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Ferrero A, Rossi M. Cognitive profile and neuropsychiatric disorders in Becker muscular dystrophy: A systematic review of literature. Neurosci Biobehav Rev 2022; 137:104648. [PMID: 35367224 DOI: 10.1016/j.neubiorev.2022.104648] [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: 10/04/2021] [Revised: 02/15/2022] [Accepted: 03/29/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Brain co-morbidities in DMD are well-documented, less is known about the cognitive, behavioral and psychosocial functioning of patients with BMD. METHODS The systematic review was carried out on two databases (Pubmed and Scopus) according to the PRISMA guidelines. We included all research articles specific to BMD written after 1995. RESULTS Studies examining neuropsychological and neurobehavioral functioning in BMD are few and have several methods limitations. BMD population is characterized by high rates of cognitive impairment, with specific involvement of different cognitive areas. Unlike DMD, verbal skills are better preserved. Neurodevelopmental and emotional/behavioral disorders have great importance in BMD, due to their high prevalence. Lack of Dp140 or Dp71 can cause intellectual disability, these isoforms are probably responsible for the other brain-related comorbidities as well. DISCUSSION The results suggest that cognitive and neuropsychiatric comorbid symptoms may affect a significant proportion of BMD patients therefore it is important to mental health and neuropsychological screening. Finding tools for an adequate assessment is a priority in order to include brain outcome measures in clinical trials.
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Affiliation(s)
- Amanda Ferrero
- Department of Brain and Behavioural Sciences, Unit of Child Neurology and Psychiatry, University of Pavia, Pavia, Italy.
| | - Marta Rossi
- Child Neurology and Psychiatry Unit, IRCCS Mondino Foundation, Pavia, Italy
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2
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Passos-Bueno MR, Costa CIS, Zatz M. Dystrophin genetic variants and autism. DISCOVER MENTAL HEALTH 2022; 2:4. [PMID: 37861890 PMCID: PMC10501027 DOI: 10.1007/s44192-022-00008-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 02/07/2022] [Indexed: 10/21/2023]
Abstract
Loss-of-function variants in the dystrophin gene, a well-known cause of muscular dystrophies, have emerged as a mutational risk mechanism for autism spectrum disorder (ASD), which in turn is a highly prevalent (~ 1%) genetically heterogeneous neurodevelopmental disorder. Although the association of intellectual disability with the dystrophinopathies Duchenne (DMD) and Becker muscular dystrophy (BMD) has been long established, their association with ASD is more recent, and the dystrophin genotype-ASD phenotype correlation is unclear. We therefore present a review of the literature focused on the ASD prevalence among dystrophinopathies, the relevance of the dystrophin isoforms, and most particularly the relevance of the genetic background to the etiology of ASD in these patients. Four families with ASD-DMD/BMD patients are also reported here for the first time. These include a single ASD individual, ASD-discordant and ASD-concordant monozygotic twins, and non-identical ASD triplets. Notably, two unrelated individuals, which were first ascertained because of the ASD phenotype at ages 15 and 5 years respectively, present rare dystrophin variants still poorly characterized, suggesting that some dystrophin variants may compromise the brain more prominently. Whole exome sequencing in these ASD-DMD/BMD individuals together with the literature suggest, although based on preliminary data, a complex and heterogeneous genetic architecture underlying ASD in dystrophinopathies, that include rare variants of large and medium effect. The need for the establishment of a consortia for genomic investigation of ASD-DMD/BMD patients, which may shed light on the genetic architecture of ASD, is discussed.
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Affiliation(s)
- Maria Rita Passos-Bueno
- Departamento de Genética e Biologia Evolutiva, Centro de Estudos do Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil.
| | - Claudia Ismania Samogy Costa
- Departamento de Genética e Biologia Evolutiva, Centro de Estudos do Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Mayana Zatz
- Departamento de Genética e Biologia Evolutiva, Centro de Estudos do Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
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3
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Szabo SM, Gooch KL, Mickle AT, Salhany RM, Connolly AM. The impact of genotype on outcomes in individuals with Duchenne muscular dystrophy: A systematic review. Muscle Nerve 2021; 65:266-277. [PMID: 34878187 DOI: 10.1002/mus.27463] [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: 11/12/2020] [Revised: 11/09/2021] [Accepted: 11/12/2021] [Indexed: 11/07/2022]
Abstract
Duchenne muscular dystrophy (DMD) is associated with progressive muscle weakness, loss of ambulation (LOA), and early mortality. In this review we have synthesized published data on the clinical course of DMD by genotype. Using a systematic search implemented in Medline and Embase, 53 articles were identified that describe the clinical course of DMD, with pathogenic variants categorizable by exon skip or stop-codon readthrough amenability and outcomes presented by age. Outcomes described included those related to ambulatory, cardiac, pulmonary, or cognitive function. Estimates of the mean (95% confidence interval) age at LOA ranged from 9.1 (8.7-9.6) years among 90 patients amenable to skipping exon 53 to 11.5 (9.5-13.5) years among three patients amenable to skipping exon 8. Although function worsened with age, the impact of genotype was less clear for other outcomes (eg, forced vital capacity and left ventricular ejection fraction). Understanding the distribution of pathogenic variants is important for studies in DMD, as this research suggests major differences in the natural history of disease. In addition, specific details of the use of key medications, including corticosteroids, antisense oligonucleotides, and cardiac medications, should be reported.
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Affiliation(s)
- Shelagh M Szabo
- Broadstreet Heath Economics & Outcomes Research, Vancouver, British Columbia, Canada
| | | | - Alexis T Mickle
- Broadstreet Heath Economics & Outcomes Research, Vancouver, British Columbia, Canada
| | | | - Anne M Connolly
- Division of Neurology, Nationwide Children's Hospital, Ohio State University, Columbus, Ohio, USA
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Reimann J, Kornblum C. Towards Central Nervous System Involvement in Adults with Hereditary Myopathies. J Neuromuscul Dis 2021; 7:367-393. [PMID: 32773394 PMCID: PMC7592671 DOI: 10.3233/jnd-200507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
There is increasing evidence of central nervous system involvement in numerous neuromuscular disorders primarily considered diseases of skeletal muscle. Our knowledge on cerebral affection in myopathies is expanding continuously due to a better understanding of the genetic background and underlying pathophysiological mechanisms. Intriguingly, there is a remarkable overlap of brain pathology in muscular diseases with pathomechanisms involved in neurodegenerative or neurodevelopmental disorders. A rapid progress in advanced neuroimaging techniques results in further detailed insight into structural and functional cerebral abnormalities. The spectrum of clinical manifestations is broad and includes movement disorders, neurovascular complications, paroxysmal neurological symptoms like migraine and epileptic seizures, but also behavioural abnormalities and cognitive dysfunction. Cerebral involvement implies a high socio-economic and personal burden in adult patients sometimes exceeding the everyday challenges associated with muscle weakness. It is especially important to clarify the nature and natural history of brain affection against the background of upcoming specific treatment regimen in hereditary myopathies that should address the brain as a secondary target. This review aims to highlight the character and extent of central nervous system involvement in patients with hereditary myopathies manifesting in adulthood, however also includes some childhood-onset diseases with brain abnormalities that transfer into adult neurological care.
