hepatoerythropoietic porphyria (HEP) /hep′ə·tō·ərith′rōpoi·et′ik/ [Gk, hēpar, liver + erythros, red + poiein, to make] , a severe homozygous form of porphyria cutanea tarda (PCT) believed to result from an autosomal-dominant defect in the same enzyme activity as PCT. It is clinically identical to PCT, but onset is in early childhood, and activity of the affected enzyme in liver, erythrocytes, and fibroblasts is virtually absent.
