 screens]. Available from: https://ufhealth.org/galactosemia
  16. University of Iowa Stead Family Children's Hospital [Internet]. Iowa City (IA): The University of Iowa; c2021. Obtaining blood via heel stick; [cited 2021 Apr 29]; [about 2 screens]. Available from: https://uichildrens.org/health-library/obtaining-blood-heel-stick
  17. University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2021. Health Encyclopedia: Galactosemia; [cited 2021 Apr 29]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=galactosemia
  18. Very Well Health [Internet]. New York: About, Inc.; c2021. Signs and Symptoms of Galactosemia; 2019 Nov 29 [cited 2021 Apr 29]; [about 3 screens]. Available from: https://www.verywellhealth.com/galactosemia-2633504

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.