How is galactosemia inherited?
Galactosemia is inherited in an autosomal recessive manner. It affects both boys and girls equally. Everyone has a pair of genes that make the GALT enzyme. In children with galactosemia, neither of these genes works correctly. These children inherit one non-working gene for the condition from each parent. Parents of children with galactosemia rarely have the condition themselves. Instead, each parent has a single non-working gene for galactosemia. They are called carriers. Carriers do not have galactosemia because the other gene of this pair is working correctly. When both parents are carriers, there is a 25% chance in each pregnancy for the child to have galactosemia. There is a 50% chance for the child to be a carrier, just like the parents. And, there is a 25% chance for the child to have two working genes.
