 The delAGTG causes a loss of an α-helix which is replaced by a β-sheet.Previously known mutations in the ALAS2 resulted in a loss-of-function mutation causing X-linked sideroblastic anemia.Erythropoietic protoporphyria (EPP) has similar symptoms as X-linked dominant erythropoietic protoporphyria but the mutation occurs as a loss-of-function in the FECH (ferrochelatase) enzyme; the very last enzyme in the pathway.