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Gatto F, Benemei S, Piluso G, Bello L. The complex landscape of DMD mutations: moving towards personalized medicine. Front Genet 2024; 15:1360224. [PMID: 38596212 PMCID: PMC11002111 DOI: 10.3389/fgene.2024.1360224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 02/26/2024] [Indexed: 04/11/2024] Open
Abstract
Duchenne muscular dystrophy (DMD) is a severe genetic disorder characterized by progressive muscle degeneration, with respiratory and cardiac complications, caused by mutations in the DMD gene, encoding the protein dystrophin. Various DMD mutations result in different phenotypes and disease severity. Understanding genotype/phenotype correlations is essential to optimize clinical care, as mutation-specific therapies and innovative therapeutic approaches are becoming available. Disease modifier genes, trans-active variants influencing disease severity and phenotypic expressivity, may modulate the response to therapy, and become new therapeutic targets. Uncovering more disease modifier genes via extensive genomic mapping studies offers the potential to fine-tune prognostic assessments for individuals with DMD. This review provides insights into genotype/phenotype correlations and the influence of modifier genes in DMD.
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Affiliation(s)
| | | | - Giulio Piluso
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, Napoli, Italy
| | - Luca Bello
- Department of Neurosciences DNS, University of Padova, Padova, Italy
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Vinciguerra C, Iacono S, Bevilacqua L, Landolfi A, Piscosquito G, Ginanneschi F, Schirò G, Di Stefano V, Brighina F, Barone P, Balistreri CR. Sex differences in neuromuscular disorders. Mech Ageing Dev 2023; 211:111793. [PMID: 36806604 DOI: 10.1016/j.mad.2023.111793] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/13/2023] [Accepted: 02/16/2023] [Indexed: 02/19/2023]
Abstract
The prevalence, onset, pathophysiology, and clinical course of many neuromuscular disorders (NMDs) may significantly differ between males and females. Some NMDs are more frequently observed in females, and characterized to show a higher grade of severity during or after the pregnancy. Meanwhile, others tend to have an earlier onset in males and exhibit a more variable progression. Prevalently, sex differences in NMDs have a familiar character given from genetic inheritance. However, they may also influence clinical presentation and disease severity of acquired NMD forms, and are represented by both hormonal and genetic factors. Consequently, to shed light on the distinctive role of biological factors in the different clinical phenotypes, we summarize in this review the sex related differences and their distinctive biological roles emerging from the current literature in both acquired and inherited NMDs.
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Affiliation(s)
- Claudia Vinciguerra
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, 84131 Salerno, Italy.
| | - Salvatore Iacono
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Liliana Bevilacqua
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, 84131 Salerno, Italy
| | - Annamaria Landolfi
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, 84131 Salerno, Italy
| | - Giuseppe Piscosquito
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, 84131 Salerno, Italy
| | - Federica Ginanneschi
- Department of Medical, Surgical and Neurological Sciences, University of Siena, 53100 Siena, Italy
| | - Giuseppe Schirò
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Vincenzo Di Stefano
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Filippo Brighina
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Paolo Barone
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, 84131 Salerno, Italy
| | - Carmela Rita Balistreri
- Cellular and Molecular Laboratory, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90134 Palermo
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Kurt M, Savaş D, Şimşek TT, Yiş U. Factors associated with balance ability in Duchenne and Becker muscular dystrophies. Gait Posture 2023; 99:139-145. [PMID: 36435068 DOI: 10.1016/j.gaitpost.2022.11.008] [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] [Received: 06/19/2022] [Revised: 10/08/2022] [Accepted: 11/14/2022] [Indexed: 11/18/2022]
Abstract
BACKGROUND Problems such as progressive muscle function loss, postural deteriorations, and contractures seen in patients with Duchenne and Becker muscular dystrophies (D/BMD) may affect children's balance ability, and impaired balance ability may lead to limitations in children's functional level. RESEARCH QUESTION What factors are associated with balance ability in children with D/BMD? METHODS Twenty participants with D/BMD were included in the study. Participants' ages were asked; height, body weight, and body mass index (BMI) were recorded. Children's functional level was assessed with the Motor Function Measurement-32 (MFM-32), Brooke and Vignos Scales. Muscle strength of hip flexion and extension, knee flexion and extension, and ankle dorsiflexion was measured with a handheld dynamometer. Balance measurements were performed using the Balance Master System. The relationship between balance and continuous independent variables was determined using Spearman's test. RESULTS The mean age of the participants was 8.57 ± 3.27 years. The balance abilities of children with BMD were better than those of children with DMD (p < 0.05). The balance diminished with age (p < 0.05), while there was a positive correlation between balance and weight, height, BMI (p < 0.05). There was a positive correlation between the balance and the MFM-32 total and subsection scores. Muscle strength was positively related to balance (p < 0.05). SIGNIFICANCE The results showed the balance ability in children with D/BMD was affected by age, height, weight, BMI, functional level, and muscle strength. Based on the results of this study, balance and strength training should be an integral part of the rehabilitation of children with D/BMD.
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Affiliation(s)
- Merve Kurt
- Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Izmir Katip Celebi University, Izmir, Turkey; Graduate School of Health Sciences, Dokuz Eylul University, Izmir, Turkey.
| | - Dilan Savaş
- Graduate School of Health Sciences, Dokuz Eylul University, Izmir, Turkey.
| | - Tülay Tarsuslu Şimşek
- Faculty of Physical Therapy and Rehabilitation, Dokuz Eylul University, Izmir, Turkey.
| | - Uluç Yiş
- Dokuz Eylül University Department of Pediatrics, Pediatric Neurology, İzmir, Turkey.
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Kariyawasam D, D’Silva A, Mowat D, Russell J, Sampaio H, Jones K, Taylor P, Farrar M. Incidence of Duchenne muscular dystrophy in the modern era; an Australian study. Eur J Hum Genet 2022; 30:1398-1404. [PMID: 35754057 PMCID: PMC9712523 DOI: 10.1038/s41431-022-01138-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 04/20/2022] [Accepted: 06/13/2022] [Indexed: 11/09/2022] Open
Abstract
Duchenne muscular dystrophy (DMD), an X-linked recessive condition is maternally inherited in two-thirds of affected boys. It is important to establish carrier status of female relatives to restore reproductive confidence for non-carriers and facilitate reproductive options and cardiac surveillance for carriers. This study investigates disease incidence within an Australian model of cascade screening and evolving genetic diagnostic technologies. A retrospective population-based cohort study of all genetically and/or histopathologically confirmed males with DMD, born in New South Wales and the Australian Capital Territory was undertaken from 2002-2012. Cases were identified using state-wide molecular laboratory and clinical databases. The annual disease incidence and "theoretically" preventable cases were extrapolated over the study period. Proband genotype/phenotype, pedigree analysis, carrier-risk and extent of cascade screening were also determined. The cumulative incidence of disease was 19.7 per 100,000 male live births and 1 in 5076 live born males were diagnosed with DMD. Differences in disease incidence were not statistically different when compared between 2002-2007 and 2008-2012 (incidence rate ratio = 1.13, 95% CI 0.76-1.69, p = 0.52). The incidence rate ratio of theoretically preventable cases did not significantly change between 2002-2007 and 2008-2012 (incidence rate ratio = 2.07, 95% CI 0.58-9.21, p = 0.23). Current diagnostic and cascade screening models have limitations in their impact on disease incidence, due to a spectrum of logistical, patient and condition related factors. Innovative approaches to reduce DMD incidence may be better achieved by preconception or early pregnancy carrier screening, prenatal exome sequencing and newborn screening.
