galactosaemia Genetic disease; inability to metabolize the sugar galactose. Unless galactose is excluded from the diet, the infants suffer mental retardation, growth failure, vomiting, and jaundice, with enlargement of liver and spleen and development of cataracts. Special infant foods are prepared entirely free from lactose, which is the only important source of galactose in the diet.

galactosaemia (gă-lak-toh-see-miă) n. an inborn inability to utilize the sugar galactose, which in consequence accumulates in the blood. Untreated, affected infants fail to thrive and show developmental delay, but if galactose is eliminated from the diet growth and development may be normal.