galactosemia (gəlăkˌtəsēˈmēə) [key], inherited metabolic disorder caused by an enzyme deficiency and transmitted as a recessive trait; it results in the accumulation of the sugar galactose in the body. The disorder is manifested soon after birth by feeding problems and diarrhea. Galactose is accumulated principally in the liver of the newborn infant, where it may induce cirrhosis, and in the lens of the eye, where cataracts may develop. Low glucose levels cause sufficient hypoglycemia to affect the central nervous system with resulting mental retardation. These ill effects can be prevented by removing milk and all other foods containing galactose and lactose from the diet.