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Affiliation(s)
- Didu Kariyawasam
- Department of Neurology, Sydney Children's Hospital, Randwick, Sydney, NSW, Australia. .,School of Clinical Medicine, UNSW Medicine and Health, Randwick Clinical Campus, Discipline of Paediatrics, University of New South Wales, Sydney, NSW, Australia.
| | - Arlene D’Silva
- grid.1005.40000 0004 4902 0432School of Clinical Medicine, UNSW Medicine and Health, Randwick Clinical Campus, Discipline of Paediatrics, University of New South Wales, Sydney, NSW Australia
| | - David Mowat
- grid.1005.40000 0004 4902 0432School of Clinical Medicine, UNSW Medicine and Health, Randwick Clinical Campus, Discipline of Paediatrics, University of New South Wales, Sydney, NSW Australia ,grid.414009.80000 0001 1282 788XCentre for Clinical Genetics, Sydney Children’s Hospital, Randwick, Sydney, NSW Australia
| | - Jacqui Russell
- grid.414009.80000 0001 1282 788XCentre for Clinical Genetics, Sydney Children’s Hospital, Randwick, Sydney, NSW Australia
| | - Hugo Sampaio
- grid.414009.80000 0001 1282 788XDepartment of Neurology, Sydney Children’s Hospital, Randwick, Sydney, NSW Australia
| | - Kristi Jones
- grid.413973.b0000 0000 9690 854XDepartment of Clinical Genetics, Children’s Hospital Westmead, Westmead, NSW Australia ,grid.1013.30000 0004 1936 834XPaediatrics and Child Health, Sydney Medical School, University of Sydney NSW Australia, Sydney, NSW Australia
| | - Peter Taylor
- Genomic Diagnostics, Healius Pathology, Melbourne, Vic Australia
| | - Michelle Farrar
- grid.414009.80000 0001 1282 788XDepartment of Neurology, Sydney Children’s Hospital, Randwick, Sydney, NSW Australia ,grid.1005.40000 0004 4902 0432School of Clinical Medicine, UNSW Medicine and Health, Randwick Clinical Campus, Discipline of Paediatrics, University of New South Wales, Sydney, NSW Australia
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CRISPR-Based Therapeutic Gene Editing for Duchenne Muscular Dystrophy: Advances, Challenges and Perspectives. Cells 2022; 11:cells11192964. [PMID: 36230926 PMCID: PMC9564082 DOI: 10.3390/cells11192964] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/06/2022] [Accepted: 09/09/2022] [Indexed: 11/19/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a severe neuromuscular disease arising from loss-of-function mutations in the dystrophin gene and characterized by progressive muscle degeneration, respiratory insufficiency, cardiac failure, and premature death by the age of thirty. Albeit DMD is one of the most common types of fatal genetic diseases, there is no curative treatment for this devastating disorder. In recent years, gene editing via the clustered regularly interspaced short palindromic repeats (CRISPR) system has paved a new path toward correcting pathological mutations at the genetic source, thus enabling the permanent restoration of dystrophin expression and function throughout the musculature. To date, the therapeutic benefits of CRISPR genome-editing systems have been successfully demonstrated in human cells, rodents, canines, and piglets with diverse DMD mutations. Nevertheless, there remain some nonignorable challenges to be solved before the clinical application of CRISPR-based gene therapy. Herein, we provide an overview of therapeutic CRISPR genome-editing systems, summarize recent advancements in their applications in DMD contexts, and discuss several potential obstacles lying ahead of clinical translation.
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A genetic basis is identified in 74% cases of paediatric hyperCKaemia without weakness presenting to a tertiary paediatric neuromuscular centre. Neuromuscul Disord 2022; 32:707-717. [DOI: 10.1016/j.nmd.2022.07.401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 06/23/2022] [Accepted: 07/25/2022] [Indexed: 11/20/2022]
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DMD exon 2 duplication due to a complex genomic rearrangement is associated with a somatic mosaicism. Neuromuscul Disord 2021; 32:263-269. [DOI: 10.1016/j.nmd.2021.12.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 11/24/2021] [Accepted: 12/13/2021] [Indexed: 12/23/2022]
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Apkon S, Kinnett K, Cripe L, Duan D, Jackson JL, Kornegay JN, Mah ML, Nelson SF, Rao V, Scavina M, Wong BL, Flanigan KM. Parent Project Muscular Dystrophy Females with Dystrophinopathy Conference, Orlando, Florida June 26 - June 27, 2019. J Neuromuscul Dis 2021; 8:315-322. [PMID: 33361607 PMCID: PMC10497321 DOI: 10.3233/jnd-200555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Susan Apkon
- Department of Physical Medicine and Rehabilitation, University of Colorado Denver and Children’s Hospital Colorado, Aurora, CO, USA
| | - Kathi Kinnett
- Parent Project Muscular Dystrophy, Hackensack, NJ, USA
| | - Linda Cripe
- The Heart Center, Nationwide Children’s Hospital and the Ohio State University, Columbus, OH, USA
| | - Dongsheng Duan
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
| | - Jamie L. Jackson
- Center for Biobehavioral Health, Abigail Wexner Research Institute at Nationwide Children’s Hospital; Assistant Professor of Pediatrics and Psychology, The Ohio State University, Columbus, OH, USA
| | - Joe N. Kornegay
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, 4458 TAMU, College Station, TX, USA
| | - May Ling Mah
- The Heart Center, Nationwide Children’s Hospital and the Ohio State University, Columbus, OH, USA
| | - Stanley F. Nelson
- Department of Human Genetics, Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Vamshi Rao
- Department of Pediatrics, Division of Neurology, Ann and Robert H. Lurie Children’s Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL USA
| | - Mena Scavina
- Department of Neurology, Nemours/duPont Hospital for Children, Wilmington, DE, USA
| | - Brenda L. Wong
- Department of Pediatrics and Neurology, University of Massachusetts Medical School, Worcester, MA USA
| | - Kevin M. Flanigan
- Center for Gene Therapy, Nationwide Children’s Hospital and Departments of Pediatrics and Neurology, Ohio State University, Columbus, Ohio, USA
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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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Chen J, Zheng H, Wang Z, Wang J, He F, Zhang C, Xiong F. A female carrier of a novel DMD mutation with slightly skewed X-chromosome inactivation shows a suspected case of Becker muscular dystrophy in a Chinese family. Mol Genet Genomics 2021; 296:541-549. [PMID: 33566169 DOI: 10.1007/s00438-020-01757-8] [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: 06/21/2020] [Accepted: 12/21/2020] [Indexed: 11/28/2022]
Abstract
Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are both caused by mutations in DMD gene effecting the expression of dystrophin. Generally female carriers are asymptomatic; however, it has been suggested that carriers may exhibit symptoms. We investigated a 6-year-old Chinese girl exhibiting a suspected BMD phenotype, including persistently elevated creatine kinase and creatine kinase isoenzyme levels. The proband harbored a novel heterozygous mutation, c.3458_3459insAA, within exon 26 of the DMD gene inherited from her mother who had a completely normal phenotype and presented with mosaicism in her lymphocytes with 45, X [17%]/46, XX [83%]. In addition, X-chromosome inactivation (XCI) patterns in the peripheral blood of the child were slightly skewed: proband with 62% (mutant allele)/38% (normal allele) when compared with her mother with 32/68%. Amplification of regions of the cDNA revealed different ratios for the expression of these alleles: proband with 50/50% and her mother with 20/80%. Real-time PCR showed that mRNA expression was significantly decreased in both. We proposed that a frameshift or nonsense mutation may contribute to the development of symptoms in carriers. These phenotypes correlate with nonrandom XCI patterns and are compounded by the locus of the mutation. For incompletely skewed XCI patterns, although the mutant allele could suppress the expression of a normal allele, carriers would remain asymptomatic as long as there was adequate compensation from the normal allele. We also proposed a mechanism where mRNA from the mutant allele may be unstable and easily degraded, allowing for phenotypic compensation by the wildtype allele.
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Affiliation(s)
- Jianfan Chen
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, People's Republic of China
| | - Hui Zheng
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China
| | - Zhongju Wang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, People's Republic of China
| | - Jian Wang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, People's Republic of China
| | - Fei He
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, People's Republic of China
- Guangdong Provincial Key Laboratory of Single Cell Technology and Application, Guangzhou, Guangdong Province, People's Republic of China
| | - Cheng Zhang
- Department of Neurology, First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Fu Xiong
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, People's Republic of China.
