Rearrangements of chromosome 9 in different hematological neoplasias

In the present article the frequency of anomalies in chromosome 9 among children with hematological neoplasias amounted to 25/112 in acute lymphoblastic leukemia (ALL), 10/83 in acute myeloid leukemia (AML), and 3/20 in myelodysplastic syndrome (MDS). In ALL, deletions are encountered more often than translocations. Deletions are found in both single anomalies and as an element in complex karyotypes. The rearrangements involve the bands 9q34 and 9q22 the most often. The translocation t(9;22)(q34; q11) is encountered in 7.1% of all cases of ALL. In AML, translocation are found more often than deletions. Structural rearrangements most often involved the long arm, at bands 9q22 and 9q34. Deletions, duplications, and translocations were recorded in MDS. No relationship with the initial hematological indicators, including blastosis, were found. The studies attest to different directions of the clinical prognosis in the course of acute leukemia (AL) where there are deletions. Multidrug resistance and the continuing progress of the disease in the course of chemotherapy is found in t(9;22)(q34; q11).