[Karyotype analysis in 119 patients with chronic myeloid leukemia at blast crisis]

To investigate the karyotype of chronic myeloid leukemia in blast crisis (CML-BC), karyotype analysis was performed with R-banding technique in 119 patients with CML-BC. Dual fusion fluorescence in situ hybridization (FISH) was used to detect derivative chromosome 9 deletions in randomly selected 28 cases of them. The results showed that 11 cases (8.9%) were Ph negative; 113 cases (91.1%) were Ph positive; 104 cases (83.9%) had standard Ph translocation; 9 cases (7.2%) showed variant translocation, including 4 cases (3.2%) with simple variant translocation and 5 cases (4.0%) with complex variant translocation. 72.6% of Ph negative CML-BC had extra chromosomal abnormalities, with the most common ones being i (17q) and +14. 72.3% of Ph positive CML-BC had extra cytogenetic changes and +Ph, +8, i (17q) were the most frequent. The average time between diagnosis and blast crisis was 29.0 months (range 2 to 66 months) for Ph negative cases and 34.2 months (range 1 to 127 months) for Ph positive cases. 5 cases (5/28, 17.9%) with der (9) deletions were detected by FISH technique. It is concluded that extra chromosomal abnormalities are common in CML-BC patients and FISH can effectively detect the der (9) deletions.