B_Cell_Chronic_Lymphocytic_Leukemia

We used high density oligonucleotide arrays to identify molecular correlates of genetically and clinically distinct subgroups of B-cell chronic lymphocytic leukemia (B-CLL). Gene expression profiling was used to profile the five most frequent genomic aberrations, namely deletions affecting chromosome bands 13q14, 11q22-q23, 17p13 and 6q21, and gains of genomic material affecting chromosome band 12q13. A strikingly high degree of correlation between loss or gain of genomic material and the amount of transcripts from the affected regions leads to the hypothesis of gene dosage as a significant pathogenic factor. Furthermore, the influence of the immunoglobulin variable heavy chain (VH) mutation status was determined. A clear distinction in the expression profiles of unmutated and mutated VH samples exists, which can be discovered using unsupervised learning methods. However, when samples were separated by gender, this separation could only be detected in samples from male patients. Since the samples were either hybridized onto HG-U95A arrays or onto HG-U95Av2 arrays, only genes common to both arrays were used for further analysis. This study is described in more detail in Haslinger C, et al. 2004. J Clin Oncol. 22:3937-3949 Series _keyword: CLL, chronic lymphocytic leukemia, immunoglobulin somatic hypermutation, genomic aberrations Keywords: other