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Stephen F. Dierdorf

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date: 13 June 2021

Heme, and iron containing compound that forms the nonprotein portion of hemoglobin, is essential to life. Heme synthesis requires eight enzymatic steps, and a deficiency in any one of the eight enzymes can lead to the accumulation of potentially toxic intermediates. Some forms of porphyria may be asymptomatic until the patient receives a triggering agent, and acute porphyrias can also be difficult to diagnose because of the nonspecific clinical features. The most serious of the clinical manifestations is severe neurologic dysfunction. An attack can be triggered by medications administered during the perioperative period, and failure to act promptly can result in mortality rates as high as 5%.

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