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Affiliation(s)
- Jens Reimann
- Department of Neurology, Section of Neuromuscular Diseases, University Hospital Bonn, Germany.,Center for Rare Diseases, University Hospital Bonn, Germany
| | - Cornelia Kornblum
- Department of Neurology, Section of Neuromuscular Diseases, University Hospital Bonn, Germany.,Center for Rare Diseases, University Hospital Bonn, Germany
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Wang L, Lin J, Xiong F, Liang Y, Li H, Liao Z, Zhang C. A rare case of monozygotic triplets with Duchenne muscular dystrophy. Neuromuscul Disord 2021; 31:456-461. [PMID: 33741227 DOI: 10.1016/j.nmd.2021.02.005] [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: 09/06/2020] [Revised: 01/23/2021] [Accepted: 02/04/2021] [Indexed: 11/24/2022]
Abstract
Twins with Duchenne muscular dystrophy (DMD) have been widely studied. We report the first rare case of monozygotic triplets with DMD who shared consistent phenotypes, including delayed motor and language milestones, muscle wasting and weakness, joint contracture, and lumbar lordosis. Muscle magnetic resonance imaging and biopsy revealed the similar muscle injury characteristics and dystrophin absence. Short tandem repeat analysis confirmed monozygosity. A de novo mutation (exon 49-52 deletion) was found in the triplets but not in their mother. Treatment included prednisone, idebenone, and rehabilitation management. At the 2-year follow-up, motor function had deteriorated, and muscle fatty infiltration was more extensive and severe. Our case offers a unique opportunity for genetic and therapeutic research. Furthermore, it highlights the critical role of genetic factors in DMD phenotypes and provides a potential choice for treatment observations.
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Affiliation(s)
- Liang Wang
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology. Guangzhou, China
| | - Jinfu Lin
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology. Guangzhou, China
| | - Fu Xiong
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Yingyin Liang
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, 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, 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, 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, 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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Naidoo M, Anthony K. Dystrophin Dp71 and the Neuropathophysiology of Duchenne Muscular Dystrophy. Mol Neurobiol 2020; 57:1748-1767. [PMID: 31836945 PMCID: PMC7060961 DOI: 10.1007/s12035-019-01845-w] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 11/22/2019] [Indexed: 12/13/2022]
Abstract
Duchenne muscular dystrophy (DMD) is caused by frameshift mutations in the DMD gene that prevent the body-wide translation of its protein product, dystrophin. Besides a severe muscle phenotype, cognitive impairment and neuropsychiatric symptoms are prevalent. Dystrophin protein 71 (Dp71) is the major DMD gene product expressed in the brain and mutations affecting its expression are associated with the DMD neuropsychiatric syndrome. As with dystrophin in muscle, Dp71 localises to dystrophin-associated protein complexes in the brain. However, unlike in skeletal muscle; in the brain, Dp71 is alternatively spliced to produce many isoforms with differential subcellular localisations and diverse cellular functions. These include neuronal differentiation, adhesion, cell division and excitatory synapse organisation as well as nuclear functions such as nuclear scaffolding and DNA repair. In this review, we first describe brain involvement in DMD and the abnormalities observed in the DMD brain. We then review the gene expression, RNA processing and functions of Dp71. We review genotype-phenotype correlations and discuss emerging cellular/tissue evidence for the involvement of Dp71 in the neuropathophysiology of DMD. The literature suggests changes observed in the DMD brain are neurodevelopmental in origin and that their risk and severity is associated with a cumulative loss of distal DMD gene products such as Dp71. The high risk of neuropsychiatric syndromes in Duchenne patients warrants early intervention to achieve the best possible quality of life. Unravelling the function and pathophysiological significance of dystrophin in the brain has become a high research priority to inform the development of brain-targeting treatments for Duchenne.
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Affiliation(s)
- Michael Naidoo
- Centre for Physical Activity and Life Sciences, Faculty of Arts, Science and Technology, University of Northampton, University Drive, Northampton, Northamptonshire, NN1 5PH, UK
| | - Karen Anthony
- Centre for Physical Activity and Life Sciences, Faculty of Arts, Science and Technology, University of Northampton, University Drive, Northampton, Northamptonshire, NN1 5PH, UK.
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Lambert JT, Darmahkasih AJ, Horn PS, Rybalsky I, Shellenbarger KC, Tian C, Wong BL. Neurodevelopmental, behavioral, and emotional symptoms in Becker muscular dystrophy. Muscle Nerve 2019; 61:156-162. [PMID: 31650559 DOI: 10.1002/mus.26750] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 10/11/2019] [Accepted: 10/19/2019] [Indexed: 11/10/2022]
Abstract
INTRODUCTION Becker muscular dystrophy (BMD) results in decreased dystrophin with implications for mental health. METHODS This is a retrospective case series of neurodevelopmental, behavioral, and emotional symptoms and respective pharmacotherapies of 70 patients with BMD. RESULTS Fifty-four (77.1%) patients exhibited at least one symptom, and 19 (27.1%) patients exhibited four or more symptoms. The most prevalent symptoms were specific learning disabilities or special education needs (31.4%), inattention/hyperactivity (35.7%), language/speech delays (35.7%), and emotional or behavioral dysregulation (38.6%). Fisher's exact tests indicated that anxiety was more prevalent with mutations upstream of exon 30 (P = .049), but the prevalence of other symptoms did not differ with respect to mutation sites. Similarly, the number of symptoms individual patients with BMD exhibited did not differ with respect to mutation sites. Seventeen (24.3%) patients required pharmacotherapy to manage symptoms. DISCUSSION Neurodevelopmental, behavioral, and emotional symptoms are prevalent in patients with BMD regardless of dystrophin gene mutation site.
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Affiliation(s)
- Joshua T Lambert
- Neurology Division, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Andrew J Darmahkasih
- Pediatric Residency Program, University of California-Irvine/Children's Hospital of Orange County, Orange, California
| | - Paul S Horn
- Division of Neurology, Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, Ohio
| | - Irina Rybalsky
- Neurology Division, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Karen C Shellenbarger
- Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Cuixia Tian
- Division of Neurology, Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, Ohio
| | - Brenda L Wong
- Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts
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8
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Vicari S, Piccini G, Mercuri E, Battini R, Chieffo D, Bulgheroni S, Pecini C, Lucibello S, Lenzi S, Moriconi F, Pane M, D’Amico A, Astrea G, Baranello G, Riva D, Cioni G, Alfieri P. Implicit learning deficit in children with Duchenne muscular dystrophy: Evidence for a cerebellar cognitive impairment? PLoS One 2018; 13:e0191164. [PMID: 29338029 PMCID: PMC5770044 DOI: 10.1371/journal.pone.0191164] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 12/31/2017] [Indexed: 11/19/2022] Open
Abstract
This study aimed at comparing implicit sequence learning in individuals affected by Duchenne Muscular Dystrophy without intellectual disability and age-matched typically developing children. A modified version of the Serial Reaction Time task was administered to 32 Duchenne children and 37 controls of comparable chronological age. The Duchenne group showed a reduced rate of implicit learning even if in the absence of global intellectual disability. This finding provides further evidence of the involvement of specific aspects of cognitive function in Duchenne muscular dystrophy and on its possible neurobiological substrate.
