Hereditary Bovine Protoporphyria, a “Total Body” Deficiency of Ferrochelatase: Some Basic Distinctions From Hypochromic Anemias

Abstract

The only type of hereditary porphyria described in nonhuman species is the rare erythropoietic (“congenital,” or “Gunther1s”) type. Hereditary bovine protoporphyria, which exhibits an acute photosensitivity even during the 1st week of life, has now been documented (3) in four calves sired by the same clinically normal bull. Their normal-appearing dams were genetically related to this bull. Teeth and urine were normal in color, and had no red fluorescence on exposure to nearly UV light. Concentrations of protoporphyrin in red cells and feces were higher by far than any reported in human protoporphyria; both exceeded 35,000 yg/100 ml (g). Fecal urobilinogen (u’gen) was markedly increased. Ferrochelatase activity was decreased to less than 15% of normal in kidney, spleen, lung, and marrow. It was also decreased in cultured skin fibroblasts (Sassa, unpublished studies), but was approximately half normal in the liver of each of four carrier dams. ALA synthase activity (B. Schacter) was increased slightly, and only in the liver of protoporphyrics. These and other findings are summarized in Table 1. In animals removed from pasture to a dimly lit barn, fecal protoporphyrin and urobilinogen values rapidly approached normal and skin lesions healed, but red cell porphyrin remained above 35,000 yg/100 ml.