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Costa-Roger M, Blasco-Pérez L, Gerin L, Codina-Solà M, Leno-Colorado J, Gómez-García De la Banda M, Garcia-Uzquiano R, Saugier-Veber P, Drunat S, Quijano-Roy S, Tizzano EF. Complex SMN Hybrids Detected in a Cohort of 31 Patients With Spinal Muscular Atrophy. Neurol Genet 2024; 10:e200175. [PMID: 39035824 PMCID: PMC11259531 DOI: 10.1212/nxg.0000000000200175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 06/06/2024] [Indexed: 07/23/2024]
Abstract
Background and Objectives Spinal muscular atrophy (SMA) is a recessive neuromuscular disorder caused by the loss or presence of point pathogenic variants in the SMN1 gene. The main positive modifier of the SMA phenotype is the number of copies of the SMN2 gene, a paralog of SMN1, which only produces around 10%-15% of functional SMN protein. The SMN2 copy number is inversely correlated with phenotype severity; however, discrepancies between the SMA type and the SMN2 copy number have been reported. The presence of SMN2-SMN1 hybrids has been proposed as a possible modifier of SMA disease. Methods We studied 31 patients with SMA, followed at a single center and molecularly diagnosed by Multiplex Ligand-Dependent Probe Amplification (MLPA), with a specific next-generation sequencing protocol to investigate their SMN2 genes in depth. Hybrid characterization also included bioinformatics haplotype phasing and specific PCRs to resolve each SMN2-SMN1 hybrid structure. Results We detected SMN2-SMN1 hybrid genes in 45.2% of the patients (14/31), the highest rate reported to date. This represents a total of 25 hybrid alleles, with 9 different structures, of which only 4 are detectable by MLPA. Of particular interest were 2 patients who presented 4 SMN2-SMN1 hybrid copies each and no pure SMN2 copies, an event reported here for the first time. No clear trend between the presence of hybrids and a milder phenotype was observed, although 5 of the patients with hybrid copies showed a better-than-expected phenotype. The higher hybrid detection rate in our cohort may be due to both the methodology applied, which allows an in-depth characterization of the SMN genes and the ethnicity of the patients, mainly of African origin. Discussion Although hybrid genes have been proposed to be beneficial for patients with SMA, our work revealed great complexity and variability between hybrid structures; therefore, each hybrid structure should be studied independently to determine its contribution to the SMA phenotype. Large-scale studies are needed to gain a better understanding of the function and implications of SMN2-SMN1 hybrid copies, improving genotype-phenotype correlations and prediction of the evolution of patients with SMA.
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Affiliation(s)
- Mar Costa-Roger
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Laura Blasco-Pérez
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Lorene Gerin
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Marta Codina-Solà
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Jordi Leno-Colorado
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Marta Gómez-García De la Banda
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Rocio Garcia-Uzquiano
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Pascale Saugier-Veber
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Séverine Drunat
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Susana Quijano-Roy
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Eduardo F Tizzano
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
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Palma S, Pereira P. Subclinical spinal muscular atrophy in a 60-year-old man. Neuromuscul Disord 2024; 39:42-45. [PMID: 38772073 DOI: 10.1016/j.nmd.2024.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 05/04/2024] [Accepted: 05/08/2024] [Indexed: 05/23/2024]
Abstract
Spinal muscular atrophy is an autosomal recessive genetic disease that can manifest with different phenotypes, classified as types 1 to 4, being type 4 the mildest form. We report a case of a 60-year-old man presenting with sudden onset of numbness in the right upper limb and with a family history of a 48-year-old brother with progressive weakness. At the first visit, his exam was unremarkable, except for a mild paresis of the right elbow extension and reduced right bicipital and tricipital reflexes. Electromyography revealed chronic motor neuronopathy and the genetic study confirmed a diagnosis of spinal muscular atrophy. At the follow-up visit his complains improved and his neurologic exam returned to normal. To our knowledge, this patient is the oldest asymptomatic SMA individual ever reported. This case highlights the need to exclude late onset spinal muscular atrophy in patients with indolent motor neuronopathy.
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Affiliation(s)
- Sandra Palma
- Hospital Garcia de Orta (Portugal), Avenida Torrado da Silva, 2805-267, Almada, Portugal.
| | - Pedro Pereira
- Hospital Garcia de Orta (Portugal), Avenida Torrado da Silva, 2805-267, Almada, Portugal.
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Wang N, Jiao K, He J, Zhu B, Cheng N, Sun J, Chen L, Chen W, Gong L, Qiao K, Xi J, Wu Q, Zhao C, Zhu W. Diagnosis of Challenging Spinal Muscular Atrophy Cases with Long-Read Sequencing. J Mol Diagn 2024; 26:364-373. [PMID: 38490302 DOI: 10.1016/j.jmoldx.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/17/2024] [Accepted: 02/07/2024] [Indexed: 03/17/2024] Open
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder primarily caused by the deletion or mutation of the survival motor neuron 1 (SMN1) gene. This study assesses the diagnostic potential of long-read sequencing (LRS) in three patients with SMA. For Patient 1, who has a heterozygous SMN1 deletion, LRS unveiled a missense mutation in SMN1 exon 5. In Patient 2, an Alu/Alu-mediated rearrangement covering the SMN1 promoter and exon 1 was identified through a blend of multiplex ligation-dependent probe amplification, LRS, and PCR across the breakpoint. The third patient, born to a consanguineous family, bore four copies of hybrid SMN genes. LRS determined the genomic structures, indicating two distinct hybrids of SMN2 exon 7 and SMN1 exon 8. However, a discrepancy was found between the SMN1/SMN2 ratio interpretations by LRS (0:2) and multiplex ligation-dependent probe amplification (0:4), which suggested a limitation of LRS in SMA diagnosis. In conclusion, this newly adapted long PCR-based third-generation sequencing introduces an additional avenue for SMA diagnosis.
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Affiliation(s)
- Ningning Wang
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Kexin Jiao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jin He
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Bochen Zhu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Nachuan Cheng
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jian Sun
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Lan Chen
- Department of Neurology, Nantong First People's Hospital, Nantong, China
| | - Wanjin Chen
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Lingyun Gong
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Kai Qiao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jianying Xi
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Qihan Wu
- Shanghai Ministry of Science and Technology Key Laboratory of Health and Disease Genomics, National Health Commission Key Lab of Reproduction Regulation, Shanghai Institute for Biomedical and Pharmaceutical Technologies, Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Wenhua Zhu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
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Qu Y, Bai J, Jiao H, Qi H, Huang W, OuYang S, Peng X, Jin Y, Wang H, Song F. Variants located in intron 6 of SMN1 lead to misdiagnosis in genetic detection and screening for SMA. Heliyon 2024; 10:e28015. [PMID: 38515714 PMCID: PMC10955315 DOI: 10.1016/j.heliyon.2024.e28015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 02/28/2024] [Accepted: 03/11/2024] [Indexed: 03/23/2024] Open
Abstract
Accurate genetic diagnosis is necessary for guiding the treatment of spinal muscular atrophy (SMA). An updated consensus for the diagnosis and management of SMA was published in 2018. However, clinicians should remain alert to some pitfalls of genetic testing that can occur when following a routine diagnosis. In this study, we report the diagnosis of three unrelated individuals who were initially misdiagnosed as carrying a homozygous deletion of SMN1 exon 7. MLPA (P060 and P021) and qPCR were used to detect the copy number of SMN. SMN1 variants were identified by SMN1 clone and next-generation sequencing (NGS). Transcription of SMN1 variants was detected using qRT-PCR and ex vivo splicing analysis. Among the three individuals, one was identified as a patient with SMA carrying a heterozygous deletion and a pathogenic variant (c.835-17_835-14delCTTT) of SMN1, one was a healthy carrier only carrying a heterozygous deletion of SMN1 exon 7, and the third was a patient with nemaline myopathy 2 carrying a heterozygous deletion of SMN1 exon 7. The misdiagnosis of these individuals was attributed to the presence of the c.835-17_835-14delCTTT or c.835-17C > G variants in SMN1 intron 6, which affect the amplification of SMN1 exon 7 during MLPA-P060 and qPCR testing. However, MLPA-P021 and NGS analyses were unaffected by these variants. These results support that additional detection methods should be employed in cases where the SMN1 copy number is ambiguous to minimize the misdiagnosis of SMA.
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Affiliation(s)
- Yujin Qu
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Jinli Bai
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Hui Jiao
- Department of Neurology, Children’s Hospital Affiliated to Capital Institute of Pediatrics, Beijing, China
| | - Hong Qi
- Prenatal Diagnosis Center, Beijing Haidian District Maternal and Child Health Care Hospital, Beijing, China
| | - Wenchen Huang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Shijia OuYang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Xiaoyin Peng
- Department of Neurology, Children’s Hospital Affiliated to Capital Institute of Pediatrics, Beijing, China
| | - Yuwei Jin
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Hong Wang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Fang Song
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
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Bjelica B, Wohnrade C, Cespedes I, Osmanovic A, Schreiber-Katz O, Petri S. Risdiplam therapy in adults with 5q-SMA: observational study on motor function and treatment satisfaction. BMC Neurol 2024; 24:67. [PMID: 38368338 PMCID: PMC10873992 DOI: 10.1186/s12883-024-03562-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 02/02/2024] [Indexed: 02/19/2024] Open
Abstract
BACKGROUND We aimed to describe the experience of a single neuromuscular center in Germany in treating adult spinal muscular atrophy (SMA) patients with risdiplam and to analyze motor function and treatment satisfaction during a follow-up period up to 20 months. METHODS Fourteen patients with type 2 or 3 SMA (seven with SMA type 2, six with SMA type 3; age range: 18-51) were included. The Revised Upper Limb Module (RULM) and the Hammersmith Functional Motor Scale Expanded (HFMSE) were recorded at baseline and at follow-up (month 4, 8, 12, 16, 20). Treatment adverse events were collected at every follow-up visit. Patients' treatment satisfaction was assessed by the Treatment Satisfaction Questionnaire for Medication (TSQM). RESULTS Half of the patients reached the 20-month follow-up. Based on the HFMSE score, no patients had clinically meaningful improvement. Twelve remained stable (92.3%), two showed transient clinically meaningful deterioration (15.4%) and one experienced lasting clinically meaningful deterioration (7.7%). Based on the RULM scores, seven patients were either stable or demonstrated clinically meaningful improvement (53.8%) and six showed clinically meaningful deterioration (46.2%). There was no treatment withdrawal during the follow-up. The most common adverse events were skin rash/increased skin sensitivity to sunlight (n = 3), diarrhea (n = 3), aphthous ulcer (n = 3) and abdominal pain (n = 2). Most patients stated to be at least "satisfied" with the medication. CONCLUSIONS Risdiplam was well tolerated. Half of the patients remained stable or improved after risdiplam initiation. Larger and multicentric studies are needed to better understand the long-term effects of risdiplam in adult SMA.
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Affiliation(s)
- Bogdan Bjelica
- Department of Neurology, Hannover Medical School, 1, Carl-Neuberg-Straße, Hannover, 30625, Germany.
| | - Camilla Wohnrade
- Department of Neurology, Hannover Medical School, 1, Carl-Neuberg-Straße, Hannover, 30625, Germany
| | - Iraima Cespedes
- Department of Neurology, Hannover Medical School, 1, Carl-Neuberg-Straße, Hannover, 30625, Germany
| | - Alma Osmanovic
- Department of Neurology, Hannover Medical School, 1, Carl-Neuberg-Straße, Hannover, 30625, Germany
- Essen Center for Rare Diseases (EZSE), University Hospital Essen, Essen, Germany
| | - Olivia Schreiber-Katz
- Department of Neurology, Hannover Medical School, 1, Carl-Neuberg-Straße, Hannover, 30625, Germany
| | - Susanne Petri
- Department of Neurology, Hannover Medical School, 1, Carl-Neuberg-Straße, Hannover, 30625, Germany
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Yeo CJJ, Tizzano EF, Darras BT. Challenges and opportunities in spinal muscular atrophy therapeutics. Lancet Neurol 2024; 23:205-218. [PMID: 38267192 DOI: 10.1016/s1474-4422(23)00419-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 09/12/2023] [Accepted: 10/26/2023] [Indexed: 01/26/2024]
Abstract
Spinal muscular atrophy was the most common inherited cause of infant death until 2016, when three therapies became available: the antisense oligonucleotide nusinersen, gene replacement therapy with onasemnogene abeparvovec, and the small-molecule splicing modifier risdiplam. These drugs compensate for deficient survival motor neuron protein and have improved lifespan and quality of life in infants and children with spinal muscular atrophy. Given the lifelong implications of these innovative therapies, ways to detect and manage treatment-modified disease characteristics are needed. All three drugs are more effective when given before development of symptoms, or as early as possible in individuals who have already developed symptoms. Early subtle symptoms might be missed, and disease onset might occur in utero in severe spinal muscular atrophy subtypes; in some countries, newborn screening is allowing diagnosis soon after birth and early treatment. Adults with spinal muscular atrophy report stabilisation of disease and less fatigue with treatment. These subjective benefits need to be weighed against the high costs of the drugs to patients and health-care systems. Clinical consensus is required on therapeutic windows and on outcome measures and biomarkers that can be used to monitor drug benefit, toxicity, and treatment-modified disease characteristics.
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Affiliation(s)
- Crystal J J Yeo
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, UK; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore; Agency for Science, Technology and Research, Singapore; National Neuroscience Institute, Tan Tock Seng and Singapore General Hospital, Singapore; Duke-NUS Medical School, Singapore
| | - Eduardo F Tizzano
- Department of Clinical and Molecular Genetics, Vall d'Hebron University Hospital, Barcelona, Spain; Genetics Medicine, Vall d'Hebron Research Institute, Barcelona, Spain
| | - Basil T Darras
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
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Yang Y, Xia C, Song X, Tang X, Nie X, Xu W, Du C, Zhang H, Luo P. Application of a Multiplex Ligation-Dependent Probe Amplification-Based Next-Generation Sequencing Approach for the Detection of Pathogenesis of Duchenne Muscular Dystrophy and Spinal Muscular Atrophy Caused by Copy Number Aberrations. Mol Neurobiol 2024; 61:200-211. [PMID: 37596438 PMCID: PMC10791777 DOI: 10.1007/s12035-023-03572-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 08/04/2023] [Indexed: 08/20/2023]
Abstract
Both Duchenne muscular dystrophy (DMD; OMIM no. 310200) and spinal muscular atrophy (SMA; OMIM no. 253300/253550/253400/271150) are genetic disorders characterized by progressive muscle degeneration and weakness. Genetic copy number aberrations in the pathogenetic genes DMD and SMN1 lead to alterations in functional proteins, resulting in DMD and SMA, respectively. Multiplex ligation-dependent probe amplification (MLPA) has become a standard method for the detection of common copy number aberrations (CNAs), including DMD and SMN1 deletions, both of which are associated with poor clinical outcomes. However, traditional MLPA assays only accommodate a maximum of 60 MLPA probes per test. To increase the number of targeted sequences in one assay, an MLPA-based next-generation sequencing (NGS) assay has been developed that is based on the standard MLPA procedure, allows high-throughput screening for a large number of fragments and samples by integrating additional indices for detection, and can be analyzed on all Illumina NGS platforms.
