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Xie Y, Luo J, Zhong J, Lan D. Clinical Diagnosis and Genetic Analysis of Children With Muscular Dystrophies. Clin Pediatr (Phila) 2024:99228241272029. [PMID: 39198981 DOI: 10.1177/00099228241272029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/01/2024]
Abstract
More than 90% suspected muscular dystrophy (MD) can be confirmed with multiplex ligation-dependent probe amplification (MLPA) combined with targeted panel, although there are a few that cannot be identified. A total of 312 suspected MD patients were enrolled into the study. The MLPA combined with a targeted myopathy panel were performed. Patients with negative results were subjected to whole exome sequencing (WES), whole genome sequencing (WGS), and/or RNA sequencing (RNA-seq). A total of 275 cases were diagnosed as Duchenne/Becker muscular dystrophy (DMD/BMD) and 20 cases were other types of myopathy or nonmuscular diseases. Six female DMD/BMD patients suffered from varying degrees of typical DMD-like symptoms and 2 others were suspected to be gonadal mosaicism. The systematic application of WES, WGS, and/or RNA-seq highlighted the need for the detection of variants missed by the current standard diagnostic procedures. The identification of female patients and mosaic carriers was crucial to predict the risk of recurrence and allow for optimal genetic counseling.
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Affiliation(s)
- Yanshu Xie
- Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jingsi Luo
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, The Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, The Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Jingzi Zhong
- Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Dan Lan
- Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
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Zhao L, Shi Y, Hu C, Zhou S, Li H, Zhang L, Qian C, Zhou Y, Wang Y, Li X. Comprehensive analysis of 2097 patients with dystrophinopathy based on a database from 2011 to 2021. Orphanet J Rare Dis 2024; 19:311. [PMID: 39182149 PMCID: PMC11344408 DOI: 10.1186/s13023-024-03217-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 05/13/2024] [Indexed: 08/27/2024] Open
Abstract
BACKGROUND An increasing number of clinical trials for new therapeutic strategies are underway or being considered for dystrophinopathy. Having detailed data on the natural progression of this condition is crucial for assessing the effectiveness of new drugs. However, there's a lack of data regarding the long-term data on the natural course and how it's managed in China. In this study, we offer a comprehensive overview of clinical and molecular findings, as well as treatment outcomes in the Chinese population. METHODS Institutional data on all patients with dystrophinopathy from August 2011 to August 2021 were retrospectively reviewed. The data included geographic distribution, age at diagnosis, molecular findings, and treatment options, such as corticosteroids, cardiac interventions, and clinical outcomes. RESULTS In total, 2097 patients with dystrophinopathy, including 1703 cases of Duchenne muscular dystrophy (DMD), 311 cases of Becker muscular dystrophy (BMD), 46 cases of intermediate muscular dystrophy (IMD), and 37 cases categorized as "pending" (individuals with an undetermined phenotype), were registered in the Children's Hospital of Fudan University database for dystrophinopathy from August 2011 to August 2021. The spectrum of identified variants included exonic deletions (66.6%), exonic duplications (10.7%), nonsense variants (10.3%), splice-site variants (4.5%), small deletions (3.5%), small insertions/duplications (1.8%), and missense variants (0.9%). Four deep intronic variants and two inversion variants were identified. Regarding treatment, glucocorticoids were administered to 54.4% of DMD patients and 39.1% of IMD patients. The median age at loss of ambulation was 2.5 years later in DMD patients who received glucocorticoid treatment. Overall, one cardiac medicine at least was prescribed to 7.4% of DMD patients, 8.3% of IMD patients, and 2.6% of BMD patients. Additionally, ventilator support was required by four DMD patients. Eligibility for exon skipping therapy was found in 55.3% of DMD patients, with 12.9%, 10%, and 9.6% of these patients being eligible for skipping exons 51, 53, and 45, respectively. CONCLUSIONS This is one of the largest studies to have evaluated the natural history of dystrophinopathy in China, which is particularly conducive to the recruitment of eligible patients for clinical trials and the provision of real-world data to support drug development.
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Affiliation(s)
- Lei Zhao
- Department of Neurology, Children's Hospital of Fudan University, No.399, Wanyuan Road, Minhang District, Shanghai, 201102, China
| | - Yiyun Shi
- Department of Neurology, Children's Hospital of Fudan University, No.399, Wanyuan Road, Minhang District, Shanghai, 201102, China
| | - Chaoping Hu
- Department of Neurology, Children's Hospital of Fudan University, No.399, Wanyuan Road, Minhang District, Shanghai, 201102, China
| | - Shuizhen Zhou
- Department of Neurology, Children's Hospital of Fudan University, No.399, Wanyuan Road, Minhang District, Shanghai, 201102, China
| | - Hui Li
- Department of Rehabilitation, Children's Hospital of Fudan University, Shanghai, China
| | - Lifeng Zhang
- Pediatric Heart Center, Children's Hospital of Fudan University, Shanghai, China
| | - Chuang Qian
- Department of Orthopedics, Children's Hospital of Fudan University, Shanghai, China
| | - Yiyao Zhou
- Department of Clinical Nutrition, Children's Hospital of Fudan University, Shanghai, China
| | - Yi Wang
- Department of Neurology, Children's Hospital of Fudan University, No.399, Wanyuan Road, Minhang District, Shanghai, 201102, China.
| | - Xihua Li
- Department of Neurology, Children's Hospital of Fudan University, No.399, Wanyuan Road, Minhang District, Shanghai, 201102, China.
