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Jaspersen SL, Stacy AV, McGlynn MC, Gooch CF, Wilson DB, Bolton KL. Phenotypic heterogeneity associated with a novel MECOM variant: Mild thrombocytopenia to hydrops fetalis. Pediatr Blood Cancer 2024; 71:e30991. [PMID: 38602302 DOI: 10.1002/pbc.30991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 04/12/2024]
Affiliation(s)
- Sue L Jaspersen
- Department of Pediatrics, Division of Hematology and Oncology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Andrea V Stacy
- Department of Pediatrics, Division of Hematology and Oncology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Mary Claire McGlynn
- Department of Pediatrics, Division of Hematology and Oncology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Catherine F Gooch
- Department of Pediatrics, Division of Genetics and Genomic Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - David B Wilson
- Department of Pediatrics, Division of Hematology and Oncology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Kelly L Bolton
- John T. Milliken Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
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Huang D, Jiang M, Zhu Y, Li D, Lu X, Gao J. A novel missense mutation in the MECOM gene in a Chinese boy with radioulnar synostosis with amegakaryocytic thrombocytopenia. BMC Pediatr 2024; 24:62. [PMID: 38245683 PMCID: PMC10799460 DOI: 10.1186/s12887-024-04552-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 01/11/2024] [Indexed: 01/22/2024] Open
Abstract
Radioulnar synostosis with amegakaryocytic thrombocytopenia (RUSAT) type 2, caused by MDS1 and EVI1 complex locus (MECOM) gene mutations, is a rare inherited bone marrow failure syndrome (IBMFS) with skeletal anomalies, characterized by varying presentation of congenital thrombocytopenia (progressing to pancytopenia), bilateral proximal radioulnar synostosis, and other skeletal abnormalities. Due to limited knowledge and heterogenous manifestations, clinical diagnosis of the disease is challenging. Here we reported a novel MECOM mutation in a Chinese boy with typical clinical features for RUSAT-2. Trio-based whole exome sequencing of buccal swab revealed a novel heterozygous missense mutation in exon 11 of the MECOM gene (chr3:168818673; NM_001105078.3:c.2285G > A). The results strongly suggest that the variant was a germline mutation and disease-causing mutation. The patient received matched unrelated donor hematopoetic stem cell transplantation (HSCT). This finding was not only expanded the pathogenic mutation spectrum of MECOM gene, but also provided key information for clinical diagnosis and treatment of RUSAT-2.
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Affiliation(s)
- Duowen Huang
- Department of Pediatric Hematology and Oncology, West China Second University Hospital, Sichuan University, No. 20 Section 3, South Renmin Road, Chengdu, 610041, Sichuan Province, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, 610041, Sichuan Province, China
| | - Mingyan Jiang
- Department of Pediatric Hematology and Oncology, West China Second University Hospital, Sichuan University, No. 20 Section 3, South Renmin Road, Chengdu, 610041, Sichuan Province, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, 610041, Sichuan Province, China
| | - Yiping Zhu
- Department of Pediatric Hematology and Oncology, West China Second University Hospital, Sichuan University, No. 20 Section 3, South Renmin Road, Chengdu, 610041, Sichuan Province, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, 610041, Sichuan Province, China
| | - Dongjun Li
- Department of Pediatric Hematology and Oncology, West China Second University Hospital, Sichuan University, No. 20 Section 3, South Renmin Road, Chengdu, 610041, Sichuan Province, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, 610041, Sichuan Province, China
| | - Xiaoxi Lu
- Department of Pediatric Hematology and Oncology, West China Second University Hospital, Sichuan University, No. 20 Section 3, South Renmin Road, Chengdu, 610041, Sichuan Province, China.
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, 610041, Sichuan Province, China.
| | - Ju Gao
- Department of Pediatric Hematology and Oncology, West China Second University Hospital, Sichuan University, No. 20 Section 3, South Renmin Road, Chengdu, 610041, Sichuan Province, China.
- Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, 610041, Sichuan Province, China.
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Voit RA, Sankaran VG. MECOM Deficiency: from Bone Marrow Failure to Impaired B-Cell Development. J Clin Immunol 2023:10.1007/s10875-023-01545-0. [PMID: 37407873 DOI: 10.1007/s10875-023-01545-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 06/26/2023] [Indexed: 07/07/2023]
Abstract
MECOM deficiency is a recently identified inborn error of immunity and inherited bone marrow failure syndrome caused by haploinsufficiency of the hematopoietic transcription factor MECOM. It is unique among inherited bone marrow failure syndromes, many of which present during later childhood or adolescence, because of the early age of onset and severity of the pancytopenia, emphasizing the importance and gene dose dependency of MECOM during hematopoiesis. B-cell lymphopenia and hypogammaglobulinemia have been described in a subset of patients with MECOM deficiency. While the mechanisms underlying the B-cell deficiency are currently unknown, recent work has provided mechanistic insights into the function of MECOM in hematopoietic stem cell (HSC) maintenance. MECOM binds to regulatory enhancers that control the expression of a network of genes essential for HSC maintenance and self-renewal. Heterozygous mutations, as seen in MECOM-deficient bone marrow failure, lead to dysregulated MECOM network expression. Extra-hematopoietic manifestations of MECOM deficiency, including renal and cardiac anomalies, radioulnar synostosis, clinodactyly, and hearing loss, have been reported. Individuals with specific genotypes have some of the systemic manifestations with isolated mild thrombocytopenia or without hematologic abnormalities, highlighting the tissue specificity of mutations in some MECOM domains. Those infants with MECOM-associated bone marrow failure require HSC transplantation for survival. Here, we review the expanding cohort of patient phenotypes and accompanying genotypes resulting in MECOM deficiency, and the proposed mechanisms underlying MECOM regulation of human HSC maintenance and B-cell development.
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Affiliation(s)
- Richard A Voit
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 02115, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
| | - Vijay G Sankaran
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 02115, USA.
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA.
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