[Deletions of derivative chromosome 9 in 138 patients with chronic myeloid leukemia]

To investigate the frequency of derivative chromosome 9 [der (9)] deletions in patients with chronic myelogenous leukemia (CML), karyotype analysis in 138 patients with CML was performed with R-banding technique, and dual fusion fluorescence in situ hybridization (FISH) was used to detect der (9) deletion. The results showed that among 138 cases, 126 cases were Ph positive (91.3%) from which 122 cases were typical Ph translocation, 12 cases were Ph negative (8.7%). FISH detection revealed 23 with der (9) deletions out of 138 cases (16.7%), 20 out of 122 cases with typical Ph translocation showed typical Ph translocation (16.4%) and 3 out of 4 cases with variant Ph translocation had variant Ph translocation (75%). 20 cases were in chronic phase (CP) (17.2%), 3 cases were in blast crisis (BC) (17.6%), there was no significant difference in the frequency of the der (9) deletions between the cases in CP and in BC (p < 0.05). It is concluded that incidence of der (9) partial deletions in CML patients is 16.7%, FISH can effectively detect the der (9) deletions, and there is no correlation of der (9) deletion frequency between cases in different phases of CML.