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Affiliation(s)
- Yongchen Yang
- Department of Laboratory Medicine, Shanghai Children's Hospital, School of Medicine, Shanghai Jiao Tong University, Building 7, 24, Lane 1400, West Beijing Road, Jing'an, Shanghai, 200040, People's Republic of China.
| | - Chaoran Xia
- Zhejiang Shaoxing Topgen Biomedical Technology Co. Ltd. Block B, Building 19, No. 3399 Kangxin Road, Pudong District, Shanghai, 201321, People's Republic of China.
| | - Xiaozhen Song
- Department of Laboratory Medicine, Shanghai Children's Hospital, School of Medicine, Shanghai Jiao Tong University, Building 7, 24, Lane 1400, West Beijing Road, Jing'an, Shanghai, 200040, People's Republic of China
| | - Xiaojun Tang
- Department of Laboratory Medicine, Shanghai Children's Hospital, School of Medicine, Shanghai Jiao Tong University, Building 7, 24, Lane 1400, West Beijing Road, Jing'an, Shanghai, 200040, People's Republic of China
| | - Xueling Nie
- Shanghai Shiji Medical Laboratory Institute, Floor 5, No. 3805, Zhoujiazui Road, Yangpu District, Shanghai, 200093, People's Republic of China
| | - Wuhen Xu
- Department of Laboratory Medicine, Shanghai Children's Hospital, School of Medicine, Shanghai Jiao Tong University, Building 7, 24, Lane 1400, West Beijing Road, Jing'an, Shanghai, 200040, People's Republic of China
| | - Chengkan Du
- Department of Laboratory Medicine, Shanghai Children's Hospital, School of Medicine, Shanghai Jiao Tong University, Building 7, 24, Lane 1400, West Beijing Road, Jing'an, Shanghai, 200040, People's Republic of China
| | - Hong Zhang
- Department of Laboratory Medicine, Shanghai Children's Hospital, School of Medicine, Shanghai Jiao Tong University, Building 7, 24, Lane 1400, West Beijing Road, Jing'an, Shanghai, 200040, People's Republic of China
| | - Peng Luo
- Zhejiang Shaoxing Topgen Biomedical Technology Co. Ltd. Block B, Building 19, No. 3399 Kangxin Road, Pudong District, Shanghai, 201321, People's Republic of China
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8
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Li L, Perera L, Varghese SA, Shiloh-Malawsky Y, Hunter SE, Sneddon TP, Powell CM, Matera AG, Fan Z. A homozygous missense variant in the YG box domain in an individual with severe spinal muscular atrophy: a case report and variant characterization. Front Cell Neurosci 2023; 17:1259380. [PMID: 37841286 PMCID: PMC10571918 DOI: 10.3389/fncel.2023.1259380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 09/04/2023] [Indexed: 10/17/2023] Open
Abstract
The vast majority of severe (Type 0) spinal muscular atrophy (SMA) cases are caused by homozygous deletions of survival motor neuron 1 (SMN1). We report a case in which the patient has two copies of SMN1 but clinically presents as Type 0 SMA. The patient is an African American male carrying a homozygous maternally inherited missense variant (c.796T>C) in a cis-oriented SMN1 duplication on one chromosome and an SMN1 deletion on the other chromosome (genotype: 2*+0). Initial extensive genetic workups including exome sequencing were negative. Deletion analysis used in the initial testing for SMA also failed to detect SMA as the patient has two copies of SMN1. Because of high clinical suspicion, SMA diagnosis was finally confirmed based on full-length SMN1 sequencing. The patient was initially treated with risdiplam and later gene therapy with onasemnogene abeparvovec at 5 months without complications. The patient's muscular weakness has stabilized with mild improvement. The patient is now 28 months old and remains stable and diffusely weak, with stable respiratory ventilatory support. This case highlights challenges in the diagnosis of SMA with a non-deletion genotype and provides a clinical example demonstrating that disruption of functional SMN protein polymerization through an amino acid change in the YG-box domain represents a little known but important pathogenic mechanism for SMA. Clinicians need to be mindful about the limitations of the current diagnostic approach for SMA in detecting non-deletion genotypes.
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Affiliation(s)
- Leping Li
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Lalith Perera
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Sonia A. Varghese
- Division of Pediatric Neurology, Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Yael Shiloh-Malawsky
- Division of Pediatric Neurology, Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Senyene E. Hunter
- Division of Pediatric Neurology, Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Tam P. Sneddon
- Department of Pathology and Lab Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Cynthia M. Powell
- Division of Genetics and Metabolism, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - A. Gregory Matera
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Zheng Fan
- Division of Pediatric Neurology, Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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9
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Tan J, Zhang J, Sun R, Jiang Z, Wang Y, Ma D, Jiao J, Chen H, Lin Y, Zhang Q, Xu Z, Hu P. Evaluating the performance of four assays for carrier screening of spinal muscular atrophy. Clin Chim Acta 2023; 548:117496. [PMID: 37479010 DOI: 10.1016/j.cca.2023.117496] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/19/2023] [Accepted: 07/18/2023] [Indexed: 07/23/2023]
Abstract
BACKGROUND AND AIMS Spinal muscular atrophy (SMA) is an autosomal recessive inherited neuromuscular condition caused by biallelic mutations in the survival of motor neuron 1 (SMN1) gene. A homozygous deletion of the SMN1 gene accounts for approximately 95-98% of SMA patients. A highly homologous gene survival motor neuron 2 (SMN2) can partially compensate for SMN1 deletion, and its copy number is associated with disease severity. Population-based carrier screening by simultaneous quantification of SMN1 and SMN2 copy numbers is the best method to prevent SMA. MATERIALS AND METHODS In this study, a total of 516 samples were re-tested for the SMN1 copy number by using quantitative polymerase chain reaction (qPCR), multiplex ligation probe amplification (MLPA), droplet digital PCR (ddPCR), high-resolution melting (HRM) analysis, and PCR-based capillary electrophoresis (PCR/CE) simultaneously. Then, the performance of these methods was compared by using MLPA results as the reference. RESULTS The results of qPCR, ddPCR, HRM, and PCR/CE in detecting heterozygous deletion of SMN1 exon 7 and the results of ddPCR, HRM, and PCR/CE in detecting ≥2 copies of SMN1 exon7 are totally consistent with those of MLPA. The sensitivity and specificity of qPCR for detection of 2 copies of SMN1 exon 7 were 99.7% and 98.8%, respectively. The sensitivity and specificity of qPCR for detection of >2 copies of SMN1 exon 7 were 96.3% and 99.8%, respectively. Compared with the MLPA results, the sensitivity and specificity of qPCR and HRM for detection of heterozygous deletion of SMN1 exon 8 were 100% and 100%, respectively. They were 99.4% and 100%, respectively for detection of 2 copies, and 100% and 100%, respectively for detection of >2 copies. The results of PCR/CE in detecting SMN1 exon 8 were consistent with those of MLPA. CONCLUSION All these four methods show excellent performance in detecting heterozygous deletion of SMN1 exon 7. All PCR/CE results are totally concordant with those of MLPA. As the most cost-effective method, qPCR also shows high sensitivity and specificity in detecting SMN1. Taken together, our study provides useful information to select appropriate methods for SMA carrier screening.
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Affiliation(s)
- Jianxin Tan
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Jingjing Zhang
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Ruihong Sun
- Department of Laboratory Medicine, The First School of Clinical Medicine, Nanjing Medical University, Nanjing 210029, People's Republic of China
| | - Zhu Jiang
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Yuguo Wang
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Dingyuan Ma
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Jiao Jiao
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Hao Chen
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Yingchun Lin
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Qinxin Zhang
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China
| | - Zhengfeng Xu
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China.
| | - Ping Hu
- Department of Prenatal Diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing 210004, People's Republic of China.
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10
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Weidlich D, Servais L, Kausar I, Howells R, Bischof M. Cost-Effectiveness of Newborn Screening for Spinal Muscular Atrophy in England. Neurol Ther 2023; 12:1205-1220. [PMID: 37222861 PMCID: PMC10310612 DOI: 10.1007/s40120-023-00489-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 04/26/2023] [Indexed: 05/25/2023] Open
Abstract
INTRODUCTION We sought to evaluate the cost-effectiveness of newborn screening (NBS) versus no NBS for 5q spinal muscular atrophy (SMA) in England. METHODS A cost-utility analysis using a combination of decision tree and Markov model structures was developed to estimate the lifetime health effects and costs of NBS for SMA, compared with no NBS, from the perspective of the National Health Service (NHS) in England. A decision tree was designed to capture NBS outcomes, and Markov modeling was used to project long-term health outcomes and costs for each patient group following diagnosis. Model inputs were based on existing literature, local data, and expert opinion. Sensitivity and scenario analyses were conducted to assess the robustness of the model and the validity of the results. RESULTS The introduction of NBS for SMA in England is estimated to identify approximately 56 (96% of cases) infants with SMA per year. Base-case results indicate that NBS is dominant (less costly and more effective) than a scenario without NBS, with a yearly cohort of newborns accruing incremental savings of £62,191,531 and an estimated gain in quality-adjusted life-years of 529 years over their lifetime. Deterministic and probabilistic sensitivity analyses demonstrated the robustness of the base-case results. CONCLUSIONS NBS improves health outcomes for patients with SMA and is less costly compared with no screening; therefore, it is a cost-effective use of resources from the perspective of the NHS in England.
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Affiliation(s)
- Diana Weidlich
- Health Economics, Clarivate, Munich, Germany.
- Clarivate, Landsberger Straße 302, 80687, Munich, Germany.
| | - Laurent Servais
- MDUK Oxford Neuromuscular Centre and NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
- Neuromuscular Center of Liège, Department of Paediatrics, Hospital and University of Liège, Liège, Belgium
| | | | - Ruth Howells
- Health Technology Assessment, Clarivate, Manchester, UK
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11
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Bai J, Qu Y, OuYang S, Jiao H, Wang Y, Li J, Huang W, Zhao Y, Peng X, Wang D, Jin Y, Wang H, Song F. Novel Alu-mediated deletions of the SMN1 gene were identified by ultra-long read sequencing technology in patients with spinal muscular atrophy. Neuromuscul Disord 2023; 33:382-390. [PMID: 37023488 DOI: 10.1016/j.nmd.2023.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 02/20/2023] [Accepted: 03/01/2023] [Indexed: 03/11/2023]
Abstract
Spinal muscular atrophy (SMA) is a neuromuscular disease caused by biallelic variants of the survival motor neuron 1 (SMN1) gene. In this study, our aim was to make a molecular diagnosis in two patients with SMA carrying only one SMN1 copy number. Using ultra-long read sequencing (Ultra-LRS), 1415 bp deletion and 3348 bp deletion of the SMN1 gene were identified in patient 1 and the father of patient 2, respectively. Ultra-LRS revealed two novel deletions, starting from the SMN1 promoter to intron 1. It also accurately provided the location of the deletion breakpoints in the SMN1 gene: chr5 g.70,924,798-70,926,212 for a 1415 bp deletion; chr5 g.70,922,695-70,926,042 for a 3348 bp deletion. By analyzing the breakpoint junctions, we identified that these genomic sequences were composed of Alu sequences, including AluJb, AluYm1, AluSq, and AluYm1, indicating that Alu-mediated rearrangements are a mechanism of SMN1 deletion events. In addition, full-length SMN1 transcripts and SMN protein in patient 1 were significantly decreased (p < 0.01), suggesting that a 1415 bp deletion that included the transcription and translation initiation sites of the SMN1 gene had severe consequences for SMN expression. Ultra-LRS can easily distinguish highly homozygous genes compared to other detection technologies, which is useful for detecting SMN1 intragenic mutations, to quickly discover structural rearrangements and to precisely present the breakpoint positions.
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12
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Chen X, Harting J, Farrow E, Thiffault I, Kasperaviciute D, Hoischen A, Gilissen C, Pastinen T, Eberle MA. Comprehensive SMN1 and SMN2 profiling for spinal muscular atrophy analysis using long-read PacBio HiFi sequencing. Am J Hum Genet 2023; 110:240-250. [PMID: 36669496 PMCID: PMC9943720 DOI: 10.1016/j.ajhg.2023.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 12/20/2022] [Indexed: 01/21/2023] Open
Abstract
Spinal muscular atrophy, a leading cause of early infant death, is caused by bi-allelic mutations of SMN1. Sequence analysis of SMN1 is challenging due to high sequence similarity with its paralog SMN2. Both genes have variable copy numbers across populations. Furthermore, without pedigree information, it is currently not possible to identify silent carriers (2+0) with two copies of SMN1 on one chromosome and zero copies on the other. We developed Paraphase, an informatics method that identifies full-length SMN1 and SMN2 haplotypes, determines the gene copy numbers, and calls phased variants using long-read PacBio HiFi data. The SMN1 and SMN2 copy-number calls by Paraphase are highly concordant with orthogonal methods (99.2% for SMN1 and 100% for SMN2). We applied Paraphase to 438 samples across 5 ethnic populations to conduct a population-wide haplotype analysis of these highly homologous genes. We identified major SMN1 and SMN2 haplogroups and characterized their co-segregation through pedigree-based analyses. We identified two SMN1 haplotypes that form a common two-copy SMN1 allele in African populations. Testing positive for these two haplotypes in an individual with two copies of SMN1 gives a silent carrier risk of 88.5%, which is significantly higher than the currently used marker (1.7%-3.0%). Extending beyond simple copy-number testing, Paraphase can detect pathogenic variants and enable potential haplotype-based screening of silent carriers through statistical phasing of haplotypes into alleles. Future analysis of larger population data will allow identification of more diverse haplotypes and genetic markers for silent carriers.
