Hepatoerythropoietic porphyria: a variant of childhood-onset porphyria cutanea tarda. Porphyrin profiles and enzymatic studies of two cases in a family.

Hepatoerythropoietic porphyria is a rare variant of porphyria cutanea tarda, manifested clinically as photosensitivity starting in early childhood. Biochemically, there are elevated levels of protoporphyrin in erythrocytes and acetate-substituted porphyrins in the plasma, urine, and feces. Uroporphyrinogen decarboxylase activities in these patients are markedly suppressed. Thus far, only nine patients have been reported. We hereby describe the clinical manifestations, histologic changes, porphyrin profiles, and erythrocyte uroporphyrinogen decarboxylase determinations of two additional patients, 9-year-old and 7-year-old siblings, that are consistent with those of nine previously reported patients with hepatoerythropoietic porphyria.