Investigations on karyotype evolution in patients with chronic myeloid leukemia (CML)

In an attempt to relate karyotype evolution to clinical and hematological data serial chromosomal analyses were performed in 31 patients with chronic myeloid leukemia (CML), both in chronic and acute phases. Our results in Philadelphia chromosome (Ph¹)-positive CML are in line with karyotype profiles described in the literature. In addition, we report on chromosomal findings in 4 cases of Ph¹-negative disease, one presenting with an iso17q chromosome in the acute phase, an aberration otherwise typical for acute transformation in Ph¹-positive CML. The same chromosomal abnormality was observed in a small population of Ph¹-negative cells present in one of two patients with mixed Ph¹-positive/Ph¹-negative CML. The first case of a female patient with the loss of a sex chromosome in Ph¹-positive cells is reported. Two patients with unusually long and mild chronic phases despite the presence of trisomy 8 in their karyotypes are described. Our findings suggest that the order of appearance of additional chromosomal changes of CML is of prognostic significance for the progression and the clinical picture of the disease.