Conditions Galactoepimerase Deficiency

Galactoepimerase deficiency (GALE) is an inherited condition in which the body is unable to properly break down galactose, a sugar found in all foods that contain milk and in some fruits and vegetables. This condition can cause harmful amounts of undigested sugars to build up in the blood. There are three forms of GALE (generalized, peripheral, and intermediate). Some of these forms are more severe, while others are milder. Severe forms of GALE can lead to eye problems (cataracts), delayed growth and development, intellectual disabilities, liver disease, kidney problems or even death. However, when GALE is identified through newborn screening and proper treatment is started early, affected children can often lead healthy lives.

GALE is only one type of a broader condition group called galactosemia. The different types of galactosemia each have different causes and outcomes. You can read about other types of galactosemia on the pages for classic galactosemia and galactokinase deficiency.

Condition Type

Other Disorders


The incidence of galactoepimerase deficiency (GALE) varies by ethnicity. It occurs most often in African American populations with 1 out of every 6,700 newborns diagnosed with GALE. It is less common in other ethnic groups, affecting about 1 in 70,000 European individuals.

Also known as

  • GALE
  • GALE deficiency
  • Galactose epimerase deficiency
  • Galactosemia type III
  • UDP-galactose-4-epimerase deficiency

Follow-Up Testing

Your baby’s doctor may ask you if your baby is showing any of the signs of GALE (see Early Signs below). If your baby has certain signs, your baby’s doctor may suggest starting immediate treatment.

If your baby’s newborn screening result for galactoepimerase deficiency (GALE) was out of the normal range, your baby’s doctor or the state screening program will contact you to arrange for your baby to have additional testing. It is important to remember that an out-of-range screening result does not necessarily mean that your child has the condition. An out-of-range result may occur because the initial blood sample was too small or the test was performed too early. However, a few babies do have the condition so it is very important that you go to your follow-up appointment for a confirmatory test. Because the harmful effects of untreated generalized GALE can develop shortly after birth, follow-up testing must be completed as soon as possible to determine whether or not your baby has the condition and, if so, which form.

Follow-up testing will involve a blood test to measure certain substances in a your baby’s blood. Babies with GALE will have low amounts of an enzyme called UDP-galactose-4-epimerase in their blood. Your baby’s doctor may also measure the amount of undigested sugars present in a sample of your child’s urine. Undigested sugars build up in the body when a child has GALE, so measuring the amounts of these sugars and other substances can help doctors determine if your baby has a condition. Babies with generalized GALE generally have high amounts of undigested sugars in their urine while babies with peripheral or intermediate GALE may show much lower amounts. Genetic testing for GALE may also be necessary to confirm the diagnosis.

About Galactoepimerase Deficiency

Early Signs

There are three forms of galactoepimerase deficiency (GALE), which vary by the severity of their signs: generalized, peripheral, and intermediate.

Signs of generalized GALE usually start shortly after birth. This is why identification through newborn screening is so important.

Early signs of generalized GALE include:

  • Weak muscle tone (hypotonia)
  • Poor feeding and sucking
  • Vomiting
  • Weight loss

If your baby has any of these signs, tell your baby’s doctor as soon as possible.

Babies with peripheral or intermediate GALE generally do not develop any signs of the condition.


Children with generalized galactoepimerase deficiency (GALE) require immediate treatment, while many children with peripheral or intermediate GALE may not require any form of treatment. Your baby’s doctor can evaluate your baby and determine a treatment plan that meets their individual needs.

Dietary Treatments

Your baby may need to avoid foods with galactose (a sugar found in milk) to prevent the toxic build-up of undigested sugars in their blood. Many children with generalized GALE need to avoid all milk products.

Your baby’s doctor can recommend foods and formulas that do not contain galactose. These formulas will likely need to be continued through adulthood.

Certain fruits and vegetables also contain galactose. Your baby may need to avoid these as well. A dietician or nutritionist can help you plan a healthy diet for your child.