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Wei C, Li D, Zhang M, Zhao Y, Liu Y, Fan Y, Wang L, Liu J, Chang X, Jiang Y, Xiong H. Prevalence of Adeno-Associated Virus-9-Neutralizing Antibody in Chinese Patients with Duchenne Muscular Dystrophy. Hum Gene Ther 2024; 35:26-35. [PMID: 38084965 DOI: 10.1089/hum.2023.117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023] Open
Abstract
The delivery of a mini-dystrophin gene to skeletal muscles using recombinant adeno-associated virus serotype (AAV) holds great potential as a gene therapy for Duchenne muscular dystrophy (DMD). However, the presence of anti-AAV-neutralizing antibodies (NAbs) may impede the effectiveness of gene transduction. This study aimed to evaluate the prevalence of anti-AAV9 NAbs in Chinese patients with DMD, and to characterize the target population for an AAV gene therapy. A total of one hundred male patients with DMD were included in this study, and demographic and clinical data were collected. A blood specimen was obtained from each participant for the purpose of evaluating the existence of anti-AAV9 NAbs through a cell-based functional assay conducted at a central laboratory. A NAb titer exceeding 1:4 was considered positive. The positivity rates of anti-AAV9 NAb were compared among different subgroups. The median age of this DMD cohort was 8 years old, ranging from 3 to 15 years of age. Forty-two percent of patients tested positive for anti-AAV9 NAb. Notably, all samples from patients under 4 years of age tested negative, and the positivity rates of anti-AAV9 NAb differed significantly across the three age subgroups (<4 years old, ≥4 years old and <12 years old, and ≥12 years old, χ2 = 7.221, p = 0.023). Further investigation into the living environment revealed a higher positivity rate of anti-AAV9 NAb in rural patients compared with urban patients (χ2 = 3.923, p = 0.048). Moreover, the prevalence in patients from different cities/provinces varied greatly (χ2 = 16.550, p = 0.003). There was no statistically significant difference in the positivity rate of NAb among subgroups of patients with different motor functions (ambulatory or nonambulatory) and different treatment strategies (taking or not taking glucocorticoid). In Chinese DMD patients, the prevalence of anti-AAV9 NAb was found to reach 42%. Moreover, the antibody-positive rate in children <4 years of age was low and revealed notable regional discrepancies.
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Affiliation(s)
- Cuijie Wei
- Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
| | - Dongliang Li
- Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
| | - Meng Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
| | - Yanping Zhao
- Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
| | - Yidan Liu
- Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
| | - Yanbin Fan
- Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
| | - Lu Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
| | - Jieyu Liu
- Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
| | - Xingzhi Chang
- Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
| | - Yuwu Jiang
- Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
| | - Hui Xiong
- Department of Pediatrics, Peking University First Hospital, Beijing, P.R. China
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Braga VLL, Lima DP, Mariano TC, Lima PLGDSB, Maia ABDA, da Silva Meireles WW, de Oliveira Pessoa KT, de Oliveira CM, Ribeiro EM, Nóbrega PR, Pessoa ALS. Higher Prevalence of Nonsense Pathogenic DMD Variants in a Single-Center Cohort from Brazil: A Genetic Profile Study That May Guide the Choice of Disease-Modifying Treatments. Brain Sci 2023; 13:1521. [PMID: 38002481 PMCID: PMC10669865 DOI: 10.3390/brainsci13111521] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/24/2023] [Accepted: 10/26/2023] [Indexed: 11/26/2023] Open
Abstract
Dystrophinopathies are muscle diseases caused by pathogenic variants in DMD, the largest gene described in humans, representing a spectrum of diseases ranging from asymptomatic creatine phosphokinase elevation to severe Duchenne muscular dystrophy (DMD). Several therapeutic strategies are currently in use or under development, each targeting different pathogenic variants. However, little is known about the genetic profiles of northeast Brazilian patients with dystrophinopathies. We describe the spectrum of pathogenic DMD variants in a single center in northeast Brazil. This is an observational, cross-sectional study carried out through molecular-genetic analysis of male patients diagnosed with dystrophinopathies using Multiplex Ligation-dependent Probe Amplification (MLPA) followed by Next-Generation Sequencing (NGS)-based strategies. A total of 94 male patients were evaluated. Deletions (43.6%) and duplications (10.6%) were the most recurring patterns of pathogenic variants. However, small variants were present in 47.1% of patients, most of them nonsense variants (27.6%). This is the largest South American single-center case series of dystrophinopathies to date. We found a higher frequency of treatment-amenable nonsense single-nucleotide variants than most previous studies. These findings may have implications for diagnostic strategies in less-known populations, as a higher frequency of nonsense variants may mean a higher possibility of treating patients with disease-modifying drugs.
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Affiliation(s)
- Vitor Lucas Lopes Braga
- Division of Pediatry, Hospital Infantil Albert Sabin, Fortaleza 60410-794, CE, Brazil; (V.L.L.B.); (A.B.d.A.M.)
| | - Danielle Pessoa Lima
- Division of Geriatry, Walter Cantidio University Hospital, Federal University of Ceara, Fortaleza 60430-372, CE, Brazil;
| | - Tamiris Carneiro Mariano
- Division of Neurogenetics and Neuromuscular Disorders, Hospital Infantil Albert Sabin, Fortaleza 60410-794, CE, Brazil;
| | | | - Ana Beatriz de Almeida Maia
- Division of Pediatry, Hospital Infantil Albert Sabin, Fortaleza 60410-794, CE, Brazil; (V.L.L.B.); (A.B.d.A.M.)
| | | | | | | | | | - Paulo Ribeiro Nóbrega
- Division of Neurology, Walter Cantidio University Hospital, Federal University of Ceara, Fortaleza 60430-372, CE, Brazil
- Campus Parque Ecológico, Centro Universitário Christus, Fortaleza 60160-230, CE, Brazil
| | - André Luiz Santos Pessoa
- Albert Sabin Children’s Hospital, Fortaleza 60410-794, CE, Brazil;
- Faculty of Medicine, State University of Ceará (UECE), Fortaleza 60714-903, CE, Brazil
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Kekou K, Svingou M, Vogiatzakis N, Nitsa E, Veltra D, Marinakis NM, Tilemis FN, Tzetis M, Mitrakos A, Tsaroucha C, Selenti N, Papadimas GK, Papadopoulos C, Traeger-Synodinos J, Lochmuller H, Sofocleous C. Retrospective analysis of persistent HyperCKemia with or without muscle weakness in a case series from Greece highlights vast DMD variant heterogeneity. Expert Rev Mol Diagn 2023; 23:999-1010. [PMID: 37754746 DOI: 10.1080/14737159.2023.2264181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 09/25/2023] [Indexed: 09/28/2023]
Abstract
BACKGROUND Persistent hyperCKemia results from muscle dysfunction often attributed to genetic alterations of muscle-related genes, such as the dystrophin gene (DMD). Retrospective assessment of findings from DMD analysis, in association with persistent HyperCKemia, was conducted. PATIENTS AND METHODS Evaluation of medical records from 1354 unrelated cases referred during the period 1996-2021. Assessment of data concerning the detection of DMD gene rearrangements and nucleotide variants. RESULTS A total of 730 individuals (657 cases, 569 of Greek and 88 of Albanian origins) were identified, allowing an overall estimation of dystrophinopathy incidence at ~1:3800 live male births. The heterogeneous spectrum of 275 distinct DMD alterations comprised exon(s) deletions/duplications, nucleotide variants, and rare events, such as chromosome translocation {t(X;20)}, contiguous gene deletions, and a fused gene involving the DMD and the DOCK8 genes. Ethnic-specific findings include a common founder variant in exon 36 ('Hellenic' variant). CONCLUSIONS Some 50% of hyperCKemia cases were characterized as dystrophinopathies, highlighting that DMD variants may be considered the most common cause of hyperCKemia in Greece. Delineation of the broad genetic and clinical heterogeneity is fundamental for actionable public health decisions and theragnosis, as well as the establishment of guidelines addressing ethical considerations, especially related to the mild asymptomatic patient subgroup.