- Guangdong Provincial Key Laboratory of Single Cell Technology and Application, Guangzhou, Guangdong Province, People's Republic of China.
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Population-Wide Duchenne Muscular Dystrophy Carrier Detection by CK and Molecular Testing. BIOMED RESEARCH INTERNATIONAL 2020; 2020:8396429. [PMID: 33029525 PMCID: PMC7537677 DOI: 10.1155/2020/8396429] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/27/2020] [Accepted: 09/03/2020] [Indexed: 01/28/2023]
Abstract
Carrier screening of Duchenne muscular dystrophy (DMD) has not been widely evaluated. To identify definite DMD female carriers prior to or in early pregnancy, we studied a large population of reproductive age females and provided informed reproductive options to DMD carriers. 37268 females were recruited from the Hangzhou Family Planning Publicity and Technology Guidance Station/Hangzhou Health Service Center for Children and Women, Hangzhou, China, between October 10, 2017, and December 16, 2018. CK activity was measured with follow-up serum DMD genetic testing in subjects with hyperCKemia, defined as CK > 200 U/L. The calculated upper reference limit (97.5th percentile) of serum creatine kinase (CK) for females aged 20-50 years in this study was near the reference limit recommended by the manufacturer (200 U/L), above which was defined as hyperCKemia. 427 females (1.2%) harbored initially elevated CK, among which 281 females (response rate of 65.8%) accepted CK retesting. DMD genetic testing was conducted on 62 subjects with sustained serum CK > 200 U/L and 16 females with a family history of DMD. Finally, 6 subjects were confirmed to be DMD definite carriers. The estimated DMD female carrier rate in this study was 1 : 4088 (adjusting for response rate), an underestimated rate, since only 50% to 70% of DMD female carriers manifest elevated serum CK, and carriers in this study may have been missed due to lack of follow-up or inability to detect all DMD pathogenic variants by current genetic testing.
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Stay TL, Miterko LN, Arancillo M, Lin T, Sillitoe RV. In vivo cerebellar circuit function is disrupted in an mdx mouse model of Duchenne muscular dystrophy. Dis Model Mech 2019; 13:dmm040840. [PMID: 31704708 PMCID: PMC6906634 DOI: 10.1242/dmm.040840] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 10/30/2019] [Indexed: 12/20/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a debilitating and ultimately lethal disease involving progressive muscle degeneration and neurological dysfunction. DMD is caused by mutations in the dystrophin gene, which result in extremely low or total loss of dystrophin protein expression. In the brain, dystrophin is heavily localized to cerebellar Purkinje cells, which control motor and non-motor functions. In vitro experiments in mouse Purkinje cells revealed that loss of dystrophin leads to low firing rates and high spiking variability. However, it is still unclear how the loss of dystrophin affects cerebellar function in the intact brain. Here, we used in vivo electrophysiology to record Purkinje cells and cerebellar nuclear neurons in awake and anesthetized female mdx (also known as Dmd) mice. Purkinje cell simple spike firing rate is significantly lower in mdx mice compared to controls. Although simple spike firing regularity is not affected, complex spike regularity is increased in mdx mutants. Mean firing rate in cerebellar nuclear neurons is not altered in mdx mice, but their local firing pattern is irregular. Based on the relatively well-preserved cytoarchitecture in the mdx cerebellum, our data suggest that faulty signals across the circuit between Purkinje cells and cerebellar nuclei drive the abnormal firing activity. The in vivo requirements of dystrophin during cerebellar circuit communication could help explain the motor and cognitive anomalies seen in individuals with DMD.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Trace L Stay
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
| | - Lauren N Miterko
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Marife Arancillo
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
| | - Tao Lin
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
| | - Roy V Sillitoe
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, 1250 Moursund Street, Suite 1325, Houston, TX 77030, USA
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
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Jones HF, Bryen SJ, Waddell LB, Bournazos A, Davis M, Farrar MA, McLean CA, Mowat DR, Sampaio H, Woodcock IR, Ryan MM, Jones KJ, Cooper ST. Importance of muscle biopsy to establish pathogenicity of DMD missense and splice variants. Neuromuscul Disord 2019; 29:913-919. [PMID: 31706698 DOI: 10.1016/j.nmd.2019.09.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 07/29/2019] [Accepted: 09/22/2019] [Indexed: 01/07/2023]
Abstract
A precise genetic diagnosis of a dystrophinopathy has far-reaching implications for affected boys and their families. We present three boys with DMD single nucleotide variants associated with Becker muscular dystrophy presenting with myalgia, reduced exercise capacity, neurodevelopmental symptoms and elevated creatine kinase. The DMD variants were difficult to classify: AIII:1 a synonymous variant in exon 13 c.1602G>A, p.Lys534Lys; BIII:1 an essential splice-site variant in intron 33 c.4674+1G>A, and CII:1 a missense mutation within the cysteine-rich domain, exon 66 c.9619T>C, p.Cys3207Arg. Complementary DNA (cDNA) analysis using muscle-derived mRNA established splice-altering effects of variants for AIII:1 and BIII:1, and normal splicing in CII:1. Western blot analysis demonstrated mildly to moderately reduced dystrophin levels (17.6 - 36.1% the levels of controls), supporting dystrophinopathy as a probable diagnosis. These three cases highlight the diagnostic utility of muscle biopsy for mRNA studies and western blot to investigate DMD variants of uncertain pathogenicity, by exploring effects on splicing and dystrophin protein levels.
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Affiliation(s)
- Hannah F Jones
- Kids Neuroscience Centre, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia; Discipline of Child and Adolescent Health, University of Sydney, Sydney, New South Wales, Australia; Department of Clinical Genetics, Children's Hospital at Westmead, Sydney, New South Wales, Australia
| | - Samantha J Bryen
- Kids Neuroscience Centre, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia; Discipline of Child and Adolescent Health, University of Sydney, Sydney, New South Wales, Australia
| | - Leigh B Waddell
- Kids Neuroscience Centre, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia; Discipline of Child and Adolescent Health, University of Sydney, Sydney, New South Wales, Australia
| | - Adam Bournazos
- Kids Neuroscience Centre, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia; Discipline of Child and Adolescent Health, University of Sydney, Sydney, New South Wales, Australia
| | - Mark Davis
- Department of Diagnostic Genomics, PathWest Laboratory Medicine, QEII Medical Centre, Perth, Western Australia, Australia
| | - Michelle A Farrar
- Department of Neurology, Sydney Children's Hospital, Sydney, New South Wales, Australia; Discipline of Paediatrics, School of Women's and Children's Health, UNSW Medicine, UNSW Sydney, New South Wales, Australia
| | - Catriona A McLean
- Anatomical Pathology and Victorian Neuromuscular Laboratory Service, Alfred Health and Monash University, Australia
| | - David R Mowat
- Centre for Clinical Genetics, Sydney Children's Hospital, Sydney, New South Wales, Australia
| | - Hugo Sampaio
- Department of Neurology, Sydney Children's Hospital, Sydney, New South Wales, Australia
| | - Ian R Woodcock
- Department of Neurology Royal Children's Hospital, Murdoch Childrens Research Institute and University of Melbourne, Parkville, Victoria, Australia; Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
| | - Monique M Ryan
- Department of Neurology Royal Children's Hospital, Murdoch Childrens Research Institute and University of Melbourne, Parkville, Victoria, Australia; Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
| | - Kristi J Jones
- Kids Neuroscience Centre, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia; Discipline of Child and Adolescent Health, University of Sydney, Sydney, New South Wales, Australia; Department of Clinical Genetics, Children's Hospital at Westmead, Sydney, New South Wales, Australia
| | - Sandra T Cooper
- Kids Neuroscience Centre, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia; Discipline of Child and Adolescent Health, University of Sydney, Sydney, New South Wales, Australia.