Since many children must avoid milk-containing products, your baby may also need to take calcium supplements. Your baby’s doctor may also prescribe Vitamin C and Vitamin K supplements.

Expected Outcomes

Early and ongoing treatment can prevent the early feeding problems, vomiting, poor weight gain, liver problems, and eye problems usually associated with untreated generalized galactoepimerase deficiency (GALE).

Some children who receive treatment for generalized GALE may still have learning disabilities and developmental delays.

Children with peripheral GALE usually do not develop the signs and symptoms associated with generalized GALE, regardless of dietary treatment (see Treatment).

Little is known about the long-term effects of intermediate GALE.


When we eat food, enzymes help break it down. We need to break down the carbohydrates and sugars we eat so that they can be used for energy. Many foods, such as milk products and some fruits and vegetables, contain the sugar galactose. Galactose is broken down by several enzymes, including UDP-galactose-4-epimerase.

If your baby has galactoepimerase deficiency (GALE), their UDP-galactose-4-epimerase enzyme is either missing or not working properly in certain parts of their body. In generalized GALE, this enzyme is not working in all tissues of the body, while in peripheral or intermediate galactoepimerase deficiency, the enzyme is only not working in a few parts of the body.

When UDP-galactose-4-epimerase does not work correctly, your baby’s body cannot break down galactose. This causes undigested sugars to buildup, which can be harmful.

GALE is an autosomal recessive genetic condition. This means that a child must inherit two copies of the non-working gene for GALE, one from each parent, in order to have the condition. The parents of a child with an autosomal recessive condition each carry one copy of the non-working gene, but they typically do not show signs and symptoms of the condition. While having a child with GALE is rare, when both parents are carriers, they can have more than one child with the condition. Learn more about autosomal recessive inheritance.

Support for Galactoepimerase Deficiency

Support Services

Support groups can help connect families who have a child or other family member affected with galactoepimerase deficiency with a supportive community of people who have experience and expertise in living with the condition. These organizations offer resources for families, affected individuals, health care providers, and advocates:

Accessing Care

Work with your baby’s doctor to determine the next steps for your baby’s care. Depending on the signs and symptoms your child experiences, your baby’s doctor may recommend that you see a dietician, an eye-doctor, a doctor who treats the liver, or other medical resources in your community. Some children with galactoepimerase deficiency (GALE) have developmental delays. If you think that your baby is not meeting their developmental milestones, ask your baby’s doctor about the next steps in accessing a developmental evaluation and care.

Because galactoepimerase deficiency is a genetic condition, you may want to talk with a genetics specialist. A genetic counselor or geneticist can help you understand the causes of the condition, discuss genetic testing for GALE, and understand what this diagnosis means for other family members and future pregnancies. Speak with your baby’s doctor about getting a referral. The Clinic Services Search Engine offered by the American College of Medical Genetics and Genomics (ACMG) and the Find a Genetic Counselor tool on the National Society of Genetic Counselors (NSGC) website are two good resources for you or your baby's health care provider to use to identify local specialists.

Families' Experiences

At this time we have not located a family story for this particular condition. If your family is affected by galactoepimerase deficiency (GALE) and you would like to share your story, please contact us so other families may learn from your experience.

Each family's experience with a condition is unique, but there are some parts of the evaluation and treatment of GALE that are similar to other types of galactosemia. Please see the Families' Experiences section on our Classic Galactosemia page if you would like to read the stories of families dealing with that type of galactosemia.

References & Sources

Visit GeneReviews for more information on epimerase deficiency galactosemia

Visit MedlinePlus Genetics for more information on galactosemia

Visit Genetics Home Reference from the National Library of Medicine for more information on GALE

ACT Sheets

Healthcare professionals can learn more about confirmatory testing by reading the American College of Medical Genetics and Genomics' Algorithm for Diagnosis and ACT Sheet, a guide for follow-up after newborn screening. You can visit this page of the ACMG website here.

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