Studies on prolidase deficiency with a possible defect in collagen metabolism.

Skin collagen of a female patient with prolidase deficiency was examined for the distribution of borohydride-reducible cross-links and the proportion of type III to type I collagen. Patient's skin contained after reduction more dihydroxylysinonorleucine relative to hydroxylysinonorleucine and type III collagen than expected for normally matured skin. These findings suggest that collagen of the patient's skin failed to follow a time-related normal maturation process and the collagen metabolism was disturbed. The composition of urinary collagen metabolites was also unusual. On the the other hand, her asymptomatic brother with prolidase deficiency showed the normal urinary compositon of collagen matabolites. It is suggested that prolidase deficiency and defect in collagen metabolism independent of it are both responsible for clinical manifestation.