Abstract
Porphyrias are diseases caused by defects in haem biosynthesis. In the beginning of process of formation of haem, the cornerstone of hemoglobin, essential for life Hemoproteins and large family of cytochrome P-450 are two simple substances, glycine and succinyl-CoA.
Haem is formed by eight consecutive enzymatic steps. This synthesis is normally set extremely accurately and is excreted only minute quantities of intermediate produts of synthesis of porphyrins and haem.