General Condition Information
- Galactose epimerase deficiency
- It is unknown how many babies are born with this rare condition each year in the United States.
- Visit GeneReviews to learn more about how often this condition occurs.
What is Galactoepimerase deficiency
The body gets energy from breaking down galactose in milk and other foods. Several enzymes break down galactose into other substances that your body can use or remove. Galactosemia develops when one of these enzymes does not work properly.
The different types of galactosemia are:
- Classic galactosemia (galactosemia type I)
- Galactokinase deficiency (galactosemia type II)
- Galactoepimerase deficiency (galactosemia type III)
The type your baby has depends on which enzyme is not breaking down galactose properly.
Galactoepimerase deficiency is the least common type of galactosemia. In this type of galactosemia, the enzyme that is not working correctly is called GALE.
There are three different forms of galactoepimerase deficiency. The forms differ by how well the GALE enzyme processes galactose.
- Generalized: Can process very little galactose. Symptoms appear after consuming milk products.
- Intermediate: Can process some galactose. Symptoms may not appear right away but usually require treatment to prevent long-term symptoms.
- Peripheral: Can process enough galactose and usually do not have symptoms. Treatment is often just monitoring.
Unprocessed galactose builds up in the body and causes damage. If untreated, this damage can cause the signs and symptoms of the condition.
Newborn Screening and Follow-Up
Newborn screening for galactoepimerase deficiency is done using a small amount of blood collected from your baby’s heel. To learn more about this process, visit the Blood Spot Screening page.
During screening, a special machine measures how much of a sugar called galactose is in your baby’s blood. Babies with high levels of galactose might have galactoepimerase deficiency.
If your baby’s blood spot screening result for galactoepimerase deficiency is out-of-range, your baby’s health care provider will contact you. Together, you will discuss next steps and follow-up plans.
An out-of-range screening result does not mean that your baby definitely has the condition. It does mean that your baby needs more follow-up testing. To learn more about screening results, visit the Blood Spot Screening Results page.
Your baby may need the following tests after an out-of-range screening result:
- Blood and/or urine tests
- Genetic testing using a blood sample
You should complete any recommended follow-up testing as soon as possible. Babies with this condition may have serious health problems after birth if they are not diagnosed and treated quickly.
False-positive newborn screening results for this condition can happen. Babies with certain ethnic backgrounds (Hmong/Laotian) may have elevated total galactose results without having galactoepimerase deficiency.
Newborn screening helps babies lead healthier lives. If your baby has an out-of-range result, follow up with your health care provider quickly. It is important to follow their instructions. Your baby may need to get treatment right away, even if they are not showing signs or symptoms. In some cases, your baby’s health care provider may decide it is best to watch (monitor) your baby to decide next steps. Careful monitoring and early treatment will help your baby stay as healthy as possible.
Signs of galactoepimerase deficiency may appear within a few days of birth. Drinking milk or formula can cause symptoms. Some babies with milder types of galactoepimerase deficiency will not have any signs or symptoms.
Signs of the condition may include the following:
Galactoepimerase deficiency is caused by a change in the GALE gene. This gene gives your body instructions for making the GALE enzyme that breaks down galactose into glucose and other substances that your body uses for energy.
Without a working GALE gene, your baby cannot make enough working GALE enzyme. As a result, they cannot properly break down and get rid of galactose. High levels of galactose and other undigested sugars can damage their body.
- Galactoepimerase deficiency is an autosomal recessive condition. Babies inherit the condition when each parent passes down a nonworking GALE gene to their baby. Only babies with two nonworking GALE genes—one from the mom and one from the dad—have this condition.
- People with one working copy and one nonworking copy of the GALE gene are called carriers.
- Carriers do not have or develop the condition. However, they may pass down a nonworking copy of the gene to their children.
- If two parents are carriers of a nonworking copy of the GALE gene, they have a 1 in 4 chance of having a child with galactoepimerase deficiency.
- Carriers for galactoepimerase deficiency often do not know they are carriers before having a child with the condition. In most cases, families have no history of the condition until the birth of a child with galactoepimerase deficiency.
- Parents who already have a child with galactoepimerase deficiency still have a 1 in 4 chance of having another child with galactoepimerase deficiency. This 1 in 4 chance stays the same for all future children.
- Genetic counselors and medical geneticists can help families learn about this condition and the chance of having children with it. Visit the National Society of Genetic Counselors to find a genetic counselor and the American College of Medical Genetics and Genomics to find a medical geneticist.
Treatment and Management
It is important to talk to your health care provider about which treatment(s) are best for your baby. The goal of treatment is to prevent the health problems caused by this condition.
Treatments may include the following:
- Avoidance of foods that contain galactose and lactose
- Avoidance of all dairy products
- Special foods and formulas
- Vitamin supplements (calcium, vitamin K, vitamin D)
Children who receive early and ongoing treatment for galactoepimerase deficiency can have healthy growth and development. Some children with the generalized form of galactoepimerase deficiency who receive treatment early may still show delays in learning and development.