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Affiliation(s)
- Kyriaki Kekou
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Maria Svingou
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Nikos Vogiatzakis
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Evangelia Nitsa
- Postgraduate Program in Biostatistics School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Danai Veltra
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- St. Sophia's Children's Hospital, Research University Institute for the Study and Prevention of Genetic and Malignant Disease of Childhood, National and Kapodistrian University of Athens, Athens, Greece
| | - Nikolaos M Marinakis
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- St. Sophia's Children's Hospital, Research University Institute for the Study and Prevention of Genetic and Malignant Disease of Childhood, National and Kapodistrian University of Athens, Athens, Greece
| | - Faidon-Nikolaos Tilemis
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Maria Tzetis
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Anastasios Mitrakos
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- St. Sophia's Children's Hospital, Research University Institute for the Study and Prevention of Genetic and Malignant Disease of Childhood, National and Kapodistrian University of Athens, Athens, Greece
| | - Charalambia Tsaroucha
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Nicoletta Selenti
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Giorgos-Konstantinos Papadimas
- Department of Neurology, Eginition Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Constantinos Papadopoulos
- Department of Neurology, Eginition Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Joanne Traeger-Synodinos
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Hanns Lochmuller
- Department of Neuropediatrics and Muscle Disorders, Medical Center - University of Freiburg, Freiburg, Germany
- Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Children's Hospital of Eastern Ontario Research Institute; Division of Neurology, Department of Medicine, The Ottawa Hospital, Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada
| | - Christalena Sofocleous
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
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Tang F, Xiao Y, Zhou C, Zhang H, Wang J, Zeng Y. NGS-based targeted sequencing identified six novel variants in patients with Duchenne/Becker muscular dystrophy from southwestern China. BMC Med Genomics 2023; 16:121. [PMID: 37254189 DOI: 10.1186/s12920-023-01556-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 05/22/2023] [Indexed: 06/01/2023] Open
Abstract
BACKGROUND At present, Multiplex ligation-dependent probe amplification (MLPA) and exome sequencing are common gene detection methods in patients with Duchenne muscular dystrophy or Becker muscular dystrophy (DMD/BMD), but they can not cover the whole-genome sequence of the DMD gene. In this study, the whole genome capture of the DMD gene and next-generation sequencing (NGS) technology were used to detect the patients with DMD/BMD in Southwest China, to clarify the application value of this technology and further study the gene variant spectrum. METHODS From 2017 to 2020, 51 unrelated patients with DMD/BMD in southwestern China were clinically diagnosed at West China Second University Hospital of Sichuan University (Chengdu, China). The whole-genome of the DMD gene was captured from the peripheral blood of all patients, and next-generation sequencing was performed. Large copy number variants (CNVs) in the exon regions of the DMD gene were verified through MLPA, and small variations (such as single nucleotide variation and < 50 bp fragment insertions/deletions) were validated using Sanger sequencing. RESULTS Among the 51 patients, 49 (96.1% [49/51]) had pathogenic or likely pathogenic variants in the DMD gene. Among the 49 positive samples, 17 patients (34.7% [17/49]) had CNVs in the exon regions and 32 patients (65.3% [32/49]) had small variations. A total of six novel variants were identified: c.10916_10917del, c.1790T>A, c.1842del, c.5015del, c.5791_5792insCA, and exons 38-50 duplication. CONCLUSIONS Pathogenic or likely pathogenic variants of the DMD gene were detected in 49 patients (96.1% [49/51]), of which 6 variants (12.2% [6/49]) had not been previously reported. This study confirmed the value of NGS-based targeted sequencing for the DMD gene expanding the spectrum of variants in DMD, which may provide effective genetic counseling and prenatal diagnosis for families.
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Affiliation(s)
- Feng Tang
- Department of Medical Genetics, West China Second University Hospital of Sichuan University, Chengdu, People's Republic of China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, Sichuan, People's Republic of China
| | - Yuanyuan Xiao
- Department of Medical Genetics, West China Second University Hospital of Sichuan University, Chengdu, People's Republic of China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, Sichuan, People's Republic of China
| | - Cong Zhou
- Department of Medical Genetics, West China Second University Hospital of Sichuan University, Chengdu, People's Republic of China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, Sichuan, People's Republic of China
| | - Haixia Zhang
- Department of Medical Genetics, West China Second University Hospital of Sichuan University, Chengdu, People's Republic of China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, Sichuan, People's Republic of China
| | - Jing Wang
- Department of Medical Genetics, West China Second University Hospital of Sichuan University, Chengdu, People's Republic of China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, Sichuan, People's Republic of China
| | - Yang Zeng
- Department of Medical Genetics, West China Second University Hospital of Sichuan University, Chengdu, People's Republic of China.
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, Sichuan, People's Republic of China.
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Eisen B, Binah O. Modeling Duchenne Muscular Dystrophy Cardiomyopathy with Patients' Induced Pluripotent Stem-Cell-Derived Cardiomyocytes. Int J Mol Sci 2023; 24:ijms24108657. [PMID: 37240001 DOI: 10.3390/ijms24108657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 05/05/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked progressive muscle degenerative disease caused by mutations in the dystrophin gene, resulting in death by the end of the third decade of life at the latest. A key aspect of the DMD clinical phenotype is dilated cardiomyopathy, affecting virtually all patients by the end of the second decade of life. Furthermore, despite respiratory complications still being the leading cause of death, with advancements in medical care in recent years, cardiac involvement has become an increasing cause of mortality. Over the years, extensive research has been conducted using different DMD animal models, including the mdx mouse. While these models present certain important similarities to human DMD patients, they also have some differences which pose a challenge to researchers. The development of somatic cell reprograming technology has enabled generation of human induced pluripotent stem cells (hiPSCs) which can be differentiated into different cell types. This technology provides a potentially endless pool of human cells for research. Furthermore, hiPSCs can be generated from patients, thus providing patient-specific cells and enabling research tailored to different mutations. DMD cardiac involvement has been shown in animal models to include changes in gene expression of different proteins, abnormal cellular Ca2+ handling, and other aberrations. To gain a better understanding of the disease mechanisms, it is imperative to validate these findings in human cells. Furthermore, with the recent advancements in gene-editing technology, hiPSCs provide a valuable platform for research and development of new therapies including the possibility of regenerative medicine. In this article, we review the DMD cardiac-related research performed so far using human hiPSCs-derived cardiomyocytes (hiPSC-CMs) carrying DMD mutations.