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Affiliation(s)
| | | | - Emily Farrow
- Genomic Medicine Center, Children’s Mercy Kansas City, Kansas City, MO, USA,UMKC School of Medicine, University of Missouri Kansas City, Kansas City, MO, USA,Department of Pediatrics, Children’s Mercy Kansas City, Kansas City, MO, USA
| | - Isabelle Thiffault
- Genomic Medicine Center, Children’s Mercy Kansas City, Kansas City, MO, USA,UMKC School of Medicine, University of Missouri Kansas City, Kansas City, MO, USA,Department of Pathology and Laboratory Medicine, Children’s Mercy Kansas City, Kansas City, MO, USA
| | | | | | - Alexander Hoischen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands,Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands,Radboud Center for Infectious Diseases (RCI), Department of Internal Medicine, Radboud University Medical Center, Nijmegen, the Netherlands,Radboud Expertise Center for Immunodeficiency and Autoinflammation and Radboud Center for Infectious Disease (RCI), Radboud University Medical Center, Nijmegen, the Netherlands
| | - Christian Gilissen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands,Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Tomi Pastinen
- Genomic Medicine Center, Children’s Mercy Kansas City, Kansas City, MO, USA,UMKC School of Medicine, University of Missouri Kansas City, Kansas City, MO, USA
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13
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Vezain M, Thauvin-Robinet C, Vial Y, Coutant S, Drunat S, Urtizberea JA, Rolland A, Jacquin-Piques A, Fehrenbach S, Nicolas G, Lecoquierre F, Saugier-Veber P. Retrotransposon insertion as a novel mutational cause of spinal muscular atrophy. Hum Genet 2023; 142:125-138. [PMID: 36138164 DOI: 10.1007/s00439-022-02473-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 07/15/2022] [Indexed: 01/18/2023]
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder resulting from biallelic alterations of the SMN1 gene: deletion, gene conversion or, in rare cases, intragenic variants. The disease severity is mainly influenced by the copy number of SMN2, a nearly identical gene, which produces only low amounts of full-length (FL) mRNA. Here we describe the first example of retrotransposon insertion as a pathogenic SMN1 mutational event. The 50-year-old patient is clinically affected by SMA type III with a diagnostic odyssey spanning nearly 30 years. Despite a mild disease course, he carries a single SMN2 copy. Using Exome Sequencing and Sanger sequencing, we characterized a SINE-VNTR-Alu (SVA) type F retrotransposon inserted in SMN1 intron 7. Using RT-PCR and RNASeq experiments on lymphoblastoid cell lines, we documented the dramatic decrease of FL transcript production in the patient compared to subjects with the same SMN1 and SMN2 copy number, thus validating the pathogenicity of this SVA insertion. We described the mutant FL-SMN1-SVA transcript characterized by exon extension and showed that it is subject to degradation by nonsense-mediated mRNA decay. The stability of the SMN-SVA protein may explain the mild course of the disease. This observation exemplifies the role of retrotransposons in human genetic disorders.
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Affiliation(s)
- Myriam Vezain
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France
| | - Christel Thauvin-Robinet
- INSERM UMR1231 GAD-Génétique des Anomalies du Développement, Bourgogne Franche-Comté University, F-21000 , Dijon, France.,Genetics Center, Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (TRANSLAD), Dijon-Burgundy University Hospital, F-21000, Dijon, France
| | - Yoann Vial
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France.,Genetics Department, AP-HP, Robert-Debré University Hospital, 48 boulevard Sérurier, 75019 , Paris, France
| | - Sophie Coutant
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France
| | - Séverine Drunat
- INSERM UMR 1141, PROTECT, Paris University, F-75019, Paris, France.,Genetics Department, AP-HP, Robert-Debré University Hospital, F-75019, Paris, France
| | - Jon Andoni Urtizberea
- Myology Institute, AP-HP Pitié-Salpêtrière University Hospital, F-75013, Paris, France
| | - Anne Rolland
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Pediatrics Department, Valence Hospital, 179 boulevard du Maréchal Juin, 26000, Valence, France
| | - Agnès Jacquin-Piques
- Department of Neurology, Clinical Neurophysiology, Competence Center of Neuromuscular Diseases, Dijon-Burgundy University Hospital, F-21000, Dijon, France
| | - Séverine Fehrenbach
- Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France
| | - Gaël Nicolas
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France
| | - François Lecoquierre
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France
| | - Pascale Saugier-Veber
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France. .,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France. .,Laboratoire de Génétique Moléculaire, UFR-Santé, 22 boulevard Gambetta, 76183, Rouen, France.
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14
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Younger DS. On the path to evidence-based therapy in neuromuscular disorders. HANDBOOK OF CLINICAL NEUROLOGY 2023; 195:315-358. [PMID: 37562877 DOI: 10.1016/b978-0-323-98818-6.00007-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Neuromuscular disorders encompass a diverse group of acquired and genetic diseases characterized by loss of motor functionality. Although cure is the goal, many therapeutic strategies have been envisioned and are being studied in randomized clinical trials and entered clinical practice. As in all scientific endeavors, the successful clinical translation depends on the quality and translatability of preclinical findings and on the predictive value and feasibility of the clinical models. This chapter focuses on five exemplary diseases: childhood spinal muscular atrophy (SMA), Charcot-Marie-Tooth (CMT) disorders, chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), acquired autoimmune myasthenia gravis (MG), and Duchenne muscular dystrophy (DMD), to illustrate the progress made on the path to evidenced-based therapy.
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Affiliation(s)
- David S Younger
- Department of Clinical Medicine and Neuroscience, CUNY School of Medicine, New York, NY, United States; Department of Medicine, Section of Internal Medicine and Neurology, White Plains Hospital, White Plains, NY, United States.
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15
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Abstract
Spinal muscular atrophy (SMA) is caused by biallelic mutations in the SMN1 (survival motor neuron 1) gene on chromosome 5q13.2, which leads to a progressive degeneration of alpha motor neurons in the spinal cord and in motor nerve nuclei in the caudal brainstem. It is characterized by progressive proximally accentuated muscle weakness with loss of already acquired motor skills, areflexia and, depending on the phenotype, varying degrees of weakness of the respiratory and bulbar muscles. Over the past decade, disease-modifying therapies have become available based on splicing modulation of the SMN2 with SMN1 gene replacement, which if initiated significantly modifies the natural course of the disease. Newborn screening for SMA has been implemented in an increasing number of centers; however, available evidence for these new treatments is often limited to a small spectrum of patients concerning age and disease stage.
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Affiliation(s)
- David S Younger
- Department of Clinical Medicine and Neuroscience, CUNY School of Medicine, New York, NY, United States; Department of Medicine, Section of Internal Medicine and Neurology, White Plains Hospital, White Plains, NY, United States.
| | - Jerry R Mendell
- Department of Neurology and Pediatrics, Center for Gene Therapy, Abigail Wexner Research Institute, The Ohio State University, Nationwide Children's Hospital, Columbus, OH, United States
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16
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Hassan HA, Fahmy NA, El-Bagoury NM, Eissa NR, Sharaf-Eldin WE, Issa MY, Zaki MS, Essawi ML. MLPA analysis for molecular diagnosis of spinal muscular atrophy and correlation of 5q13.2 genes with disease phenotype in Egyptian patients. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2022. [DOI: 10.1186/s43042-022-00373-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Abstract
Background
Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease representing the most prevalent monogenic cause of infant mortality. It results from the loss of SMN1 gene, but retention of its paralog SMN2 whose copy number can modulate the disease severity and guide the therapeutic regimen.
Methods
For SMA molecular analysis, 236 unrelated Egyptian patients were enrolled at our institution. The Multiplex ligation-dependent probe amplification analysis (MLPA) was applied to investigate the main genetic defect in the enrolled patients (SMN1 loss) and to determine a possible genotype–phenotype correlation between the copy number of other genes in the SMN locus (5q13.2) and disease severity in Egyptian patients with SMA. A small cohort of healthy subjects (n = 57) was also included to investigate the possible differences in the distributions of SMN2 and NAIP genes between patients and healthy individuals.
Results
Disease diagnosis was confirmed in only 148 patients (62.7%) highlighting the clinical overlapping of the disease and emphasizing the importance of molecular diagnosis. In patients with homozygous SMN1 loss, the disease was mediated by gene deletion and conversion in 135 (91.2%) and 13 (8.8%) patients, respectively. In the study cohort, SMN2 and NAIP copy numbers were inversely correlated with disease severity. However, no significant association was detected between GTF2H2A and SERF1B copy numbers and patient phenotype. Significant differences were demonstrated in the copy numbers of SMN2 and NAIP between SMA patients and healthy subjects.
Conclusion
Molecular analysis of SMA is essential for disease diagnosis. Consistent with previous studies on other populations, there is a close relationship between SMN2 and NAIP copy numbers and clinical phenotype. Additionally, potential differences in these two genes distributions are existing between patients and healthy subjects. National program for carrier screening should be established as a preventive disease strategy. On the other hand, neonatal testing would provide accurate estimation for disease incidence.
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17
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Maggi L, Bello L, Bonanno S, Govoni A, Caponnetto C, Passamano L, Grandis M, Trojsi F, Cerri F, Gardani A, Ferraro M, Gadaleta G, Zangaro V, Caumo L, Maioli M, Tanel R, Saccani E, Meneri M, Vacchiano V, Ricci G, Sorarù G, D'Errico E, Bortolani S, Pavesi G, Gellera C, Zanin R, Corti S, Silvestrini M, Politano L, Schenone A, Previtali SC, Berardinelli A, Turri M, Verriello L, Coccia M, Mantegazza R, Liguori R, Filosto M, Marrosu G, Tiziano FD, Siciliano G, Simone IL, Mongini T, Comi G, Pegoraro E. Adults with spinal muscular atrophy: a large-scale natural history study shows gender effect on disease. J Neurol Neurosurg Psychiatry 2022; 93:1253-1261. [PMID: 36220341 DOI: 10.1136/jnnp-2022-329320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 09/27/2022] [Indexed: 11/07/2022]
Abstract
BACKGROUND Natural history of spinal muscular atrophy (SMA) in adult age has not been fully elucidated yet, including factors predicting disease progression and response to treatments. Aim of this retrospective, cross-sectional study, is to investigate motor function across different ages, disease patterns and gender in adult SMA untreated patients. METHODS Inclusion criteria were as follows: (1) clinical and molecular diagnosis of SMA2, SMA3 or SMA4 and (2) clinical assessments performed in adult age (>18 years). RESULTS We included 64 (38.8%) females and 101 (61.2%) males (p=0.0025), among which 21 (12.7%) SMA2, 141 (85.5%) SMA3 and 3 (1.8%) SMA4. Ratio of sitters/walkers within the SMA3 subgroup was significantly (p=0.016) higher in males (46/38) than in females (19/38). Median age at onset was significantly (p=0.0071) earlier in females (3 years; range 0-16) than in males (4 years; range 0.3-28), especially in patients carrying 4 SMN2 copies. Median Hammersmith Functional Rating Scale Expanded scores were significantly (p=0.0040) lower in males (16, range 0-64) than in females (40, range 0-62); median revised upper limb module scores were not significantly (p=0.059) different between males (24, 0-38) and females (33, range 0-38), although a trend towards worse performance in males was observed. In SMA3 patients carrying three or four SMN2 copies, an effect of female sex in prolonging ambulation was statistically significant (p=0.034). CONCLUSIONS Our data showed a relevant gender effect on SMA motor function with higher disease severity in males especially in the young adult age and in SMA3 patients.
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Affiliation(s)
- Lorenzo Maggi
- Neuroimmunology and Neuromuscular Disease Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Luca Bello
- Department of Neurosciences, University of Padova, Padova, Italy
| | - Silvia Bonanno
- Neuroimmunology and Neuromuscular Disease Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Alessandra Govoni
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | | | - Luigia Passamano
- Cardiomyology and Medical Genetics Unit, University Hospital "L Vanvitelli", Napoli, Italy
| | - Marina Grandis
- IRCCS Ospedale Policlinico San Martino, Genova, Italy.,Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), Università di Genova, Genova, Italy
| | - Francesca Trojsi
- Department of Advanced Medical and Surgical Sciences, Università degli Studi della Campania "Luigi Vanvitelli", Napoli, Italy
| | - Federica Cerri
- Department of Neurology, IRCCS Ospedale San Raffaele, Milano, Italy
| | | | - Manfredi Ferraro
- Department of Neurosciences Rita Levi Montalcini, University of Turin, Turin, Italy
| | - Giulio Gadaleta
- Department of Neurosciences Rita Levi Montalcini, University of Turin, Turin, Italy
| | - Vittoria Zangaro
- Department of Neurosciences, University of Padova, Padova, Italy
| | - Luca Caumo
- Department of Neurosciences, University of Padova, Padova, Italy
| | | | | | - Elena Saccani
- Specialistic Medicine Unit, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
| | - Megi Meneri
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Veria Vacchiano
- IRCCS Istituto Delle Scienze Neurologiche di Bologna, Bologna, Italy.,Department of Biomedical and Neuromotor Sciences, Universita degli Studi di Bologna, Bologna, Italy
| | - Giulia Ricci
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Gianni Sorarù
- Department of Neurosciences, University of Padova, Padova, Italy
| | - Eustachio D'Errico
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari, Bari, Italy
| | - Sara Bortolani
- Department of Neurosciences Rita Levi Montalcini, University of Turin, Turin, Italy
| | - Giovanni Pavesi
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Cinzia Gellera
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Riccardo Zanin
- Developmental Neurology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Stefania Corti
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Mauro Silvestrini
- Department of Neurological Sciences, Ospedali Riuniti di Ancona, Ancona, Italy.,Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
| | - Luisa Politano
- Cardiomyology and Medical Genetics Unit, University Hospital "L Vanvitelli", Napoli, Italy
| | - Angelo Schenone
- IRCCS Ospedale Policlinico San Martino, Genova, Italy.,Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), Università di Genova, Genova, Italy
| | | | | | - Mara Turri
- Department of Neurology/Stroke Unit, San Maurizio Hospital, Bolzano, Italy
| | - Lorenzo Verriello
- Department of Neurosciences, Santa Maria della Misericordia University Hospital, Udine, Italy
| | - Michela Coccia
- Department of Neurological Sciences, Ospedali Riuniti di Ancona, Ancona, Italy
| | - Renato Mantegazza
- Neuroimmunology and Neuromuscular Disease Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Rocco Liguori
- IRCCS Istituto Delle Scienze Neurologiche di Bologna, Bologna, Italy.,Department of Biomedical and Neuromotor Sciences, Universita degli Studi di Bologna, Bologna, Italy
| | - Massimiliano Filosto
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.,NeMO-Brescia Clinical Center for Neuromuscular Diseases, Brescia, Italy
| | | | - Francesco Danilo Tiziano
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università Cattolica del Sacro Cuore Facoltà di Medicina e Chirurgia, Roma, Italy.,Department of Laboratory Science and Infectious Diseases, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Roma, Italy
| | - Gabriele Siciliano
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Isabella Laura Simone
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari, Bari, Italy
| | - Tiziana Mongini
- Department of Neurosciences Rita Levi Montalcini, University of Turin, Turin, Italy
| | - Giacomo Comi
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.,Department of Pathophysiology and Transplantation (DEPT), Dino Ferrari Centre, University of Milan, Milano, Italy
| | - Elena Pegoraro
- Department of Neurosciences, University of Padova, Padova, Italy
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18
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Milligan JN, Blasco-Pérez L, Costa-Roger M, Codina-Solà M, Tizzano EF. Recommendations for Interpreting and Reporting Silent Carrier and Disease-Modifying Variants in SMA Testing Workflows. Genes (Basel) 2022; 13:1657. [PMID: 36140824 PMCID: PMC9498682 DOI: 10.3390/genes13091657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 09/09/2022] [Accepted: 09/13/2022] [Indexed: 11/16/2022] Open
Abstract
Genetic testing for SMA diagnosis, newborn screening, and carrier screening has become a significant public health interest worldwide, driven largely by the development of novel and effective molecular therapies for the treatment of spinal muscular atrophy (SMA) and the corresponding updates to testing guidelines. Concurrently, understanding of the underlying genetics of SMA and their correlation with a broad range of phenotypes and risk factors has also advanced, particularly with respect to variants that modulate disease severity or impact residual carrier risks. While testing guidelines are beginning to emphasize the importance of these variants, there are no clear guidelines on how to utilize them in a real-world setting. Given the need for clarity in practice, this review summarizes several clinically relevant variants in the SMN1 and SMN2 genes, including how they inform outcomes for spinal muscular atrophy carrier risk and disease prognosis.
