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Polavarapu K, O'Neil D, Thompson R, Spendiff S, Nandeesh B, Vengalil S, Huddar A, Baskar D, Arunachal G, Kotambail A, Bhatia S, Tumulu SK, Matalonga L, Töpf A, Laurie S, Zeldin J, Nashi S, Unnikrishnan G, Nalini A, Lochmüller H. Partial loss of desmin expression due to a leaky splice site variant in the human DES gene is associated with neuromuscular transmission defects. Neuromuscul Disord 2024; 39:10-18. [PMID: 38669730 DOI: 10.1016/j.nmd.2024.03.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 02/15/2024] [Accepted: 03/20/2024] [Indexed: 04/28/2024]
Abstract
Recessive desminopathies are rare and often present as severe early-onset myopathy. Here we report a milder phenotype in three unrelated patients from southern India (2 M, 1F) aged 16, 21, and 22 years, who presented with childhood-onset, gradually progressive, fatigable limb-girdle weakness, ptosis, speech and swallowing difficulties, without cardiac involvement. Serum creatine kinase was elevated, and repetitive nerve stimulation showed decrement in all. Clinical improvement was noted with pyridostigmine and salbutamol in two patients. All three patients had a homozygous substitution in intron 5: DES(NM_001927.4):c.1023+5G>A, predicted to cause a donor splice site defect. Muscle biopsy with ultrastructural analysis suggested myopathy with myofibrillar disarray, and immunohistochemistry showed partial loss of desmin with some residual staining, while western blot analysis showed reduced desmin. RT-PCR of patient muscle RNA revealed two transcripts: a reduced normal desmin transcript and a larger abnormal transcript suggesting leaky splicing at the intron 5 donor site. Sequencing of the PCR products confirmed the inclusion of intron 5 in the longer transcript, predicted to cause a premature stop codon. Thus, we provide evidence for a leaky splice site causing partial loss of desmin associated with a unique phenotypic presentation of a milder form of desmin-related recessive myopathy overlapping with congenital myasthenic syndrome.
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Affiliation(s)
- Kiran Polavarapu
- Childrens Hospital of Eastern Ontario Research Institute, Ottawa, Canada
| | - Daniel O'Neil
- Childrens Hospital of Eastern Ontario Research Institute, Ottawa, Canada
| | - Rachel Thompson
- Childrens Hospital of Eastern Ontario Research Institute, Ottawa, Canada
| | - Sally Spendiff
- Childrens Hospital of Eastern Ontario Research Institute, Ottawa, Canada
| | - Bevinahalli Nandeesh
- Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Seena Vengalil
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Akshata Huddar
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Dipti Baskar
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Gautham Arunachal
- Department of Human Genetics, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | | | - Saloni Bhatia
- Department of Human Genetics, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Seetam Kumar Tumulu
- Department of Neuroradiology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Leslie Matalonga
- Centro Nacional de Análisis Genómico, Baldiri Reixac 4, Barcelona 08028, Spain
| | - Ana Töpf
- John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Steven Laurie
- Centro Nacional de Análisis Genómico, Baldiri Reixac 4, Barcelona 08028, Spain
| | - Joshua Zeldin
- Childrens Hospital of Eastern Ontario Research Institute, Ottawa, Canada
| | - Saraswati Nashi
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | | | - Atchayaram Nalini
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India.
| | - Hanns Lochmüller
- Childrens Hospital of Eastern Ontario Research Institute, Ottawa, Canada; Centro Nacional de Análisis Genómico, Baldiri Reixac 4, Barcelona 08028, Spain; Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, Canada; Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada; Department of Neuropediatrics and Muscle Disorders, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany.
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Onore ME, Savarese M, Picillo E, Passamano L, Nigro V, Politano L. Bi-Allelic DES Gene Variants Causing Autosomal Recessive Myofibrillar Myopathies Affecting Both Skeletal Muscles and Cardiac Function. Int J Mol Sci 2022; 23:ijms232415906. [PMID: 36555543 PMCID: PMC9785402 DOI: 10.3390/ijms232415906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/09/2022] [Accepted: 12/11/2022] [Indexed: 12/15/2022] Open
Abstract
Mutations in the human desmin gene (DES) may cause both autosomal dominant and recessive cardiomyopathies leading to heart failure, arrhythmias and atrio-ventricular blocks, or progressive myopathies. Cardiac conduction disorders, arrhythmias and cardiomyopathies usually associated with progressive myopathy are the main manifestations of autosomal dominant desminopathies, due to mono-allelic pathogenic variants. The recessive forms, due to bi-allelic variants, are very rare and exhibit variable phenotypes in which premature sudden cardiac death could also occur in the first or second decade of life. We describe a further case of autosomal recessive desminopathy in an Italian boy born of consanguineous parents, who developed progressive myopathy at age 12, and dilated cardiomyopathy four years later and died of intractable heart failure at age 17. Next Generation Sequencing (NGS) analysis identified the homozygous loss-of-function variant c.634C>T; p.Arg212*, which was likely inherited from both parents. Furthermore, we performed a comparison of clinical and genetic results observed in our patient with those of cases so far reported in the literature.
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Affiliation(s)
- Maria Elena Onore
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Marco Savarese
- Folkhälsan Research Center, 00280 Helsinki, Finland
- Department of Medical and Clinical Genetics, Medicum, University of Helsinki, 00280 Helsinki, Finland
| | - Esther Picillo
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Luigia Passamano
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Vincenzo Nigro
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
- Telethon Institute of Genetics and Medicine, 80078 Pozzuoli, Italy
| | - Luisa Politano
- Cardiomyology and Medical Genetics, Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
- Correspondence:
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