A group of inherited enzyme deficiencies which feature elevations of galactose in the blood. This condition may be associated with deficiencies of galactokinase; udpglucose-hexose-1-phosphate uridylyltransferase; or udpglucose 4-epimerase. The classic form is caused by udpglucose-hexose-1-phosphate uridylyltransferase deficiency, and presents in infancy with failure to thrive; vomiting; and intracranial hypertension. Affected individuals also may develop MENTAL RETARDATION; jaundice; hepatosplenomegaly; ovarian failure (primary ovarian insufficiency); and cataracts. (From Menkes, Textbook of child neurology, 5th ed, pp61-3)