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Affiliation(s)
- Binyamin Eisen
- Cardiac Research Laboratory, Department of Physiology, Biophysics and Systems Biology, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Ofer Binah
- Cardiac Research Laboratory, Department of Physiology, Biophysics and Systems Biology, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
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8
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Viggiano E, Picillo E, Passamano L, Onore ME, Piluso G, Scutifero M, Torella A, Nigro V, Politano L. Spectrum of Genetic Variants in the Dystrophin Gene: A Single Centre Retrospective Analysis of 750 Duchenne and Becker Patients from Southern Italy. Genes (Basel) 2023; 14:214. [PMID: 36672955 PMCID: PMC9859256 DOI: 10.3390/genes14010214] [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: 11/07/2022] [Revised: 12/29/2022] [Accepted: 01/11/2023] [Indexed: 01/18/2023] Open
Abstract
Dystrophinopathies are X-linked recessive muscle disorders caused by mutations in the dystrophin (DMD) gene that include deletions, duplications, and point mutations. Correct diagnosis is important for providing adequate patient care and family planning, especially at this time when mutation-specific therapies are available. We report a large single-centre study on the spectrum of DMD gene variants observed in 750 patients analyzed for suspected Duchenne (DMD) or Becker (BMD) muscular dystrophy, over the past 30 years, at the Cardiomyology and Medical Genetics of the University of Campania. We found 534 (71.21%) large deletions, 73 (9.73%) large duplications, and 112 (14.93%) point mutations, of which 44 (5.9%) were small ins/del causing frame-shifts, 57 (7.6%) nonsense mutations, 8 (1.1%) splice site and 3 (0.4%) intronic mutations, and 31 (4.13%) non mutations. Moreover, we report the prevalence of the different types of mutations in patients with DMD and BMD according to their decade of birth, from 1930 to 2020, and correlate the data to the different techniques used over the years. In the most recent decades, we observed an apparent increase in the prevalence of point mutations, probably due to the use of Next-Generation Sequencing (NGS). In conclusion, in southern Italy, deletions are the most frequent variation observed in DMD and BMD patients followed by point mutations and duplications, as elsewhere in the world. NGS was useful to identify point mutations in cases of strong suspicion of DMD/BMD negative on deletions/duplications analyses. In the era of personalized medicine and availability of new causative therapies, a collective effort is necessary to enable DMD and BMD patients to have timely genetic diagnoses and avoid late implementation of standard of care and late initiation of appropriate treatment.
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Affiliation(s)
- Emanuela Viggiano
- Department of Prevention, Hygiene and Public Health Service, ASL Roma 2, 00157 Rome, Italy
| | - Esther Picillo
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Luigia Passamano
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Maria Elena Onore
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Giulio Piluso
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Marianna Scutifero
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Annalaura Torella
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Vincenzo Nigro
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
- Telethon Institute of Genetics and Medicine, 80078 Pozzuoli, Italy
| | - Luisa Politano
- Cardiomyology and Medical Genetics, Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
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Gaina G, Vossen RHAM, Manole E, Plesca DA, Ionica E. Combining Protein Expression and Molecular Data Improves Mutation Characterization of Dystrophinopathies. Front Neurol 2021; 12:718396. [PMID: 34950096 PMCID: PMC8689184 DOI: 10.3389/fneur.2021.718396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 11/05/2021] [Indexed: 11/16/2022] Open
Abstract
Duchenne and Becker muscular dystrophy are X-linked recessive inherited disorders characterized by progressive weakness due to skeletal muscle degeneration. Different mutations in the DMD gene, which encodes for dystrophin protein, are responsible for these disorders. The aim of our study was to investigate the relationship between type, size, and location of the mutation that occurs in the DMD gene and their effect on dystrophin protein expression in a cohort of 40 male dystrophinopathy patients and nine females, possible carriers. We evaluated the expression of dystrophin by immunofluorescence and immunoblotting. The mutational spectrum of the DMD gene was established by MLPA for large copy number variants, followed by HRM analysis for point mutations and sequencing of samples with an abnormal melting profile. MLPA revealed 30 deletions (75%) and three duplications (7.5%). HRM analysis accounted for seven-point mutations (17.5%). We also report four novel small mutations (c. 8507G>T, c.3021delG, c.9563_9563+1insAGCATGTTTATGATACAGCA, c.7661-60T>A) in DMD gene. Our work shows that the DNA translational open reading frame and the location of the mutation both influence the expression of dystrophin and disease severity phenotype. The proposed algorithm used in this study demonstrates its accuracy for the characterization of dystrophinopathy patients.
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Affiliation(s)
- Gisela Gaina
- Department of Biochemistry and Molecular Biology, University of Bucharest, Bucharest, Romania
- Laboratory of Cell Biology, Neuroscience and Experimental Myology, Victor Babes National Institute of Pathology, Bucharest, Romania
- *Correspondence: Gisela Gaina ;
| | - Rolf H. A. M. Vossen
- Center for Human and Clinical Genetics, Leiden Genome Technology Center, Leiden, Netherlands
| | - Emilia Manole
- Laboratory of Cell Biology, Neuroscience and Experimental Myology, Victor Babes National Institute of Pathology, Bucharest, Romania
- Colentina Clinical Hospital, Bucharest, Romania
| | - Doina Anca Plesca
- Department of Pediatrics, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
- Department of Clinical Pediatrics, Victor Gomoiu Children Clinical Hospital, Bucharest, Romania
| | - Elena Ionica
- Department of Biochemistry and Molecular Biology, University of Bucharest, Bucharest, Romania
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10
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Lin J, Li H, Liao Z, Wang L, Zhang C. Comparison of Carrier and de novo Pathogenic Variants in a Chinese DMD/BMD Cohort. Front Neurol 2021; 12:714677. [PMID: 34421809 PMCID: PMC8375267 DOI: 10.3389/fneur.2021.714677] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 07/14/2021] [Indexed: 01/14/2023] Open
Abstract
Background: Duchenne and Becker muscular dystrophy (DMD/BMD) are X-linked recessively inherited neuromuscular disorders caused by deletions, duplications, or small mutations in the DMD gene. With advances in prenatal diagnosis decreasing the number of affected offspring from carrier mothers, the frequency of de novo variants could increase. Therefore, determining the differences between the carrier and de novo variants of the DMD gene, which are rarely explored, is important for trial planning and genetic diagnosis in the future. Methods: A total of 440 patients, 349 of whom had DMD and 91 had BMD, diagnosed in our department between 2012 and 2019, along with their respective mothers, were included in this study. Multiplex ligation-dependent probe amplification was used to detected deletions and duplications in patients and their mothers. Small mutations were detected using next-generation sequencing in the patients, followed by Sanger sequencing in the mothers. Results: Deletions, duplications, and small mutations were identified in 204, 46, and 99 of the 349 patients with DMD and in 50, 10, and 31 of the 91 patients with BMD, respectively. De novo deletions were more concentrated in hotspot regions than carrier deletions of DMD/BMD. No clear bias was observed in the variant distribution between carriers, de novo duplications, and small mutations in DMD/BMD. The carrier frequency of DMD (61.6%) was lower than that of BMD (69.2%), but the difference was not statistically significant. The carrier frequency of deletions of the DMD gene (51.2%) was significantly lower than those of duplications (75%) and small mutations (81.5%). Conclusion: Compared to de novo deletions, deletions from carrier mothers had a wider distribution. Moreover, there was no significant difference between the carrier frequencies of DMD and BMD. Duplications and small mutations were more commonly inherited, while deletions were present de novo.
