Analysis of the REL, BCL11A, and MYCN proto-oncogenes belonging to the 2p amplicon in chronic lymphocytic leukemia

The genetic profile of chronic lymphocytic leukemia (CLL) is characterized by a pool of recurrent lesions, including trisomy 12, deletions of 13q14, 11q22-q23, 17p13, and 6q21, and t(14)(q32) translocations [1]. The aforementioned lesions can be detected by FISH and may harbor prognostic information [1]. Array-based comparative genomic hybridization (aCGH) has identified gain of multiple regions on the short arm of chromosome 2 as a recurrent CLL lesion, that contain the REL, BCL11A, and MYCN proto-oncogenes that are involved in hematologic malignancies [2-5]. The exact prevalence of REL, BCL11A, and MYCN gains at the time of CLL diagnosis is currently unknown in consecutive series of the disease. Moreover, some studies indicate that 2p gains as a whole may herald progressive and/or poor risk disease, yet the prognostic contribution of the individual genes included in the amplicon, i.e., REL, BCL11A, and MYCN, remains undefined [4-6]. The aim of this study was twofold: (i) characterize the prevalence of REL, BCL11A, and MYCN gains in a consecutive CLL series at the time of diagnosis; (ii) define the prognostic relevance of REL, BCL11A, and MYCN gains in CLL.