ABSTRACT
The second documented case of prolidase deficiency is presented. Clinical manifestations include chronic otitis media and sinusitis, dermatitis, and splenomegaly. Prolidase is undetectable in the white blood cells of the patient and near or less than the lower range of normal in each parent. The peptide chromatographic pattern of the urine is similar to that of the previously reported patient with prolidase deficiency. The quantity of amino acids excreted in urine per 24 hours is at least three times that of the upper range of normal (of these same amino acids) for the patients age group. More than 80% of the total amino acids excreted are in peptide form. The proline-to-hydroxyproline ratio suggests that the dipeptides are the catabolic products of other proteins in addition to collagen.