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P.1.1 Natural history of Ullrich congenital muscular dystrophy
Abstracts / Neuromuscular Disorders 23 (2013) 738–852 included myosin accumulation and aggregates of fragmented sarcomeres with preserved A-bands and M-lines. We studied a family with three affected members suffering from cardiomyopathy or cardioskeletal myopathy. We performed sequencing analysis of TRIM63 and TRIM54 encoding MuRF1 and MuRF3, respectively. Transfection of wild-type MuRF1 in cultured patient myoblast was performed to assess the rescue assay. To characterize the behaviour of TRIM54 mutation, control myoblasts were transfected with wild-type or mutant MuRF3. We identified a homozygous MuRF1 null mutation and heterozygous MuRF3 mutation in the patient with cardioskeletal myopathy. Myopathological features were highly reminiscent of that of MuRF1 / / MuRF3 / mice. Cultured myotubes from patient showed perturbed myofibrillogenesis and abnormal organization of the microtubule network. Transfection of wild-type MuRF1 in cultured patient myocytes rescued the phenotype. Transfection of control myoblasts with mutant MuRF3 induced the formation of irregular filamentous structures demonstrating the pathogenic effect of the MuRF3 mutation. We describe a novel protein aggregate myopathy and cardiomyopathy due to MuRF1 deficiency and a deleterious MuRF3 missense mutation. Unique morphological features including myosin accumulation, disrupted microtubule structures and fragmented sarcomeres with preserved Abands and M-lines in the absence of thin filaments and Z-lines characterize the disease associated with combined MuRF1 and MuRF3 deficiency. http://dx.doi:10.1016/j.nmd.2013.06.383
O.6 Restricting MTM1 transgene expression to skeletal muscle in AAVmediated gene therapy for myotubular myopathy R. Joubert 1, C. Moal 1, A. Vignaud 1, S. Martin 1, I. Richard 1, P. Moullier 2, A.H. Beggs 3, M.K. Childers 4, F. Mavilio 1, A. Buj-Bello 1 1 Genethon, Evry, France; 2 Inserm U649, Laboratoire de The´rapie Ge´nique, Nantes, France; 3 The Manton Center for Orphan Disease Research, Harvard Medical School, Boston, United States; 4 University of Washington, Seattle, United States Myotubular myopathy (XLMTM) is a severe congenital disease that affects skeletal musculature, which is characterized by the presence of small myofibers with frequent occurrence of central nuclei. The disease is due to mutations in the MTM1 gene, encoding a phosphoinositide phosphatase named myotubularin, and specific treatment is currently unavailable. We have previously demonstrated the efficacy of local administration of AAV vectors carrying the Mtm1 cDNA to treat the disease, and have more recently extended these studies to the whole body. In order to express MTM1 preferentially in skeletal muscles after systemic gene delivery, we have constructed several AAV vectors that contain the Mtm1 cDNA under the potent desmin promoter and miRNA target sequences for cardiac detargeting. We show that intravenous delivery of these vectors leads to myotubularin expression in skeletal muscles scattered throughout the body, including the diaphragm, and reduced expression in heart. We have selected one of these vectors for gene therapy in XLMTM mice and show the results in survival, pathology and contractile force. We demonstrate that this strategy is very efficient to drive selected expression of transgenes in skeletal muscles, avoiding potential side effects in heart, and is useful for the treatment of disorders that mainly affect the skeletal musculature, such as myotubular myopathy. http://dx.doi:10.1016/j.nmd.2013.06.384
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CONGENITAL MUSCULAR DYSTROPHIES P.1.1 Natural history of Ullrich congenital muscular dystrophy T. Yonekawa 1, H. Komaki 2, M. Okada 1, Y.K. Hayashi 1, S. Noguchi 1, I. Nonaka 1, K. Sugai 2, M. Sasaki 2, I. Nishino 1 1 National Institute of Neuroscience, National Center of Neurology and Psychiatry, Department of Neuromuscular Research, Tokyo, Japan; 2 National Center Hospital, National Center of Neurology and Psychiatry, Department of Child Neurology, Tokyo, Japan Ullrich congenital muscular dystrophy (UCMD) is the second most common CMD in Japan. Mutations in either COL6A1, COL6A2, or COL6A3 gene, each