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14
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Wang D, Gao M, Zhang K, Jin R, Lv Y, Liu Y, Ma J, Wan Y, Gai Z, Liu Y. Molecular Genetics Analysis of 70 Chinese Families With Muscular Dystrophy Using Multiplex Ligation-Dependent Probe Amplification and Next-Generation Sequencing. Front Pharmacol 2019; 10:814. [PMID: 31404137 PMCID: PMC6669794 DOI: 10.3389/fphar.2019.00814] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 06/24/2019] [Indexed: 12/12/2022] Open
Abstract
Background: Muscular dystrophy (MD) includes multiple types, of which dystrophinopathies caused by dystrophin (DMD) mutations are the most common types in children. An accurate identification of the causative mutation at the genomic level is critical for genetic counseling of the family, and analysis of genotype-phenotype correlations, as well as a reference for the development of gene therapy. Methods: Totally, 70 Chinese families with suspected MD probands were enrolled in the study. The multiplex ligation-dependent probe amplification (MLPA) was first performed to screen large deletions/duplications of DMD exons in the patients, and then, next-generation sequencing (NGS) was carried out to detect small mutations in the MLPA-negative patients. Results: Totally, 62 mutations of DMD were found in 62 probands with DMD/BMD, and two compound heterozygous mutations in LAMA2 were identified in two probands with MDC1A (a type of congenital MD), indicating that the diagnostic yield was 91.4% by MLPA plus NGS for MD diagnosis in this cohort. Out of the mutations, 51 large mutations encompassing 47 (75.8%) deletions and four duplications (6.5%) were identified by MLPA; 11 small mutations including six (9.7%) nonsense, two (3.2%) small deletions, two splice-site mutations (3.2%), and one small insertion (1.6%) were found by NGS. Large mutations were found most frequently in the hotspot region between exons 45 and 55 (70.6%). Out of the 11 patients harboring point mutations in DMD, 8 were novel mutations. Additionally, one novel mutation in LAMA2 was identified. All the novel mutations were analyzed and predicted as pathogenic according to American College of Medical Genetics and Genomics (ACMG) guideline. Finally, 34 DMD, 4 BMD, 24 BMD/DMD, and 2 MDC1A were diagnosed in the cohort. Conclusion: Our data indicated that the MLPA plus NGS can be a comprehensive and effective tool for precision diagnosis and potential treatment of MD and is particularly necessary for the patients at very young age with only two clinical indicators (persistent hyperCKemia and typical myopathy performance on electromyogram) but no definite clinical manifestations.
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Affiliation(s)
- Dong Wang
- Pediatric Research Institute, Qilu Children’s Hospital, Shandong University, Ji’nan, China
| | - Min Gao
- Pediatric Research Institute, Qilu Children’s Hospital, Shandong University, Ji’nan, China
| | - Kaihui Zhang
- Pediatric Research Institute, Qilu Children’s Hospital, Shandong University, Ji’nan, China
| | - Ruifeng Jin
- Neurology Department, Qilu Children’s Hospital, Shandong University, Ji’nan, China
| | - Yuqiang Lv
- Pediatric Research Institute, Qilu Children’s Hospital, Shandong University, Ji’nan, China
| | - Yong Liu
- Neurology Department, Qilu Children’s Hospital, Shandong University, Ji’nan, China
| | - Jian Ma
- Pediatric Research Institute, Qilu Children’s Hospital, Shandong University, Ji’nan, China
| | - Ya Wan
- Pediatric Research Institute, Qilu Children’s Hospital, Shandong University, Ji’nan, China
| | - Zhongtao Gai
- Pediatric Research Institute, Qilu Children’s Hospital, Shandong University, Ji’nan, China
| | - Yi Liu
- Pediatric Research Institute, Qilu Children’s Hospital, Shandong University, Ji’nan, China
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15
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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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16
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Zhong J, Xie Y, Bhandari V, Chen G, Dang Y, Liao H, Zhang J, Lan D. Clinical and genetic characteristics of female dystrophinopathy carriers. Mol Med Rep 2019; 19:3035-3044. [PMID: 30816495 PMCID: PMC6423608 DOI: 10.3892/mmr.2019.9982] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 02/05/2019] [Indexed: 12/16/2022] Open
Abstract
The present study aimed to determine the genetic status of manifesting carriers (MCs) of Duchenne muscular dystrophy (DMD)/Becker muscular dystrophy (BMD) and asymptomatic carriers with a family history of DMD/BMD, and identify potential simple and reliable methods for screening dystrophinopathy carriers. Clinical data from probable carriers and MCs were collected and analyzed. MCs underwent multiplex ligation‑dependent probe amplification (MLPA) for dystrophin gene exons combined with muscle disease panel test based on a next‑generation sequencing (NGS) platform. In addition, the status of probable carriers was determined by MLPA or Sanger sequencing, according to the mutations of probands. A total of 154 female were enrolled, among which 78 cases were found to be carriers, including 4 MCs and 74 asymptomatic female carriers. The 4 MCs exhibited duplication mutations. Among the 74 asymptomatic carriers, 41.89% harbored deletion mutations, including 2 cases with suspected germline mosaicism and no mutation in the dystrophin gene, while 44.59% harbored point mutations in exons and only 10 cases (13.51%) carried duplication mutations. The area under the receiver operating characteristic (ROC) curve of creatine kinase (CK) was 0.822, with a sensitivity of 65.38% and specificity of 92.1%. In addition, DMD was positively correlated with the CK, alanine transaminase and aspartate transaminase levels of the carriers. MLPA for exons of the dystrophin gene, along with NGS and Sanger sequencing, was effective for the diagnosis of MCs and for determining the status of probable carriers. The ROC curve analysis also demonstrated that CK level was an excellent predictor for distinguishing DMD/BMD carriers.
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Affiliation(s)
- Jingzi Zhong
- Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Yanshu Xie
- Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Vidata Bhandari
- Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Gang Chen
- Department of Pathology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Yiwu Dang
- Department of Pathology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Haixia Liao
- Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Jiapeng Zhang
- Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Dan Lan
- Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
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17
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Zimowski JG, Pawelec M, Purzycka JK, Szirkowiec W, Zaremba J. Deletions, not duplications or small mutations, are the predominante new mutations in the dystrophin gene. J Hum Genet 2017; 62:885-888. [PMID: 28680110 DOI: 10.1038/jhg.2017.70] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 04/20/2017] [Accepted: 05/26/2017] [Indexed: 01/15/2023]
Abstract
Examination of the carrier state was performed in 744 unrelated mothers of the Duchenne muscular dystrophy/Becker muscular dystrophy (DMD/BMD) probands with identified mutations in the dystrophin gene. Owing to that it was possible to assess frequency and type of new mutations in the gene. Contrary to the Japanese observations of Lee et al. published in this journal, we did not find significant differences in the carrier frequency between mothers of DMD and BMD patients. However, we found that new mutations in patients with deletions were significantly more frequent than in those with duplications and small mutations: of 564 unrelated patients with deletions, 236 (41.8%) carried new mutations, the respective values for duplications and small mutations were 21 of 95 patients (22.1%) and 18 of 85 patients (21.2%)-the differences highly significant (P<0.0001).
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Affiliation(s)
- Janusz G Zimowski
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Magdalena Pawelec
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Joanna K Purzycka
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | | | - Jacek Zaremba
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
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18
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Induction of Pluripotent Stem Cells from a Manifesting Carrier of Duchenne Muscular Dystrophy and Characterization of Their X-Inactivation Status. Stem Cells Int 2017; 2017:7906843. [PMID: 28491099 PMCID: PMC5405591 DOI: 10.1155/2017/7906843] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 02/13/2017] [Accepted: 02/22/2017] [Indexed: 01/05/2023] Open
Abstract
Three to eight percent of female carriers of Duchenne muscular dystrophy (DMD) develop dystrophic symptoms ranging from mild muscle weakness to a rapidly progressive DMD-like muscular dystrophy due to skewed inactivation of X chromosomes during early development. Here, we generated human induced pluripotent stem cells (hiPSCs) from a manifesting female carrier using retroviral or Sendai viral (SeV) vectors and determined their X-inactivation status. Although manifesting carrier-derived iPS cells showed normal expression of human embryonic stem cell markers and formed well-differentiated teratomas in vivo, many hiPS clones showed bi-allelic expression of the androgen receptor (AR) gene and loss of X-inactivation-specific transcript and trimethyl-histone H3 (Lys27) signals on X chromosomes, suggesting that both X chromosomes of the hiPS cells are in an active state. Importantly, normal dystrophin was expressed in multinucleated myotubes differentiated from a manifesting carrier of DMD-hiPS cells with XaXa pattern. AR transcripts were also equally transcribed from both alleles in induced myotubes. Our results indicated that the inactivated X chromosome in the patient's fibroblasts was activated during reprogramming, and XCI occurred randomly during differentiation.