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Affiliation(s)
| | - Laura Blasco-Pérez
- Department of Clinical and Molecular Genetics, University Hospital Vall d’Hebron, 08035 Barcelona, Spain
| | - Mar Costa-Roger
- Department of Clinical and Molecular Genetics, University Hospital Vall d’Hebron, 08035 Barcelona, Spain
| | - Marta Codina-Solà
- Department of Clinical and Molecular Genetics, University Hospital Vall d’Hebron, 08035 Barcelona, Spain
| | - Eduardo F. Tizzano
- Department of Clinical and Molecular Genetics, University Hospital Vall d’Hebron, 08035 Barcelona, Spain
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19
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Detering NT, Schüning T, Hensel N, Claus P. The phospho-landscape of the survival of motoneuron protein (SMN) protein: relevance for spinal muscular atrophy (SMA). Cell Mol Life Sci 2022; 79:497. [PMID: 36006469 PMCID: PMC11071818 DOI: 10.1007/s00018-022-04522-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 07/27/2022] [Accepted: 08/09/2022] [Indexed: 11/03/2022]
Abstract
Spinal muscular atrophy (SMA) is caused by low levels of the survival of motoneuron (SMN) Protein leading to preferential degeneration of lower motoneurons in the ventral horn of the spinal cord and brain stem. However, the SMN protein is ubiquitously expressed and there is growing evidence of a multisystem phenotype in SMA. Since a loss of SMN function is critical, it is important to decipher the regulatory mechanisms of SMN function starting on the level of the SMN protein itself. Posttranslational modifications (PTMs) of proteins regulate multiple functions and processes, including activity, cellular trafficking, and stability. Several PTM sites have been identified within the SMN sequence. Here, we map the identified SMN PTMs highlighting phosphorylation as a key regulator affecting localization, stability and functions of SMN. Furthermore, we propose SMN phosphorylation as a crucial factor for intracellular interaction and cellular distribution of SMN. We outline the relevance of phosphorylation of the spinal muscular atrophy (SMA) gene product SMN with regard to basic housekeeping functions of SMN impaired in this neurodegenerative disease. Finally, we compare SMA patient mutations with putative and verified phosphorylation sites. Thus, we emphasize the importance of phosphorylation as a cellular modulator in a clinical perspective as a potential additional target for combinatorial SMA treatment strategies.
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Affiliation(s)
- Nora Tula Detering
- SMATHERIA gGmbH - Non-Profit Biomedical Research Institute, Hannover, Germany
- Center for Systems Neuroscience (ZSN), Hannover, Germany
| | - Tobias Schüning
- SMATHERIA gGmbH - Non-Profit Biomedical Research Institute, Hannover, Germany
- Center for Systems Neuroscience (ZSN), Hannover, Germany
| | - Niko Hensel
- Ottawa Hospital Research Institute (OHRI), Ottawa, Canada
- Center for Systems Neuroscience (ZSN), Hannover, Germany
| | - Peter Claus
- SMATHERIA gGmbH - Non-Profit Biomedical Research Institute, Hannover, Germany.
- Center for Systems Neuroscience (ZSN), Hannover, Germany.
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20
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Maggi L, Vita G, Marconi E, Taddeo D, Davì M, Lovato V, Cricelli C, Lapi F. Opportunities for an early recognition of spinal muscular atrophy in primary care: a nationwide, population-based, study in Italy. Fam Pract 2022; 40:308-313. [PMID: 35950319 DOI: 10.1093/fampra/cmac091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Spinal muscular atrophy (SMA) is a rare genetic disease with a broad spectrum of severity. Although an early diagnosis of SMA is crucial to allow proper management of patients, the diagnostic delay is still an issue. Therefore, this study aimed to investigate the clinical correlates of SMA among primary care patients. METHODS The Health Search Database (HSD) was adopted. To estimate the prevalence and incidence rate of SMA, a cohort study was conducted on the population (aged ≥6 years) being registered in HSD from 1 January 2000 up to 31 December 2019. To investigate the clinical correlates of SMA, a nested case-control study was performed. SMA cases have been classified according to a clinically based iterative process as "certain", "probable" or "possible". To test the association between clinical correlates and SMA cases a multivariate conditional logistic regression model was estimated. RESULTS The SMA prevalence combining "certain", "probable" and "possible" cases was 5.1 per 100,000 in 2019 (i.e. 1.12 per 100,000 when limited to "certain" cases), while the yearly incidence rate ranged from 0.12 to 0.56 cases per 100,000. Comparing "certain" cases with matched controls, the presence of neurology visits (OR = 6.5; 95% CI: 1.6-25.6) and prescription of electromyography (OR = 4.6; 95% CI: 1.1-18.7) were associated with higher odds of SMA diagnosis. CONCLUSIONS Our findings suggest that primary care databases may be used to enhance the early identification of SMA. Additional efforts are needed to exploit the electronic health records of general practitioners to allow early recognition of SMA.
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Affiliation(s)
- Lorenzo Maggi
- Neuroimmunology and Neuromuscular Disease Unit, IRCCS Foundation Carlo Besta Neurological Institute, Milano, Italy
| | - Gianluca Vita
- Unit of Neurology, IRCCS Centro Neurolesi Bonino-Pulejo P.O. Piemonte, Messina, Italy
| | - Ettore Marconi
- Health Search, Italian College of General Practitioners and Primary Care, Florence, Italy
| | - Daiana Taddeo
- Italian College of General Practitioners and Primary Care, Florence, Italy
| | | | | | - Claudio Cricelli
- Italian College of General Practitioners and Primary Care, Florence, Italy
| | - Francesco Lapi
- Health Search, Italian College of General Practitioners and Primary Care, Florence, Italy
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21
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Deep Molecular Characterization of Milder Spinal Muscular Atrophy Patients Carrying the c.859G>C Variant in SMN2. Int J Mol Sci 2022; 23:ijms23158289. [PMID: 35955418 PMCID: PMC9368089 DOI: 10.3390/ijms23158289] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 02/01/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a severe neuromuscular disorder caused by biallelic loss or pathogenic variants in the SMN1 gene. Copy number and modifier intragenic variants in SMN2, an almost identical paralog gene of SMN1, are known to influence the amount of complete SMN proteins. Therefore, SMN2 is considered the main phenotypic modifier of SMA, although genotype−phenotype correlation is not absolute. We present eleven unrelated SMA patients with milder phenotypes carrying the c.859G>C-positive modifier variant in SMN2. All were studied by a specific NGS method to allow a deep characterization of the entire SMN region. Analysis of two homozygous cases for the variant allowed us to identify a specific haplotype, Smn2-859C.1, in association with c.859G>C. Two other cases with the c.859G>C variant in their two SMN2 copies showed a second haplotype, Smn2-859C.2, in cis with Smn2-859C.1, assembling a more complex allele. We also identified a previously unreported variant in intron 2a exclusively linked to the Smn2-859C.1 haplotype (c.154-1141G>A), further suggesting that this region has been ancestrally conserved. The deep molecular characterization of SMN2 in our cohort highlights the importance of testing c.859G>C, as well as accurately assessing the SMN2 region in SMA patients to gain insight into the complex genotype−phenotype correlations and improve prognostic outcomes.
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22
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Targeted-Deletion of a Tiny Sequence via Prime Editing to Restore SMN Expression. Int J Mol Sci 2022; 23:ijms23147941. [PMID: 35887289 PMCID: PMC9317564 DOI: 10.3390/ijms23147941] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/13/2022] [Accepted: 07/17/2022] [Indexed: 01/27/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a devastating autosomal recessive motor neuron disease associated with mutations in the survival motor neuron 1 (SMN1) gene, the leading genetic cause of infant mortality. A nearly identical copy gene (SMN2) is retained in almost all patients with SMA. However, SMN2 fails to prevent disease development because of its alternative splicing, leading to a lack of exon 7 in the majority of SMN2 transcripts and yielding an unstable truncated protein. Several splicing regulatory elements, including intronic splicing silencer-N1 (ISS-N1) of SMN2 have been described. In this study, targeted-deletion of ISS-N1 was achieved using prime editing (PE) in SMA patient-specific induced pluripotent stem cells (SMA-iPSCs) with a high efficiency of 7/24. FL-SMN expression was restored in the targeted-deletion iPS clones and their derived motor neurons (iMNs). Notably, the apoptosis of the iMNs, caused by the loss of SMN protein that leads to the hyperactivity of endoplasmic reticulum (ER) stress, was alleviated in targeted-deletion iPSCs derived-iMNs. Thus, this is the first study to demonstrate that the targeted-deletion of ISS-N1 via PE for restoring FL-SMN expression holds therapeutic promise for SMA.
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23
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Barton AR, Hujoel MLA, Mukamel RE, Sherman MA, Loh PR. A spectrum of recessiveness among Mendelian disease variants in UK Biobank. Am J Hum Genet 2022; 109:1298-1307. [PMID: 35649421 PMCID: PMC9300759 DOI: 10.1016/j.ajhg.2022.05.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 05/12/2022] [Indexed: 01/09/2023] Open
Abstract
Recent work has found increasing evidence of mitigated, incompletely penetrant phenotypes in heterozygous carriers of recessive Mendelian disease variants. We leveraged whole-exome imputation within the full UK Biobank cohort (n ∼ 500K) to extend such analyses to 3,475 rare variants curated from ClinVar and OMIM. Testing these variants for association with 58 quantitative traits yielded 102 significant associations involving variants previously implicated in 34 different diseases. Notable examples included a POR missense variant implicated in Antley-Bixler syndrome that associated with a 1.76 (SE 0.27) cm increase in height and an ABCA3 missense variant implicated in interstitial lung disease that associated with reduced FEV1/FVC ratio. Association analyses with 1,134 disease traits yielded five additional variant-disease associations. We also observed contrasting levels of recessiveness between two more-common, classical Mendelian diseases. Carriers of cystic fibrosis variants exhibited increased risk of several mitigated disease phenotypes, whereas carriers of spinal muscular atrophy alleles showed no evidence of altered phenotypes. Incomplete penetrance of cystic fibrosis carrier phenotypes did not appear to be mediated by common allelic variation on the functional haplotype. Our results show that many disease-associated recessive variants can produce mitigated phenotypes in heterozygous carriers and motivate further work exploring penetrance mechanisms.
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Affiliation(s)
- Alison R Barton
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Bioinformatics and Integrative Genomics Program, Department of Biomedical Informatics, Harvard Medical School, Boston, MA 02115, USA.
| | - Margaux L A Hujoel
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Ronen E Mukamel
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Maxwell A Sherman
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Po-Ru Loh
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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24
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Jin W, Yang Z, Tang X, Wang X, Huang Y, Hui C, Yao J, Luan J, Tang S, Wu S, Jin S, Ding C. Simultaneous quantification of SMN1 and SMN2 copy numbers by MALDI-TOF mass spectrometry for spinal muscular atrophy genetic testing. Clin Chim Acta 2022; 532:45-52. [DOI: 10.1016/j.cca.2022.05.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/22/2022] [Indexed: 11/25/2022]
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25
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Abstract
Risdiplam (Evrysdi®) is the first oral drug developed to treat spinal muscular atrophy (SMA) and is approved in multiple countries worldwide. It is approved for the treatment of SMA in patients aged ≥ 2 months in the USA and the EU, with this approval further specified in the EU for the treatment of 5q-autosomal recessive SMA with a clinical diagnosis of SMA types 1, 2, or 3 or with one to four survival motor neuron 2 (SMN2) copies. As an SMN2 pre-mRNA splicing modifier, risdiplam increases the production of full-length SMN protein, the lack of which drives the pathophysiology of SMA. In phase 2/3 clinical trials, risdiplam significantly improved motor function in infants with SMA type 1 and in patients aged 2-25 years with SMA types 2 or 3. These motor improvements were maintained with up to 2 years of treatment with risdiplam. Risdiplam was generally well tolerated, with a favourable benefit to risk balance. As an oral drug, risdiplam provides a convenient and useful treatment option across a broad range of patient ages and subtypes of SMA.
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Affiliation(s)
- Julia Paik
- Springer Nature, Mairangi Bay, Private Bag 65901, Auckland, 0754, New Zealand.
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26
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Sarv S, Kahre T, Vaidla E, Pajusalu S, Muru K, Põder H, Gross-Paju K, Ütt S, Žordania R, Talvik I, Õiglane-Shlik E, Muhu K, Õunap K. The Birth Prevalence of Spinal Muscular Atrophy: A Population Specific Approach in Estonia. Front Genet 2022; 12:796862. [PMID: 35003227 PMCID: PMC8729775 DOI: 10.3389/fgene.2021.796862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 12/07/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Rare diseases are an important population health issue and many promising therapies have been developed in recent years. In light of novel genetic treatments expected to significantly improve spinal muscular atrophy (SMA) patients' quality of life and the urgent need for SMA newborn screening (NBS), new epidemiological data were needed to implement SMA NBS in Estonia. Objective: We aimed to describe the birth prevalence of SMA in the years 1996-2020 and to compare the results with previously published data. Methods: We retrospectively analyzed clinical and laboratory data of SMA patients referred to the Department of Clinical Genetics of Tartu University Hospital and its branch in Tallinn. Results: Fifty-seven patients were molecularly diagnosed with SMA. SMA birth prevalence was 1 per 8,286 (95% CI 1 per 6,130-11,494) in Estonia. Patients were classified as SMA type 0 (1.8%), SMA I (43.9%), SMA II (22.8%), SMA III (29.8%), and SMA IV (1.8%). Two patients were compound heterozygotes with an SMN1 deletion in trans with a novel single nucleotide variant NM_000344.3:c.410dup, p.(Asn137Lysfs*11). SMN2 copy number was assessed in 51 patients. Conclusion: In Estonia, the birth prevalence of SMA is similar to the median birth prevalence in Europe. This study gathered valuable information on the current epidemiology of SMA, which can guide the implementation of spinal muscular atrophy to the newborn screening program in Estonia.
