Erythropoietic protoporphyria is a genetic disease in which ferrochelatase is defective. Protoporphyrin accumulates in erythrocytes, leaks into the plasma and results in severe skin photosensitivity.

FIGURE 1. The biosynthesis and degradation of heme. Abbreviations: δ-aminolevulinic acid (ALA); coproporphyrinogen III (CP); protoporphyrin IX (PPIX); ferrochelatase (FECH); feline leukemia virus ...