1. Identification of novel, clonally stable, somatic mutations targeting transcription factors PAX5 and NKX2-3, the epigenetic regulator LRIF1, and BRAF in a case of atypical B-cell chronic lymphocytic leukemia harboring a t(14;18)(q32;q21)
- Author
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Laurent Delva, François Bailly, Camille Sauter, Marc Maynadié, Julien Guy, Benjamin Tournier, Cyril Fournier, Selim Ramla, Marie-Lorraine Chretien, Cédric Rossi, Nathalie Nadal, Laurent Martin, Bénédicte Burlet, Yannis Duffourd, Juliette Albuisson, Mary Callanan, Olivier Casasnovas, Catherine Thieblemont, Caroline Chapusot, Sylviane Ragot, Romain Aucagne, Denis Caillot, Maria Jimena Abrey-Recalde, Céline Buriller, Jean-Noël Bastie, Jessica Racine, and Cyril Broccardo
- Subjects
Male ,Proto-Oncogene Proteins B-raf ,Chronic lymphocytic leukemia ,Cell Cycle Proteins ,Biology ,medicine.disease_cause ,Somatic evolution in cancer ,Translocation, Genetic ,Epigenesis, Genetic ,hematological neoplasm ,Clonal Evolution ,immune system diseases ,hemic and lymphatic diseases ,Exome Sequencing ,medicine ,Humans ,Epigenetics ,Receptor, Notch1 ,neoplasms ,Loss function ,Exome sequencing ,Aged ,Homeodomain Proteins ,Mutation ,PAX5 Transcription Factor ,General Medicine ,medicine.disease ,Prognosis ,Leukemia, Lymphocytic, Chronic, B-Cell ,Proto-Oncogene Proteins c-bcl-2 ,Cancer research ,PAX5 ,Tumor Suppressor Protein p53 ,IGHV@ ,Rapid Cancer Communication ,Transcription Factors - Abstract
Diagnosis of B-cell chronic lymphocytic leukemia (B-CLL) is usually straightforward, involving clinical, immunophenotypic (Matutes score), and (immuno)genetic analyses (to refine patient prognosis for treatment). CLL cases with atypical presentation (e.g., Matutes ≤ 3) are also encountered, and for these diseases, biology and prognostic impact are less clear. Here we report the genomic characterization of a case of atypical B-CLL in a 70-yr-old male patient; B-CLL cells showed a Matutes score of 3, chromosomal translocation t(14;18)(q32;q21) (BCL2/IGH), mutated IGHV, deletion 17p, and mutations in BCL2, NOTCH1 (subclonal), and TP53 (subclonal). Quite strikingly, a novel PAX5 mutation that was predicted to be loss of function was also seen. Exome sequencing identified, in addition, a potentially actionable BRAF mutation, together with novel somatic mutations affecting the homeobox transcription factor NKX2-3, known to control B-lymphocyte development and homing, and the epigenetic regulator LRIF1, which is implicated in chromatin compaction and gene silencing. Neither NKX2-3 nor LRIF1 mutations, predicted to be loss of function, have previously been reported in B-CLL. Sequencing confirmed the presence of these mutations together with BCL2, NOTCH1, and BRAF mutations, with the t(14;18)(q32;q21) translocation, in the initial diagnostic sample obtained 12 yr prior. This is suggestive of a role for these novel mutations in B-CLL initiation and stable clonal evolution, including upon treatment withdrawal. This case extends the spectrum of atypical B-CLL with t(14;18)(q32;q21) and highlights the value of more global precision genomics for patient follow-up and treatment in these patients.
- Published
- 2021