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Affiliation(s)
- Jinfu Lin
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China
| | - Huan Li
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China
| | - Ziyu Liao
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China
| | - Liang Wang
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China
| | - Cheng Zhang
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China
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11
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Nagabushana D, Polavarapu K, Bardhan M, Arunachal G, Gunasekaran S, Preethish-Kumar V, Anjanappa RM, Thomas P, Sadasivan A, Vengalil S, Nashi S, Chawla T, Warrier M, Keerthipriya M, Raju S, Mohan D, Nalini A. Comparison of The Carrier Frequency of Pathogenic Variants of DMD Gene in an Indian Cohort. J Neuromuscul Dis 2021; 8:525-535. [PMID: 33843695 DOI: 10.3233/jnd-210658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD) is an X-linked disorder caused due to large deletions, duplications,and small pathogenic variants. This article compares the carrier frequency of different pathogenic variants in the DMD gene for the first time in an Indian cohort. METHODS Ninety-one mothers of genetically confirmed DMD probands are included in this study. Pathogenic variants in the DMD gene in probands were detected by multiplex ligation-dependent probe amplification (MLPA) or next-generation sequencing (NGS). Maternal blood samples were evaluated either by MLPA or Sanger sequencing. The demographic and clinical details for screening of muscle weakness and cardiomyopathy were collected from the confirmed carriers. RESULTS Out of 91 probands, large deletions and duplications were identified in 46 and 6 respectively, while 39 had small variants. Among the small variants, substitutions predicted to cause nonsense mutations were the most common (61.5%), followed by frameshift causing small insertion/deletions (25.6%) and splice affecting intronic variants (12.8%). Notably, 19 novel small variants predicted to be disease-causing were identified. Of the 91 mothers, 53 (58.7%) were confirmed to be carriers. Exonic deletions had a significantly lower carrier frequency of 47.8% as compared to small variants (64.1%). The mean age of the carriers at evaluation was 30 years. Among the carriers, two were symptomatic with onset in the 4th decade, manifesting with progressive proximal muscle weakness and dilated cardiomyopathy. CONCLUSION Carrier frequency of small pathogenic variants differs significantly from large deletions. Small pathogenic variants are more commonly inherited, whereas large deletions arise de novo.
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Affiliation(s)
- Divya Nagabushana
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Kiran Polavarapu
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India.,Children's Hospital of Eastern Ontario Research Institute, Children's Hospital of Eastern Ontario, Ottawa, ON, Canada.,Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, ON, Canada.,Brain and Mind Research Institute, University of Ottawa, ON, Canada
| | - Mainak Bardhan
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Gautham Arunachal
- Department of Human Genetics, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Swetha Gunasekaran
- Department of Human Genetics, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | | | - Ram Murthy Anjanappa
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - PriyaTreesa Thomas
- Department of Psychiatric Social Work, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Arun Sadasivan
- Department of Psychiatric Social Work, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Seena Vengalil
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Saraswati Nashi
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Tanushree Chawla
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Manjusha Warrier
- Department of Psychiatric Social Work, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Muddasu Keerthipriya
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Sanita Raju
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Dhaarini Mohan
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Atchayaram Nalini
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
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12
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Ma P, Zhang S, Zhang H, Fang S, Dong Y, Zhang Y, Hao W, Wu S, Zhao Y. Correction to: Comprehensive genetic characteristics of dystrophinopathies in China. Orphanet J Rare Dis 2021; 16:252. [PMID: 34078427 PMCID: PMC8173831 DOI: 10.1186/s13023-021-01853-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Peipei Ma
- Department of Neurology, the General Hospital of Chinese People's Armed Police Force, Beijing, China
| | - Shu Zhang
- Department of Neurology, the General Hospital of Chinese People's Armed Police Force, Beijing, China
| | - Hao Zhang
- Department of Neurology, the General Hospital of Chinese People's Armed Police Force, Beijing, China
| | - Siying Fang
- Department of Neurology, the General Hospital of Chinese People's Armed Police Force, Beijing, China
| | - Yuru Dong
- Department of Magnetic Resonance, the General Hospital of Chinese People's Armed Police Force, Beijing, China
| | - Yan Zhang
- Department of Precision Medicine Laboratory, the General Hospital of Chinese People's Armed Police Force, Beijing, China
| | - Weiwei Hao
- Department of Precision Medicine Laboratory, the General Hospital of Chinese People's Armed Police Force, Beijing, China
| | - Shiwen Wu
- Department of Neurology, the General Hospital of Chinese People's Armed Police Force, Beijing, China.
| | - Yuying Zhao
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, Shandong, China.