encoding a subunit of collagen VI (COL6) are known to cause UCMD. To date, there is no cure for this disease and only limited information on the rate of disease progression. To characterize the natural history of UCMD, questionnaire-based nationwide survey was conducted from October 2010 to February 2011. We enrolled 33 patients (age at survey, 11.0 ± 6.6 years (mean ± SD)) with COL6 deficiency on immunohistochemistry in skeletal muscle: 5with complete and 28 with sarcolemma specific COL6 deficiency. Sequence analysis of COL6 genes was performed using genomic DNA from 32 patients, 19 (59.4%) of whom carried identifiable mutations. We analyzed the information on perinatal and developmental abnormalities, clinical manifestations, data of Cobb angle and % vital capacity (%VC). Age at muscle biopsy was 3.2 ± 2.0 years. Creatine kinase level was 315 ± 110 (IU/L) (n = 31). Twenty-five (81%) of 31 patients walked independently by age 1.7 ± 0.5 years but lost this ability by age 8.8 ± 2.9 years (n = 11). Six patients never walked independently. %VC was decreased exponentially with age, resulting in severe respiratory dysfunction before pubescence. Noninvasive ventilation was initiated at age 11.2 ± 3.6 years (n = 13). Cobb angle over 30° was noted at age 9.9 ± 5.3 years (n = 17). The maximum progression rate was 16.2 ± 10.0°/year (n = 13). Scoliosis surgery was performed in 3 patients at respective ages 5, 9 and 10 years. Postoperative %VC was relatively well maintained in the youngest patient. The natural history of walking ability, respiratory function and scoliosis in UCMD patients was characterized. Although the age of onset varied, scoliosis, as well as restrictive respiratory dysfunction, progressed rapidly within years, once they appeared. http://dx.doi:10.1016/j.nmd.2013.06.385
P.1.2 Natural history of pulmonary function in collagen VI-related myopathies: An international study A.R. Foley 1, S. Quijano-Roy 2, J. Collins 3, V. Straub 4, M. McCallum 4, N. Deconinck 5, E. Mercuri 6, M. Pane 6, A. D’Amico 7, E. Bertini 7, K. North 8, M.M. Ryan 9, S. Auh 10, F. Muntoni 1, C.G. Bo¨nnemann 11 1 Dubowitz Neuromuscular Centre, UCL Institute of Child Health and Great Ormond Street Hospital, London, United Kingdom; 2 Garches Neuromuscular Centre (GNMH), Raymond Poincare´ University Hospital (UVSQ), Garches, France; 3 Cincinnati Children’s Hospital Medical Center, Neurology Division, Cincinnati, United States; 4 Institute of Human Genetics, International Centre for Life, University of Newcastle, Newcastle upon Tyne, United Kingdom; 5 Hoˆpital Universitaire des Enfants Reine Fabiola, Department of Neurology, Brussels, Belgium; 6 Catholic University, Department of Paediatric Neurology, Rome, Italy; 7 Bambino Gesu` Children’s Hospital, Laboratory of Molecular Medicine, Rome, Italy; 8 Children’s Hospital at Westmead, University of Sydney, Institute for Neuroscience and Muscle Research, Sydney, Australia; 9 Royal Children’s Hospital, Murdoch Childrens Research Institute, University of
O.6 Restricting MTM1 transgene expression to skeletal muscle in AAVmediated gene therapy for myotubular myopathy R. Joubert 1, C. Moal 1, A. Vignaud 1, S. Martin 1, I. Richard 1, P. Moullier 2, A.H. Beggs 3, M.K. Childers 4, F. Mavilio 1, A. Buj-Bello 1 1 Genethon, Evry, France; 2 Inserm U649, Laboratoire de The´rapie Ge´nique, Nantes, France; 3 The Manton Center for Orphan Disease Research, Harvard Medical School, Boston, United States; 4 University of Washington, Seattle, United States Myotubular myopathy (XLMTM) is a severe congenital disease that affects skeletal musculature, which is characterized by the presence of small myofibers with frequent occurrence of central nuclei. The disease is due to mutations in the MTM1 gene, encoding a phosphoinositide phosphatase named myotubularin, and specific treatment is currently unavailable. We have previously demonstrated the efficacy of local administration of AAV vectors carrying the Mtm1 cDNA to treat the disease, and have more recently extended these studies to the whole body. In order to express MTM1 preferentially in skeletal muscles after systemic gene delivery, we have constructed several AAV vectors that contain the Mtm1 cDNA under the potent desmin promoter and miRNA target sequences for cardiac detargeting. We show that intravenous delivery of these vectors leads to myotubularin expression in skeletal muscles scattered throughout the body, including the diaphragm, and reduced expression in heart. We have selected one of these vectors for gene therapy in XLMTM mice and show the results in survival, pathology and contractile force. We demonstrate that this strategy is very efficient to drive selected expression of transgenes in skeletal muscles, avoiding potential side effects in heart, and is useful for the treatment of disorders that mainly affect the skeletal musculature, such as myotubular myopathy. http://dx.doi:10.1016/j.nmd.2013.06.384
