No abstract

No abstract

The chromosome constitution in marrow cells was determined in 219 cases of acute leukemia, 113 with the myeloblastic and 106 with the lymphoblastic forms. Aneuploidy was found in 50% of the cases; the remaining 50% were diploid. The karyotypes showed remarkable variability from case to case and, except for a small number of cases with groupC trisomy, no consistent or characteristic chromosomal changes were found in acute leukemia. Even though minor variations may appear with time, generally the karyotypes of the leukemic cells showed considerable stability during phases of remission and relapse. Hyperdiploidy characterized the aneuploid lymphoblastic leukemia, whereas the myeloblastic cases may be accompanied by either hypoor hyperidploidy. A statistical analysis revealed that no one chromosomal subgroup can be implicated more than another in the karyotypic changes of acute leukemia. The chromosomal findings were interpreted in relation to their possible role in causation of acute leukemia; the view was advanced that the large proportion of diploid acute leukemia and the variability of the karyotypic changes indicate that the chromosomal changes were secondary to the leukemic state. The variation of the karyotypes from case to case points to the possibility that the variable genotypes of the patients are reflected in the variable aneuploidy observed in the leukemic cells.

No abstract

The frequency of the Ph1 chromosome in freshly aspirated marrow cells of 14 patients with typical chronic myelocytic leukemia processed by a "direct technic" without resort to culture or colchicine was significantly higher (> 75 per cent) than that observed in the cultured blood cells (< 35 per cent) of the same subjects. The karyotypic abnormally of the abbreviated G-group chromosome would appear not to be related to therapy, since the frequency with which it occurred was not materially affected by treatment (including radiation). The Ph1 chromosome was not observed in any of the metaphases of blood or marrow of 12 subjects who had developed a leukemia-like picture complicating either myelofibrosis, polycythemia vera or myeloid metaplasia. A new chromosome abnormality—a shortened D-group chromosome—was observed with about the same frequency in the blood and marrow metaphases of a female patient with treated chronic myelocytic leukemia. This new karyotypic abnormality was associated with the highest frequency of the Ph1 chromosome in cultured blood cells in the group studied. The Ph1 chromosome was observed in the metaphases of a patient with the blastic phase of chronic myelocytic leukemia. The variations of the morphology of the Ph1 chromosome are discussed and illustrated, especially in relation to the Y-chromosome. In four patients with an atypical picture of CML, the Ph1 chromosome was not observed either in the marrow or cultured blood.