Fructosaemia: Observations on seven cases

The mode of presentation and the clinical course in seven new cases of fructosaemia are described. Two main categories are recognized. The introduction of fructose (sucrose) into the diet, at under six months of age, results in vomiting, anorexia, failure to thrive and evidence of hepatorenal dysfunction, sometimes with hypoglycaemic convulsions, and a transient bleeding tendency. One patient presented with severe multiple renal tubular dysfunction, which returned to normal on exclusion of fructose from the diet. Two infants died in the neonatal period. When fructose is included in the diet at a later age the illness is less severe, even asymptomatic, or presents as spontaneous hypoglycaemia. None of the surviving patients is retarded mentally or physically. In all cases an oral dose of fructose caused a marked increase in blood fructose, a decrease in blood glucose and phosphate, and an increase in plasma magnesium.