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Affiliation(s)
- Siiri Sarv
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
| | - Tiina Kahre
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia.,Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
| | - Eve Vaidla
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
| | - Sander Pajusalu
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia.,Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
| | - Kai Muru
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia.,Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
| | - Haide Põder
- Tallinn Children's Hospital, Tallinn, Estonia
| | - Katrin Gross-Paju
- Centre for Neurological Diseases, West-Tallinn Central Hospital, Tallinn, Estonia.,Department of Health Technologies, eMed Lab, TalTech, Tallinn, Estonia
| | - Sandra Ütt
- Centre for Neurological Diseases, West-Tallinn Central Hospital, Tallinn, Estonia
| | - Riina Žordania
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
| | - Inga Talvik
- Tallinn Children's Hospital, Tallinn, Estonia
| | - Eve Õiglane-Shlik
- Children's Clinic, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia.,Children's Clinic, Tartu University Hospital, Tartu, Estonia
| | - Kristina Muhu
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
| | - Katrin Õunap
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia.,Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
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27
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Genetic architecture of motor neuron diseases. J Neurol Sci 2021; 434:120099. [PMID: 34965490 DOI: 10.1016/j.jns.2021.120099] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/26/2021] [Accepted: 12/14/2021] [Indexed: 12/18/2022]
Abstract
Motor neuron diseases (MNDs) are rare and frequently fatal neurological disorders in which motor neurons within the brainstem and spinal cord regions slowly die. MNDs are primarily caused by genetic mutations, and > 100 different mutant genes in humans have been discovered thus far. Given the fact that many more MND-related genes have yet to be discovered, the growing body of genetic evidence has offered new insights into the diverse cellular and molecular mechanisms involved in the aetiology and pathogenesis of MNDs. This search may aid in the selection of potential candidate genes for future investigation and, eventually, may open the door to novel interventions to slow down disease progression. In this review paper, we have summarized detailed existing research findings of different MNDs, such as amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), spinal bulbar muscle atrophy (SBMA) and hereditary spastic paraplegia (HSP) in relation to their complex genetic architecture.
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Alternative Splicing Role in New Therapies of Spinal Muscular Atrophy. Genes (Basel) 2021; 12:genes12091346. [PMID: 34573328 PMCID: PMC8468182 DOI: 10.3390/genes12091346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/24/2021] [Accepted: 08/25/2021] [Indexed: 11/17/2022] Open
Abstract
It has been estimated that 80% of the pre-mRNA undergoes alternative splicing, which exponentially increases the flow of biological information in cellular processes and can be an attractive therapeutic target. It is a crucial mechanism to increase genetic diversity. Disturbed alternative splicing is observed in many disorders, including neuromuscular diseases and carcinomas. Spinal Muscular Atrophy (SMA) is an autosomal recessive neurodegenerative disease. Homozygous deletion in 5q13 (the region coding for the motor neuron survival gene (SMN1)) is responsible for 95% of SMA cases. The nearly identical SMN2 gene does not compensate for SMN loss caused by SMN1 gene mutation due to different splicing of exon 7. A pathologically low level of survival motor neuron protein (SMN) causes degeneration of the anterior horn cells in the spinal cord with associated destruction of α-motor cells and manifested by muscle weakness and loss. Understanding the regulation of the SMN2 pre-mRNA splicing process has allowed for innovative treatment and the introduction of new medicines for SMA. After describing the concept of splicing modulation, this review will cover the progress achieved in this field, by highlighting the breakthrough accomplished recently for the treatment of SMA using the mechanism of alternative splicing.
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The Importance of Digging into the Genetics of SMN Genes in the Therapeutic Scenario of Spinal Muscular Atrophy. Int J Mol Sci 2021; 22:ijms22169029. [PMID: 34445733 PMCID: PMC8396600 DOI: 10.3390/ijms22169029] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/13/2021] [Accepted: 08/19/2021] [Indexed: 12/12/2022] Open
Abstract
After 26 years of discovery of the determinant survival motor neuron 1 and the modifier survival motor neuron 2 genes (SMN1 and SMN2, respectively), three SMN-dependent specific therapies are already approved by FDA and EMA and, as a consequence, worldwide SMA patients are currently under clinical investigation and treatment. Bi-allelic pathogenic variants (mostly deletions) in SMN1 should be detected in SMA patients to confirm the disease. Determination of SMN2 copy number has been historically employed to correlate with the phenotype, predict disease evolution, stratify patients for clinical trials and to define those eligible for treatment. In view that discordant genotype-phenotype correlations are present in SMA, besides technical issues with detection of SMN2 copy number, we have hypothesized that copy number determination is only the tip of the iceberg and that more deepen studies of variants, sequencing and structures of the SMN2 genes are necessary for a better understanding of the disease as well as to investigate possible influences in treatment responses. Here, we highlight the importance of a comprehensive approach of SMN1 and SMN2 genetics with the perspective to apply for better prediction of SMA in positive neonatal screening cases and early diagnosis to start treatments.
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Veepaschit J, Viswanathan A, Bordonné R, Grimm C, Fischer U. Identification and structural analysis of the Schizosaccharomyces pombe SMN complex. Nucleic Acids Res 2021; 49:7207-7223. [PMID: 33754639 PMCID: PMC8287938 DOI: 10.1093/nar/gkab158] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/11/2021] [Accepted: 02/26/2021] [Indexed: 01/20/2023] Open
Abstract
The macromolecular SMN complex facilitates the formation of Sm-class ribonucleoproteins involved in mRNA processing (UsnRNPs). While biochemical studies have revealed key activities of the SMN complex, its structural investigation is lagging behind. Here we report on the identification and structural determination of the SMN complex from the lower eukaryote Schizosaccharomyces pombe, consisting of SMN, Gemin2, 6, 7, 8 and Sm proteins. The core of the SMN complex is formed by several copies of SMN tethered through its C-terminal alpha-helices arranged with alternating polarity. This creates a central platform onto which Gemin8 binds and recruits Gemins 6 and 7. The N-terminal parts of the SMN molecules extrude via flexible linkers from the core and enable binding of Gemin2 and Sm proteins. Our data identify the SMN complex as a multivalent hub where Sm proteins are collected in its periphery to allow their joining with UsnRNA.
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Affiliation(s)
- Jyotishman Veepaschit
- Department of Biochemistry, Biocenter, University of Würzburg, Würzburg 97074, Germany
| | - Aravindan Viswanathan
- Department of Biochemistry, Biocenter, University of Würzburg, Würzburg 97074, Germany
| | - Rémy Bordonné
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier 34293, France
| | - Clemens Grimm
- Department of Biochemistry, Biocenter, University of Würzburg, Würzburg 97074, Germany
| | - Utz Fischer
- Department of Biochemistry, Biocenter, University of Würzburg, Würzburg 97074, Germany
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Blatnik AJ, McGovern VL, Burghes AHM. What Genetics Has Told Us and How It Can Inform Future Experiments for Spinal Muscular Atrophy, a Perspective. Int J Mol Sci 2021; 22:8494. [PMID: 34445199 PMCID: PMC8395208 DOI: 10.3390/ijms22168494] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/28/2021] [Accepted: 08/04/2021] [Indexed: 02/06/2023] Open
Abstract
Proximal spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disorder characterized by motor neuron loss and subsequent atrophy of skeletal muscle. SMA is caused by deficiency of the essential survival motor neuron (SMN) protein, canonically responsible for the assembly of the spliceosomal small nuclear ribonucleoproteins (snRNPs). Therapeutics aimed at increasing SMN protein levels are efficacious in treating SMA. However, it remains unknown how deficiency of SMN results in motor neuron loss, resulting in many reported cellular functions of SMN and pathways affected in SMA. Herein is a perspective detailing what genetics and biochemistry have told us about SMA and SMN, from identifying the SMA determinant region of the genome, to the development of therapeutics. Furthermore, we will discuss how genetics and biochemistry have been used to understand SMN function and how we can determine which of these are critical to SMA moving forward.
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Affiliation(s)
| | | | - Arthur H. M. Burghes
- Department of Biological Chemistry & Pharmacology, The Ohio State University Wexner Medical Center, Rightmire Hall, Room 168, 1060 Carmack Road, Columbus, OH 43210, USA; (A.J.B.III); (V.L.M.)
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Butchbach MER. Genomic Variability in the Survival Motor Neuron Genes ( SMN1 and SMN2): Implications for Spinal Muscular Atrophy Phenotype and Therapeutics Development. Int J Mol Sci 2021; 22:ijms22157896. [PMID: 34360669 PMCID: PMC8348669 DOI: 10.3390/ijms22157896] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/14/2021] [Accepted: 07/21/2021] [Indexed: 02/07/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a leading genetic cause of infant death worldwide that is characterized by loss of spinal motor neurons leading to muscle weakness and atrophy. SMA results from the loss of survival motor neuron 1 (SMN1) gene but retention of its paralog SMN2. The copy numbers of SMN1 and SMN2 are variable within the human population with SMN2 copy number inversely correlating with SMA severity. Current therapeutic options for SMA focus on increasing SMN2 expression and alternative splicing so as to increase the amount of SMN protein. Recent work has demonstrated that not all SMN2, or SMN1, genes are equivalent and there is a high degree of genomic heterogeneity with respect to the SMN genes. Because SMA is now an actionable disease with SMN2 being the primary target, it is imperative to have a comprehensive understanding of this genomic heterogeneity with respect to hybrid SMN1–SMN2 genes generated by gene conversion events as well as partial deletions of the SMN genes. This review will describe this genetic heterogeneity in SMA and its impact on disease phenotype as well as therapeutic efficacy.
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Affiliation(s)
- Matthew E. R. Butchbach
- Center for Applied Clinical Genomics, Nemours Children’s Health Delaware, Wilmington, DE 19803, USA;
- Center for Pediatric Research, Nemours Children’s Health Delaware, Wilmington, DE 19803, USA
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
- Department of Pediatrics, Thomas Jefferson University, Philadelphia, PA 19107, USA
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Sansa A, Hidalgo I, Miralles MP, de la Fuente S, Perez-Garcia MJ, Munell F, Soler RM, Garcera A. Spinal Muscular Atrophy autophagy profile is tissue-dependent: differential regulation between muscle and motoneurons. Acta Neuropathol Commun 2021; 9:122. [PMID: 34217376 PMCID: PMC8254901 DOI: 10.1186/s40478-021-01223-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 06/24/2021] [Indexed: 11/10/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a neuromuscular genetic disease caused by reduced survival motor neuron (SMN) protein. SMN is ubiquitous and deficient levels cause spinal cord motoneurons (MNs) degeneration and muscle atrophy. Nevertheless, the mechanism by which SMN reduction in muscle contributes to SMA disease is not fully understood. Therefore, studies evaluating atrophy mechanisms in SMA muscles will contribute to strengthening current knowledge of the pathology. Here we propose to evaluate autophagy in SMA muscle, a pathway altered in myotube atrophy. We analized autophagy proteins and mTOR in muscle biopsies, fibroblasts, and lymphoblast cell lines from SMA patients and in gastrocnemius muscles from a severe SMA mouse model. Human MNs differentiated from SMA and unaffected control iPSCs were also included in the analysis of the autophagy. Muscle biopsies, fibroblasts, and lymphoblast cell lines from SMA patients showed reduction of the autophagy marker LC3-II. In SMA mouse gastrocnemius, we observed lower levels of LC3-II, Beclin 1, and p62/SQSTM1 proteins at pre-symptomatic stage. mTOR phosphorylation at Ser2448 was decreased in SMA muscle cells. However, in mouse and human cultured SMA MNs mTOR phosphorylation and LC3-II levels were increased. These results suggest a differential regulation in SMA of the autophagy process in muscle cells and MNs. Opposite changes in autophagy proteins and mTOR phosphorylation between muscle cells and neurons were observed. These differences may reflect a specific response to SMN reduction, which could imply diverse tissue-dependent reactions to therapies that should be taken into account when treating SMA patients.
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Zhang C, Li Z, Chen M, Hu Z, Wu L, Zhou M, Liang D. Cas12a and Lateral Flow Strip-Based Test for Rapid and Ultrasensitive Detection of Spinal Muscular Atrophy. BIOSENSORS-BASEL 2021; 11:bios11050154. [PMID: 34068874 PMCID: PMC8153588 DOI: 10.3390/bios11050154] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/09/2021] [Accepted: 05/12/2021] [Indexed: 12/12/2022]
Abstract
Spinal muscular atrophy (SMA) is characterized by severe lethality and irreversible progression. Early diagnosis of SMA is of more practical significance with the emergence of effective therapy. However, existing techniques to identify SMA patients rely on cumbersome instruments, hindering their accessibility and application. An SMA-Cas12a-strip assay was developed with the integration of Cas12a-based nucleic acid detection, isothermal amplification, and lateral flow strip. The analytical performance of the assay was assessed with clinical samples. To explore its extensible utility, various specimens were tested. Validated with 168 clinical samples, the sensitivity and specificity of the SMA-Cas12a-strip assay were both 100%. The minimum detectable concentration of genomic DNA containing the target gene achieved 526 aM. The assay was compatible with specimens from several sources, and the turnaround time could be within 1.5 h. We developed a simple, cost-effective, and highly sensitive and specific assay to detect SMA patients. With little and field-portable equipment, the assay holds great promise in the detection of SMA patients, particularly in low-resource regions.
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Affiliation(s)
| | | | | | | | | | - Miaojin Zhou
- Correspondence: (M.Z.); (D.L.); Tel.: +86-731-84805252 (M.Z. & D.L.); Fax: +86-731-84478152 (M.Z. & D.L.)
| | - Desheng Liang
- Correspondence: (M.Z.); (D.L.); Tel.: +86-731-84805252 (M.Z. & D.L.); Fax: +86-731-84478152 (M.Z. & D.L.)