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Affiliation(s)
- Stefano Vicari
- Department of Neuroscience, Child Neuropsychiatric Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Giorgia Piccini
- Department of Neuroscience, Child Neuropsychiatric Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Eugenio Mercuri
- Pediatric Neurology Unit, Catholic University and Nemo Center, Rome, Italy
| | - Roberta Battini
- Department of Developmental Neuroscience, IRCCS Stella Maris, Calambrone (Pisa), Italy
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Daniela Chieffo
- Pediatric Neurology Unit, Catholic University and Nemo Center, Rome, Italy
| | - Sara Bulgheroni
- Developmental Neurology Division, IRCCS Fondazione Istituto Neurologico C. Besta, Milan, Italy
| | - Chiara Pecini
- Department of Developmental Neuroscience, IRCCS Stella Maris, Calambrone (Pisa), Italy
| | - Simona Lucibello
- Pediatric Neurology Unit, Catholic University and Nemo Center, Rome, Italy
| | - Sara Lenzi
- Department of Developmental Neuroscience, IRCCS Stella Maris, Calambrone (Pisa), Italy
| | - Federica Moriconi
- Pediatric Neurology Unit, Catholic University and Nemo Center, Rome, Italy
| | - Marika Pane
- Pediatric Neurology Unit, Catholic University and Nemo Center, Rome, Italy
| | - Adele D’Amico
- Department of Neurosciences, Neuromuscular and Neurodegenerative Diseases Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Guja Astrea
- Department of Developmental Neuroscience, IRCCS Stella Maris, Calambrone (Pisa), Italy
| | - Giovanni Baranello
- Developmental Neurology Division, IRCCS Fondazione Istituto Neurologico C. Besta, Milan, Italy
| | - Daria Riva
- Developmental Neurology Division, IRCCS Fondazione Istituto Neurologico C. Besta, Milan, Italy
| | - Giovanni Cioni
- Department of Developmental Neuroscience, IRCCS Stella Maris, Calambrone (Pisa), Italy
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Paolo Alfieri
- Department of Neuroscience, Child Neuropsychiatric Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
- * E-mail:
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Shawky RM, Elsayed SM, Todorov T, Zibert A, Alawbathani S, Schmidt HHJ. Non-deletion mutations in Egyptian patients with Duchenne muscular dystrophy. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2014. [DOI: 10.1016/j.ejmhg.2014.03.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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10
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Clinical, immunohistochemical, Western blot, and genetic analysis in dystrophinopathy. J Clin Neurosci 2013; 20:1099-105. [DOI: 10.1016/j.jocn.2012.09.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 09/10/2012] [Accepted: 09/14/2012] [Indexed: 01/09/2023]
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11
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Pane M, Lombardo ME, Alfieri P, D'Amico A, Bianco F, Vasco G, Piccini G, Mallardi M, Romeo DM, Ricotti V, Ferlini A, Gualandi F, Vicari S, Bertini E, Berardinelli A, Mercuri E. Attention deficit hyperactivity disorder and cognitive function in Duchenne muscular dystrophy: phenotype-genotype correlation. J Pediatr 2012; 161:705-9.e1. [PMID: 22560791 DOI: 10.1016/j.jpeds.2012.03.020] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 01/30/2012] [Accepted: 03/08/2012] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To assess attention deficit hyperactivity disorder (ADHD) in boys affected by Duchenne muscular dystrophy (DMD) and to explore the relationship with cognitive abilities and genetic findings. STUDY DESIGN Boys with DMD (n = 103; 4-17 years of age, mean: 12.6) were assessed using a cognitive test (Wechsler scales). Assessment of ADHD was based on the Diagnostic Statistical Manual, Fourth Edition, Text Revision criteria and on the long version of the Conners Parents and Teachers Rating Scales. RESULTS ADHD was found in 33 of the 103 boys with DMD. Attention problems together with hyperactivity (17/33) or in isolation (15/33) were more frequent than hyperactivity alone, which was found in 1 patient. Intellectual disability (ID) was found in 27/103 (24.6%). Sixty-two of the 103 boys had no ID and no ADHD, 9 had ID but no ADHD, 14 had ADHD but no ID, and 18 had both. ADHD occurred more frequently in association with mutations predicted to affect Dp140 expression (exon 45-55) and in those with mutations predicted to affect all dystrophin product, including Dp71 (ie, those that have promoter region and specific first exon between exons 62 and 63 but were also relatively frequent). CONCLUSIONS Our results suggest that ADHD is a frequent feature in DMD. The risk of ADHD appears to be higher in patients carrying mutations predicted to affect dystrophin isoforms expressed in the brain and are known to be associated with higher risk of cognitive impairment.
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Affiliation(s)
- Marika Pane
- Department of Pediatrics, Child Neurology and Psychiatry, Catholic University, Rome, Italy
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Dystrophin Dp71: The Smallest but Multifunctional Product of the Duchenne Muscular Dystrophy Gene. Mol Neurobiol 2011; 45:43-60. [DOI: 10.1007/s12035-011-8218-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 11/02/2011] [Indexed: 01/06/2023]
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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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Daoud F, Angeard N, Demerre B, Martie I, Benyaou R, Leturcq F, Cossée M, Deburgrave N, Saillour Y, Tuffery S, Urtizberea A, Toutain A, Echenne B, Frischman M, Mayer M, Desguerre I, Estournet B, Réveillère C, Penisson-Besnier, Cuisset JM, Kaplan JC, Héron D, Rivier F, Chelly J. Analysis of Dp71 contribution in the severity of mental retardation through comparison of Duchenne and Becker patients differing by mutation consequences on Dp71 expression. Hum Mol Genet 2009; 18:3779-94. [PMID: 19602481 DOI: 10.1093/hmg/ddp320] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The presence of variable degrees of cognitive impairment, extending from severe mental retardation to specific deficits, in patients with dystrophinopathies is a well-recognized problem. However, molecular basis underlying mental retardation and its severity remain poorly understood and still a matter of debate. Here, we report one of the largest study based on the comparison of clinical, cognitive, molecular and expression data in a large cohort of 81 patients affected with Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) bearing mutations predicted to affect either all dystrophin products, including Dp71 or all dystrophin products, except Dp71. In addition to the consistent data defining molecular basis underlying mental retardation in DMD, we show that BMD patients with MR have mutations that significantly affect Dp71 expression or with mutations located in exons 75 and 76. We also show that mutations upstream to exon 62, with DMD phenotype, predicted to lead to a loss-of-function of all dystrophin products, except Dp71 isoform, are associated, predominantly, with normal or borderline cognitive performances. Altogether, these reliable phenotype-genotype correlations in combination with Dp71 mRNA and protein expression studies, strongly indicate that loss-of-function of all dystrophin products is systematically associated with severe form of MR, and Dp71 deficit is a factor that contributes in the severity of MR and may account for a shift of 2 SD downward of the intelligence quotient.