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19
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Correction of the Exon 2 Duplication in DMD Myoblasts by a Single CRISPR/Cas9 System. MOLECULAR THERAPY. NUCLEIC ACIDS 2017. [PMID: 28624187 PMCID: PMC5363679 DOI: 10.1016/j.omtn.2017.02.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Exonic duplications account for 10%-15% of all mutations in Duchenne muscular dystrophy (DMD), a severe hereditary neuromuscular disorder. We report a CRISPR (clustered regularly interspaced short palindromic repeat)/Cas9-based strategy to correct the most frequent (exon 2) duplication in the DMD gene by targeted deletion, and tested the efficacy of such an approach in patient-derived myogenic cells. We demonstrate restoration of wild-type dystrophin expression at transcriptional and protein level in myotubes derived from genome-edited myoblasts in the absence of selection. Removal of the duplicated exon was achieved by the use of only one guide RNA (gRNA) directed against an intronic duplicated region, thereby increasing editing efficiency and reducing the risk of off-target effects. This study opens a novel therapeutic perspective for patients carrying disease-causing duplications.
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20
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Haghshenas M, Akbari MT, Karizi SZ, Deilamani FK, Nafissi S, Salehi Z. Evaluation of point mutations in dystrophin gene in Iranian Duchenne and Becker muscular dystrophy patients: introducing three novel variants. J Genet 2016; 95:325-9. [PMID: 27350676 DOI: 10.1007/s12041-016-0641-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Duchenne and Becker muscular dystrophies (DMD and BMD) are X-linked neuromuscular diseases characterized by progressive muscular weakness and degeneration of skeletal muscles. Approximately two-thirds of the patients have large deletions or duplications in the dystrophin gene and the remaining one-third have point mutations. This study was performed to evaluate point mutations in Iranian DMD/BMD male patients. A total of 29 DNA samples from patients who did not show any large deletion/duplication mutations following multiplex polymerase chain reaction (PCR) and multiplex ligation-dependent probe amplification (MLPA) screening were sequenced for detection of point mutations in exons 50-79. Also exon 44 was sequenced in one sample in which a false positive deletion was detected by MLPA method. Cycle sequencing revealed four nonsense, one frameshift and two splice site mutations as well as two missense variants.
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Affiliation(s)
- Maryam Haghshenas
- Faculty of Sciences, Department of Biology, University of Guilan, Rasht 4199613776,
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21
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Luce LN, Dalamon V, Ferrer M, Parma D, Szijan I, Giliberto F. MLPA analysis of an Argentine cohort of patients with dystrophinopathy: Association of intron breakpoints hot spots with STR abundance in DMD gene. J Neurol Sci 2016; 365:22-30. [PMID: 27206868 DOI: 10.1016/j.jns.2016.03.047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 03/10/2016] [Accepted: 03/30/2016] [Indexed: 01/11/2023]
Abstract
Dystrophinopathies are X-linked recessive diseases caused by mutations in the DMD gene. Our objective was to identify mutations in this gene by Multiplex Ligation Probe Amplification (MLPA), to confirm the clinical diagnosis and determine the carrier status of at-risk relatives. Also, we aimed to characterize the Dystrophinopathies argentine population and the DMD gene. We analyzed a cohort of 121 individuals (70 affected boys, 11 symptomatic women, 37 at-risk women and 3 male villus samples). The MLPA technique identified 56 mutations (45 deletions, 9 duplications and 2 point mutations). These results allowed confirming the clinical diagnosis in 63% (51/81) of patients and symptomatic females. We established the carrier status of 54% (20/37) of females at-risk and 3 male villus samples. We could establish an association between the most frequent deletion intron breakpoints and the abundance of dinucleotide microsatellites loci, despite the underlying mutational molecular mechanism remains to be elucidated. The MLPA demonstrate, again, to be the appropriate first mutation screening methodology for molecular diagnosis of Dystrophinopathies. The reported results permitted to characterize the Dystrophinopathies argentine population and lead to better understanding of the genetic and molecular basis of rearrangements in the DMD gene, useful information for the gene therapies being developed.
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Affiliation(s)
- Leonela N Luce
- Laboratory of Dystrophinopathies, Department of Genetics, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina.
| | | | - Marcela Ferrer
- Molecular Neurobiology Laboratory, Neurosurgery Division, Hospital de Clínicas "José de San Martín", University of Buenos Aires, Buenos Aires, Argentina
| | - Diana Parma
- Laboratory of Dystrophinopathies, Department of Genetics, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
| | - Irene Szijan
- Laboratory of Dystrophinopathies, Department of Genetics, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
| | - Florencia Giliberto
- Laboratory of Dystrophinopathies, Department of Genetics, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
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22
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Liewluck T, Tian X, Wong LJ, Pestronk A. Dystrophinopathy mimicking metabolic myopathies. Neuromuscul Disord 2015; 25:653-7. [PMID: 25998609 DOI: 10.1016/j.nmd.2015.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 04/02/2015] [Accepted: 04/04/2015] [Indexed: 12/13/2022]
Abstract
Recurrent rhabdomyolysis warrants comprehensive evaluations to search for underlying muscle diseases, including metabolic myopathies, LPIN1-myopathy, RYR1-myopathy, and less commonly muscular dystrophies. The absence of weakness and the normal or minimally elevated creatine kinase levels between attacks are typical of metabolic myopathies, LPIN1-myopathy, and RYR1-myopathy, while the presence of weakness and the highly elevated creatine kinase levels between attacks point toward muscular dystrophies. Here we report a 32-year-old man with a one-year history of recurrent rhabdomyolysis, who had normal strength, slightly elevated baseline creatine kinase level, and normal muscle histopathology. All workups for metabolic myopathies, LPIN1-myopathy and RYR1-myopathy were unrevealing. Next generation sequencing of muscular dystrophy-related genes revealed a hemizygous deletion of exons 17-34 of the dystrophin-encoding gene. Immunohistochemical study revealed absent staining for the rod domain of dystrophin. Dystrophinopathy should be considered in patients with recurrent rhabdomyolysis despite the absence of fixed weakness or highly elevated resting creatine kinase level.
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Affiliation(s)
- Teerin Liewluck
- Department of Neurology, Anschutz Medical Campus, Mail Stop B-185, 12631 East 17th Avenue, University of Colorado School of Medicine, Aurora, Colorado 80045, USA.
| | - Xia Tian
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, NAB 2015, Houston, Texas 77030, USA
| | - Lee-Jun Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, NAB 2015, Houston, Texas 77030, USA
| | - Alan Pestronk
- Department of Neurology, Washington University School of Medicine, Campus Box 8111, 660 South Euclid Avenue, St. Louis, Missouri 63110, USA
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23
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MLPA based detection of mutations in the dystrophin gene of 180 Polish families with Duchenne/Becker muscular dystrophy. Neurol Neurochir Pol 2014; 48:416-22. [DOI: 10.1016/j.pjnns.2014.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 10/03/2014] [Accepted: 10/15/2014] [Indexed: 11/17/2022]
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24
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Targeted exon skipping to correct exon duplications in the dystrophin gene. MOLECULAR THERAPY-NUCLEIC ACIDS 2014; 3:e155. [PMID: 24643206 PMCID: PMC3982197 DOI: 10.1038/mtna.2014.8] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 01/24/2014] [Indexed: 01/16/2023]
Abstract
Duchenne muscular dystrophy is a severe muscle-wasting disease caused by mutations in the dystrophin gene that ablate functional protein expression. Although exonic deletions are the most common Duchenne muscular dystrophy lesion, duplications account for 10-15% of reported disease-causing mutations, and exon 2 is the most commonly duplicated exon. Here, we describe the in vitro evaluation of phosphorodiamidate morpholino oligomers coupled to a cell-penetrating peptide and 2'-O-methyl phosphorothioate oligonucleotides, using three distinct strategies to reframe the dystrophin transcript in patient cells carrying an exon 2 duplication. Differences in exon-skipping efficiencies in vitro were observed between oligomer analogues of the same sequence, with the phosphorodiamidate morpholino oligomer coupled to a cell-penetrating peptide proving the most effective. Differences in exon 2 excision efficiency between normal and exon 2 duplication cells, were apparent, indicating that exon context influences oligomer-induced splice switching. Skipping of a single copy of exon 2 was induced in the cells carrying an exon 2 duplication, the simplest strategy to restore the reading frame and generate a normal dystrophin transcript. In contrast, multiexon skipping of exons 2-7 to generate a Becker muscular dystrophy-like dystrophin transcript was more challenging and could only be induced efficiently with the phosphorodiamidate morpholino oligomer chemistry.
