Frequent loss of the 11q14-24 region in chronic lymphocytic leukemia: a study by comparative genomic hybridization. Tampere CLL Group.

The genetic basis and molecular pathogenesis of chronic lymphocytic leukemia (CLL) and the molecular mechanisms responsible for its progression remain poorly understood. Here, karyotyping techniques specifically optimized for CLL, comparative genomic hybridization (CGH), and fluorescence in situ hybridization were used to search for CLL-specific genetic aberrations. CGH and karyotyping both revealed copy number changes in 12 of the 25 CLL cases (48%) analyzed. Loss at 11q emerged as the most common aberration (6 cases), followed by a gain of chromosome 12 (4) and loss at 13q (3). Concordance between CGH and G-banding was found in 23 of the 25 cases (92%), which is more than reported in a recent similar CGH study of CLL. Owing to the basic differences in G-banding and CGH, however, their simultaneous clinical application is recommended. The frequent loss of 11q14-24 suggests that this chromosomal region deserves further attention as a candidate locus involved in the pathogenesis of CLL.