Cytogenetics in childhood acute lymphoblastic leukemia in Taiwan: a single-institutional experience.

The aim of the study was to define the frequency and types of acquired chromosomal aberrations in a group of Taiwanese children with ALL. The sample population consisted of 78 patients under 18 years of age with newly diagnosed ALL who underwent cytogenetic studies at diagnosis and had adequate metaphase chromosomes for analysis at the authors' hospital from 1993 to 2001. Metaphase chromosomes were banded using the conventional trypsin-Giemsa banding technique. Analysis of ploidy revealed 16 (20.5%) patients with normal diploidy, 28 (35.9%) with pseudodiploidy, 6 (7.7%) with hyperdiploidy (47-50), 19 (24.4%) with hyperdiploidy (> 50), and 9 (9.4%) hypodiploidy. Near-haploidy was not observed. Of the patients with abnormal karyotypes, recurrent structural abnormalities were determined in 31 (50%) cases, with the most frequent t(9;22). In conclusion, the frequency and type of acquired chromosomal aberrations found in these Taiwanese children with ALL are similar to those reported in the literature.