Molecular characterization of a novel chromosomal translocation t(12;14)(q23;q11.2) in T‐lymphoblastic lymphoma between the T‐cell receptor delta‐deleting elements (TRDREC and TRAJ61) and the hypothetical gene C12orf42

Abstract

Chromosomal aberrations have diagnostic, prognostic, and therapeutic relevance in hematologic malignancies. By combining fine-tiling comparative genomic hybridization (FT-CGH) and ligation-mediated PCR (LM-PCR), we established a fast, robust approach to precisely characterize chromosomal breakpoints. Using this approach, we clarified at the molecular level novel chromosomal translocation t(12;14)(q23;q11.2) in T-lymphoblastic lymphoma. The translocation occurred during the deletional rearrangement of the T-cell receptor delta gene (TRD), which is a pivotal step in T cell differentiation toward the alpha/beta vs. the gamma/delta lineage. We found that this rearrangement disrupted the hypothetical gene C12orf42 and brought the Achaete-scute complex homolog 1 gene into proximity of the TRA enhancer, which encodes a member of the basic helix-loop-helix family of transcription factors and is overexpressed in thyroid and lung cancers.