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Affiliation(s)
- Fatma Daoud
- Institut Cochin, Université Paris Descartes, INSERM, CNRS UMR, France
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15
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Jover M, Schmitz C, Bosdure E, Chabrol B, Assaiante C. Anticipatory postural adjustments in a bimanual load-lifting task in children with Duchenne muscular dystrophy. Neurosci Lett 2006; 403:271-5. [PMID: 16750880 DOI: 10.1016/j.neulet.2006.04.054] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2006] [Revised: 04/10/2006] [Accepted: 04/28/2006] [Indexed: 11/18/2022]
Abstract
We investigated the consequences of a progressive damage to the muscular system on the organization of anticipatory postural adjustments (APA) in children with Duchenne muscular dystrophy (DMD). We used a bimanual load-lifting task requiring the stabilization of the forearm position despite its voluntary or imposed unloading. Eight children with DMD from 4 to 11 years of age were compared to eight typically developing (TD) children. Elbow angle and multiple surface EMGs were recorded and assessed the use of APA. The muscle weakness did not impair (1) the proprioceptive afference and the motor efference constituting the unloading reflex; and (2) the use of an anticipatory function in children with DMD. However, APA used for the forearm stabilization were less efficient in the group of children with DMD. We conclude that in DMD the muscular weakness could be a restraint to the efficiency of APA with respect to TD children.
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Affiliation(s)
- Marianne Jover
- Groupe Développement et Pathologie de l'Action, CNRS UMR 6196, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
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16
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Carsana A, Frisso G, Tremolaterra MR, Lanzillo R, Vitale DF, Santoro L, Salvatore F. Analysis of Dystrophin Gene Deletions Indicates that the Hinge III Region of the Protein Correlates with Disease Severity. Ann Hum Genet 2005. [DOI: 10.1046/j.1469-1809.2005.00160.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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17
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Wu JY, Kuban KCK, Allred E, Shapiro F, Darras BT. Association of Duchenne muscular dystrophy with autism spectrum disorder. J Child Neurol 2005; 20:790-5. [PMID: 16417872 DOI: 10.1177/08830738050200100201] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We hypothesize that Duchenne muscular dystrophy and autism spectrum disorder/pervasive developmental disorder co-occur with a greater than random frequency. In this study, we set out to reject the hypothesis that Duchenne muscular dystrophy and autism spectrum disorder/pervasive developmental disorder co-occur no more often than expected by chance. Two index cases and six additional boys with concomitant Duchenne muscular dystrophy and autism spectrum disorder were identified in a muscular dystrophy clinic that approximates the total number of Duchenne muscular dystrophy boys (158) in the state of Massachusetts. The rate of prevalence (6 of 158) was compared with the prevalence rate of autism spectrum disorder in boys in the general population (1.6 in 1,000). We rejected the hypothesis that Duchenne muscular dystrophy and autism spectrum disorder co-occurrence was likely to be explained by chance (P = .006). We identify a previously unrecognized association of Duchenne muscular dystrophy with autism spectrum disorder. Further work might elucidate the level of association between these two conditions, either at the genetic or at the protein level, and might clarify, at least partially, the neurobiologic mechanisms associated with autism spectrum disorder.
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Affiliation(s)
- Joyce Y Wu
- Division of Pediatric Neurology, David Geffen School of Medicine, Mattel Children's Hospital at UCLA, Los Angeles, CA, USA
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18
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Muntoni F, Torelli S, Ferlini A. Dystrophin and mutations: one gene, several proteins, multiple phenotypes. Lancet Neurol 2003; 2:731-40. [PMID: 14636778 DOI: 10.1016/s1474-4422(03)00585-4] [Citation(s) in RCA: 706] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A large and complex gene on the X chromosome encodes dystrophin. Many mutations have been described in this gene, most of which affect the expression of the muscle isoform, the best-known protein product of this locus. These mutations result in the Duchenne and Becker muscular dystrophies (DMD and BMD). However, there are several other tissue specific isoforms of dystrophin, some exclusively or predominantly expressed in the brain or the retina. Mutations affecting the correct expression of these tissue-specific isoforms have been associated with the CNS involvement common in DMD. Rare mutations also account for the allelic disorder X-linked dilated cardiomyopathy, in which dystrophin expression or function is affected mostly or exclusively in the heart. Genotype definition of the dystrophin gene in patients with dystrophinopathies has taught us much about functionally important domains of the protein itself and has provided insights into several regulatory mechanisms governing the gene expression profile. Here, we focus on current understanding of the genotype-phenotype relation for mutations in the dystrophin gene and their implications for gene functions.
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Affiliation(s)
- Francesco Muntoni
- Department of Paediatrics, Imperial College London, Hammersmith Hospital Campus, London, UK.
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19
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Macioce P, Gambara G, Bernassola M, Gaddini L, Torreri P, Macchia G, Ramoni C, Ceccarini M, Petrucci TC. β-Dystrobrevin interacts directly with kinesin heavy chain in brain. J Cell Sci 2003; 116:4847-56. [PMID: 14600269 DOI: 10.1242/jcs.00805] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
β-Dystrobrevin, a member of the dystrobrevin protein family, is a dystrophin-related and -associated protein restricted to non-muscle tissues and is highly expressed in kidney, liver and brain. Dystrobrevins are now thought to play an important role in intracellular signal transduction, in addition to providing a membrane scaffold in muscle, but the precise role of β-dystrobrevin has not yet been determined. To study β-dystrobrevin's function in brain, we used the yeast two-hybrid approach to look for interacting proteins. Four overlapping clones were identified that encoded Kif5A, a neuronal member of the Kif5 family of proteins that consists of the heavy chains of conventional kinesin. A direct interaction of β-dystrobrevin with Kif5A was confirmed by in vitro and in vivo association assays. Co-immunoprecipitation with a monoclonal kinesin heavy chain antibody precipitated both α- and β-dystrobrevin, indicating that this interaction is not restricted to the β-dystrobrevin isoform. The site for Kif5A binding to β-dystrobrevin was localized in a carboxyl-terminal region that seems to be important in heavy chain-mediated kinesin interactions and is highly homologous in all three Kif5 isoforms, Kif5A, Kif5B and Kif5C. Pull-down and immunofluorescence experiments also showed a direct interaction between β-dystrobrevin and Kif5B. Our findings suggest a novel function for dystrobrevin as a motor protein receptor that might play a major role in the transport of components of the dystrophin-associated protein complex to specific sites in the cell.
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Affiliation(s)
- P Macioce
- Laboratory of Cell Biology, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
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20
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Chen TJ, Chen SS, Wang DC, Hsieh YL. Increased vulnerability of auditory system to noise exposure in mdx mice. Laryngoscope 2002; 112:520-5. [PMID: 12148865 DOI: 10.1097/00005537-200203000-00021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Dystrophin is a cytoskeletal protein mainly found just beneath the sarcolemma. Lack of dystrophin is known to be the cause of Duchenne muscular dystrophy (DMD). Other tissues, including the brain, retina, and cochlear hair cells, also express dystrophin. Recently, a gene (Xp21.2) associated with sensorineural hearing impairment has been mapped within the localization site for dystrophin in two families. Thus, it is reasonable to assume that dystrophin may play a role in auditory function. However, animal studies have produced conflicting results. STUDY DESIGN An attempt was made to clarify the differences between the auditory systems of dystrophin-deficient mdx mice and control B-10 mice by exposure to noise. METHODS In the present study, mdx mice and B-10 mice were used. Animals were exposed daily to noise for 1 month, and their auditory functions were evaluated by recording the brainstem auditory evoked potentials (BAEPs). RESULTS Before noise exposure, the mdx mouse demonstrated normal BAEP threshold when compared with the B-10 mouse. After 1 month of noise exposure, the B-10 mouse showed no apparent change in hearing threshold and BAEP latencies. In contrast, significantly increased hearing threshold and prolonged BAEP peak and interpeak latencies were observed in the mdx mouse after noise exposure. CONCLUSIONS These results indicate that the mdx mice are more vulnerable to noise damage. This involves not only the peripheral auditory system, but also the brainstem central auditory pathway. Therefore, a significant role for dystrophin in the auditory system, especially under noise stress, is suggested.
