Hartnup Disease

This condition was demonstrated in a mother and all her children ( 3 boys ranging in age from 1 to 3% years) in a family where the mother is a Greenlander and the father a Dane. Clinically the intolerance manifested itself as diarrhoea and poor thriving, as soon as the patients started having cane sugar in the diet. In the children, the disease set in as soon as they were weaned, in the case of the youngest two at 1-2 months of age and in the oldest boy at 1 year. The mother has had thin or loose stools for as long as she can remember. Investigations showed the patients to have normal glucose tolerance curves, but the normal increase in blood sugar could not be evoked by cane sugar unless the cane sugar-splitting enzyme saccharase (invertase) was given at the same time. This indicates that the patients do not have this substance in their small intestine. Moreover, a small part of the cane sugar was found to be absorbed unsplit from the intestine on an ordinary diet, being excreted with the urine, while the greater part remained in the intestinal lumen, to be excreted with the faeces. The patients could be kept symptom free and thrived normally on a cane-sugar free diet or with a supplement of saccharase to diet containing cane sugar.