Deep Insight Section

By January 2005, clonal chromosomal aberrations identified by various banding techniques had been reported in more than 47,000 human neoplasms (Mitelman et al., 2005a). An increasing number of the acquired abnormalities have now also been studied by various fluorescence in situ hybridization techniques, which have provided a new and powerful tool to identify abnormal chromosomes and to visualize very small rearrangements that escape detection by conventional chromosome banding. The new techniques have also added a further sophistication to the analyses in that breakpoints in structural aberrations can be delineated within specific genes. Furthermore, an ever increasing number of breakpoints of the cancer-associated chromosome abnormalities have been characterized at the molecular level, and the combined efforts of cytogeneticists and molecular geneticists over the past two decades have led to the identification of 275 genes rearranged as a consequence of chromosome aberrations in neoplasia (Mitelman et al., 2004).