IN-SITU HYBRIDIZATION - A SIMPLE AND SENSITIVE METHOD FOR DETECTION OF TRISOMY-12 IN CHRONIC LYMPHOCYTIC-LEUKEMIA

Chromosome aberrations are detected in only 50% of patients with chron ic lymphocytic leukemia (CLL), owing usually to the low mitotic rate e xhibited by the neoplastic lymphocytes. Fluorescence in situ hybridiza tion (FTSH) is a simple method for identifying numerical abnormalities of the target chromosome in interphase nuclei. Therefore, we used the FISH procedure with chromosome 12-specific alpha-satellite probe to e valuate 19 patients with CLL. Trisomy 12 was detected in interphase ce lls of 12 patients (63%). Cytogenetic analysis, performed in nine pati ents, yielded trisomy 12 in four (44%). FISH detected three patients w ith trisomy 12 in whom conventional cytogenetic method yielded a norma l karyotype. FISH is a simple, reliable, and sensitive method for dete ction of trisomy 12 in patients with CLL.