NONRANDOM CLONAL EVOLUTION IN 45 CASES OF CHRONIC MYELOID-LEUKEMIA

Chromosome analyses, using for the most part the RHG-banding technique, were performed on blood and bone marrow of 52 patients with chronic myeloid leukemia (CML) during blastic crisis. In 16 of these patients studies were also done on spleen and/or on lymph nodes. In 45 of our patients other chromosomal aberrations in addition to the Ph1 were found. Our studies demonstrated that the chromosomal involvement in the development of malignancy in CML is not a random event. A second Ph1 chromosome was found in 28 patients (62.2%). An additional long arm of chromosome 17 [trisomy 17 or i(17q)] was seen in 29 patients (64.4%) and a trisomy 8 in 13 patients (28.8%). These three main abberrations occurred alone or together in the same cell. We have seen 13 patients (28.8%) with 2 Ph1 and trisomy 17q without trisomy 8. Karyotypic evolution usually proceeds by addition of chromosomes. © 1979.