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Affiliation(s)
- Tsan-Ju Chen
- Department of Physiology, Graduate Institute of Medicine, Kaohsiung Medical University, Taiwan.
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21
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Rando TA. The dystrophin-glycoprotein complex, cellular signaling, and the regulation of cell survival in the muscular dystrophies. Muscle Nerve 2001; 24:1575-94. [PMID: 11745966 DOI: 10.1002/mus.1192] [Citation(s) in RCA: 281] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mutations of different components of the dystrophin-glycoprotein complex (DGC) cause muscular dystrophies that vary in terms of severity, age of onset, and selective involvement of muscle groups. Although the primary pathogenetic processes in the muscular dystrophies have clearly been identified as apoptotic and necrotic muscle cell death, the pathogenetic mechanisms that lead to cell death remain to be determined. Studies of components of the DGC in muscle and in nonmuscle tissues have revealed that the DGC is undoubtedly a multifunctional complex and a highly dynamic structure, in contrast to the unidimensional concept of the DGC as a mechanical component in the cell. Analysis of the DGC reveals compelling analogies to two other membrane-associated protein complexes, namely integrins and caveolins. Each of these complexes mediates signal transduction cascades in the cell, and disruption of each complex causes muscular dystrophies. The signal transduction cascades associated with the DGC, like those associated with integrins and caveolins, play important roles in cell survival signaling, cellular defense mechanisms, and regulation of the balance between cell survival and cell death. This review focuses on the functional components of the DGC, highlighting the evidence of their participation in cellular signaling processes important for cell survival. Elucidating the link between these functional components and the pathogenetic processes leading to cell death is the foremost challenge to understanding the mechanisms of disease expression in the muscular dystrophies due to defects in the DGC.
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Affiliation(s)
- T A Rando
- Department of Neurology and Neurological Sciences, Stanford University Medical Center, Room A-343, Stanford, California 94305-5235, USA.
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22
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Mehler MF. Brain dystrophin, neurogenetics and mental retardation. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2000; 32:277-307. [PMID: 10751678 DOI: 10.1016/s0165-0173(99)00090-9] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Duchenne muscular dystrophy (DMD) and the allelic disorder Becker muscular dystrophy (BMD) are common X-linked recessive neuromuscular disorders that are associated with a spectrum of genetically based developmental cognitive and behavioral disabilities. Seven promoters scattered throughout the huge DMD/BMD gene locus normally code for distinct isoforms of the gene product, dystrophin, that exhibit nervous system developmental, regional and cell-type specificity. Dystrophin is a complex plasmalemmal-cytoskeletal linker protein that possesses multiple functional domains, autosomal and X-linked homologs and associated binding proteins that form multiunit signaling complexes whose composition is unique to each cellular and developmental context. Through additional interactions with a variety of proteins of the extracellular matrix, plasma membrane, cytoskeleton and distinct intracellular compartments, brain dystrophin acquires the capability to participate in the modulatory actions of a large number of cellular signaling pathways. During neural development, dystrophin is expressed within the neural tube and selected areas of the embryonic and postnatal neuraxis, and may regulate distinct aspects of neurogenesis, neuronal migration and cellular differentiation. By contrast, in the mature brain, dystrophin is preferentially expressed by specific regional neuronal subpopulations within proximal somadendritic microdomains associated with synaptic terminal membranes. Increasing experimental evidence suggests that in adult life, dystrophin normally modulates synaptic terminal integrity, distinct forms of synaptic plasticity and regional cellular signal integration. At a systems level, dystrophin may regulate essential components of an integrated sensorimotor attentional network. Dystrophin deficiency in DMD/BMD patients and in the mdx mouse model appears to impair intracellular calcium homeostasis and to disrupt multiple protein-protein interactions that normally promote information transfer and signal integration from the extracellular environment to the nucleus within regulated microdomains. In DMD/BMD, the individual profiles of cognitive and behavioral deficits, mental retardation and other phenotypic variations appear to depend on complex profiles of transcriptional regulation associated with individual dystrophin mutations that result in the corresponding presence or absence of individual brain dystrophin isoforms that normally exhibit developmental, regional and cell-type-specific expression and functional regulation. This composite experimental model will allow fine-level mapping of cognitive-neurogenetic associations that encompass the interrelationships between molecular, cellular and systems levels of signal integration, and will further our understanding of complex gene-environmental interactions and the pathogenetic basis of developmental disorders associated with mental retardation.
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Affiliation(s)
- M F Mehler
- Departments of Neurology, Neuroscience and Psychiatry, the Einstein Comprehensive Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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23
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Moizard MP, Billard C, Toutain A, Berret F, Marmin N, Moraine C. Are Dp71 and Dp140 brain dystrophin isoforms related to cognitive impairment in Duchenne muscular dystrophy? AMERICAN JOURNAL OF MEDICAL GENETICS 1998; 80:32-41. [PMID: 9800909 DOI: 10.1002/(sici)1096-8628(19981102)80:1<32::aid-ajmg6>3.0.co;2-y] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Molecular study and neuropsychological analysis were performed concurrently on 49 patients with Duchenne muscular dystrophy (DMD) in order to find a molecular explanation for the cognitive impairment observed in most DMD patients. Complete analysis of the dystrophin gene was performed to define the localization of deletions and duplications in relation to the different DMD promoters. Qualitative analysis of the Dp71 transcript and testing for the specific first exon of Dp140 were also carried out. Neuropsychological analysis assessed verbal and visuospatial intelligence, verbal memory, and reading skills. Comparison of molecular and psychometric findings demonstrated that deletions and duplications that were localized in the distal part of the gene seemed to be preferentially associated with cognitive impairment. Two altered Dp71 transcripts and two deleted Dp140 DNA sequences were found in four patients with severe cerebral dysfunction. These findings suggest that some sequences located in the distal part of the gene and, in particular, some DMD isoforms expressed in the brain may be related to the cognitive impairment associated with DMD.