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13
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Zhang S, Qin D, Wu L, Li M, Song L, Wei C, Lu C, Zhang X, Hong S, Ma M, Wu S. Genotype characterization and delayed loss of ambulation by glucocorticoids in a large cohort of patients with Duchenne muscular dystrophy. Orphanet J Rare Dis 2021; 16:188. [PMID: 33910603 PMCID: PMC8082961 DOI: 10.1186/s13023-021-01837-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 04/20/2021] [Indexed: 02/05/2023] Open
Abstract
Background Duchenne muscular dystrophy (DMD) is the most common genetic muscle disease in human. We aimed to describe the genotype distribution in a large cohort of Chinese DMD patients and their delayed loss of ambulation by glucocorticoid (GC) treatments. This is to facilitate protocol designs and outcome measures for the emerging DMD clinical trials. Results A total of 1163 patients with DMD were recruited and genotyped. Genotype variations were categorized as large deletions, large duplications, and small mutations. Large deletions were further analyzed for those amenable to exon-skipping therapies. Participants aged 5 years or older were grouped into GC-treated and GC-naïve groups. Clinical progression among different genotypes and their responses to GC treatments were measured by age at loss of ambulation (LOA). Among the mutation genotypes, large deletions, large duplications, and small mutations accounted for 68.79%, 7.14%, and 24.07%, respectively. The mean age at diagnosis was 4.59 years; the median ages at LOA for the GC-naïve, prednisone/prednisolone-treated, and deflazacort-treated groups were 10.23, 12.02, and 13.95 years, respectively. The “deletion amenable to skipping exon 44” subgroup and the nonsense-mutation subgroup had older ages at LOA than the “other deletions” subgroup. Subgroups were further analyzed by both genotypes and GC status. All genotypes showed significant beneficial responses to GC treatment. Deletions amenable to skipping exon 44 showed a lower hazard ratio (0.155). The mean age at death was 18.57 years in this DMD group. Conclusion Genotype variation influences clinical progression in certain DMD groups. Beneficial responses to GC treatment were observed among all DMD genotypes. Compared with other genotypes, deletions amenable to skipping exon 44 had a lower hazard ratio, which may indicate a stronger protective effect of GC treatments on this subgroup. These data are valuable for designing future clinical trials, as clinical outcomes may be influenced by the genotypes.
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Affiliation(s)
- Shu Zhang
- Department of Neurology, First Medical Center of Chinese PLA General Hospital, Beijing, 100853, China.,Department of Neurology, Third Medical Center of Chinese PLA General Hospital, Beijing, 100039, China
| | - Dongdong Qin
- Department of Physiology, Yunnan University of Chinese Medicine, Kunming, 650500, Yunnan Province, China
| | - Liwen Wu
- Department of Neurology, Hunan Children's Hospital, Changsha, 410008, Hunan Province, China
| | - Man Li
- Department of Neurology, The Second Hospital of Shanxi Medical University, Taiyuan, 030001, Shanxi Province, China
| | - Lifang Song
- Department of Pediatric Neurology, Henan Children's Hospital, Zhengzhou, 450018, Henan Province, China
| | - Cuijie Wei
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Chunling Lu
- Department of Muscle Atrophy, Affiliated Yiling Hospital of Hebei Medical University, Shijiazhuang, 050091, Hebei Province, China
| | - Xiaoli Zhang
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, Henan Province, China
| | - Siqi Hong
- Department of Pediatrics, Chongqing Medical University Affiliated Children's Hospital, Chongqing, 400042, China
| | - Mingming Ma
- Department of Neurology, Affiliated People's Hospital of Zhengzhou University, Zhengzhou, 450003, Henan Province, China
| | - Shiwen Wu
- Department of Neurology, First Medical Center of Chinese PLA General Hospital, Beijing, 100853, China. .,Department of Neurology, Third Medical Center of Chinese PLA General Hospital, Beijing, 100039, China. .,Department of Neurology, Chinese PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing, 100853, China.
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14
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Tong YR, Geng C, Guan YZ, Zhao YH, Ren HT, Yao FX, Ling C, Wang DC, Chen L, Cui LY, Zhang SY, Dai Y. A Comprehensive Analysis of 2013 Dystrophinopathies in China: A Report From National Rare Disease Center. Front Neurol 2020; 11:572006. [PMID: 33101180 PMCID: PMC7554367 DOI: 10.3389/fneur.2020.572006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/24/2020] [Indexed: 12/17/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive neuromuscular disorders caused by mutations in DMD. A high-quality database of DMD/BMD is essential not only for clinical practice but also for fundamental research. Here, we aimed to build the largest Chinese national dystrophinopathy database using the National Rare Diseases Registry System of China. Peking Union Medical College Hospital (PUMCH) was the National Rare Diseases Center of China. This research involved 2013 patients with dystrophinopathies, whose diagnoses were confirmed; they were registered and followed up at PUMCH from March 2011 to December 2018. Family history, clinical signs, and treatment data were reported for patients with DMD and BMD at different rates. All six serum biochemical indexes could accurately distinguish between DMD and BMD patients. Copy number variations were the most frequent mutation type (79.2% in DMD and 84.3% in BMD), of which large deletions accounted for 88.4 and 88.6%, large duplications accounted for 11.6 and 11.4% in DMD and BMD, respectively. An exon deletion hotspot, located in exons 45-54, was observed in DMD, and intron 44 was the most frequent deletion starting point (26.5%). Duplication and single nucleotide variations appeared to be uniformly distributed among all exons. Eleven patients were identified to have ultrarare mutation types. Eleven other patients suffered from two separate mutations simultaneously, some of which may have taken place via dependent mechanisms. Thus, we have established the largest hospital-based Chinese dystrophinopathy database via the National Rare Diseases Registry System. This study provides valuable information for further diagnostic and therapeutic studies of dystrophinopathy.
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Affiliation(s)
- Yuan-Ren Tong
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Chang Geng
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yu-Zhou Guan
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yan-Huan Zhao
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Hai-Tao Ren
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Feng-Xia Yao
- Laboratory of Clinical Genetics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Chao Ling
- Laboratory of Clinical Genetics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Dan-Chen Wang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Lin Chen
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Li-Ying Cui
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Shu-Yang Zhang
- Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yi Dai
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
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15
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Torella A, Zanobio M, Zeuli R, del Vecchio Blanco F, Savarese M, Giugliano T, Garofalo A, Piluso G, Politano L, Nigro V. The position of nonsense mutations can predict the phenotype severity: A survey on the DMD gene. PLoS One 2020; 15:e0237803. [PMID: 32813700 PMCID: PMC7437896 DOI: 10.1371/journal.pone.0237803] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/03/2020] [Indexed: 12/23/2022] Open
Abstract
A nonsense mutation adds a premature stop signal that hinders any further translation of a protein-coding gene, usually resulting in a null allele. To investigate the possible exceptions, we used the DMD gene as an ideal model. First, because dystrophin absence causes Duchenne muscular dystrophy (DMD), while its reduction causes Becker muscular dystrophy (BMD). Second, the DMD gene is X-linked and there is no second allele that can interfere in males. Third, databases are accumulating reports on many mutations and phenotypic data. Finally, because DMD mutations may have important therapeutic implications. For our study, we analyzed large databases (LOVD, HGMD and ClinVar) and literature and revised critically all data, together with data from our internal patients. We totally collected 2593 patients. Positioning these mutations along the dystrophin transcript, we observed a nonrandom distribution of BMD-associated mutations within selected exons and concluded that the position can be predictive of the phenotype. Nonsense mutations always cause DMD when occurring at any point in fifty-one exons. In the remaining exons, we found milder BMD cases due to early 5’ nonsense mutations, if reinitiation can occur, or due to late 3’ nonsense when the shortened product retains functionality. In the central part of the gene, all mutations in some in-frame exons, such as in exons 25, 31, 37 and 38 cause BMD, while mutations in exons 30, 32, 34 and 36 cause DMD. This may have important implication in predicting the natural history and the efficacy of therapeutic use of drug-stimulated translational readthrough of premature termination codons, also considering the action of internal natural rescuers. More in general, our survey confirm that a nonsense mutation should be not necessarily classified as a null allele and this should be considered in genetic counselling.
