Primary intestinal enteropeptidase deficiency.

A rare case of primary enteropeptidase deficiency is reported. Details are given of the initial clinical presentation, treatment, and response of the patient from birth to the age of 18 months. Biochemical analysis of a small intestinal biopsy and duodenal juice samples confirmed the total absence of enteropeptidase activity. Proteolytic activity was very low in native duodenal juice, but normal levels could be induced by activation in vitro with a small amount of porcine enteropeptidase.