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25
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Bermúdez-López C, Teresa BGD, Angel AGD, Alcántara-Ortigoza MA. Germinal Mosaicism in a Sample of Families with Duchenne/Becker Muscular Dystrophy with Partial Deletions in the DMD Gene. Genet Test Mol Biomarkers 2014; 18:93-7. [DOI: 10.1089/gtmb.2013.0384] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Cesárea Bermúdez-López
- Laboratorio de Biología Molecular, Departamento de Genética Humana, Instituto Nacional de Pediatría, México, D.F., México
| | - Benilde García-de Teresa
- Laboratorio de Biología Molecular, Departamento de Genética Humana, Instituto Nacional de Pediatría, México, D.F., México
| | - Ariadna González-del Angel
- Laboratorio de Biología Molecular, Departamento de Genética Humana, Instituto Nacional de Pediatría, México, D.F., México
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26
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Affiliation(s)
- Yu Na Cho
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Young-Chul Choi
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
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27
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Sakthivel Murugan S, Arthi C, Thilothammal N, Lakshmi B. Carrier detection in Duchenne muscular dystrophy using molecular methods. Indian J Med Res 2013; 137:1102-10. [PMID: 23852291 PMCID: PMC3734715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND & OBJECTIVES Duchenne and Becker muscular dystrophies are X-linked allelic disorders which are caused by mutations in the DMD gene. Carrier analysis in DMD is complicated due to the heterozygous nature of the X chromosome. Several techniques have been tried for carrier analysis in families where the mutation is identified including quantitative multiplex PCR (qmPCR), Southern blot, and now multiplex ligation-dependent probe amplification (MLPA). Linkage analysis is used in cases without identifiable mutations. The present study was undertaken to determine the status of probable carriers in families where the DMD deletion/duplication has been identified for the affected index cases. METHODS Carrier status was present in 150 probable carriers from 110 apparently unrelated families where the patients' mutations were known. Of these 110 families, 100 were deletions, 9 duplications and 1 point mutation. Multiplex ligation-dependent probe amplification (MLPA) was used to assess the copy number changes and direct sequencing was used for the case with the point mutation. RESULTS Of the 150 cases, 49 were found to be carriers. Among the sporadic cases, it was observed that the rate of de novo mutations was very high (71%) as compared to the hereditary cases (29%), which was higher than the calculated rate (30%). It was observed that this difference was more apparent in deletion mutations than in duplications. INTERPRETATION & CONCLUSIONS Identifying the DMD carrier rates in the families with unidentified deletions and duplications and where the causative mutation could be small insertions/deletions or point mutations could throw more light into this observation. MLPA was found to be useful in detecting copy number changes in DMD carriers and this could be the method of choice for DMD carrier analysis, when the mutation is detected in the affected child.
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Affiliation(s)
| | - C. Arthi
- Molecular Diagnostics, Counseling, Care & Research Centre, Avinashilingam Deemed University for Women, Coimbatore, India
| | - N. Thilothammal
- Institute of Child Health & Hospital for Children, Chennai, India
| | - B.R. Lakshmi
- Molecular Diagnostics, Counseling, Care & Research Centre, Avinashilingam Deemed University for Women, Coimbatore, India,Reprint requests: Dr Bremadesam Raman Lakshmi, Molecular Diagnostics, Counseling, Care & Research Centre (MDCRC), Avinashilingam Deemed University for Women, Mettupalayam Road, Coimbatore 641 043, India e-mail:
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Nicolas A, Lucchetti-Miganeh C, Yaou RB, Kaplan JC, Chelly J, Leturcq F, Barloy-Hubler F, Le Rumeur E. Assessment of the structural and functional impact of in-frame mutations of the DMD gene, using the tools included in the eDystrophin online database. Orphanet J Rare Dis 2012; 7:45. [PMID: 22776072 PMCID: PMC3748829 DOI: 10.1186/1750-1172-7-45] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 06/18/2012] [Indexed: 12/21/2022] Open
Abstract
Background Dystrophin is a large essential protein of skeletal and heart muscle. It is a filamentous scaffolding protein with numerous binding domains. Mutations in the DMD gene, which encodes dystrophin, mostly result in the deletion of one or several exons and cause Duchenne (DMD) and Becker (BMD) muscular dystrophies. The most common DMD mutations are frameshift mutations resulting in an absence of dystrophin from tissues. In-frame DMD mutations are less frequent and result in a protein with partial wild-type dystrophin function. The aim of this study was to highlight structural and functional modifications of dystrophin caused by in-frame mutations. Methods and results We developed a dedicated database for dystrophin, the eDystrophin database. It contains 209 different non frame-shifting mutations found in 945 patients from a French cohort and previous studies. Bioinformatics tools provide models of the three-dimensional structure of the protein at deletion sites, making it possible to determine whether the mutated protein retains the typical filamentous structure of dystrophin. An analysis of the structure of mutated dystrophin molecules showed that hybrid repeats were reconstituted at the deletion site in some cases. These hybrid repeats harbored the typical triple coiled-coil structure of native repeats, which may be correlated with better function in muscle cells. Conclusion This new database focuses on the dystrophin protein and its modification due to in-frame deletions in BMD patients. The observation of hybrid repeat reconstitution in some cases provides insight into phenotype-genotype correlations in dystrophin diseases and possible strategies for gene therapy. The eDystrophin database is freely available: http://edystrophin.genouest.org/.
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Acsadi G, Moore SA, Chéron A, Delalande O, Bennett L, Kupsky W, El-Baba M, Le Rumeur E, Hubert JF. Novel mutation in spectrin-like repeat 1 of dystrophin central domain causes protein misfolding and mild Becker muscular dystrophy. J Biol Chem 2012; 287:18153-62. [PMID: 22453924 DOI: 10.1074/jbc.m111.284521] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mutations in the dystrophin gene without disruption of the reading frame often lead to Becker muscular dystrophy, but a genotype/phenotype correlation is difficult to establish. Amino acid substitutions may disrupt binding capacities of dystrophin and have a major impact on the functionality of this protein. We have identified two brothers (ages 8 and 10 years) with very mild proximal weakness, recurrent abdominal pain, and moderately elevated serum creatine kinase levels. Gene sequencing revealed a novel mutation in exon 11 of the dystrophin gene (c.1280T>C) leading to a L427P amino acid substitution in repeat 1 of the central rod domain. Immunostaining of skeletal muscle showed weak staining of the dystrophin region encoded by exons 7 and 8 corresponding to the end of the actin-binding domain 1 and the N-terminal part of hinge 1. Spectrofluorescence and circular dichroism analysis of the domain repeat 1-2 (R1-2) revealed partial misfolding of the L427P mutated protein as well as a reduced refolding rate after denaturation. Based on computational homology models of the wild-type and mutated R1-2, a molecular dynamics study showed an alteration in the flexibility of the structure, which also strongly affects the conformational space available in the N-terminal region of the fragment. Our results suggest that this missense mutation hinders the dynamic properties of the entire N-terminal region of dystrophin.
