The pedigree of 6 cases (2 male and 4 female) of glucose-galactose malabsorption is presented. Besides the 6 cases seen by the authors, there occurred in the same pedigree at least 4 more instances of death in early infancy due to intractable diarrhoea. It is likely that these resulted from glucose-galactose malabsorption. The parents of the patients were healthy and had no history of chronic diarrhoea in infancy or thereafter. As judged by oral GTT's on two pairs of parents they had normal glucose absorption. No renal glucosuria, present in all the patients, was found in the parents. It was concluded that glucose-galactose malabsorption has an autosomal recessive mode of inheritance.
In 5 patients (from 4 different sibships) where the urinary excretion of amino acids was examined, 4 had increased excretion of β-aminoisobutyric acid although they were in a good nutritional state. Of 7 parents examined, 2 excreted increased amounts of the same compound. The finding of this selective aminoaciduria is probably incidental and, at least in the children, is not believed to be genetically determined.