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Affiliation(s)
- Annalaura Torella
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Mariateresa Zanobio
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
| | - Roberta Zeuli
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
| | | | - Marco Savarese
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
- Folkhälsan Research Center, Medicum, University of Helsinki, Helsinki, Finland
| | - Teresa Giugliano
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
| | - Arcomaria Garofalo
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
| | - Giulio Piluso
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
| | - Luisa Politano
- Dipartimento di Medicina Sperimentale, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
| | - Vincenzo Nigro
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- * E-mail:
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16
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Wonkam‐Tingang E, Nguefack S, Esterhuizen AI, Chelo D, Wonkam A. DMD-related muscular dystrophy in Cameroon: Clinical and genetic profiles. Mol Genet Genomic Med 2020; 8:e1362. [PMID: 32543101 PMCID: PMC7434738 DOI: 10.1002/mgg3.1362] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 05/20/2020] [Accepted: 05/26/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Most of the previous studies on Duchenne Muscular Dystrophy (DMD) were conducted in Caucasian, Asian, and Arab populations. Therefore, little is known about the features of this disease in Africans. In this study, we aimed to determine the clinical characteristics of DMD, and the common mutations associated with this condition in a group of Cameroonian patients. METHODS We recruited DMD patients and performed a general physical examination on each of them. Multiplex ligand-dependant probe amplification was carried out to investigate exon deletions and duplications in the DMD gene (OMIM: 300377) of patients and their mothers. RESULTS A total of 17 male patients from 14 families were recruited, aged 14 ± 5.1 (8-23) years. The mean age at onset of symptoms was 4.6 ± 1.5 years, and the mean age at diagnosis was 12.1 ± 5.2 years. Proximal muscle weakness was noted in all patients and calf hypertrophy in the large majority of them (88.2%; 15/17). Flexion contractures were particularly frequent on the ankle (85.7%; 12/14). Wasting of shoulder girdle and thigh muscles was present in 50% (6/12) and 46.2% (6/13) of patients, respectively. No patient presented with hearing impairment. Deletions in DMD gene (OMIM: 300377) occurred in 45.5% of patients (5/11), while duplications were observed in 27.3% (3/11). Both mutation types were clustered between exons 45 and 50, and the proportion of de novo mutation was estimated at 18.2% (2/11). CONCLUSION Despite the first symptoms of DMD occurring in infancy, the diagnosis is frequently made later in adolescence, indicating an underestimation of the number of cases of DMD in Cameroon. Future screening of deletions and duplications in patients from Cameroon should focus on the distal part of the gene.
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Affiliation(s)
- Edmond Wonkam‐Tingang
- Division of Human GeneticsDepartment of PathologyUniversity of Cape TownCape TownSouth Africa
| | - Séraphin Nguefack
- Department of PaediatricsFaculty of Medicine and Biomedical SciencesUniversity of Yaoundé IYaoundéCameroon
- Paediatrics UnitDivision of Paediatric NeurologyGynaeco‐Obstetric and Paediatric HospitalYaoundéCameroon
| | - Alina I. Esterhuizen
- Division of Human GeneticsDepartment of PathologyUniversity of Cape TownCape TownSouth Africa
- National Health Laboratory ServiceGroote Schuur HospitalCape TownSouth Africa
| | - David Chelo
- Department of PaediatricsFaculty of Medicine and Biomedical SciencesUniversity of Yaoundé IYaoundéCameroon
- Division of Paediatric Cardiology, Mother and Child HospitalYaoundéCameroon
| | - Ambroise Wonkam
- Division of Human GeneticsDepartment of PathologyUniversity of Cape TownCape TownSouth Africa
- Department of MedicineUniversity of Cape TownCape TownSouth Africa
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17
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Mutation Spectrum of Dystrophinopathies in India: Implications for Therapy. Indian J Pediatr 2020; 87:495-504. [PMID: 32358784 DOI: 10.1007/s12098-020-03286-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 03/31/2020] [Indexed: 10/24/2022]
Abstract
BACKGROUND Dystrophinopathies are common X-linked recessive neuromuscular disorders caused by pathogenic variants in the dystrophin gene (DMD). Analysis of the mutational spectrum in the Indian patients would be useful for confirming the diagnosis, provide genetic counseling, offer reproductive options, and importantly to determine the eligibility for the mutation-specific therapies currently approved/or undergoing trials, such as skipping of specific exons or read-through of stop codon. METHODS In 1660 patients diagnosed as Duchenne muscular dystrophy (DMD) /Becker muscular dystrophy (BMD) deletion- duplication analysis of all 79 exons was carried out using Multiplex ligation-dependent probe amplification (MLPA) technology. In 63 patients where no mutations were detected by MLPA, the nucleotide sequence of the DMD gene was determined by next gene sequencing. In seven cases where MLPA showed deletion of a single exon, and amplification of the specific exon was successful by polymerase chain reaction (PCR), Sanger sequencing of the concerned region was carried out to detect changes in the sequence. RESULTS The mutation spectrum of 1660 patients with DMD/BMD was determined and 1188 (71.6%) patients were identified to have deletions or duplications of one or more exons. Of these, 1090 (65.7%) had true deletions of exons and 98 (5.9%) had duplications of exons. The most frequent change was the deletion of exon 45 (66/1090, 6.1%) and duplication of exon 2 (1/98, 11.2%). Sequencing of dystrophin gene was performed in 70 cases, and variants were identified in 68 patients (97.1% of those analyzed). Stop codon variants were observed in 34 (50%) patients, missense variants in 4 (5.9%), small deletions in 19 (27.9%), small insertions in 6 (8.8%) and slice site variants in 5 (7.4%) patients. Thirty one of 68 variants (45.5%) were novel. CONCLUSIONS The authors highlight the importance of identifying the type of mutation in patients with DMD. Based on the results, it is estimated that 681 (54.2%) of 1256 patients in this cohort would benefit from the currently ongoing mutation-specific therapies.