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Affiliation(s)
- M P Moizard
- Unité de Génétique, Hopital Bretonneau, Tours, France
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24
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Mital A, Kumari D, Gupta M, Goyle S. Molecular characterisation of Duchenne muscular dystrophy and phenotypic correlation. J Neurol Sci 1998; 157:179-86. [PMID: 9619643 DOI: 10.1016/s0022-510x(98)00051-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Dystrophin gene was analysed in 32 unrelated DMD families (46 subjects: 32 index cases and 14 sibs) for the presence of deletions by mPCR for 27 exons and cDNA probes for the entire gene. Deletions were identified in 32 patients (25 index cases and seven sibs) from 25 families. The concordance between the clinical phenotype and 'reading frame' hypothesis was observed in 24 (75%) cases. Of these, nine patients were wheelchair bound between 8-12 years of age, nine (age range 5-10 years) showed progressive difficulty in walking and six (age range 1.6-4 years) had onset of muscle weakness. One patient (CH), who was wheelchair bound at 12 years, the effect of mutation on the ORF could not be ascertained due to the presence of a junction fragment. Seven patients had inframe deletions of which four were wheelchair bound by the age of 13 years, and three (age range 5-7 years) although, ambulatory had difficulty in walking. There were eight patients who showed no deletion, of which four became wheelchair bound by the age of 12 years, four, though still ambulatory, were unable to run and tired easily. Correlation between phenotype and genotype of these DMD patients demonstrates that genetic studies of lymphocyte DNA may not always reflect the situation in the tissue involved in dystrophin, i.e. muscle. We describe a common dystrophin gene polymorphism in the Indian population with cDNA 11-14 that alters the Hind III restriction sites. Novel RFLPs were observed in 26 patients and their family members. Whether this is a polymorphism or, related to the diseased phenotype needs confirmation.
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Affiliation(s)
- A Mital
- Human Molecular Genetics Laboratory, School of Life Science, Jawaharlal Nehru University, New Delhi, India
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25
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Billard C, Gillet P, Barthez M, Hommet C, Bertrand P. Reading ability and processing in Duchenne muscular dystrophy and spinal muscular atrophy. Dev Med Child Neurol 1998; 40:12-20. [PMID: 9459212 DOI: 10.1111/j.1469-8749.1998.tb15351.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We analysed the reading abilities and processing of 21 children with Duchenne muscular dystrophy (DMD), 11 matched children suffering from spinal muscular atrophy (SMA) and 42 children receiving normal education. The principal result observed was that the DMD children exhibited a reading age which was significantly lower than the SMA children compared with their chronological age. These learning disabilities were not related to a deficit in non-verbal performance intelligence, but psycholinguistic evaluation showed a deficit in verbal intelligence, especially in the Similarities and Arithmetic WISC-R subtests, in phonological abilities, oral word repetition, and in digit span score. The results for the DMD children were heterogeneous, and ranged from normal to greater or lesser involvement. In an attempt to clarify the nature of this reading impairment in DMD children, the three groups (DMD, SMA, and normal control children) were tested by reading aloud a list of single words and non-words. The DMD children were significantly impaired in reading non-words, suggesting reading disability similar to dysphonetic dyslexia, the most frequent subtype of developmental dyslexia. These results are discussed in the light of psychometric data available for our DMD population and in the light of previous studies. The practical consequences of diagnosis on rehabilitation are very important. The precise description of the cognitive deficits seen in DMD is of value for future clinical and genetic studies.
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Affiliation(s)
- C Billard
- Neurosurgery and Neurology Department, Hôpital Clocheville, Tours, France
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26
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Ceccarini M, Rizzo G, Rosa G, Chelucci C, Macioce P, Petrucci TC. A splice variant of Dp71 lacking the syntrophin binding site is expressed in early stages of human neural development. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1997; 103:77-82. [PMID: 9370062 DOI: 10.1016/s0165-3806(97)00122-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Dp71, a 71 kDa C-terminal isoform of dystrophin, is the major product of the DMD gene in brain. Two alternatively spliced transcripts of Dp71 were amplified by RT-PCR from different areas of human fetal neural tissue. Both transcripts were spliced out of exons 71 and 78. The shorter transcript was also alternatively spliced of exons 72-74, a region comprising the coding sequence for the binding site to syntrophin, one component of the dystrophin-associated protein complex. Results indicate that alternatively spliced forms of Dp71 are regulated during human neural development.
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Affiliation(s)
- M Ceccarini
- Laboratorio di Biologia Cellulare, Istituto Superiore di Sanità, Rome, Italy.
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27
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Girlanda P, Quartarone A, Buceti R, Sinicropi S, Macaione V, Saad FA, Messina L, Danieli GA, Ferreri G, Vita G. Extra-muscle involvement in dystrophinopathies: an electroretinography and evoked potential study. J Neurol Sci 1997; 146:127-32. [PMID: 9077508 DOI: 10.1016/s0022-510x(96)00292-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Dystrophin is present in various tissues other than skeletal and cardiac muscles, including the central nervous system (CNS) and the outer plexiform layer of the retina. Therefore lack of dystrophin might be related to mental retardation or to changes in electrophysiological tests exploring retina and CNS. We performed electroretinography, VEPs, BAEPs, SEPs and MEPs in 18 patients with Duchenne muscular dystrophy (DMD), 18 with Becker muscular dystrophy (BMD) and 12 obligate carriers. We observed a marked reduction of the b-wave amplitude in the scotopic ERG, mainly in DMD patients. Oscillatory potentials were altered in all groups, even in carriers, suggesting that dystrophin may be also involved in retinal circulation. VEPs changes confirmed the role of dystrophin in visual function. The other evoked potentials were altered only in a small percentage of subjects but changes of different tests did not overlap in individual subjects. Neurophysiological abnormalities did not correlate with type, site and size of alteration in the dystrophin gene.
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Affiliation(s)
- P Girlanda
- Institute of Neurological and Neurosurgical Sciences, University of Messina, Italy.
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28
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Abstract
Duchenne and Becker muscular dystrophies are X-linked allelic disorders in which the association of central nervous system dysfunction, typically in the form of mental retardation, is a well recognized feature. They are both due to mutations in the dystrophin gene, whose corresponding protein products are expressed both in the muscle and central nervous system. We have observed an increased frequency of epilepsy in children with Duchenne and Becker muscular dystrophy attending our clinic. Out of 254 boys with this condition (201 Duchenne and 53 Becker), eight children, four in the Duchenne and four in the Becker group, had a confirmed diagnosis of epilepsy (cumulative incidence 3.14%, with a subgroup incidence of 1.99% in the Duchenne and 7.54% in the Becker group). Statistical analysis indicated that only the incidence of epilepsy in Becker muscular dystrophy was significant (p < 0.007). Our data suggests that epilepsy may be a rare associated feature in children with muscular dystrophy secondary to dystrophin deficiency.
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Affiliation(s)
- F Goodwin
- Department of Paediatric and Neonatal Medicine, Hammersmith Hospital, London, UK
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29
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Tracey I, Dunn JF, Parkes HG, Radda GK. An in vivo and in vitro H-magnetic resonance spectroscopy study of mdx mouse brain: abnormal development or neural necrosis? J Neurol Sci 1996; 141:13-8. [PMID: 8880686 DOI: 10.1016/0022-510x(96)00135-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked genetic disorder primarily affecting young boys, often causing mental retardation in addition to the well-known progressive muscular weakness. Normal dystrophin expression is lacking in skeletal muscle and the central nervous system (CNS) of both DMD children and the mdx mouse model. The underlying biochemical lesion causing mental impairment in DMD is unknown. 1H-magnetic resonance spectroscopy (1H-MRS) detects choline-containing compounds, creatine and N-acetyl aspartate (NAA) in vivo. NAA is commonly used as a chemical marker for neurons, and a decline in NAA is thought to correlate with neuronal loss. Control mice were compared to mdx using a combination of in vivo and in vitro 1H-MRS methods to determine whether neural necrosis or developmental abnormalities occur in dystrophic brain. NAA levels were normal in mdx brain compared to controls suggesting minor, if any, neuronal necrosis in dystrophic brain. In contrast, choline compounds and myo-inositol levels were increased, indicative of gliosis or developmental abnormalities in dystrophic brain.
