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Mutational Analysis of the VPREB1 Gene of Pre-BCR Complex in a Cohort of Sporadic Pediatric Patients With B-Cell Acute Lymphoblastic Leukemia. J Pediatr Hematol Oncol 2022; 44:210-219. [PMID: 35398858 DOI: 10.1097/mph.0000000000002456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 02/28/2022] [Indexed: 11/26/2022]
Abstract
During bone marrow B-cell development, the pre-B-cell receptor is formed by the association of the immunoglobulin heavy chain with a surrogate light chain, which is encoded by the VPREB1, and λ5 genes. It is known that pre-BCR signaling signifies a critical checkpoint at the pre-B-cell stage. Thus, failure pre-BCR signaling is proposed as a critical factor for the development of B-cell acute lymphoblastic leukemia (B-ALL). B‑ALL is the most common pediatric cancer and is one of the leading causes of death in children. Until now, several molecular analyses were performed for genomic alterations in B-ALL, but for genomic analysis of the VPREB1 gene and its rare variations, limited studies have been conducted. In this study, using polymerase chain reaction and direct sequencing of 88 pediatric patients with B-ALL, we investigated the genomic region of the VPREB1 gene to find sequence variations of this gene. Our study presented ten homozygous and heterozygous point mutations and heterozygous nucleotide deletions, in the VPREB1 gene in 36 boys and 32 girls' patients. Our Bioinformatics assay results presented that these variations may alter the RNA folding, protein structure, and therefore probable effect on the protein function. These results propose that nucleotide changes probably contribute to B-ALL pathogenesis.
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Bazinet A, Heath J, Chong AS, Simo-Cheyou ER, Worme S, Rivera Polo B, Foulkes WD, Caplan S, Johnson NA, Orthwein A, Mercier FE. Common clonal origin of chronic myelomonocytic leukemia and B-cell acute lymphoblastic leukemia in a patient with a germline CHEK2 variant. Cold Spring Harb Mol Case Stud 2021; 7:mcs.a006090. [PMID: 33986034 PMCID: PMC8208041 DOI: 10.1101/mcs.a006090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/10/2021] [Indexed: 12/17/2022] Open
Abstract
Hematological malignancies are broadly divided into myeloid and lymphoid neoplasms, reflecting the two major cellular lineages of the hematopoietic system. It is generally rare for hematological malignancies to spontaneously progress with a switch from myeloid to lymphoid lineage. We describe the exceptional case of a patient who sequentially developed myelodysplastic syndrome (MDS), chronic myelomonocytic leukemia (CMML), and B-cell acute lymphoblastic leukemia (B-ALL), as well as our investigation into the underlying pathogenesis. Using whole-exome sequencing (WES) performed on sorted CMML and B-ALL cell fractions, we identified both common and unique potential driver mutations, suggesting a branching clonal evolution giving rise to both diseases. Interestingly, we also identified a germline variant in the cancer susceptibility gene CHEK2 We validated that this variant (c.475T > C; p.Y159H), located in the forkhead-associated (FHA) domain, impairs its capacity to bind BRCA1 in cellulo. This unique case provides novel insight into the genetics of complex hematological diseases and highlights the possibility that such patients may carry inherited predispositions.
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Affiliation(s)
- Alexandre Bazinet
- Lady Davis Institute, Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada.,Division of Hematology, Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - John Heath
- Lady Davis Institute, Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Anne-Sophie Chong
- Lady Davis Institute, Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada.,Department of Human Genetics, McGill University, Montreal, Quebec H3A 0C7, Canada
| | | | - Samantha Worme
- Lady Davis Institute, Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Barbara Rivera Polo
- Lady Davis Institute, Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada.,Gerald Bronfman Department of Oncology, McGill University, Montreal, Quebec H4A 3T2, Canada
| | - William D Foulkes
- Lady Davis Institute, Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada.,Department of Human Genetics, McGill University, Montreal, Quebec H3A 0C7, Canada.,Gerald Bronfman Department of Oncology, McGill University, Montreal, Quebec H4A 3T2, Canada
| | - Stephen Caplan
- Division of Hematology, Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Nathalie A Johnson
- Lady Davis Institute, Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada.,Division of Hematology, Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Alexandre Orthwein
- Lady Davis Institute, Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada.,Gerald Bronfman Department of Oncology, McGill University, Montreal, Quebec H4A 3T2, Canada.,Department of Microbiology and Immunology, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - François E Mercier
- Lady Davis Institute, Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada.,Division of Hematology, Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
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