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35
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Blasco-Pérez L, Paramonov I, Leno J, Bernal S, Alias L, Fuentes-Prior P, Cuscó I, Tizzano EF. Beyond copy number: A new, rapid, and versatile method for sequencing the entire SMN2 gene in SMA patients. Hum Mutat 2021; 42:787-795. [PMID: 33739559 PMCID: PMC8252042 DOI: 10.1002/humu.24200] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 01/13/2021] [Accepted: 03/11/2021] [Indexed: 01/16/2023]
Abstract
Spinal muscular atrophy (SMA) is caused by bi‐allelic loss or pathogenic variants in the SMN1 gene. SMN2, the highly homologous copy of SMN1, is considered the major phenotypic modifier of the disease. Determination of SMN2 copy number is essential to establish robust genotype–phenotype correlations and predict disease evolution, to stratify patients for clinical trials, as well as to define those eligible for treatment. Discordant genotype–phenotype correlations are not uncommon in SMA, some of which are due to intragenic SMN2 variants that may influence the amount of complete SMN transcripts and, therefore, of full‐length SMN protein. Detection of these variants is crucial to predict SMA phenotypes in the present scenario of therapeutic advances and with the perspective of SMA neonatal screening and early diagnosis to start treatments. Here, we present a novel, affordable, and versatile method for complete sequencing of the SMN2 gene based on long‐range polymerase chain reaction and next‐generation sequencing. The method was validated by analyzing samples from 53 SMA patients who lack SMN1, allowing to characterize paralogous, rare variants, and single‐nucleotide polymorphisms of SMN2 as well as SMN2–SMN1 hybrid genes. The method identifies partial deletions and can be adapted to determine rare pathogenic variants in patients with at least one SMN1 copy.
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Affiliation(s)
- Laura Blasco-Pérez
- Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.,Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Barcelona, Spain
| | - Ida Paramonov
- Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.,Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Barcelona, Spain
| | - Jordi Leno
- Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.,Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Barcelona, Spain
| | - Sara Bernal
- Genetics Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER)
| | - Laura Alias
- Genetics Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER)
| | - Pablo Fuentes-Prior
- Molecular Bases of Disease, Biomedical Research Institute Sant Pau (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Ivon Cuscó
- Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.,Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER)
| | - Eduardo F Tizzano
- Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.,Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Barcelona, Spain
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Lusakowska A, Jedrzejowska M, Kaminska A, Janiszewska K, Grochowski P, Zimowski J, Sierdzinski J, Kostera-Pruszczyk A. Observation of the natural course of type 3 spinal muscular atrophy: data from the polish registry of spinal muscular atrophy. Orphanet J Rare Dis 2021; 16:150. [PMID: 33761963 PMCID: PMC7992780 DOI: 10.1186/s13023-021-01771-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 03/09/2021] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Spinal muscular atrophy (SMA) is one of the most frequent and severe genetic diseases leading to premature death or severe motor disability. New therapies have been developed in recent years that change the natural history of the disease. The aim of this study is to describe patients included in the Polish Registry of SMA, with a focus on the course of type 3 SMA (SMA3) before the availability of disease-modifying treatments. RESULTS 790 patients with SMA were included in the registry (173 with type 1 [SMA1], 218 with type 2 [SMA2], 393 with SMA3, and six with type 4 SMA [SMA4]), most (52%) of whom were adults. Data on SMN2 gene copy number were available for 672 (85%) patients. The mean age of onset was 5 months for SMA1, 11.5 months for SMA2, and 4.5 years for SMA3. In patients with SMA3, the first symptoms occurred earlier in those with three copies of SMN2 than in those with four copies of SMN2 (3.2 years vs. 6.7 years). The age of onset of SMA3 was younger in girls than in boys (3.1 years vs. 5.7 years), with no new cases observed in women older than 16 years. Male patients outnumbered female patients, especially among patients with SMA3b (49 female vs. 85 male patients) and among patients with SMA3 with four copies of SMN2 (30 female vs. 69 male patients). 44% of patients with SMA3 were still able to walk; in those who were not still able to walk, the mean age of immobilization was 14.0 years. Patients with SMA3a (age of onset < 3 years) and three copies of SMN2 had significantly worse prognosis for remaining ambulant than patients with SMA3b (age of onset ≥ 3 years) and four copies of SMN2. CONCLUSIONS The Registry of SMA is an effective tool for assessing the disease course in the real world setting. SMN2 copy number is an important prognostic factor for the age of onset and ambulation in SMA3. Sex and age of disease onset also strongly affect the course of SMA. Data supplied by this study can aid treatment decisions.
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Affiliation(s)
- Anna Lusakowska
- Department of Neurology, European Reference Network EURO-NMD, Medical University of Warsaw, Warsaw, Poland
| | - Maria Jedrzejowska
- Rare Diseases Research Platform, Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Anna Kaminska
- Department of Neurology, European Reference Network EURO-NMD, Medical University of Warsaw, Warsaw, Poland
| | - Katarzyna Janiszewska
- Department of Neurology, European Reference Network EURO-NMD, Medical University of Warsaw, Warsaw, Poland
| | - Przemysław Grochowski
- Student Research Group of Department of Neurology, Medical University of Warsaw, Warsaw, Poland
| | - Janusz Zimowski
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Janusz Sierdzinski
- Department of Medical Informatics and Telemedicine, Medical University of Warsaw, Warsaw, Poland
| | - Anna Kostera-Pruszczyk
- Department of Neurology, European Reference Network EURO-NMD, Medical University of Warsaw, Warsaw, Poland.
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Sharifi Z, Taheri M, Fallah MS, Abiri M, Golnabi F, Bagherian H, Zeinali R, Farahzadi H, Alborji M, Tehrani PG, Amini M, Asnavandi S, Hashemi M, Forouzesh F, Zeinali S. Comprehensive Mutation Analysis and Report of 12 Novel Mutations in a Cohort of Patients with Spinal Muscular Atrophy in Iran. J Mol Neurosci 2021; 71:2281-2298. [PMID: 33481221 DOI: 10.1007/s12031-020-01789-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 12/30/2020] [Indexed: 12/17/2022]
Abstract
Spinal muscular atrophies (SMAs) are a heterogeneous group of neuromuscular diseases characterized by loss of motor neurons, muscle weakness, hypotonia and muscle atrophy, with different modes of inheritance; however, the survival motor neuron 1 (SMN1) gene is predominantly involved. The aims of the current study were to clarify the genetic basis of SMA and determine the mutation spectrum of SMN1 and other associated genes, in order to provide molecular information for more accurate diagnosis and future prospects for treatment. We performed a comprehensive analysis of 5q SMA in 1765 individuals including 528 patients from 432 unrelated families with at least one child with suspected clinical presentation of SMA. Copy number variations of the SMN1 and SMN2 genes and linkage analysis were performed using multiplex ligation-dependent probe amplification (MLPA) and short tandem repeat (STR) markers linked to the SMN1 gene. Cases without mutation in the SMA locus on 5q were analyzed for the DNAJB2, IGHMBP2, SIGMAR1 and PLEKHG5 genes using linked STR markers. Sanger sequencing of whole genes was performed for cases with homozygous haplotypes. Whole-genome sequencing (WGS) and whole-exome analysis was conducted for some of the remaining cases. Mutations in the SMN1 gene were identified in 287 (66.43%) families including 269 patients (62.26%) with homozygous deletion of the entire SMN1 gene. Only one of the patients had a homozygous point mutation in the SMN1 gene. Among the remaining families, three families showed mutations in either the DNAJB2, SIGMAR1 or PLEKHG5 genes, which were linked using STR analysis and Sanger sequencing. From 10 families who underwent WGS, we found six homozygous point mutations in six families for either the TNNT1, TPM3, TTN, SACS or COL6A2 genes. Two mutations in the PLA2G6 gene were also found in another patient as compound heterozygous. This rather large cohort allowed us to identify genotype patterns in Iranian 5q SMA patients. The process of identifying 11 mutations (9 novel) in 9 different genes among non-5q SMA patients shows the diversity of genes involved in non-5q SMA in Iranians. Genotyping of patients with SMA is essential for prenatal and preimplantation genetic diagnosis (PGD), and may be very helpful for guiding treatment, with the advent of new, more effective, albeit very expensive, therapies. Also, combining linkage analysis was shown to be beneficial in many ways, including sample authenticity and segregation analysis, and for ruling out maternal cell contamination during prenatal diagnosis (PND).
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Affiliation(s)
- Zohreh Sharifi
- Department of Genetics, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.,Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | - Mohammad Taheri
- Urogenital Stem Cell Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad-Sadegh Fallah
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | - Maryam Abiri
- Department of Medical Genetics and Molecular Biology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Golnabi
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | - Hamideh Bagherian
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | - Razieh Zeinali
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | - Hossein Farahzadi
- Proteomics Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Marjan Alborji
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | | | - Masoume Amini
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | - Sadaf Asnavandi
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | - Mehrdad Hashemi
- Department of Genetics, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Flora Forouzesh
- Department of Genetics, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Sirous Zeinali
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran. .,Department of Molecular Medicine, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
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Rouzier C, Chaussenot A, Paquis-Flucklinger V. Molecular diagnosis and genetic counseling for spinal muscular atrophy (SMA). Arch Pediatr 2020; 27:7S9-7S14. [DOI: 10.1016/s0929-693x(20)30270-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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39
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Cuscó I, Bernal S, Blasco-Pérez L, Calucho M, Alias L, Fuentes-Prior P, Tizzano EF. Practical guidelines to manage discordant situations of SMN2 copy number in patients with spinal muscular atrophy. NEUROLOGY-GENETICS 2020; 6:e530. [PMID: 33324756 PMCID: PMC7713720 DOI: 10.1212/nxg.0000000000000530] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 09/29/2020] [Indexed: 12/26/2022]
Abstract
Objective Assessment of SMN2 copy number in patients with spinal muscular atrophy (SMA) is essential to establish careful genotype-phenotype correlations and predict disease evolution. This issue is becoming crucial in the present scenario of therapeutic advances with the perspective of SMA neonatal screening and early diagnosis to initiate treatment, as this value is critical to stratify patients for clinical trials and to define those eligible to receive medication. Several technical pitfalls and interindividual variations may account for reported discrepancies in the estimation of SMN2 copy number and establishment of phenotype-genotype correlations. Methods We propose a management guide based on a sequence of specified actions once SMN2 copy number is determined for a given patient. Regardless of the method used to estimate the number of SMN2 copies, our approach focuses on the manifestations of the patient to recommend how to proceed in each case. Results We defined situations according to SMN2 copy number in a presymptomatic scenario of screening, in which we predict the possible evolution, and when a symptomatic patient is genetically confirmed. Unexpected discordant cases include patients having a single SMN2 copy but noncongenital disease forms, 2 SMN2 copies compatible with type II or III SMA, and 3 or 4 copies of the gene showing more severe disease than expected. Conclusions Our proposed guideline would help to systematically identify discordant SMA cases that warrant further genetic investigation. The SMN2 gene, as the main modifier of SMA phenotype, deserves a more in-depth study to provide more accurate genotype-phenotype correlations.
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Affiliation(s)
- Ivon Cuscó
- Medicine Genetics Group (I.C., L.B.-P., M.C., E.F.T.), Vall dHebron Research Institute (VHIR), Barcelona; Department of Clinical and Molecular Genetics (I.C., L.B.-P., M.C., E.F.T.), Hospital Vall dHebron, Barcelona; Department of Genetics (S.B., L.A.), Hospital de la Santa Creu i Sant Pau, Barcelona; Biomedical Research Institute Sant Pau (IIB Sant Pau) (S.B., L.A.), Hospital de la Santa Creu i Sant Pau, Barcelona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCIII, U-705 Barcelona) (S.B., L.A.), Madrid; Molecular Bases of Disease (P.F.-P.), Biomedical Research Institute Sant Pau (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Sara Bernal
- Medicine Genetics Group (I.C., L.B.-P., M.C., E.F.T.), Vall dHebron Research Institute (VHIR), Barcelona; Department of Clinical and Molecular Genetics (I.C., L.B.-P., M.C., E.F.T.), Hospital Vall dHebron, Barcelona; Department of Genetics (S.B., L.A.), Hospital de la Santa Creu i Sant Pau, Barcelona; Biomedical Research Institute Sant Pau (IIB Sant Pau) (S.B., L.A.), Hospital de la Santa Creu i Sant Pau, Barcelona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCIII, U-705 Barcelona) (S.B., L.A.), Madrid; Molecular Bases of Disease (P.F.-P.), Biomedical Research Institute Sant Pau (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Laura Blasco-Pérez
- Medicine Genetics Group (I.C., L.B.-P., M.C., E.F.T.), Vall dHebron Research Institute (VHIR), Barcelona; Department of Clinical and Molecular Genetics (I.C., L.B.-P., M.C., E.F.T.), Hospital Vall dHebron, Barcelona; Department of Genetics (S.B., L.A.), Hospital de la Santa Creu i Sant Pau, Barcelona; Biomedical Research Institute Sant Pau (IIB Sant Pau) (S.B., L.A.), Hospital de la Santa Creu i Sant Pau, Barcelona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCIII, U-705 Barcelona) (S.B., L.A.), Madrid; Molecular Bases of Disease (P.F.-P.), Biomedical Research Institute Sant Pau (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Maite Calucho
- Medicine Genetics Group (I.C., L.B.-P., M.C., E.F.T.), Vall dHebron Research Institute (VHIR), Barcelona; Department of Clinical and Molecular Genetics (I.C., L.B.-P., M.C., E.F.T.), Hospital Vall dHebron, Barcelona; Department of Genetics (S.B., L.A.), Hospital de la Santa Creu i Sant Pau, Barcelona; Biomedical Research Institute Sant Pau (IIB Sant Pau) (S.B., L.A.), Hospital de la Santa Creu i Sant Pau, Barcelona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCIII, U-705 Barcelona) (S.B., L.A.), Madrid; Molecular Bases of Disease (P.F.-P.), Biomedical Research Institute Sant Pau (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Laura Alias
- Medicine Genetics Group (I.C., L.B.-P., M.C., E.F.T.), Vall dHebron Research Institute (VHIR), Barcelona; Department of Clinical and Molecular Genetics (I.C., L.B.-P., M.C., E.F.T.), Hospital Vall dHebron, Barcelona; Department of Genetics (S.B., L.A.), Hospital de la Santa Creu i Sant Pau, Barcelona; Biomedical Research Institute Sant Pau (IIB Sant Pau) (S.B., L.A.), Hospital de la Santa Creu i Sant Pau, Barcelona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCIII, U-705 Barcelona) (S.B., L.A.), Madrid; Molecular Bases of Disease (P.F.-P.), Biomedical Research Institute Sant Pau (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Pablo Fuentes-Prior
- Medicine Genetics Group (I.C., L.B.-P., M.C., E.F.T.), Vall dHebron Research Institute (VHIR), Barcelona; Department of Clinical and Molecular Genetics (I.C., L.B.-P., M.C., E.F.T.), Hospital Vall dHebron, Barcelona; Department of Genetics (S.B., L.A.), Hospital de la Santa Creu i Sant Pau, Barcelona; Biomedical Research Institute Sant Pau (IIB Sant Pau) (S.B., L.A.), Hospital de la Santa Creu i Sant Pau, Barcelona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCIII, U-705 Barcelona) (S.B., L.A.), Madrid; Molecular Bases of Disease (P.F.-P.), Biomedical Research Institute Sant Pau (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Eduardo F Tizzano
- Medicine Genetics Group (I.C., L.B.-P., M.C., E.F.T.), Vall dHebron Research Institute (VHIR), Barcelona; Department of Clinical and Molecular Genetics (I.C., L.B.-P., M.C., E.F.T.), Hospital Vall dHebron, Barcelona; Department of Genetics (S.B., L.A.), Hospital de la Santa Creu i Sant Pau, Barcelona; Biomedical Research Institute Sant Pau (IIB Sant Pau) (S.B., L.A.), Hospital de la Santa Creu i Sant Pau, Barcelona; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCIII, U-705 Barcelona) (S.B., L.A.), Madrid; Molecular Bases of Disease (P.F.-P.), Biomedical Research Institute Sant Pau (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
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Souza PVS, Pinto WBVR, Ricarte A, Badia BML, Seneor DD, Teixeira DT, Caetano L, Gonçalves EA, Chieia MAT, Farias IB, Bertini E, Oliveira ASB. Clinical and radiological profile of patients with spinal muscular atrophy type 4. Eur J Neurol 2020; 28:609-619. [PMID: 33090613 DOI: 10.1111/ene.14587] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 10/08/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND PURPOSE Spinal muscular atrophy (SMA) is the most important cause of motor neuron disease in childhood, and continues to represent the leading genetic cause of infant death. Adulthood-onset SMA (SMA type 4) is rare, with few isolated cases reported. The objective of the present study was to describe a cohort of patients with SMA type 4. METHODS A cross-sectional study was conducted to characterize clinical, genetic, radiological and neurophysiological features of patients with adulthood-onset SMA. Correlation analysis of functional assessment with genetic, radiological and neurophysiological data was performed. RESULTS Twenty patients with SMA type 4 were identified in a Brazilian cohort of 227 patients with SMA. The most common clinical symptom was limb-girdle muscle weakness, observed in 15 patients (75%). The most frequent neurological findings were absent tendon reflexes in 18 (90%) and fasciculations in nine patients (45%). Sixteen patients (80%) had the homozygous deletion of exon 7 in the SMN1 gene, with 12 patients (60%) showing four copies of the SMN2 gene. The functional scales Hammersmith Functional Motor Scale Expanded, Amyotrophic Lateral Sclerosis Functional Rating Scale Revised, Revised Upper Limb Module and Spinal Muscular Atrophy Functional Rating Scale, as well as the six-minute walk and the Time Up and Go tests showed a correlation with duration of disease. Motor Unit Number Index was correlated both with duration of disease and with performance in functional assessment. Radiological studies exhibited a typical pattern, with involvement of biceps femoris short head and gluteus minimus in all patients. CONCLUSION This study represents the largest cohort of patients with SMA type 4 and provides functional, genetic, radiological and neurophysiological features that can be used as potential biomarkers for the new specific genetic therapies for SMA.
