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Coproporphyria, Hereditary: An autosomal dominant porphyria that is due to a deficiency of COPROPORPHYRINOGEN OXIDASE in the LIVER, the sixth enzyme in the 8-enzyme biosynthetic pathway of HEME. Clinical features include both neurological symptoms and cutaneous lesions. Patients excrete increased levels of porphyrin precursors, 5-AMINOLEVULINATE and COPROPORPHYRINS.Coproporphyrins: Porphyrins with four methyl and four propionic acid side chains attached to the pyrrole rings. Elevated levels of Coproporphyrin III in the urine and feces are major findings in patients with HEREDITARY COPROPORPHYRIA.Coproporphyrinogen Oxidase: An enzyme that catalyzes the oxidative decarboxylation of coproporphyrinogen III to protoporphyrinogen IX by the conversion of two propionate groups to two vinyl groups. It is the sixth enzyme in the 8-enzyme biosynthetic pathway of HEME, and is encoded by CPO gene. Mutations of CPO gene result in HEREDITARY COPROPORPHYRIA.Porphyrias, Hepatic: A group of metabolic diseases due to deficiency of one of a number of LIVER enzymes in the biosynthetic pathway of HEME. They are characterized by the accumulation and increased excretion of PORPHYRINS or its precursors. Clinical features include neurological symptoms (PORPHYRIA, ACUTE INTERMITTENT), cutaneous lesions due to photosensitivity (PORPHYRIA CUTANEA TARDA), or both (HEREDITARY COPROPORPHYRIA). Hepatic porphyrias can be hereditary or acquired as a result of toxicity to the hepatic tissues.Porphyrias: A diverse group of metabolic diseases characterized by errors in the biosynthetic pathway of HEME in the LIVER, the BONE MARROW, or both. They are classified by the deficiency of specific enzymes, the tissue site of enzyme defect, or the clinical features that include neurological (acute) or cutaneous (skin lesions). Porphyrias can be hereditary or acquired as a result of toxicity to the hepatic or erythropoietic marrow tissues.Porphyrinogens: Colorless reduced precursors of porphyrins in which the pyrrole rings are linked by methylene (-CH2-) bridges.Porphyrins: A group of compounds containing the porphin structure, four pyrrole rings connected by methine bridges in a cyclic configuration to which a variety of side chains are attached. The nature of the side chain is indicated by a prefix, as uroporphyrin, hematoporphyrin, etc. The porphyrins, in combination with iron, form the heme component in biologically significant compounds such as hemoglobin and myoglobin.