Anomalies héréditaires du métabolisme du galactose et du fructose

Galactose is present in the disaccharide lactose, main carbohydrate in milk. Three inborn errors of galactose metabolism are known. Galactokinase deficiency results in isolated nuclear cataract. Galactosemia is usaually due to galactose-1-phosphate uridyl transferase deficiency. This disease provokes hepatic, renal or ocular symptoms that improve with galactose free diet. Long-term prognosis is linked to its neurological consequences. UDP-galactose 4ʼ-epimerase deficiency is very rare and provokes either benign partial forms, or very rare profound deficiency giving severe forms of galactosemia. Fructose is a widely found hexose in human diet. Three inborn errors of metabolism may affect fructose metabolism. Fructokinase deficiency is an asymptomatic abnormality. Hereditary fructose intolerance, due to fructose aldolase deficiency provokes either acute gastrointestinal symptoms, with or without hypoglycemia, or hepatic or renal expressions that may be life threatening if a fructose free diet is not begun early. Fructose-1,6-diphosphatase deficiency is an inborn error affecting neoglucogenesis resulting in hypoglycemias with hyperlactacidemia.