Dr. Greene's Answer
Galactosemia is a metabolic disease that can cause ovarian failure. Children with galactosemia are missing an enzyme needed to process a sugar called galactose. This is found in the diet primarily in lactose (in dairy products and many nutritional and pharmaceutical extenders). Galactose is now known to be present in many other foods, especially beans and peas. When you have galactosemia, the ovaries are slowly destroyed over the course of the first few decades of life (but not testicles, for unknown reasons). Although a strict galactose-free diet may be able to curtail a life-threatening metabolic derangement in newborns, continued avoidance of galactose does generally not prevent other long-term complications, including ovarian failure. The exact mechanism by which the inability to process galactose injures the ovaries is uncertain.
Widespread newborn screening for galactosemia in the United States has made undetected galactosemia uncommon. For those who have not been screened, a blood test or urine test can screen for the condition. Most people with galactosemia will develop obvious symptoms in infancy.