[Role of chromosome aberrations in the development of leukemic process].

The pathogenetic and clinical significance of karyotype features in leukemia and preleukemia are analysed. In 34.7 per cent patients with preleukemia, karyotype instability was observed which consisted in numerical and structural chromosome aberrations with clone anomaly. It was found that karyotype instability is an initial stage of anomalous clone formation and often precedes its development in preleukemia, secondary leukemias, and in preblastic stage of chronic myeloid leukemia. Acute leukemias were found to be characterized by premeditated numerical and structural chromosomal aberrations with predominant involvement of chromosomes 5, 7, 8, and 21 in non-lymphoblastic and chromosomes 6, 9, 8, and 21 in lymphoblastic forms of acute leukemia. It was also shown that the normal to abnormal metaphase ratio in acute leukemia patients is of high prognostic value.