부산대학교 도서관

Acute lymphoblastic leukemia (ALL) is a heterogeneous disease at the chromosomal and molecular levels. Several subgroups of chromosomal abnormalities have been identified in pediatric B-cell precursor ALL. With the development of specific fluorescence in situ hybridization probes to evaluate metaphase chromosomes or interphase nuclei, chromosomal abnormalities can now be detected when leukemic cells have cryptic alterations or a karyotype that cannot be determined. The frequent use of TEL-AML1 probes to evaluate the cryptic t(12;21) have identified isolated cases in which the AML1 gene is amplified or over-represented. This chromosomal abnormality is most often detected by conventional cytogenetic methods as a tandem duplication of chromosome band 21q22 or as marker chromosomes of unknown origin. However, more stringent molecular methods of detection are needed to specifically identify AML1 amplification.