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Affiliation(s)
- Gyula Acsadi
- Connecticut Children's Medical Center, Hartford, Connecticut 06106, USA
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Ota M, Takeshima Y, Nishida A, Awano H, Lee T, Yagi M, Matsuo M. A G-to-T transversion at the splice acceptor site of dystrophin exon 14 shows multiple splicing outcomes that are not exemplified by transition mutations. Genet Test Mol Biomarkers 2011; 16:3-8. [PMID: 21854195 DOI: 10.1089/gtmb.2010.0276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mutations at splicing consensus sequences have been shown to induce splicing errors such as exon skipping or cryptic splice site activation. Here, we identified eight splicing products caused by a G-to-T transversion mutation at the splice acceptor site of exon 14 of the dystrophin gene (c.1603-1G>T). Unexpectedly, the most abundant product showed skipping of the two consecutive exons 14 and 15, and exon 14 skipping was observed as the second most abundant product. To examine the cause of this splicing multiplicity, minigenes containing dystrophin exons 14 and 15 with their flanking introns were constructed and subjected to in vitro splicing. Minigenes with the wild-type sequence or a G>A transition at position c.1603-1 produced only the mature mRNA. On the other hand, the minigenes with a G>T or G>C transversion mutation produced multiple splicing products. A time-course analysis of the in vitro splicing revealed that splicing of the middle intron, intron 14, was the first step in transcript maturation for all four minigene constructs. The identity of the mutant nucleotide, but not its position, is a factor leading to multiple splicing outcomes. Our results suggest that exon skipping therapy for Duchenne's muscular dystrophy should be carefully monitored for their splicing outcomes.
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Affiliation(s)
- Mitsunori Ota
- Department of Pediatrics, Graduate School of Medicine, Kobe University, Kobe, Japan
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Magri F, Del Bo R, D'Angelo MG, Govoni A, Ghezzi S, Gandossini S, Sciacco M, Ciscato P, Bordoni A, Tedeschi S, Fortunato F, Lucchini V, Cereda M, Corti S, Moggio M, Bresolin N, Comi GP. Clinical and molecular characterization of a cohort of patients with novel nucleotide alterations of the Dystrophin gene detected by direct sequencing. BMC MEDICAL GENETICS 2011; 12:37. [PMID: 21396098 PMCID: PMC3061890 DOI: 10.1186/1471-2350-12-37] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 03/11/2011] [Indexed: 01/13/2023]
Abstract
Background Duchenne and Becker Muscular dystrophies (DMD/BMD) are allelic disorders caused by mutations in the dystrophin gene, which encodes a sarcolemmal protein responsible for muscle integrity. Deletions and duplications account for approximately 75% of mutations in DMD and 85% in BMD. The implementation of techniques allowing complete gene sequencing has focused attention on small point mutations and other mechanisms underlying complex rearrangements. Methods We selected 47 patients (41 families; 35 DMD, 6 BMD) without deletions and duplications in DMD gene (excluded by multiplex ligation-dependent probe amplification and multiplex polymerase chain reaction analysis). This cohort was investigated by systematic direct sequence analysis to study sequence variation. We focused our attention on rare mutational events which were further studied through transcript analysis. Results We identified 40 different nucleotide alterations in DMD gene and their clinical correlates; altogether, 16 mutations were novel. DMD probands carried 9 microinsertions/microdeletions, 19 nonsense mutations, and 7 splice-site mutations. BMD patients carried 2 nonsense mutations, 2 splice-site mutations, 1 missense substitution, and 1 single base insertion. The most frequent stop codon was TGA (n = 10 patients), followed by TAG (n = 7) and TAA (n = 4). We also analyzed the molecular mechanisms of five rare mutational events. They are two frame-shifting mutations in the DMD gene 3'end in BMD and three novel splicing defects: IVS42: c.6118-3C>A, which causes a leaky splice-site; c.9560A>G, which determines a cryptic splice-site activation and c.9564-426 T>G, which creates pseudoexon retention within IVS65. Conclusion The analysis of our patients' sample, carrying point mutations or complex rearrangements in DMD gene, contributes to the knowledge on phenotypic correlations in dystrophinopatic patients and can provide a better understanding of pre-mRNA maturation defects and dystrophin functional domains. These data can have a prognostic relevance and can be useful in directing new therapeutic approaches, which rely on a precise definition of the genetic defects as well as their molecular consequences.
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Affiliation(s)
- Francesca Magri
- Dino Ferrari Centre, Department of Neurological Sciences, University of Milan, IRCCS Foundation Cà Granda, Ospedale Maggiore Policlinico, Milan, Italy
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Soltanzadeh P, Friez MJ, Dunn D, von Niederhausern A, Gurvich OL, Swoboda KJ, Sampson JB, Pestronk A, Connolly AM, Florence JM, Finkel RS, Bönnemann CG, Medne L, Mendell JR, Mathews KD, Wong BL, Sussman MD, Zonana J, Kovak K, Gospe SM, Gappmaier E, Taylor LE, Howard MT, Weiss RB, Flanigan KM. Clinical and genetic characterization of manifesting carriers of DMD mutations. Neuromuscul Disord 2010; 20:499-504. [PMID: 20630757 DOI: 10.1016/j.nmd.2010.05.010] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2009] [Revised: 04/30/2010] [Accepted: 05/18/2010] [Indexed: 10/19/2022]
Abstract
Manifesting carriers of DMD gene mutations may present diagnostic challenges, particularly in the absence of a family history of dystrophinopathy. We review the clinical and genetic features in 15 manifesting carriers identified among 860 subjects within the United Dystrophinopathy Project, a large clinical dystrophinopathy cohort whose members undergo comprehensive DMD mutation analysis. We defined manifesting carriers as females with significant weakness, excluding those with only myalgias/cramps. DNA extracted from peripheral blood was used to study X-chromosome inactivation patterns. Among these manifesting carriers, age at symptom onset ranged from 2 to 47 years. Seven had no family history and eight had male relatives with Duchenne muscular dystrophy (DMD). Clinical severity among the manifesting carriers varied from a DMD-like progression to a very mild Becker muscular dystrophy-like phenotype. Eight had exonic deletions or duplications and six had point mutations. One patient had two mutations (an exonic deletion and a splice site mutation), consistent with a heterozygous compound state. The X-chromosome inactivation pattern was skewed toward non-random in four out of seven informative deletions or duplications but was random in all cases with nonsense mutations. We present the results of DMD mutation analysis in this manifesting carrier cohort, including the first example of a presumably compound heterozygous DMD mutation. Our results demonstrate that improved molecular diagnostic methods facilitate the identification of DMD mutations in manifesting carriers, and confirm the heterogeneity of mutational mechanisms as well as the wide spectrum of phenotypes.
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Affiliation(s)
- Payam Soltanzadeh
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA
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Takeshima Y, Yagi M, Okizuka Y, Awano H, Zhang Z, Yamauchi Y, Nishio H, Matsuo M. Mutation spectrum of the dystrophin gene in 442 Duchenne/Becker muscular dystrophy cases from one Japanese referral center. J Hum Genet 2010; 55:379-88. [PMID: 20485447 DOI: 10.1038/jhg.2010.49] [Citation(s) in RCA: 169] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Recent developments in molecular therapies for Duchenne muscular dystrophy (DMD) demand accurate genetic diagnosis, because therapies are mutation specific. The KUCG (Kobe University Clinical Genetics) database for DMD and Becker muscular dystrophy is a hospital-based database comprising 442 cases. Using a combination of complementary DNA (cDNA) and chromosome analysis in addition to conventional genomic DNA-based method, mutation detection was successfully accomplished in all cases, and the largest mutation database of Japanese dystrophinopathy was established. Among 442 cases, deletions and duplications encompassing one or more exons were identified in 270 (61%) and 38 (9%) cases, respectively. Nucleotide changes leading to nonsense mutations or disrupting a splice site were identified in 69 (16%) or 24 (5%) cases, respectively. Small deletion/insertion mutations were identified in 34 (8%) cases. Remarkably, two retrotransposon insertion events were also identified. Dystrophin cDNA analysis successfully revealed novel transcripts with a pseudoexon created by a single-nucleotide change deep within an intron in four cases. X-chromosome abnormalities were identified in two cases. The reading frame rule was upheld for 93% of deletion and 66% of duplication mutation cases. For the application of molecular therapies, induction of exon skipping was deemed the first priority for dystrophinopathy treatment. At one Japanese referral center, the hospital-based mutation database of the dystrophin gene was for the first time established with the highest levels of quality and patient's number.
