G-banding and fluorescence in situ hybridization in childhood acute myeloid leukemia from South India.

BACKGROUND The current WHO classification of hematologic malignancies defines distinct entities of myeloid disorders based on the presence of recurrent cytogenetic abnormalities. Diagnostic clonal chromosomal abnormalities provide important prognostic information and are among the most important factors in predicting initial response to chemotherapy, duration of remission and overall survival.  METHODS This study analyzed chromosomal abnormalities in bone marrow aspirates of 50 children diagnosed with acute myeloid leuckemia (AML).  RESULTS The culture success rate was 94%, clonal chromosomal abnormalities constituted 62% and recurrent chromosomal abnormalities were 56%. In the favorable prognostic category, there were 51.6% of cases with t(8;21)(q22;q22), 16.1% had t(15;17)(q22;q21), and a total of 12.9% had chromosome 16 rearrangement. The adverse risk category showed a low frequency of t(9;11)(p22;q13); t(1;22)(p13;q13); inv(3)( q21q26); add 4(q35) and ring chromosome. According to fluorescent in situ hybridization (FISH) results in 16 cytogenetically normal patients, there were no CBFβ/MYH11 fusion genes observed in chromosome 16 rearrangements.  DISCUSSION Larger studies of this kind may provide more information about chromosome 16 rearrangements in cytogenetically normal patients. The present analysis suggests that both age and cytogenetics are important strategies for risk stratification (outcome). Additional laboratory parameters should also be considered in childhood AML.