About galactose-1-phosphate uridyl transferase deficiency

What is galactose-1-phosphate uridyl transferase deficiency?

Galactosemia is a rare, hereditary disorder of carbohydrate metabolism that affects the body's ability to convert galactose (a sugar contained in milk, including human mother's milk) to glucose (a different type of sugar). Galactose is converted to glucose by a series of three enzyme reactions. The disorder is caused by a deficiency of an enzyme known as "galactose-1-phosphate uridyl transferase" which is vital to this process.

Galactosemia may also be referred to as classic galactosemia because a few variants of the gene for galactosemia have been identified. One variant causes a milder form of the disorder known as Duarte galactosemia. Classic galactosemia is the most severe form.

Because milk is the staple of an infant's diet, early diagnosis and treatment of this disorder is absolutely essential to avoid serious lifelong disability.

What are the symptoms for galactose-1-phosphate uridyl transferase deficiency?

Symptoms of galactosemia usually develop several days or weeks after birth. The most common symptoms include:

  • loss of appetite
  • vomiting
  • jaundice, which is yellowing of the skin and other parts of the body
  • liver enlargement
  • liver damage
  • fluid building up in the abdomen and swelling
  • abnormal bleeding
  • diarrhea
  • irritability
  • Fatigue or lethargy
  • weight loss
  • weakness
  • higher risk of infection

Babies who have galactosemia have problems eating and tend to lose weight. This is also known as failure to thrive. Learn more about what Failure to thrive means for your child.

What are the causes for galactose-1-phosphate uridyl transferase deficiency?

Galactosemia is caused by mutations in genes and a deficiency of enzymes. That causes the sugar galactose to build up in the blood. It’s an inherited disorder, and parents can pass it down to their biological children. The parents are considered carriers of this disease.

Galactosemia is a recessive genetic disorder, so two copies of the defective gene have to be inherited for the disease to appear. This usually means a person inherits one defective gene from each parent.

What are the treatments for galactose-1-phosphate uridyl transferase deficiency?

The most common treatment for galactosemia is a low-galactose diet. This means that milk and other foods that contain lactose or galactose can’t be consumed. There is no cure for galactosemia or approved medication to replace the enzymes.

Although a low-galactose diet can prevent or reduce the risk of some complications, it may not stop all of them. In some cases, children still develop problems such as speech delays, learning disabilities, and reproductive issues.

Speech problems and delays are common complications, so some children may benefit from speech therapy as part of the treatment plan.

In addition, children who have learning disabilities and other delays may benefit from individual education plans and interventions.

Galactosemia can increase the risk of infections, so controlling infections when they occur is crucial. Antibiotic treatments or other medications may be necessary.

Genetic counseling and hormone replacement therapy may also be recommended. Galactosemia can affect puberty, so hormone replacement therapy may help.

It’s important to talk to your doctor and address concerns early.


To follow a low-galactose diet, avoid foods with lactose, including:

  • milk
  • butter
  • cheese
  • ice cream
  • other dairy products

You can replace many of these foods with dairy-free alternatives, like almond or soy milk, sorbet, or coconut oil. Learn about almond milk for babies and toddlers.

Human breast milk also contains lactose and isn’t recommended for babies diagnosed with this condition. Some babies with Duarte variant galactosemia may still be able to drink breast milk, however. Talk to your doctor if you have any concerns about not being able to breastfeed your baby.

While the Centers for Disease Control and Prevention (CDC) recommends breast milk as the best way for infants to receive nutrients, they don’t recommend breastfeeding an infant with galactosemia. Instead, you’ll need to use a lactose-free formula. Ask your doctor about formula options.

If you plan to use formula, look for a lactose-free version. Many dairy products are fortified with vitamin D. Talk to your doctor about vitamin D supplements and whether they are appropriate for your child.

Video related to galactose-1-phosphate uridyl transferase deficiency