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  • Cynthia M. Johnson, MA
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Galactosemia is a rare genetic disorder in which the body does not have the enzyme needed to break down a sugar called galactose into another sugar called glucose. Galactose is found in milk products. If it is not broken down, it builds up in the body where it can become toxic and damage organs and tissues.

There are three types of galactosemia that are each caused by a different faulty gene. This sheet will focus on classic (type 1) galactosemia.


Galactosemia is caused by a faulty gene that is inherited from both parents.

Risk Factors

The risk of this problem is higher in children of parents who carry the faulty gene.


An infant with galactosemia usually appears normal at birth. Symptoms usually occur within the first few days or weeks of life after the baby drinks breastmilk or a lactose containing formula.

Problems may be mild to severe and include:

  • Vomiting
  • Diarrhea
  • Weakness
  • Feeding problems
  • Poor weight gain
  • Yellowing of the skin and whites of the eyes
  • Belly swelling

Some long term complications may be:

  • Poor growth
  • Learning problems
  • Speech problems
  • Ovarian failure
  • Cataracts
  • Kidney disease
  • Liver failure


It is possible to diagnose galactosemia during pregnancy with amniocentesis. This test is only done if the baby is at high risk for an illness or health problem.

Most infants in the US are screened for galactosemia at birth. A small sample of blood is taken with a heel prick. If this screen is positive, then more testing will be done to confirm the diagnosis. This may include genetic testing.

A doctor may also suspect galactosemia after a urine test. The diagnosis can be confirmed with a blood test.


Amniocentesishttp://services.epnet.com/getimage.aspx?imageiid=73337333si55550976.jpgsi55550976.jpgNULLjpgsi55550976.jpgNULL\\hgfiler01a\intellect\images\si55550976.jpgNULL28NULL2008-11-07284390Copyright © Nucleus Medical Media, Inc.


Galactosemia cannot be cured. A team of specialists will be needed to manage this health problem. It will need lifelong managing to lower the risk of complications.


There are no current guidelines to prevent galactosemia.


All items that contain or produce galactose must be avoided, such as standard formula, breast milk, and dairy products. Some non milk products also contain it and must be avoided, such as legumes, organ meats, and tomato sauces. A dietitian will be needed to help with feeding and meal planning.





  • Berry GT. Classic cglactosemia and clinical variant galactosemia. GeneReviews website. Available at: http://www.ncbi.nlm.nih.gov/books/NBK1518.
  • Galactose screening test for galactosemia. EBSCO DynaMed website. Available at: https://www.dynamed.com/lab-monograph/galactose-screening-test-for-galactosemia.
  • A parent's guide to understanding galactosemia. Galactosemia Foundation website. Available at: https://galactosemia.org/resources/understanding-galactosemia.
  • Welling L, et al. International clinical guideline for the management of classical galactosemia: diagnosis, treatment, and follow-up. J Inherit Metab Dis. 2017; 40(2): 171-176.
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This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.