title: The porphyrias.
abstract: The porphyrias are a group of disorders of heme metabolism that result from partial defects in the several enzymes that control heme biosynthesis. Accumulation of porphyrins or porphyrin precursors in several different patterns results from these defects and biochemically characterizes each specific syndrome. Patterns of cutaneous photosensitivity and associated systemic symptoms among the several porphyrias result from the types of porphyrins or precursors accumulated in each.
mesh_terms: D000208:Acute Disease; D003306:Coproporphyrins / Q000235:genetics; D004920:Erythropoiesis; D006801:Humans; D008107:Liver Diseases / Q000235:genetics; D011164:Porphyrias / Q000151:congenital / Q000235:genetics; D011524:Protoporphyrins / Q000235:genetics; D012871:Skin Diseases / Q000151:congenital / Q000235:genetics
chemical_list: D003306:Coproporphyrins; D011524:Protoporphyrins