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Affiliation(s)
- P V S Souza
- Department of Neurology and Neurosurgery, Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - W B V R Pinto
- Department of Neurology and Neurosurgery, Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - A Ricarte
- Neurotherapy Rehabilitation Center, São Paulo, SP, Brazil
| | - B M L Badia
- Department of Neurology and Neurosurgery, Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - D D Seneor
- Department of Neurology and Neurosurgery, Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - D T Teixeira
- Neurotherapy Rehabilitation Center, São Paulo, SP, Brazil
| | - L Caetano
- Neurotherapy Rehabilitation Center, São Paulo, SP, Brazil
| | - E A Gonçalves
- Department of Neurology and Neurosurgery, Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - M A T Chieia
- Department of Neurology and Neurosurgery, Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - I B Farias
- Department of Neurology and Neurosurgery, Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - E Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy
| | - A S B Oliveira
- Department of Neurology and Neurosurgery, Federal University of São Paulo (UNIFESP), São Paulo, SP, Brazil
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Eggermann K, Gläser D, Abicht A, Wirth B. Spinal muscular atrophy (5qSMA): best practice of diagnostics, newborn screening and therapy. MED GENET-BERLIN 2020. [DOI: 10.1515/medgen-2020-2033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Abstract
Proximal spinal muscular atrophy (SMA) is an autosomal-recessive inherited neuromuscular disorder caused by the degeneration of alpha motor neurons in the anterior horn of the spinal cord. Patients show hypotonia, muscular atrophy and weakness of voluntary proximal muscles. SMA is one of the most common genetic diseases, with a frequency of about 1 in 7,000 newborns in Germany. The vast majority of patients carry a homozygous deletion of exons 7 and 8 of the survival motor neuron (SMN) 1 gene on chromosome 5q13.2; only about 3–4 % of patients are compound heterozygous for this common mutation and an additional subtle mutation in SMN1. The severity of the disease is mainly influenced by the copy number of the highly homologous SMN2.
Since the discovery of the underlying genetic defect 25 years ago, both the diagnostics of SMA and its treatment have undergone constant and in recent times rapid improvements. SMA has become one of the first neuromuscular disorders with effective therapies based on gene targeted strategies such as splice correction of SMN2 via antisense oligonucleotides or small molecules or gene replacement therapy with a self-complementary adeno-associated virus 9 expressing the SMN1-cDNA. With the availability of treatment options, which are most effective when therapy starts at a pre-symptomatic stage, a newborn screening is indispensable and about to be introduced in Germany. New challenges for diagnostic labs as well as for genetic counsellors are inevitable.
This article aims at summarising the current state of SMA diagnostics, treatment and perspectives for this disorder and offering best practice testing guidelines to diagnostic labs.
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Affiliation(s)
- Katja Eggermann
- Institute of Human Genetics, Medical Faculty , RWTH Aachen University , Pauwelsstr. 30 , Aachen , Germany
| | - Dieter Gläser
- genetikum®, Center for Human Genetics , Wegenerstr. 15 , Neu-Ulm , Germany
| | - Angela Abicht
- Medical Genetics Center Munich , Munich , Germany
- Department of Neurology, Friedrich-Baur-Institute , Klinikum der Ludwig-Maximilians-University , Munich , Germany
| | - Brunhilde Wirth
- Institute of Human Genetics, Center for Molecular Medicine Cologne and Center for Rare Diseases , University of Cologne , Kerpener Str. 34 , Cologne , Germany
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De Wel B, Goosens V, Sobota A, Van Camp E, Geukens E, Van Kerschaver G, Jagut M, Claes K, Claeys KG. Nusinersen treatment significantly improves hand grip strength, hand motor function and MRC sum scores in adult patients with spinal muscular atrophy types 3 and 4. J Neurol 2020; 268:923-935. [PMID: 32935160 DOI: 10.1007/s00415-020-10223-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/30/2020] [Accepted: 09/08/2020] [Indexed: 11/26/2022]
Abstract
BACKGROUND Nusinersen recently became available as the first treatment for Spinal Muscular Atrophy (SMA) and data on its effectiveness and safety in adult SMA patients are still scarce. METHODS We evaluated the effectiveness and safety of nusinersen treatment during 14 months in 16 adult patients with SMA types 3 and 4 in a prospective study, and retrospectively detailed the natural history of 48 adult SMA patients types 2, 3 and 4. RESULTS Hand grip strength (p = 0.03), hand motor function (p = 0.04) as assessed by a sub-score of the Revised Upper Limb Module (RULM) and the Medical Research Council (MRC) sum score (p = 0.04) improved significantly at month 14. Importantly, the MRC sum score had declined significantly (p < 0.01) prior to start of treatment in these patients. A minimal clinically important difference (MCID) in the Hammersmith Functional Motor Scale Expanded (HFMSE) and RULM scores was achieved in 31% and 50% of the patients, respectively, but the mean changes from baseline failed to reach significance. Forced Vital Capacity (FVC) transiently increased at month 6 (p = 0.01), whereas the Peak Expiratory Flow (PEF) did not. The Activity Limitations scale declined significantly prior to start of treatment (p < 0.01) and showed an improvement with nusinersen which was not significant. The safety evaluation did not reveal serious adverse events and no signs of nephrotoxicity or antisense oligonucleotide (ASO)-mediated inflammation. CONCLUSIONS We conclude that hand grip strength and hand motor function, as well as MRC sum scores improved significantly in nusinersen-treated adult patients with SMA types 3 and 4.
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Affiliation(s)
- Bram De Wel
- Department of Neurology, University Hospitals Leuven, Campus Gasthuisberg, Herestraat 49, 3000, Leuven, Belgium
- Laboratory for Muscle Diseases and Neuropathies, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Veerle Goosens
- Department of Radiology, University Hospitals Leuven, Leuven, Belgium
| | - Atka Sobota
- Department of Physical and Rehabilitation Medicine (Physiotherapy), University Hospitals Leuven, Leuven, Belgium
| | - Elke Van Camp
- Department of Physical and Rehabilitation Medicine (Physiotherapy), University Hospitals Leuven, Leuven, Belgium
| | - Ellen Geukens
- Department of Physical and Rehabilitation Medicine (Occupational Therapy), University Hospitals Leuven, Leuven, Belgium
| | - Griet Van Kerschaver
- Department of Physical and Rehabilitation Medicine (Occupational Therapy), University Hospitals Leuven, Leuven, Belgium
| | - Marlène Jagut
- Belgian Neuromuscular Diseases Registry, Sciensano, Brussels, Belgium
| | - Kathleen Claes
- Department of Nephrology, University Hospitals Leuven, Leuven, Belgium
- Department of Microbiology, Immunology and Transplantation, Nephrology and Renal Transplantation Research Group, KU Leuven, Leuven, Belgium
| | - Kristl G Claeys
- Department of Neurology, University Hospitals Leuven, Campus Gasthuisberg, Herestraat 49, 3000, Leuven, Belgium.
- Laboratory for Muscle Diseases and Neuropathies, Department of Neurosciences, KU Leuven, Leuven, Belgium.
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Mendonça RDH, Matsui C, Polido GJ, Silva AMS, Kulikowski L, Torchio Dias A, Zanardo EA, Solla DJF, Gurgel-Giannetti J, de Moura ACML, Sampaio GPC, Oliveira ASB, de Souza PVS, Pinto WBVDR, Gonçalves EA, Farias IB, Nardes F, Araújo APDQC, Marques W, Tomaselli PJ, Ribeiro MDO, Kitajima JP, Paoli Monteiro F, Saute JAM, Becker MM, Saraiva-Pereira ML, Brusius-Facchin AC, van der Linden V, Florêncio RN, Barbosa AVS, Machado-Costa MC, Pessoa ALS, Souza LS, Franca MC, Kok F, Reed UC, Zanoteli E. Intragenic variants in the SMN1 gene determine the clinical phenotype in 5q spinal muscular atrophy. NEUROLOGY-GENETICS 2020; 6:e505. [PMID: 33062891 PMCID: PMC7524579 DOI: 10.1212/nxg.0000000000000505] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 07/09/2020] [Indexed: 02/01/2023]
Abstract
Objective The aim of the study was to report the proportion of homozygous and compound heterozygous variants in the survival motor neuron 1 (SMN1) gene in a large population of patients with spinal muscular atrophy (SMA) and to correlate the severity of the disease with the presence of specific intragenic variants in SMN1 and with the SMN2 copy number. Methods Four hundred fifty Brazilian patients with SMA were included in a retrospective study, and clinical data were analyzed compared with genetic data; the SMN2 copy number was obtained by multiplex ligation-dependent probe amplification and pathogenic variants in SMN1 by next-generation sequencing. Results Four hundred two patients (89.3%) presented homozygous exon 7-SMN1 deletion, and 48 (10.7%) were compound heterozygous for the common deletion in one allele and a point mutation in the other allele. Recurrent variants in exons 3 and 6 (c.460C>T, c.770_780dup and c.734_735insC) accounted for almost 80% of compound heterozygous patients. Another recurrent pathogenic variant was c.5C>G at exon 1. Patients with c.770_780dup and c.734_735insC had a clinical phenotype correlated with SMN2 copy number, whereas the variants c.460C>T and c.5C>G determined a milder phenotype independently of the SMN2 copies. Conclusions Patients with specific pathogenic variants (c.460C>T and c.5C>G) presented a milder phenotype, and the SMN2 copy number did not correlate with disease severity in this group.