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CONGENITAL MUSCULAR DYSTROPHIES P.1.1 Natural history of Ullrich congenital muscular dystrophy T. Yonekawa 1, H. Komaki 2, M. Okada 1, Y.K. Hayashi 1, S. Noguchi 1, I. Nonaka 1, K. Sugai 2, M. Sasaki 2, I. Nishino 1 1 National Institute of Neuroscience, National Center of Neurology and Psychiatry, Department of Neuromuscular Research, Tokyo, Japan; 2 National Center Hospital, National Center of Neurology and Psychiatry, Department of Child Neurology, Tokyo, Japan Ullrich congenital muscular dystrophy (UCMD) is the second most common CMD in Japan. Mutations in either COL6A1, COL6A2, or COL6A3 gene, each encoding a subunit of collagen VI (COL6) are known to cause UCMD. To date, there is no cure for this disease and only limited information on the rate of disease progression. To characterize the natural history of UCMD, questionnaire-based nationwide survey was conducted from October 2010 to February 2011. We enrolled 33 patients (age at survey, 11.0 ± 6.6 years (mean ± SD)) with COL6 deficiency on immunohistochemistry in skeletal muscle: 5with complete and 28 with sarcolemma specific COL6 deficiency. Sequence analysis of COL6 genes was performed using genomic DNA from 32 patients, 19 (59.4%) of whom carried identifiable mutations. We analyzed the information on perinatal and developmental abnormalities, clinical manifestations, data of Cobb angle and % vital capacity (%VC). Age at muscle biopsy was 3.2 ± 2.0 years. Creatine kinase level was 315 ± 110 (IU/L) (n = 31). Twenty-five (81%) of 31 patients walked independently by age 1.7 ± 0.5 years but lost this ability by age 8.8 ± 2.9 years (n = 11). Six patients never walked independently. %VC was decreased exponentially with age, resulting in severe respiratory dysfunction before pubescence. Noninvasive ventilation was initiated at age 11.2 ± 3.6 years (n = 13). Cobb angle over 30° was noted at age 9.9 ± 5.3 years (n = 17). The maximum progression rate was 16.2 ± 10.0°/year (n = 13). Scoliosis surgery was performed in 3 patients at respective ages 5, 9 and 10 years. Postoperative %VC was relatively well maintained in the youngest patient. The natural history of walking ability, respiratory function and scoliosis in UCMD patients was characterized. Although the age of onset varied, scoliosis, as well as restrictive respiratory dysfunction, progressed rapidly within years, once they appeared. http://dx.doi:10.1016/j.nmd.2013.06.385
P.1.2 Natural history of pulmonary function in collagen VI-related myopathies: An international study A.R. Foley 1, S. Quijano-Roy 2, J. Collins 3, V. Straub 4, M. McCallum 4, N. Deconinck 5, E. Mercuri 6, M. Pane 6, A. D’Amico 7, E. Bertini 7, K. North 8, M.M. Ryan 9, S. Auh 10, F. Muntoni 1, C.G. Bo¨nnemann 11 1 Dubowitz Neuromuscular Centre, UCL Institute of Child Health and Great Ormond Street Hospital, London, United Kingdom; 2 Garches Neuromuscular Centre (GNMH), Raymond Poincare´ University Hospital (UVSQ), Garches, France; 3 Cincinnati Children’s Hospital Medical Center, Neurology Division, Cincinnati, United States; 4 Institute of Human Genetics, International Centre for Life, University of Newcastle, Newcastle upon Tyne, United Kingdom; 5 Hoˆpital Universitaire des Enfants Reine Fabiola, Department of Neurology, Brussels, Belgium; 6 Catholic University, Department of Paediatric Neurology, Rome, Italy; 7 Bambino Gesu` Children’s Hospital, Laboratory of Molecular Medicine, Rome, Italy; 8 Children’s Hospital at Westmead, University of Sydney, Institute for Neuroscience and Muscle Research, Sydney, Australia; 9 Royal Children’s Hospital, Murdoch Childrens Research Institute, University of