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Boyd RJ, Murry JB, Morsberger LA, Klausner M, Chen S, Gocke CD, McCallion AS, Zou YS. Ring Chromosomes in Hematological Malignancies Are Associated with TP53 Gene Mutations and Characteristic Copy Number Variants. Cancers (Basel) 2023; 15:5439. [PMID: 38001699 PMCID: PMC10670249 DOI: 10.3390/cancers15225439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 10/28/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
Ring chromosomes (RC) are present in <10% of patients with hematological malignancies and are associated with poor prognosis. Until now, only small cohorts of patients with hematological neoplasms and concomitant RCs have been cytogenetically characterized. Here, we performed a conventional chromosome analysis on metaphase spreads from >13,000 patients diagnosed with hematological malignancies at the Johns Hopkins University Hospital and identified 98 patients with RCs-90 with myeloid malignancies and 8 with lymphoid malignancies. We also performed a targeted Next-Generation Sequencing (NGS) assay, using a panel of 642 cancer genes, to identify whether these patients harbor relevant pathogenic variants. Cytogenetic analyses revealed that RCs and marker chromosomes of unknown origin are concurrently present in most patients by karyotyping, and 93% of patients with NGS data have complex karyotypes. A total of 72% of these individuals have pathogenic mutations in TP53, most of whom also possess cytogenetic abnormalities resulting in the loss of 17p, including the loss of TP53. All patients with a detected RC and without complex karyotypes also lack TP53 mutations but have pathogenic mutations in TET2. Further, 70% of RCs that map to a known chromosome are detected in individuals without TP53 mutations. Our data suggest that RCs in hematological malignancies may arise through different mechanisms, but ultimately promote widespread chromosomal instability.
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Affiliation(s)
- Rachel J. Boyd
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; (R.J.B.); (A.S.M.)
| | - Jaclyn B. Murry
- Johns Hopkins Genomics, Baltimore, MD 21205, USA; (J.B.M.); (L.A.M.); (M.K.); (S.C.); (C.D.G.)
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Cytogenetics Laboratory, Johns Hopkins Medicine, Baltimore, MD 21205, USA
| | - Laura A. Morsberger
- Johns Hopkins Genomics, Baltimore, MD 21205, USA; (J.B.M.); (L.A.M.); (M.K.); (S.C.); (C.D.G.)
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Cytogenetics Laboratory, Johns Hopkins Medicine, Baltimore, MD 21205, USA
| | - Melanie Klausner
- Johns Hopkins Genomics, Baltimore, MD 21205, USA; (J.B.M.); (L.A.M.); (M.K.); (S.C.); (C.D.G.)
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Cytogenetics Laboratory, Johns Hopkins Medicine, Baltimore, MD 21205, USA
| | - Suping Chen
- Johns Hopkins Genomics, Baltimore, MD 21205, USA; (J.B.M.); (L.A.M.); (M.K.); (S.C.); (C.D.G.)
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Christopher D. Gocke
- Johns Hopkins Genomics, Baltimore, MD 21205, USA; (J.B.M.); (L.A.M.); (M.K.); (S.C.); (C.D.G.)
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Andrew S. McCallion
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; (R.J.B.); (A.S.M.)
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ying S. Zou
- Johns Hopkins Genomics, Baltimore, MD 21205, USA; (J.B.M.); (L.A.M.); (M.K.); (S.C.); (C.D.G.)
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Cytogenetics Laboratory, Johns Hopkins Medicine, Baltimore, MD 21205, USA
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Treatment-related myelodysplastic syndrome in a child with acute myeloid leukemia and TPMT heterozygosity. J Pediatr Hematol Oncol 2015; 37:e242-4. [PMID: 25000470 DOI: 10.1097/mph.0000000000000211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
INTRODUCTION We describe a patient diagnosed with acute myeloid leukemia (AML) and low activity of thiopurine methyltransferase (TPMT) who developed secondary myelodysplastic syndrome after treatment. OBSERVATION A 10-year-old boy presented with AML-M2 with t(8;21)(q22;q22) and genotyping revealing 3*B TPMT heterozygosity. The patient was treated according to the NOPHO-AML 2004 protocol. Two years after the treatment, the patient presented with neutropenia and thrombocytopenia. Bone marrow, including fluorescent in situ hybridization and retrospective aCGH analysis, verified therapy-related myelodysplastic syndrome with ring chromosome 6. DISCUSSION The clinical course of this patient raises the possibility that low-activity TPMT genotypes may influence 6TG toxicity in patients with AML and lead to an increased risk of developing secondary malignant neoplasms.
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