RESUMO
<p><b>OBJECTIVE</b>To characterize the genetic aberrations in pediatric acute lymphoblastic leukemia (ALL).</p><p><b>METHODS</b>Ninety ALL cases were enrolled in the study from January 2009 to November 2011. Chromosome banding analysis and fluorescence in situ hybridization (FISH) were used to detect genetic aberrations.</p><p><b>RESULTS</b>(1) Chromosome analysis: 35 (53.0%) of 66 cases who had metaphase were abnormal, and 24 cases had no metaphase. (2) FISH analysis: among the 31 cases who had normal karyotypes and 24 who had no metaphase detected by chromosome banding technique, 7 (22.6%) and 14 (58.3%) cases were abnormal detected by FISH, respectively. There were no statistically significant differences compared with chromosome analysis (P = 0.655). Among these 55 ALL cases TEL/AML1, bcr-abl and MLL fusion genes were observed in 16 (29.1%), 3(5.5%) and 2(3.6%) cases, respectively. (3) Cytogenetic aberration was observed in 56 of total 90 ALL cases (62.2%).</p><p><b>CONCLUSIONS</b>Cytogenetic changes are common in childhood ALL. Conventional cytogenetic study could reliably detected chromosomal abnormalities for ALL with assessable metaphase. FISH should be used as a complementary method for ALL patients who have poor chromosomal morphology or no metaphase cells, and combination of both methods can improve the detection rate of genetic abnormalities in childhood leukemia.</p>
