Chromosomes and causation of human cancer and leukemia. XIII. An evaluation of karyotypic findings in erythroleukemia.

This study was an attempt at defining the cytogenetic features of erythroleukemia (EL), particularly as related to the group of AML patients with MAKA (major karyotypic abnormalities), which generally were caused by three or more cellular events of translocation or nondisjunction. Eight of the 17 patients with MAKA had a diagnosis of EL or possible EL. In most cases, MAKA was featured by hypodiploidy, karyotypic instability, and polyploidy in the leukemic cells. The most common abnormalities were loss of B or G group chromosomes and gain of a no. 16 or one or more marker chromosomes. Each of the markers of 2q+, Dq+, mar(A2, st), mar(C12, M), r(?F) and minute metacentric and acentric markers was observed in two or more patients. The extent of polyploidy seemed to be correlated with the proportion of erythroid precursor cells in the marrow and with the karyotypic instability. Since the patients exhibited the same chromosomal features, whether or not they had a diagnosis of EL or possible EL, and since patients without such a diagnosis also had cytologic suggestions of EL, a close relation of MAKA to EL is assumed. It is believed that patients with MAKA constitute one of the three chromosomally classifiable groups of EL.