Study of deletion of derivative chromosome 9 in patients with Ph+ chronic myeloid leukemia / 中华血液学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To determine the frequency of the derivative 9 [der(9)] deletion among chronic myeloid leukemia (CML) patients with classic and variant Ph translocations, and assess the correlation between this deletion and clinical prognosis.</p><p><b>METHODS</b>Cytogenetic analysis of bone marrow cells was performed by direct method and/or 24 h culture method. RHG banding was used for karyotype analysis. Dual-color and dual-fusion DNA probe was used to perform FISH for investigating the deletion of der(9) in Ph+ CML patients.</p><p><b>RESULTS</b>Cytogenetics studies showed typical Ph translocation in 76/105 and variant Ph translocation in 29/105 cases. Interphase-FISH studies showed deletion of der(9) in 12 (15.8%) of 76 patients with classic Ph translocation and in 4 (13.7%) of 29 patients with variant translocation. The frequency of deletion was similar in classic and variant translocations (P > 0.05). When the deletion was seen in the patient, it was present in all the Ph+ metaphases and nuclei. In 3 patients there were mixed cell populations with either 5'-abl or 3'-bcr deletion and all the 3 patients had both 5'-abl and 3'-bcr deletion. The median survival time of patients with deletion was significantly shorter than those without deletion (34 months vs 76 months; P < 0.05).</p><p><b>CONCLUSION</b>Deletion of der(9) is seen in about 1/6 of Ph+ CML patients in our study on Chinese CML patients, Ph+ CML patients with the deletion have shorter median survival time than those without it, indicating that it is a poor prognostic index.</p>