TY - CHAP M1 - Book, Section TI - Methemoglobinemia and Other Dyshemoglobinemias A1 - Lichtman, Marshall A. A1 - Kaushansky, Kenneth A1 - Prchal, Josef T. A1 - Levi, Marcel M. A1 - Burns, Linda J. A1 - Linch, David C. PY - 2022 T2 - Williams Manual of Hematology, 10e AB - Increased methemoglobin from a baseline of less than 1% occurs due to oxidation of ferro to ferric iron of hemoglobin due to environmental agents or due to underlying germline mutations causing diminished reduction of methemoglobin to hemoglobin. Cyanosis is seen when total methemoglobin exceeds 15 g/L; thus, at 10% of methemoglobin, those with hemoglobin concentrations above 150 g/L would have cyanosis, whereas those with hemoglobin below 150 g/L would not.Dyshemoglobinemia is a term used for modified hemoglobins (eg, methemoglobin, carboxyhemoglobin, nitrosohemoglobin, and sulfhemoglobin) that are associated with normal amino acid sequence of hemoglobin tetramers; however, in M hemoglobins, the globins are mutated changing amino acid in hemoglobin tetramers. They can result in varying degrees of clinical manifestations. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - hemonc.mhmedical.com/content.aspx?aid=1189333342 ER -