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Affiliation(s)
- I Tracey
- MRC Biochemical and Clinical Magnetic Resonance Unit, Department of Biochemistry, Oxford University, UK.
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30
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Fanin M, Freda MP, Vitiello L, Danieli GA, Pegoraro E, Angelini C. Duchenne phenotype with in-frame deletion removing major portion of dystrophin rod: threshold effect for deletion size? Muscle Nerve 1996; 19:1154-60. [PMID: 8761273 DOI: 10.1002/mus.880190902] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In a 9-year-old boy with Duchenne muscular dystrophy we found a large in-frame deletion, spanning exons 10 to 53 of the dystrophin gene. The deletion removed almost all of the central rod domain of dystrophin. Using carboxyterminal dystrophin antibodies the immunohistochemical reaction was normal in all muscle fibers. In immunoblot studies we found dystrophin of abnormal size (160 kDa) and normal amount (about 100%). The immunochemical features and the reading frame deduced from DNA analysis are usually associated with Becker muscular dystrophy, but the clinical characteristics were those of the severe Duchenne phenotype. All the cases of in-frame dystrophin deletions reported so far, which involved more than 36 exons, invariably resulted in a severe phenotype. Therefore, a threshold effect for dystrophin length may be reasonably suspected. Very short dystrophin molecules might induce a severe disarray of the dystrophin network.
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Affiliation(s)
- M Fanin
- Department of Neurology, University of Padua, Italy
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31
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Villanova M, Malandrini A, Biancotti R, Löfgren A, Mongini T, Six J, Salvestroni R, Parrotta E, Van Broeckhoven C, Paolozzi C, Guazzi G. Muscular dystrophy, mental retardation and cardiomyopathy not associated with dystrophin deficiency. Neuromuscul Disord 1996; 6:167-72. [PMID: 8784804 DOI: 10.1016/0960-8966(96)00016-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We report on a male patient aged 38, affected by a syndrome whose characteristic features include onset in early childhood, slow progression, diffuse muscle weakness, mental retardation and cardiomyopathy. Muscle biopsy showed myopathic changes compatible with muscular dystrophy. However, immunostaining for dystrophin as well as 50 and 43 kDa dystrophin-associated glycoproteins (DAGs) was normal. Genetic analysis suggested that direct involvement of the dystrophin gene was highly unlikely. No other family members were affected. Although the clinical picture is reminiscent of Duchenne/Becker muscular dystrophy, the immunologically and genetically documented lack of dystrophin involvement suggests that this particular syndrome is as yet undescribed.
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Affiliation(s)
- M Villanova
- Laboratory of Neuropathology, University of Siena, Italy
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32
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Tracey I, Scott RB, Thompson CH, Dunn JF, Barnes PR, Styles P, Kemp GJ, Rae CD, Pike M, Radda GK. Brain abnormalities in Duchenne muscular dystrophy: phosphorus-31 magnetic resonance spectroscopy and neuropsychological study. Lancet 1995; 345:1260-4. [PMID: 7746055 DOI: 10.1016/s0140-6736(95)90923-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Duchenne muscular dystrophy (DMD) is one of a range of muscular dystrophies caused by abnormalities of the short arm of the X chromosome (Xp21), which often cause mental retardation in addition to progressive muscular weakness. Normal dystrophin expression is lacking in both skeletal muscle and brain of affected subjects. Phosphorus-31 magnetic resonance spectroscopy has shown several abnormalities in skeletal muscle in DMD. We looked for similar abnormalities in brain in patients with DMD and related the findings to neuropsychological test results. We studied by magnetic resonance spectroscopy 19 boys (aged 76-167 months) diagnosed as having DMD and 19 control boys of similar age (87-135 months). Intelligence quotient (IQ) was assessed with the Wechsler Intelligence Scale for children. The DMD patients had significantly higher values than the controls in the brain ratios of inorganic phosphate to adenosine triphosphate (mean 0.53 [SD 0.21] vs 0.36 [0.09], p = 0.003), to phosphomonoesters (0.40 [0.07] vs 0.29 [0.07], p = 0.0001), and to phosphocreatine (0.44 [0.10] vs 0.37 [0.08], p = 0.02). There were significant differences between the DMD patients and the controls in full-scale IQ (76 [16] vs 101 [16], p = 0.0001), performance IQ (78 [17] vs 94 [14], p = 0.003), and verbal IQ (78 [17] vs 106 [17], p = 0.0001). These altered metabolite ratios parallel the findings in dystrophic muscle and suggest bioenergetic similarities in tissues that lack dystrophin.
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Affiliation(s)
- I Tracey
- MRC Biochemical and Clinical Magnetic Resonance Unit, Oxford Radcliffe Hospital, UK
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Bushby KM, Appleton R, Anderson LV, Welch JL, Kelly P, Gardner-Medwin D. Deletion status and intellectual impairment in Duchenne muscular dystrophy. Dev Med Child Neurol 1995; 37:260-9. [PMID: 7890131 DOI: 10.1111/j.1469-8749.1995.tb12000.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The authors collected Verbal, Performance and Full-scale IQs for 74 patients in whom complete analysis of the dystrophin gene for deletions and duplications had been performed. There was a significant difference in the mean Full-scale IQ between patients with deletions at the 5' and 3' ends of the gene, with no patients with 5' deletions having mental retardation. No relationship was established between mental retardation and the presence or absence of deletions or length of deletions, and similar deletions were observed in the presence and absence of mental retardation. Although distal deletions were more commonly associated with mental retardation, there was no clear evidence for a particular region of the dystrophin gene being specifically responsible for IQ. The intellectual deficit seen in DMD may be a consequence of cerebral hypoxia, ue to malfunction of smooth muscle dystrophin.
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Affiliation(s)
- K M Bushby
- Department of Human Genetics, University of Newcastle upon Tyne, UK
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Tuffery S, Lenk U, Roberts RG, Coubes C, Demaille J, Claustres M. Protein truncation test: analysis of two novel point mutations at the carboxy-terminus of the human dystrophin gene associated with mental retardation. Hum Mutat 1995; 6:126-35. [PMID: 7581396 DOI: 10.1002/humu.1380060205] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Approximately one-third of the mutations responsible for Duchenne muscular dytrophy (DMD) do not involve gross rearrangements of the dystrophin gene. Methods for intensive mutation screening have recently been applied to this immense gene, which resulted in the identification of a number of point mutations in DMD patients, mostly translation-terminating mutations. A number of data raised the possibility that the C-terminal region of dystrophin might be involved in some cases of mental retardation associated with DMD. Using single-strand conformation analysis of products amplified by polymerase chain reaction (PCR-SSCA) to screen the terminal domains of the dystrophin gene (exons 60-79) of 20 unrelated patients with DMD or BMD, we detected two novel point mutations in two mentally retarded DMD patients: a 1-bp deletion in exon 70 (10334delC) and a 5' splice donor site alteration in intron 69 (10294 + 1G-->T). Both mutations should result in a premature translation termination of dystrophin. The possible effects on the reading frame were analyzed by the study of reverse transcripts amplified from peripheral blood lymphocytes mRNA and by the protein truncation test.
