RESUMO
The frequencies of chromosome 9 abnormalities in children with hematological neoplasia have constituted: 25/112 in acute lymphoblastic leukemia (ALL), 10/83--in acute myeloid leukemia (AML), 3/20--in refractory anemia (RA). The frequency of deletions was higher than of translocations in ALL. Deletions were found as sole abnormalities as in complexity karyotypes. More often the rearrangements affected bands 9q34 and 9q22. Translocation t (9;22)(q34; q11) occured in 7.1% cases ALL. In AML the translocations were detected with greater frequency than deletions. The long arm bands 9q22 and 9q34 were more often involved in structural rearrangements. Deletions, translocations and duplications were registered in MDS. Comparison with clinical features showed no correlation with age and the main hematological indexes including the amount of blast cells in initial period. Multidrug resistance and disease progression during chemotherapy were noted in t (9;22).
