A to Z: Galactosemia
May also be called: Galactose-1-Phosphate Uridyltransferase Deficiency; Galactokinase Deficiency; Galactose-6-Phosphatase Emirase Deficiency; GALT Deficiency; Galactose Epimerase Deficiency; Classic Galactosemia; Galactosemia Type II; Galactosemia Type III
Galactosemia (guh-lak-tuh-SEE-mee-uh) is an inherited disorder in which the body can't break down a type of sugar called galactose.
More to Know
Galactose is one of the two sugars found in lactose, or milk sugar. It's also in some fruits and vegetables. Galactosemia is caused by mutations in genes that help make enzymes the body needs to convert galactose into glucose.
The parents of a child with galactosemia are carriers of the mutation, meaning that they have the gene in their bodies and can pass it on, but they themselves won't show any signs or symptoms of the condition.
Babies with galactosemia lack the enzyme that converts galactose into glucose, a sugar the body is able to use. If they consume milk or other products with lactose or galactose, galactose can build up in the body and damage cells and organs. This can lead to blindness, severe intellectual disability, growth problems, and in some cases even death.
Galactosemia usually appears within the first few days or weeks after a baby's birth. Newborns with galactosemia often have symptoms like vomiting, poor feeding, loss of appetite, yellowing of the skin and whites of the eyes (jaundice), and failure to thrive, which means that they are not able to grow and gain weight properly. They also may have enlarged livers (hepatomegaly).
To treat galactosemia, milk (including breast milk), other dairy products, and other sources of lactose and galactose must be removed from the baby's diet. This may help control symptoms, but even with the proper dietary changes, galactosemia often causes serious long-term issues.
Keep in Mind
If not treated, galactosemia quickly can become life threatening. Fortunately, newborns can be screened for the condition, and treatment is usually started before a child becomes seriously ill and suffers permanent organ damage. Children who are diagnosed early and eat a lactose-free and galactose-free diet usually reach adulthood.
All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.