Galactosemia is an enzyme defect in galactose metabolism. Galactose is a simple sugar. Lactose, which is found in milk products, is the predominant source of galactose. Galactosemia is an inherited condition, and occurs in one out of every 60,000 Caucasian births. If a newborn with galactosemia is given breast milk or formula, symptoms include vomiting, jaundice, failure to gain weight and possibly, sepsis. After diagnosis, a life-long galactose-free diet will need to be followed.