Erythropoietic porphyrias, which include erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP), result from mutations of the ferrochelatase (FECH) gene in EPP and mutations in the aminolevulinic acid synthase-2 (ALAS2) gene in XLP [1–3]. The gene discussed is ALAS2; the disease is X-linked lymphoproliferative disease.