How does galactosemia affect infants who consume milk?

Galactosemia is a hereditary metabolic disease characterized by the body's inability to properly process galactose, a sugar found in lactose, which is the primary carbohydrate in milk.1

When infants with this condition consume milk, they cannot metabolize galactose into glucose because a specific enzyme required for the second step of the metabolic pathway is inactive. This leads to the toxic accumulation of galactose-1-phosphate in body tissues.12

Clinical manifestations typically appear shortly after milk feeding begins and include:
* Gastrointestinal and systemic distress: Vomiting, lethargy, and failure to gain weight.12
* Organ dysfunction: Enlargement of the liver, jaundice, and kidney disease.12
* Severe complications: Increased susceptibility to bacterial infections (notably Escherichia coli), cataracts, and intellectual disability.12

Promptly eliminating milk and milk products from the diet is essential, as it allows most symptoms to regress and can prevent long-term damage.12