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Affiliation(s)
- Yasuhiro Takeshima
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan.
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Taylor PJ, Betts GA, Maroulis S, Gilissen C, Pedersen RL, Mowat DR, Johnston HM, Buckley MF. Dystrophin gene mutation location and the risk of cognitive impairment in Duchenne muscular dystrophy. PLoS One 2010; 5:e8803. [PMID: 20098710 PMCID: PMC2808359 DOI: 10.1371/journal.pone.0008803] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Accepted: 12/31/2009] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND A significant component of the variation in cognitive disability that is observed in Duchenne muscular dystrophy (DMD) is known to be under genetic regulation. In this study we report correlations between standardised measures of intelligence and mutational class, mutation size, mutation location and the involvement of dystrophin isoforms. METHODS AND RESULTS Sixty two male subjects were recruited as part of a study of the cognitive spectrum in boys with DMD conducted at the Sydney Children's Hospital (SCH). All 62 children received neuropsychological testing from a single clinical psychologist and had a defined dystrophin gene (DMD) mutation; including DMD gene deletions, duplications and DNA point mutations. Full Scale Intelligence Quotients (FSIQ) in unrelated subjects with the same mutation were found to be highly correlated (r = 0.83, p = 0.0008), in contrast to results in previous publications. In 58 cases (94%) it was possible to definitively assign a mutation as affecting one or more dystrophin isoforms. A strong association between the risk of cognitive disability and the involvement of groups of DMD isoforms was found. In particular, improvements in the correlation of FSIQ with mutation location were identified when a new classification system for mutations affecting the Dp140 isoform was implemented. SIGNIFICANCE These data represent one of the largest studies of FSIQ and mutational data in DMD patients and is among the first to report on a DMD cohort which has had both comprehensive mutational analysis and FSIQ testing through a single referral centre. The correlation between FSIQ results with the location of the dystrophin gene mutation suggests that the risk of cognitive deficit is a result of the cumulative loss of central nervous system (CNS) expressed dystrophin isoforms, and that correct classification of isoform involvement results in improved estimates of risk.
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Affiliation(s)
- Peter J. Taylor
- Molecular and Cytogenetics Unit, Department of Haematology and Genetics, Prince of Wales Hospital, Randwick, Sydney, New South Wales, Australia
- Sydney Neuromuscular Centre, Sydney Children's Hospital, Randwick, Sydney, New South Wales, Australia
| | - Grant A. Betts
- Sydney Neuromuscular Centre, Sydney Children's Hospital, Randwick, Sydney, New South Wales, Australia
| | - Sarah Maroulis
- Molecular and Cytogenetics Unit, Department of Haematology and Genetics, Prince of Wales Hospital, Randwick, Sydney, New South Wales, Australia
| | - Christian Gilissen
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Robyn L. Pedersen
- Sydney Neuromuscular Centre, Sydney Children's Hospital, Randwick, Sydney, New South Wales, Australia
| | - David R. Mowat
- Sydney Neuromuscular Centre, Sydney Children's Hospital, Randwick, Sydney, New South Wales, Australia
- The School of Women's and Children's Health, University of New South Wales, Sydney, New South Wales, Australia
| | - Heather M. Johnston
- Sydney Neuromuscular Centre, Sydney Children's Hospital, Randwick, Sydney, New South Wales, Australia
| | - Michael F. Buckley
- Molecular and Cytogenetics Unit, Department of Haematology and Genetics, Prince of Wales Hospital, Randwick, Sydney, New South Wales, Australia
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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Basak J, Dasgupta UB, Mukherjee SC, Das SK, Senapati AK, Banerjee TK. Deletional mutations of dystrophin gene and carrier detection in eastern India. Indian J Pediatr 2009; 76:1007-12. [PMID: 19907931 DOI: 10.1007/s12098-009-0214-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Accepted: 12/29/2008] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To determine the pattern of deletions of the dystrophin gene, the major class of mutations among the Duchenne and Becker muscular dystrophy patients of eastern India and to analyze the carrier frequency of the female members of the proband's family. METHODS Deletional mutations occurring in patients have been characterized by multiplex polymerase chain reaction. Carrier state of mothers and sisters of probands were analyzed by either of two methods: 1) typing polymorphic short tandem repeat markers in or around the regions of deletion, by radioactive polymerase chain reaction and 2) quantitative real time amplification of the region of deletion. RESULTS Deletions were detected in 67 (62.04%) out of 108 male patients, about 76.12% of these being localized in the central hot spot region of the gene, i.e., between exon 42 to exon 53 and 17.91% at the proximal hot spot i.e., between exon 1 to exon 20. In the present study were found 43 types of deletions, out of which 25 (58%) were new deletions, which were not described earlier among the Indian patients. Distribution pattern of deletions in different hot spot regions has been compared with that of other countries and statistical analysis reveals significant difference between countries (p<0.001). Correlation of the pattern of deletion with clinical phenotype of patients has been discussed. Interesting case of germline mosaicism and its implications in counseling has also been discussed. CONCLUSION About half the mothers of affected probands were not carriers of the deletion, underscoring the need to use real time techniques for carrier detection.
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Affiliation(s)
- Jayasri Basak
- Department of Biophysics, Molecular Biology and Genetics, University of Calcutta, Kolkata, India.
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Guyon JR, Goswami J, Jun SJ, Thorne M, Howell M, Pusack T, Kawahara G, Steffen LS, Galdzicki M, Kunkel LM. Genetic isolation and characterization of a splicing mutant of zebrafish dystrophin. Hum Mol Genet 2009; 18:202-11. [PMID: 18957474 PMCID: PMC2644651 DOI: 10.1093/hmg/ddn337] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Sapje-like (sap(cl100)) was one of eight potential zebrafish muscle mutants isolated as part of an early-pressure screen of 500 families. This mutant shows a muscle tearing phenotype similar to sapje (dys-/-) and both mutants fail to genetically complement suggesting they have a mutation in the same gene. Protein analysis confirms a lack of dystrophin in developing sapje-like embryos. Sequence analysis of the sapje-like dystrophin mRNA shows that exon 62 is missing in the dystrophin transcript causing exon 63 to be translated out of frame terminating translation at a premature stop codon at the end of exon 63. Sequence analysis of sapje-like genomic DNA identified a mutation in the donor splice junction at the end of dystrophin exon 62. This mutation is similar to splicing mutations associated with human forms of Duchenne Muscular Dystrophy. Sapje-like is the first zebrafish dystrophin splicing mutant identified to date and represents a novel disease model which can be used in future studies to identify therapeutic compounds for treating diseases caused by splicing defects.
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Affiliation(s)
- Jeffrey R. Guyon
- Division of Genetics, Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Julie Goswami
- Division of Genetics, Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Susan J. Jun
- Division of Genetics, Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Marielle Thorne
- Division of Genetics, Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Melanie Howell
- Division of Genetics, Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Timothy Pusack
- Division of Genetics, Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Genri Kawahara
- Division of Genetics, Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Leta S. Steffen
- Division of Genetics, Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Michal Galdzicki
- Division of Genetics, Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Louis M. Kunkel
- Division of Genetics, Children's Hospital, Boston, MA, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Howard Hughes Medical Institute, Children's Hospital Boston, Boston, MA, USA
- To whom correspondence should be addressed at: Program in GenomicsChildren's Hospital BostonEnders Rm 570 300 Longwood Ave, Boston, MA 02115, USA. Tel: +1 6173558200; Fax: +1 6173557588;
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