Galactosaemia

Alternative name Galactose-1-phosphate uridyltransferase (GUT) deficiency
About the condition Classical galactosaemia is a carbohydrate disorder. It is a hereditary disease that is caused by a missing enzyme needed to metabolise galactose. Galactose is a product of the digestion of lactose or milk sugar. Without treatment, galactose accumulates in the blood and causes organ toxicity.
Inheritance Autosomal recessive
Year screening started in WA 1980
Incidence in WA 1 in 60,000 births
Enzyme defects Deficiency of the enzyme galactose-1-phosphate uridyltransferase. Galactokinase and UDP-galactose-4-epimerase deficiencies may also be detected.
Symptoms if untreated Infants with classical galactosaemia are usually normal at birth; however, they soon develop jaundice and vomiting, and they fail to gain weight. Other symptoms of the condition include:
  • Liver failure and renal dysfunction
  • E.coli sepsis
  • Intellectual disability
  • Cataracts
Infants who are diagnosed early have good long-term outlooks although some may develop problems with their speech and women may suffer from infertility. Galactokinase deficiency only causes cataracts.
Metabolites on bloodspot screening
  • Increased galactose and galactose-1-phosphate
  • Decreased GUT enzyme activity
Diagnostic tests
  • Blood galactose-1-phosphate and plasma galactose
  • RBC GUT activity
Treatment Treatment with a lactose-free diet prevents the life-threatening complications.
Screening issues
  • The galactose metabolites are only increased if the affected baby is on milk feeds
  • Where milk feeding has not been established the screening laboratory measures GUT activity instead
  • The screening test should be performed before exchange transfusion
  • The screening test my detect other rare forms of galactosaemia: galactokinase and epimerase deficiencies