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[A predictive analysis of the association between clinical phenotypes and genotypes in children with Becker muscular dystrophy/Duchenne muscular dystrophy]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2020; 22. [PMID: 32571459 PMCID: PMC7390220 DOI: 10.7499/j.issn.1008-8830.1912133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE To study the association between clinical phenotypes and genotypes in children with Becker muscular dystrophy (BMD)/Duchenne muscular dystrophy (DMD) so as to provide a theoretical basis for disease management, gene therapy, and prenatal diagnosis. METHODS A retrospective analysis was performed for the clinical data and gene detection results of 52 children with BMD/DMD. Multiplex ligation-dependent probe amplification (MLPA) was used to detect the DMD gene. The children with negative results of MLPA were further screened by exon chip capture combined with next-generation sequencing (NGS). The mothers of 20 probands were validated by sequencing. RESULTS The pathogenic genes for BMD/DMD were detected in 50 children by MLPA and NGS, with a detection rate of 96%. Among the 52 children, 36 (69%) had gene deletion, 7 (13%) had duplication, and 7 (13%) had micromutation. Among the 43 children with deletion/duplication, 32 had DMD and 11 had BMD; 37 children (86%) met the reading frame rule, among whom 27 (96%) had DMD and 10 (67%) had BMD. All 7 children with micromutation had DMD. CONCLUSIONS The reading frame rule has an extremely high predictive value for DMD but a limited predictive value for BMD.
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Zamani G, Hosseini Bereshneh A, Azizi Malamiri R, Bagheri S, Moradi K, Ashrafi MR, Tavasoli AR, Mohammadi M, Badv RS, Ghahvechi Akbari M, Heidari M. The First Comprehensive Cohort of the Duchenne Muscular Dystrophy in Iranian Population: Mutation Spectrum of 314 Patients and Identifying Two Novel Nonsense Mutations. J Mol Neurosci 2020; 70:1565-1573. [DOI: 10.1007/s12031-020-01594-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 05/14/2020] [Indexed: 12/17/2022]
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Yang YM, Yan K, Liu B, Chen M, Wang LY, Huang YZ, Qian YQ, Sun YX, Li HG, Dong MY. Comprehensive genetic diagnosis of patients with Duchenne/Becker muscular dystrophy (DMD/BMD) and pathogenicity analysis of splice site variants in the DMD gene. J Zhejiang Univ Sci B 2020; 20:753-765. [PMID: 31379145 DOI: 10.1631/jzus.b1800541] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are caused by mutations in the DMD gene. The aim of this study is to identify pathogenic DMD variants in probands and reduce the risk of recurrence of the disease in affected families. Variations in 100 unrelated DMD/BMD patients were detected by multiplex ligation-dependent probe amplification (MLPA) and next-generation sequencing (NGS). Pathogenic variants in DMD were successfully identified in all cases, and 11 of them were novel. The most common mutations were intragenic deletions (69%), with two hotspots located in the 5' end (exons 2-19) and the central of the DMD gene (exons 45-55), while point mutations were observed in 22% patients. Further, c.1149+1G>A and c.1150-2A>G were confirmed by hybrid minigene splicing assay (HMSA). This two splice site mutations would lead to two aberrant DMD isoforms which give rise to severely truncated protein. Therefore, the clinical use of MLPA, NGS, and HMSA is an effective strategy to identify variants. Importantly, eight embryos were terminated pregnancies according to prenatal diagnosis and a healthy boy was successfully delivered by preimplantation genetic diagnosis (PGD). Early and accurate genetic diagnosis is essential for prenatal diagnosis/PGD to reduce the risk of recurrence of DMD in affected families.
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Affiliation(s)
- Yan-Mei Yang
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Kai Yan
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Bei Liu
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Min Chen
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Li-Ya Wang
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Ying-Zhi Huang
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Ye-Qing Qian
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Yi-Xi Sun
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Hong-Ge Li
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Min-Yue Dong
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
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Tomar S, Moorthy V, Sethi R, Chai J, Low PS, Hong STK, Lai PS. Mutational spectrum of dystrophinopathies in Singapore: Insights for genetic diagnosis and precision therapy. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2019; 181:230-244. [DOI: 10.1002/ajmg.c.31704] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 04/21/2019] [Accepted: 04/22/2019] [Indexed: 12/26/2022]
Affiliation(s)
- Swati Tomar
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of Singapore Singapore
| | - Vikaesh Moorthy
- Yong Loo Lin School of MedicineNational University of Singapore Singapore
| | - Raman Sethi
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of Singapore Singapore
| | - Josiah Chai
- Department of Neurology, National Neuroscience Institute Singapore
| | - Poh Sim Low
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of Singapore Singapore
| | - Stacey Tay Kiat Hong
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of Singapore Singapore
| | - Poh San Lai
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of Singapore Singapore
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Multiple Exon Skipping in the Duchenne Muscular Dystrophy Hot Spots: Prospects and Challenges. J Pers Med 2018; 8:jpm8040041. [PMID: 30544634 PMCID: PMC6313462 DOI: 10.3390/jpm8040041] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/24/2018] [Accepted: 12/04/2018] [Indexed: 12/19/2022] Open
Abstract
Duchenne muscular dystrophy (DMD), a fatal X-linked recessive disorder, is caused mostly by frame-disrupting, out-of-frame deletions in the dystrophin (DMD) gene. Antisense oligonucleotide-mediated exon skipping is a promising therapy for DMD. Exon skipping aims to convert out-of-frame mRNA to in-frame mRNA and induce the production of internally-deleted dystrophin as seen in the less severe Becker muscular dystrophy. Currently, multiple exon skipping has gained special interest as a new therapeutic modality for this approach. Previous retrospective database studies represented a potential therapeutic application of multiple exon skipping. Since then, public DMD databases have become more useful with an increase in patient registration and advances in molecular diagnosis. Here, we provide an update on DMD genotype-phenotype associations using a global DMD database and further provide the rationale for multiple exon skipping development, particularly for exons 45–55 skipping and an emerging therapeutic concept, exons 3–9 skipping. Importantly, this review highlights the potential of multiple exon skipping for enabling the production of functionally-corrected dystrophin and for treating symptomatic patients not only with out-of-frame deletions but also those with in-frame deletions. We will also discuss prospects and challenges in multiple exon skipping therapy, referring to recent progress in antisense chemistry and design, as well as disease models.
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