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Affiliation(s)
- S Tuffery
- Laboratoire de Biochimie Génétique, INSERM U249/CNRS UPR 9008, Institut de Biologie, Montpellier, France
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Muntoni F, Gobbi P, Sewry C, Sherratt T, Taylor J, Sandhu SK, Abbs S, Roberts R, Hodgson SV, Bobrow M. Deletions in the 5' region of dystrophin and resulting phenotypes. J Med Genet 1994; 31:843-7. [PMID: 7853367 PMCID: PMC1016656 DOI: 10.1136/jmg.31.11.843] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Deletions in the dystrophin gene give rise to both Duchenne and Becker muscular dystrophies. Good correlation is generally found between the severity of the phenotype and the effect of the deletion on the reading frame: deletions that disrupt the reading frame result in a severe phenotype, while in frame deletions are associated with a milder disease course. Rare exceptions to this rule, mainly owing to frameshift mutations in the 5' region of the gene (in particular deletions involving exons 3 to 7) which are associated with a milder than expected phenotype, have been reported previously. In order to characterise better the relationship between genotype and phenotype as a result of mutations arising in the 5' region of the gene, we have studied a large cohort of patients with small in frame and out of frame deletions in the first 13 exons of the dystrophin gene. Fifty-five patients with a deletion in this area were identified; approximately one third of them had a phenotype different from that theoretically expected. Patients were divided into two groups: (1) patients with a severe clinical phenotype despite the presence of a small, in frame deletion and (2) patients with a mild phenotype and an out of frame deletion. Noticeable examples observed in the first group were Duchenne boys with a deletion of exon 5, of exon 3, and of exons 3-13. In the second group we observed several patients with an intermediate or Becker phenotype and out of frame deletions involving not only the usual exons 3-7 but also 5-7 and 3-6. These data indicate that a high proportion of patients with a deletion in the 5' end of the gene have a phenotype that is not predictable on the basis of the effect of the deletion on the reading frame. The N-terminus of dystrophin has at least one actin binding domain that might be affected by the small, in frame deletions in this area. The effect of the in frame deletions of exon 3, 5, and 3-13 on this domain might account for the severe phenotype observed in these patients. Other mechanisms, such as unexpected effect of the deletion on splicing behaviour, might, however, also be implicated in determining the phenotype outcome.
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Affiliation(s)
- F Muntoni
- Department of Paediatrics & Neonatal Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London, UK
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Nicholson LV, Johnson MA, Bushby KM, Gardner-Medwin D, Curtis A, Ginjaar IB, den Dunnen JT, Welch JL, Butler TJ, Bakker E. Integrated study of 100 patients with Xp21 linked muscular dystrophy using clinical, genetic, immunochemical, and histopathological data. Part 2. Correlations within individual patients. J Med Genet 1993; 30:737-44. [PMID: 8411068 PMCID: PMC1016530 DOI: 10.1136/jmg.30.9.737] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
This report is the second part of a trilogy from a multidisciplinary study which was undertaken to record the relationships between clinical severity and dystrophin gene and protein expression. The aim in part 2 was to correlate the effect of gene deletions on protein expression in individual patients with well defined clinical phenotypes. Among the DMD patients, most of the deletions/duplications disrupted the open reading frame, but three patients had in frame deletions. Some of the intermediate D/BMD patients had mutations which were frameshifting while others were in frame. All of the deletions/duplications in the BMD patients maintained the open reading frame and 25/26 deletions in typical BMD group 5 started with exon 45. The deletion of single exon 44 was the most common mutation in patients from groups 1 to 3. Dystrophin was detected in sections and blots from 58% of the DMD patients with a size that was compatible with synthesis from mRNA in which the reading frame had been restored. Certain deletions were particularly associated with the occurrence of limited dystrophin synthesis in DMD patients. For example, 9/11 DMD patients missing single exons had some detectable dystrophin labelling compared with 10/24 who had deletions affecting more than one exon. All patients missing single exon 44 or 45 had some dystrophin. Deletions starting or finishing with exons 3 or 51 (8/9) cases were usually associated with dystrophin synthesis whereas those starting or finishing with exons 46 or 52 (11/11) were not. Formal IQ assessments (verbal, performance, and full scores) were available for 47 patients. Mean IQ score among the DMD patients was 83 and no clear relationship was found between gene mutations and IQ. The mutations in patients with a particularly severe deficit of verbal IQ were spread throughout the gene.
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Affiliation(s)
- L V Nicholson
- Muscular Dystrophy Group Research Laboratories, Newcastle General Hospital, Newcastle upon Tyne, UK
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Nicholson LV, Johnson MA, Bushby KM, Gardner-Medwin D, Curtis A, Ginjaar IB, den Dunnen JT, Welch JL, Butler TJ, Bakker E. Integrated study of 100 patients with Xp21 linked muscular dystrophy using clinical, genetic, immunochemical, and histopathological data. Part 1. Trends across the clinical groups. J Med Genet 1993; 30:728-36. [PMID: 8411067 PMCID: PMC1016529 DOI: 10.1136/jmg.30.9.728] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
This multidisciplinary study was undertaken to record the variation in gene and protein expression in a large cohort of patients with well defined clinical phenotypes. The patients, whose ages ranged from 4 years to 66 years, spanned a wide range of disease severity. They represented the first 100 patients who had been examined in Newcastle, had undergone a muscle biopsy, and provided a blood sample for DNA analysis. The study had three aims: to observe any trends in the analyses across the clinical groups, to correlate gene and protein expression in individual patients, and to use the data collected to assess the relative usefulness of different techniques in the diagnosis and prognosis of patients with Duchenne and Becker dystrophy (DMD/BMD). In part 1, we describe the clinical assessment of the patients and the trends that were observed across the cohort. The patients were divided into seven groups. Group 1 had severe DMD (n = 21), group 2 had milder DMD (n = 20), group 3 were intermediate D/BMD patients (n = 9), group 4 had severe BMD (n = 5), and group 5 were more typical BMD patients (n = 31). Some patients were too young to be classified (n = 7) and a group of all the female patients were also classified separately (n = 7). The number of DMD and BMD patients was about equal, in accord with disease prevalence in the north of England, but an unusually high proportion were sporadic cases. Dystrophin labelling (performed with up to three antibodies) on both blots and sections increased gradually across the clinical groups. All histopathological indices, except the proportion of fat in biopsy sections, showed clear trends across the groups.
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Affiliation(s)
- L V Nicholson
- Muscular Dystrophy Group Research Laboratories, Newcastle General Hospital, Newcastle upon Tyne, UK
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