Congenital erythropoietic porphyria: a family study.

Abstract

We present the results of a study of the porphyrin‐forming enzymes in the erythrocytes of a recently detected case of CBP, in the immediate family, and in the family of a second cousin who died in infancy with a clinical picture similar lo that seen in the present patient. Except for a moderate increase in the activity of the uroporphyrinogen synthetase in the patient's lysates no patological changes have been found either in the patient or in any of the other persons studied.Our findings do not exclude the possibility that impaired activity of the isomerase (uroporphyrinogen‐III‐cosynthetase) plays a role, but they do indicate that this is not the only or even the most important metabolic error in the present type of erythropoictic porphyria.A study of the kinship between the two families seems to make a simple autosomal recessive in. heritance unlikely, hut does not exclude dominant inheritance by a rare single gene with low penetrance carried by the fathers. It is possible that the present case may represent a type of porphyria variegata in which the metabolic defect in porphyrin biosynthesis is located not in the liver hut in the bone marrow.