Galactosemia

Galactosemia is a group of inherited disorders that impair galactose metabolism, allowing galactose or its metabolites to accumulate and cause illness.

Leloir pathway: The main metabolic pathway that converts galactose into glucose-1-phosphate. Galactosemia results when an enzyme in this pathway fails to process galactose normally.
Newborn screening: Population testing of newborns for conditions that benefit from early detection and treatment. Screening can identify galactosemia before symptoms become severe.
Classic galactosemia: The severe form of galactosemia caused by profound GALT deficiency. It can cause neonatal liver disease, infection, and metabolic crisis after milk feeding.
Autosomal recessive inheritance: Inheritance in which a disorder typically occurs when both copies of a gene carry disease-causing variants. Most forms of galactosemia follow this pattern, giving carrier parents a 25% recurrence risk per pregnancy.
Hereditary fructose intolerance: An inherited metabolic disorder in which fructose-1-phosphate accumulates after fructose ingestion. It also causes dietary-triggered liver illness but involves fructose rather than galactose metabolism.
Galactose-1-phosphate uridylyltransferase: An enzyme in the Leloir pathway that transfers a uridyl group from UDP-glucose to galactose-1-phosphate. Deficiency of this enzyme causes classic galactosemia, the most common severe form.
Galactosemia screening test: A newborn blood test measuring galactose metabolites or enzyme activity to detect galactosemia. Programs commonly assess GALT activity, total galactose, or both.
Duarte galactosemia: A usually mild biochemical form associated with a Duarte variant of the GALT gene. Its clinical significance and need for dietary restriction differ from classic disease.
GALT gene: The gene that encodes galactose-1-phosphate uridylyltransferase. Pathogenic variants in GALT cause classic galactosemia and Duarte variants.
Glycogen storage disease type I: An inherited disorder of glucose production caused by deficiency of glucose-6-phosphatase or its transporter. Its fasting hypoglycemia and liver enlargement can resemble metabolic liver disease from galactosemia.

Linked from 3 pages