[Chromosome analysis and FISH method]

In hematologic malignancies activation of oncogenes or inactivation of tumor suppressor genes are thought to be responsible for its carcinogenesis, just like other solid tumors. As these genetic changes are detected as chromosome abnormalities, cytogenetic analysis has been used as a tool for diagnosis and follow up after therapy. The fluorescence in situ hybridization (FISH) method is a new technic which enables us to detect genetic changes both in mitotic and interphase cells. It is a useful method in the clinical field which covers the disadvantages in cytogenetic analysis, RT-PCR and Southern blotting. We practically used the FISH method in diagnosis and follow-up observation of minimal residual disease in several kinds of hematologic malignancies. By the morphology-FISH method, the relationship between cell morphology and genetic changes could be analyzed simultaneously. The FISH method was also applied to probe mapping to identify a novel breakpoint cluster region in the 11q23 area in adult hematological disease. FISH method is a rapid and powerful tool both in clinical and basic study in hematologic disorders.