[Cytogenetic study of acute and chronic leukemias].

From 1983 to 1987 we studied 30 patients with leukemia searching for chromosomal alterations. Cytogenetic studies of bone marrow showed an abnormal karyotype in 19 (67%). Seven out of 14 cases of acute leukemia presented different chromosomic alterations. The Philadelphia chromosome was found in 11 patients with chronic myeloid leukemia and 3 patients with chronic lymphatic leukemia; a Pseudo-Philadelphia chromosome was present in one patient, this being the first such finding in Chile. Thus, the karyotype is a valuable complementary study not only in chronic myeloid leukemia but also in chronic lymphatic leukemia and the acute lymphoblastic and non-lymphoblastic varieties.