TY - CHAP M1 - Book, Section TI - Classification and Clinical Manifestations of the Clonal Myeloid Disorders A1 - Lichtman, Marshall A. A1 - Kaushansky, Kenneth A1 - Kipps, Thomas J. A1 - Prchal, Josef T. A1 - Levi, Marcel M. Y1 - 2011 N1 - T2 - Williams Manual of Hematology, 8e AB - Result from a mutation(s) of DNA within a single pluripotential marrow hematopoietic cell or very early progenitor cell. Mutations disturb the function of the gene product.Overt cytogenetic abnormalities can be found in 80 percent of cases of acute myelogenous leukemia (AML) in experienced laboratories (see Williams Hematology, 8th ed, Chap. 11, Fig. 11–3, p. 153).— Translocations (e.g., t(15;17)) and inversions of chromosomes (e.g., inv16) can result in the expression of fusion genes that encode fusion proteins that are oncogenic.— Overexpression or underexpression of genes that encode molecules critical to the control of cell growth or programmed cell death, often within signal transduction pathways or involving transcription factors occur.— Deletions of all or part of a chromosome (e.g., 5q- or -7) or duplication of all or part of a chromosome may be evident (e.g., trisomy 8).An early multipotential hematopoietic cell undergoes clonal expansion but retains the ability to differentiate and mature, albeit with varying degrees of pathologic features, into various blood cell lineages.The result is often abnormal blood cell concentrations (either above or below normal), abnormal blood cell structure and function; the abnormalities may range from minimal to severe.Resulting disease phenotypes are numerous and varied because of the nine differentiation lineages from a multipotential hematopoietic cell.Neoplasms that result can be grouped, somewhat arbitrarily, by the degree of loss of differentiation and maturation potential and by the rate of disease progression.Most patients can be grouped into the classic diagnostic designations listed in Table 41–1. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/04/19 UR - hemonc.mhmedical.com/content.aspx?aid=1126652532 ER -