Porphyrias are a group of disorders, which induce excess production of porphyrins, as well as cause their accumulation in the tissues. They also increases the excretion of metabolites, as a result of inherited or acquired deficiencies in the activities of the enzymes of the heme biosynthetic pathway. There are 8 types of porphyria. Like other congenital metabolic disorders, this disorder is very rare, has attracted attention for a long time because of its specific symptoms. Porphyria manifests a wide variety of symptoms, including cutaneous, psychoneurotic, gastrointestinal, and endocrine; endogenous and exogenous environmental factors influence the manifestation of these symptoms. Therefore, acute porphyria may be fatal because of false and/or delayed diagnosis. A poor prognosis may be anticipated. Therefore, it is important that we have accurate knowledge of porphyria. This article reviews on the abnormal porphyrin metabolic disorder.遺伝性ポルフィリン症総説論文、以下のPDF参照（近藤雅雄、2017.1）PDF：Porphyrias
