RT Book, Section A1 Lichtman, Marshall A. A1 Kaushansky, Kenneth A1 Prchal, Josef T. A1 Levi, Marcel M. A1 Burns, Linda J. A1 Linch, David C. SR Print(0) ID 1189333786 T1 The Porphyrias T2 Williams Manual of Hematology, 10e YR 2022 FD 2022 PB McGraw-Hill Education PP New York, NY SN 9781264269204 LK hemonc.mhmedical.com/content.aspx?aid=1189333786 RD 2023/12/11 AB The porphyrias are inherited or acquired disorders due to altered activities of enzymes in the heme biosynthetic pathway. Metabolic intermediates are produced in excess, initially either in the marrow or the liver, and result in neurologic and/or photocutaneous symptoms and signs.