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Oliveira JL, Thompson CH, Saravanaperumal SA, Koganti T, Jenkinson G, Hein MS, Kohorst MA, Hasadsri L, Nguyen PL, Matern D, Kipp BR, Klee EW, Wieben ED, Hoyer JD, Rangan A. εγ-Thalassemia, a New Hemoglobinopathy Category. Clin Chem 2023:7136664. [PMID: 37086467 DOI: 10.1093/clinchem/hvad038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 03/07/2023] [Indexed: 04/24/2023]
Abstract
BACKGROUND Large β-globin gene cluster deletions (hereditary persistence of fetal hemoglobin [Hb] or β-, δβ-, γδβ-, and ϵγδβ-thalassemia), are associated with widely disparate phenotypes, including variable degrees of microcytic anemia and Hb F levels. When present, increased Hb A2 is used as a surrogate marker for β-thalassemia. Notably, ϵγδβ-thalassemias lack the essential regulatory locus control region (LCR) and cause severe transient perinatal anemia but normal newborn screen (NBS) results and Hb A2 levels. Herein, we report a novel deletion of the ϵ, Aγ, Gγ, and ψβ loci with intact LCR, δ-, and β-regions in 2 women and newborn twins. METHODS Capillary electrophoresis (CE), high-performance liquid chromatography (HPLC), DNA sequencing, multiplex ligation-dependent probe amplification (MLPA), gap-polymerase chain reaction (gap-PCR), and long-read sequencing (LRS) were performed. RESULTS NBS showed an Hb A > Hb F pattern for both twins. At 20 months, Hb A2 was increased similarly to that in the mother and an unrelated woman. Unexplained microcytosis was absent and the twins lacked severe neonatal anemia. MLPA, LRS, and gap-PCR confirmed a 32 599 base pair deletion of ϵ (HBE1) through ψβ (HBBP1) loci. CONCLUSIONS This deletion represents a hemoglobinopathy category with a distinct phenotype that has not been previously described, an ϵγ-thalassemia. Both the NBS Hb A > F pattern and the subsequent increased Hb A2 without microcytosis are unusual. A similar deletion should be considered when this pattern is encountered and appropriate test methods selected for detection. Knowledge of the clinical impact of this new category will improve genetic counselling, with distinction from the severe transient anemia associated with ϵγδβ-thalassemia.
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Affiliation(s)
- Jennifer L Oliveira
- Division of Hematopathology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | | | | | - Tejaswi Koganti
- Department of Clinical Genomics, Quantitative Health Sciences - Computational Biology, Mayo Clinic, Rochester, MN, United States
| | - Garrett Jenkinson
- Department of Clinical Genomics, Quantitative Health Sciences - Computational Biology, Mayo Clinic, Rochester, MN, United States
| | - Molly S Hein
- Division of Hematopathology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Mira A Kohorst
- Department of Pediatric Hematology-Oncology, Mayo Clinic, Rochester, MN, United States
| | - Linda Hasadsri
- Division of Laboratory Genetics and Genomics, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Phuong L Nguyen
- Division of Hematopathology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Dietrich Matern
- Division of Laboratory Genetics and Genomics, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Benjamin R Kipp
- Division of Laboratory Genetics and Genomics, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Eric W Klee
- Department of Clinical Genomics, Quantitative Health Sciences - Computational Biology, Mayo Clinic, Rochester, MN, United States
| | - Eric D Wieben
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, United States
- Department of Clinical Genomics, Quantitative Health Sciences - Computational Biology, Mayo Clinic, Rochester, MN, United States
| | - James D Hoyer
- Division of Hematopathology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Aruna Rangan
- Division of Hematopathology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
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Minaidou A, Tamana S, Stephanou C, Xenophontos M, Harteveld CL, Bento C, Kleanthous M, Kountouris P. A Novel Tool for the Analysis and Detection of Copy Number Variants Associated with Haemoglobinopathies. Int J Mol Sci 2022; 23:ijms232415920. [PMID: 36555557 PMCID: PMC9782104 DOI: 10.3390/ijms232415920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/05/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022] Open
Abstract
Several types of haemoglobinopathies are caused by copy number variants (CNVs). While diagnosis is often based on haematological and biochemical parameters, a definitive diagnosis requires molecular DNA analysis. In some cases, the molecular characterisation of large deletions/duplications is challenging and inconclusive and often requires the use of specific diagnostic procedures, such as multiplex ligation-dependent probe amplification (MLPA). Herein, we collected and comprehensively analysed all known CNVs associated with haemoglobinopathies. The dataset of 291 CNVs was retrieved from the IthaGenes database and was further manually annotated to specify genomic locations, breakpoints and MLPA probes relevant for each CNV. We developed IthaCNVs, a publicly available and easy-to-use online tool that can facilitate the diagnosis of rare and diagnostically challenging haemoglobinopathy cases attributed to CNVs. Importantly, it facilitates the filtering of available entries based on the type of breakpoint information, on specific chromosomal and locus positions, on MLPA probes, and on affected gene(s). IthaCNVs brings together manually curated information about CNV genomic locations, functional effects, and information that can facilitate CNV characterisation through MLPA. It can help laboratory staff and clinicians confirm suspected diagnosis of CNVs based on molecular DNA screening and analysis.
