• Definition

    Porphyrias are a group of rare disorders passed down through families, in which an important part of hemoglobin, called heme, is not made properly. Heme is also found in myoglobin, a protein found in certain muscles.

    Alternative Names

    Acute intermittent porphyria; Hereditary coproporphyria; Congenital erythropoietic porphyria; Erythropoietic protoporphyria

    Causes, incidence, and risk factors

    Normally, the body makes heme in a multi-step process. Porphyrins are made during several steps of this process. Patients with porphyria have a deficiency of certain enzymes needed for this process. This causes abnormal amounts of porphyrins or related chemicals to build up in the body.

    There are many different forms of porphyria. The most common type is porphyria cutanea tarda (PCT).

    Drugs, infection, alcohol, and hormones such as estrogen may trigger attacks of certain types of porphyria.