Defects in the ferrochelatase (FECH), delta-aminolevulinate synthase 2 (ALAS2) or caseinolytic mitochondrial matrix peptidase chaperone subunit (CLPX) genes are associated with erythropoietic protoporphyria (EPP), a disease usually presenting in children, due to the accumulation of protoporphyrin-IX (PPIX) in erythrocytes, skin and liver [1]. The gene discussed is ALAS2; the disease is erythropoietic protoporphyria.