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Affiliation(s)
- Anna Minaidou
- Molecular Genetics Thalassaemia Department, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus
| | - Stella Tamana
- Molecular Genetics Thalassaemia Department, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus
| | - Coralea Stephanou
- Molecular Genetics Thalassaemia Department, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus
| | - Maria Xenophontos
- Molecular Genetics Thalassaemia Department, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus
| | - Cornelis L. Harteveld
- Human and Clinical Genetics Department, Leiden University Medical Center, P.O. Box 9600, 2333 ZC Leiden, The Netherlands
| | - Celeste Bento
- Department of Haematology, Centro Hospitalar e Universitário de Coimbra, 3000-075 Coimbra, Portugal
| | - Marina Kleanthous
- Molecular Genetics Thalassaemia Department, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus
| | - Petros Kountouris
- Molecular Genetics Thalassaemia Department, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus
- Correspondence: ; Tel.: +357-22392623
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Abstract
The World Health Organization estimates that approximately a quarter of the world's population suffers from anemia, including almost half of preschool-age children. Globally, iron deficiency anemia is the most common cause of anemia. Other important causes of anemia in children are hemoglobinopathies, infection, and other chronic diseases. Anemia is associated with increased morbidity, including neurologic complications, increased risk of low birth weight, infection, and heart failure, as well as increased mortality. When approaching a child with anemia, detailed historical information, particularly diet, environmental exposures, and family history, often yield important clues to the diagnosis. Dysmorphic features on physical examination may indicate syndromic causes of anemia. Diagnostic testing involves a stepwise approach utilizing various laboratory techniques. The increasing availability of genetic testing is providing new mechanistic insights into inherited anemias and allowing diagnosis in many previously undiagnosed cases. Population-based approaches are being taken to address nutritional anemias. Novel pharmacologic agents and advances in gene therapy-based therapeutics have the potential to ameliorate anemia-associated disease and provide treatment strategies even in the most difficult and complex cases.
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Affiliation(s)
- Patrick G Gallagher
- Departments of Pediatrics, Pathology, and Genetics, Yale University School of Medicine, New Haven, CT
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Fotzi I, Pegoraro F, Chiocca E, Casini T, Mogni M, Veltroni M, Favre C. Case Report: Clinical and Hematological Characteristics of ε γδβ Thalassemia in an Italian Patient. Front Pediatr 2022; 10:839775. [PMID: 35372167 PMCID: PMC8969019 DOI: 10.3389/fped.2022.839775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 02/07/2022] [Indexed: 12/01/2022] Open
Abstract
INTRODUCTION εγδβ thalassemia is a rare form of β-thalassemia mostly described in children originating from Northern Europe. Only anecdotic cases from the Mediterranean area are reported. The diagnosis is challenging, considering the rarity of the disease and its heterogeneous clinical presentation. Most patients have neonatal microcytic anemia, sometimes requiring in utero and/or neonatal transfusions, and typically improving with age. CASE DESCRIPTION We report on an Italian newborn presenting with severe neonatal anemia that required red blood cell transfusion. After the first months of life, hemoglobin levels improved with residual very low mean corpuscular volume. β and α thalassemia, IRIDA syndrome, and sideroblastic anemia were excluded. Finally, a diagnosis of εγδβ thalassemia was made after microarray analysis of single nucleotide polymorphisms revealed a 26 kb single copy loss of chromosome 11p15.4, including the HBD, HBBP1, HBG1, and HBB genes. CONCLUSIONS Despite its rarity, the diagnosis of εγδβ thalassemia should be considered in newborns with severe neonatal anemia requiring in utero and/or neonatal transfusions, but also in older infants with microcytic anemia, after excluding more prevalent red blood cell disorders.
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Affiliation(s)
- Ilaria Fotzi
- Department of Pediatric Hematology/Oncology and Hematopoietic Stem Cell Transplantation (HSCT), Meyer Children's University Hospital, Florence, Italy
| | - Francesco Pegoraro
- Department of Pediatric Hematology/Oncology and Hematopoietic Stem Cell Transplantation (HSCT), Meyer Children's University Hospital, Florence, Italy.,Department of Health Science, University of Florence, Florence, Italy
| | - Elena Chiocca
- Department of Pediatric Hematology/Oncology and Hematopoietic Stem Cell Transplantation (HSCT), Meyer Children's University Hospital, Florence, Italy
| | - Tommaso Casini
- Department of Pediatric Hematology/Oncology and Hematopoietic Stem Cell Transplantation (HSCT), Meyer Children's University Hospital, Florence, Italy
| | - Massimo Mogni
- Human Genetics Laboratory, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Giannina Gaslini, Genoa, Italy
| | - Marinella Veltroni
- Department of Pediatric Hematology/Oncology and Hematopoietic Stem Cell Transplantation (HSCT), Meyer Children's University Hospital, Florence, Italy
| | - Claudio Favre
- Department of Pediatric Hematology/Oncology and Hematopoietic Stem Cell Transplantation (HSCT), Meyer Children's University Hospital, Florence, Italy
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