Intestinal enterokinase deficiency. Occurrence in two sibs and age dependency of clinical expression

Abstract

Intestinal enterokinase deficiency in 2 sibs is described. A boy failed to gain weight and had vomiting, diarrhea, edema, hypoproteinemia, and anemia in early infancy. His duodenal juice contained very low or absent proteolytic enzyme activity, which increased markedly after addition of enterokinase. He was treated with pancreatic extract and gained weight rapidly. At 44 mth of age he is normal, apart from some developmental delay, and no longer needs pancreatic extract. His older sister who had had similar symptoms in early infancy but then grew normally, had the same abnormality in her duodenal juice when seen at 4 yr of age. Enterokinase activity was virtually absent in the duodenal mucosa of both patients. Mucosal morphology was normal. The findings suggest that enterokinase deficiency is an inherited congenital defect and not the result of mucosal damage. Affected patients may show spontaneous improvements and normal growth after the age of 6 to 12 mth. This phenomenon may be related to the decreasing growth velocity during the first 2 yr of life and the concomitant decrease in protein requirements per unit bodyweight.