Glucose-galactose malabsorption.

Abstract
A female infant, who developed severe diarrhea on breast-feeding, had failure of intestinal absorption of the actively-transported monosaccharides, glucose and galactose, but normal absorption of fructose. When the latter was substituted for other carbohydrates in the feed, diarrhea stopped with subsequent thriving. Disaccharidase activity in the jejunal mucosa was normal. Parenterally administered glucose and galactose were normally metabolized. Renal tubular glucose reabsorption was also normal. There was no rise in plasma insulin levels following oral glucose. A vitamin deficiency rash cleared with supplements of pantothenic acid, the lack of which is probably the cause of the skin lesions in children on synthetic foods. The father was intolerant to lactose, with a low lactase activity of his jejunal mucosa; but this was thought to be incidental.