What is galactosemia?

Condition analysis:
Galactosemia is a rare hereditary disease that can lead to cirrhosis in infants, and early, devastating illness if not diagnosed quickly.

This disease is caused by elevated levels of galactose (a sugar in milk) in the blood resulting from a deficiency of the liver enzyme required for its metabolism (breakdown).

Instructions:
Risk Factors of Galactosemia    
The incidence of galactosemia varies in different populations. In the United Kingdom, one in 70,000 individuals is affected. In the United States, one in 60,000 individuals is affected. One in 30,000 individuals is affected in Ireland. Galactosemia is thought to be very rare in Asian populations.

Because galactosemia is inherited, the only known risk factor is a family history of the disorder. Galactosemia is inherited as an autosomal recessive trait. Individuals have two copies of most genes, one inherited from the father and one from the mother. To inherit a recessive genetic disorder, an individual must receive two copies of the defective gene for the disease to appear.

People who have only one mutated gene are called "carriers." If only one parent is a carrier, none of the children will have galactosemia, but each child will have a 50% chance of being a carrier; if both parents are carriers, then each child has a 50% chance of being a carrier, a 25% chance of not inheriting either mutated gene, and a 25% chance of having galactosemia.