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Affiliation(s)
- Rodrigo de Holanda Mendonça
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Ciro Matsui
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Graziela Jorge Polido
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - André Macedo Serafim Silva
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Leslie Kulikowski
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Alexandre Torchio Dias
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Evelin Aline Zanardo
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Davi Jorge Fontoura Solla
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Juliana Gurgel-Giannetti
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Ana Carolina Monteiro Lessa de Moura
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Gabriela Palhares Campolina Sampaio
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Acary Souza Bulle Oliveira
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Paulo Victor Sgobbi de Souza
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Wladimir Bocca Vieira de Rezende Pinto
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Eduardo Augusto Gonçalves
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Igor Braga Farias
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Flávia Nardes
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Alexandra Prufer de Queiroz Campos Araújo
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Wilson Marques
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Pedro José Tomaselli
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Mara Dell Ospedale Ribeiro
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - João Paulo Kitajima
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Fabíola Paoli Monteiro
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Jonas Alex Morales Saute
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Michele Michelin Becker
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Maria Luiza Saraiva-Pereira
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Ana Carolina Brusius-Facchin
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Vanessa van der Linden
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Rodrigo Neves Florêncio
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - André Vinícius Soares Barbosa
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Marcela Camara Machado-Costa
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - André Luiz Santos Pessoa
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Leticia Silva Souza
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Marcondes Cavalcante Franca
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Fernando Kok
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Umbertina Conti Reed
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
| | - Edmar Zanoteli
- Department of Neurology (R.H.M., C.M., G.J.P., A.M.S.S., D.J.F.S., F.K., U.C.R., E.Z.); Department of Pathology (L.K., A.T.D., E.A.Z.), Faculdade de Medicina da Universidade de São Paulo (FMUSP); Departamento de Pediatria e Neuropediatria (J.G.-G., A.C.M.L.M., G.P.C.S.), Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte; Departamento de Neurologia - UNIFESP (A.S.B.O., P.V.S.S., W.B.V.R.P., E.A.G., I.B.F.), São Paulo; Departamento de Pediatria, Seção de Neurologia Infantil - UFRJ (F.N., A.P.Q.C.A.), Rio de Janeiro; Departamento de Neurologia (W.M., P.J.T.), FMUSP-RP, Ribeirao Preto; Mendelics Análise Genômica (M.D.O.R., J.P.K., F.P.M., F.K.), São Paulo; Serviço de Neurologia (J.A.M.S.), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre; Unidade de Neurologia Infantil (M.M.B.), Hospital de Clinicas de Porto Alegre; Serviço de Genética Médica (J.A.M.S., M.L.S.-P., A.C.B.-F.), Hospital de Clinicas de Porto Alegre; UFRGS, Porto Alegre; Departamento de Bioquímica - UFRGS (M.L.S.-P.), Porto Alegre; Hospital Maria Lucinda (V.L., R.N.F.), Recife; Hospital Infantil Joao Paulo II (A.V.S.B.), Fundação Hospitalar de Minas Gerais, Belo Horizonte; Escola Bahiana de Medicina e Saúde Pública (M.C.M.-C.), Salvador; Hospital Infantil Albert Sabin (A.L.S.P.), Universidade Estadual do Ceará, Fortaleza; and Departamento de Neurologia (L.S.S., M.C.F.), Unicamp, Campinas, Brazil
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Dual Mechanism of a New SMN1 Variant (c.835G>C, p.Gly279Arg) by Interrupting Exon 7 Skipping and YG Oligomerization in Causation of Spinal Muscular Atrophy. J Mol Neurosci 2020; 71:112-121. [PMID: 32812185 DOI: 10.1007/s12031-020-01631-7] [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: 03/10/2020] [Accepted: 06/08/2020] [Indexed: 10/23/2022]
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder caused by deletion or subtle variant of survival motor neuron 1 (SMN1) gene. By multiplex ligation-dependent probe amplification, genomic sequencing, and T-A cloning on cDNA level, we identified one novel SMN1 subtle variant c.835G>C (p.Gly279Arg) in a non-homozygous patient with type 1 SMA. Full-length SMN1 (fl-SMN1) transcripts in the peripheral bloods of the patient were significantly decreased compared with those in healthy individuals and the carries (p < 0.05). And two fragments of SMN1 transcripts including fl-SMN1 and △7-SMN1 were observed by RT-PCR, which indicated Exon 7 skipping of SMN1 gene. To further evaluate its splicing effects on Exon 7, we performed ex vivo splicing analysis, which showed that the mutant mini gene with c.835G>C reduced Exon 7 inclusion to 54%. In addition, self-oligomerization between mutant SMN protein with the c.835G>C (p.Gly279Arg) and wild SMN was decreased in self-interaction assays. Our study clearly demonstrates that the c.835G>C (p.Gly279Arg) variant can lead to a decrease in fl-SMN1 transcripts by interrupting correct splicing of SMN1. What is more, the variant also affects SMN self-oligomerization via amino acid substitution from Gly to Arg at amino acid position of 279. This work presents the first evidence that it does exit double-hit events for the novel variant, which is crucial to understanding a severe SMA phenotype (type 1).
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Tan CA, Westbrook MJ, Truty R, Kvitek DJ, Kennemer M, Winder TL, Shieh PB. Incorporating Spinal Muscular Atrophy Analysis by Next-Generation Sequencing into a Comprehensive Multigene Panel for Neuromuscular Disorders. Genet Test Mol Biomarkers 2020; 24:616-624. [PMID: 32721234 DOI: 10.1089/gtmb.2019.0282] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Background: Spinal muscular atrophy (SMA) is traditionally molecularly diagnosed by multiplex ligation-dependent probe amplification or quantitative polymerase chain reaction (qPCR). SMA analyses are not routinely incorporated into gene panel analyses for individuals with suspected SMA or broader neuromuscular indications. Aim: We sought to determine whether a next-generation sequencing (NGS) approach that integrates SMA analyses into a multigene neuromuscular disorders panel could detect undiagnosed SMA. Materials and Methods: Sequence and copy number variants of the SMN1/SMN2 genes were simultaneously analyzed in samples from 5304 unselected individuals referred for testing using an NGS-based 122-gene neuromuscular panel. This diagnostic approach was validated using DNA from 68 individuals who had been previously diagnosed with SMA via quantitative PCR for SMN1/SMN2. Results: Homozygous loss of SMN1 was detected in 47 unselected individuals. Heterozygous loss of SMN1 was detected in 118 individuals; 8 had an indeterminate variant in "SMN1 or SMN2" that supported an SMA diagnosis but required additional disambiguation. Of the remaining SMA carriers, 44 had pathogenic variants in other genes. Concordance rates between NGS and qPCR were 100% and 93% for SMN1 and SMN2 copy numbers, respectively. Where there was disagreement, phenotypes were more consistent with the SMN2 results from NGS. Conclusion: Integrating NGS-based SMA testing into a multigene neuromuscular panel allows a single assay to diagnose SMA while comprehensively assessing the spectrum of variants that can occur in individuals with broad differential diagnoses or nonspecific/overlapping neuromuscular features.
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Affiliation(s)
| | | | | | | | | | | | - Perry B Shieh
- Department of Neurology, University of California, Los Angeles, Los Angeles, California, USA
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Zhao X, Wang Y, Mei S, Chen C, Liu L, Wang C, Zhao G, Kong X. Identification of two novel SMN1 point mutations associated with a very severe SMA-I phenotype. Eur J Med Genet 2020; 63:104006. [PMID: 32659294 DOI: 10.1016/j.ejmg.2020.104006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/30/2020] [Accepted: 07/07/2020] [Indexed: 02/05/2023]
Abstract
Spinal muscular atrophy (SMA) is a common autosomal recessive genetic disorder characterized by degeneration of motor neurons and weakness and muscle atrophy. Approximately 95% of SMA patients are caused by homozygous deletions of the SMN1 gene, whereas the remaining 5% of patients harbor compound heterozygous mutations such as an SMN1 deletion allele and an intragenic mutation (insertions, deletions, or point mutations) in the other SMN1 allele. Although analysis for the SMN1/SMN2 copy number is relatively easy, molecular genetic testing for patients with subtle mutations is still compromised due to the presence of a highly homologous SMN2 gene. Herein, we analyzed the SMN1/SMN2 copy number by multiplex ligation-dependent probe amplification (MLPA) and subtle mutations by long-range PCR (LR-PCR) for two "nondeletion" SMA patients. We identified a missense mutation (c.280G > T, p. (Val94Phe)) and a splicing mutation c.*3+3A > T in SMN1 gene not previously described in the scientific literature. Giving the severe phenotype of the two patients, we speculated that these two point mutations could significantly affect the function of SMN proteins. Our results provide important information for genetic counseling and prenatal diagnosis in these families and enrich the SMN1 mutation database.
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Affiliation(s)
- Xuechao Zhao
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Jianshe Rd, Erqi District, Zhengzhou, Henan, 450052, People's Republic of China.
| | - Yanhong Wang
- Henan Provincial Key Laboratory of Children's Genetics and Metabolic Diseases, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou Children's Hospital, No-33, Longhu Waihuan East Road, Zhengzhou, He Nan Province, 450018, People's Republic of China.
| | - Shiyue Mei
- Henan Provincial Key Laboratory of Children's Genetics and Metabolic Diseases, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou Children's Hospital, No-33, Longhu Waihuan East Road, Zhengzhou, He Nan Province, 450018, People's Republic of China.
| | - Chen Chen
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Jianshe Rd, Erqi District, Zhengzhou, Henan, 450052, People's Republic of China.
| | - Lina Liu
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Jianshe Rd, Erqi District, Zhengzhou, Henan, 450052, People's Republic of China.
| | - Conghui Wang
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Jianshe Rd, Erqi District, Zhengzhou, Henan, 450052, People's Republic of China.
| | - Ganye Zhao
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Jianshe Rd, Erqi District, Zhengzhou, Henan, 450052, People's Republic of China.
| | - Xiangdong Kong
- Genetics and Prenatal Diagnosis Center, The First Affiliated Hospital of Zhengzhou University, Henan Engineering Research Center for Gene Editing of Human Genetic Disease, Jianshe Rd, Erqi District, Zhengzhou, Henan, 450052, People's Republic of China.
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Wadman RI, Jansen MD, Stam M, Wijngaarde CA, Curial CAD, Medic J, Sodaar P, Schouten J, Vijzelaar R, Lemmink HH, van den Berg LH, Groen EJN, van der Pol WL. Intragenic and structural variation in the SMN locus and clinical variability in spinal muscular atrophy. Brain Commun 2020; 2:fcaa075. [PMID: 32954327 PMCID: PMC7425299 DOI: 10.1093/braincomms/fcaa075] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/17/2020] [Accepted: 04/22/2020] [Indexed: 11/15/2022] Open
Abstract
Clinical severity and treatment response vary significantly between patients with spinal muscular atrophy. The approval of therapies and the emergence of neonatal screening programmes urgently require a more detailed understanding of the genetic variants that underlie this clinical heterogeneity. We systematically investigated genetic variation other than SMN2 copy number in the SMN locus. Data were collected through our single-centre, population-based study on spinal muscular atrophy in the Netherlands, including 286 children and adults with spinal muscular atrophy Types 1–4, including 56 patients from 25 families with multiple siblings with spinal muscular atrophy. We combined multiplex ligation-dependent probe amplification, Sanger sequencing, multiplexed targeted resequencing and digital droplet polymerase chain reaction to determine sequence and expression variation in the SMN locus. SMN1, SMN2 and NAIP gene copy number were determined by multiplex ligation-dependent probe amplification. SMN2 gene variant analysis was performed using Sanger sequencing and RNA expression analysis of SMN by droplet digital polymerase chain reaction. We identified SMN1–SMN2 hybrid genes in 10% of spinal muscular atrophy patients, including partial gene deletions, duplications or conversions within SMN1 and SMN2 genes. This indicates that SMN2 copies can vary structurally between patients, implicating an important novel level of genetic variability in spinal muscular atrophy. Sequence analysis revealed six exonic and four intronic SMN2 variants, which were associated with disease severity in individual cases. There are no indications that NAIP1 gene copy number or sequence variants add value in addition to SMN2 copies in predicting the clinical phenotype in individual patients with spinal muscular atrophy. Importantly, 95% of spinal muscular atrophy siblings in our study had equal SMN2 copy numbers and structural changes (e.g. hybrid genes), but 60% presented with a different spinal muscular atrophy type, indicating the likely presence of further inter- and intragenic variabilities inside as well as outside the SMN locus. SMN2 gene copies can be structurally different, resulting in inter- and intra-individual differences in the composition of SMN1 and SMN2 gene copies. This adds another layer of complexity to the genetics that underlie spinal muscular atrophy and should be considered in current genetic diagnosis and counselling practices.
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Affiliation(s)
- Renske I Wadman
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Marc D Jansen
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Marloes Stam
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Camiel A Wijngaarde
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Chantall A D Curial
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Jelena Medic
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Peter Sodaar
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Jan Schouten
- MRC Holland BV, 1057 DL Amsterdam, the Netherlands
| | | | - Henny H Lemmink
- Department of Genetics, University Medical Center Groningen, 9713 GZ Groningen, the Netherlands
| | - Leonard H van den Berg
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - Ewout J N Groen
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
| | - W Ludo van der Pol
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, 3584 CX Utrecht, the Netherlands
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48
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Lomonte P, Baklouti F, Binda O. The Biochemistry of Survival Motor Neuron Protein Is Paving the Way to Novel Therapies for Spinal Muscle Atrophy. Biochemistry 2020; 59:1391-1397. [PMID: 32227847 DOI: 10.1021/acs.biochem.9b01124] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Spinal muscle atrophy (SMA) is the leading genetic cause of infant mortality. SMA originates from the loss of functional survival motor neuron (SMN) protein. In most SMA cases, the SMN1 gene is deleted. However, in some cases, SMN is mutated, impairing its biological functions. SMN mutants could provide clues about the biological functions of SMN and the specific impact on SMA, potentially leading to the identification of new pathways and thus providing novel treatment alternatives, and even personalized care. Here, we discuss the biochemistry of SMN and the most recent SMA treatment strategies.
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Affiliation(s)
- Patrick Lomonte
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U 1217, Institut NeuroMyoGène (INMG), 69008 Lyon, France
| | - Faouzi Baklouti
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U 1217, Institut NeuroMyoGène (INMG), 69008 Lyon, France
| | - Olivier Binda
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U 1217, Institut NeuroMyoGène (INMG), 69008 Lyon, France
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49
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Finkel RS, Day JW, De Vivo DC, Kirschner J, Mercuri E, Muntoni F, Shieh PB, Tizzano E, Desguerre I, Quijano-Roy S, Saito K, Droege M, Dabbous O, Khan F, Renault L, Anderson FA, Servais L. RESTORE: A Prospective Multinational Registry of Patients with Genetically Confirmed Spinal Muscular Atrophy - Rationale and Study Design. J Neuromuscul Dis 2020; 7:145-152. [PMID: 32039859 PMCID: PMC7739962 DOI: 10.3233/jnd-190451] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Background: Dramatic improvements in spinal muscular atrophy (SMA) treatment have changed the prognosis for patients with this disease, leading to important new questions. Gathering representative, real-world data about the long-term efficacy and safety of emerging SMA interventions is essential to document their impact on patients and caregivers. Objectives: This registry will assess outcomes in patients with genetically confirmed SMA and provide information on the effectiveness and long-term safety of approved and emerging treatments. Design and Methods: RESTORE is a prospective, multicenter, multinational observational registry. Patients will be managed according to usual clinical practice. Both newly recruitedSMAtreatment centers and sites involved in existing SMA registries, including iSMAC, Treat-NMD, French SMA Assistance Publique- Hôpitaux de Paris (AP-HP), Cure-SMA, SMArtCARE, will be eligible to participate; de novo; sites already participating in another registry may be included via consortium agreements. Data from patients enrolled in partnering registries will be shared with the RESTORE Registry and data for newly diagnosed patients will be added upon enrollment. Patients will be enrolled over a 5-year period and followed for 15 years or until death. Assessments will include SMA history and treatment, pulmonary, nutritional, and motor milestones, healthcare resource utilization, work productivity, activity impairment, adverse events, quality of life, caregiver burden, and survival. Status: Recruitment started in September 2018. As of January 3, 2020, 64 patients were enrolled at 25 participating sites. Conclusions: The RESTORE Registry has begun recruiting recently diagnosed patients with genetically confirmed SMA, enabling assessment of both short- and long-term patient outcomes.
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Affiliation(s)
- Richard S Finkel
- Department of Pediatrics, Division of Neurology, Nemours Children's Hospital, Orlando, FL, United States
| | - John W Day
- Department of Neurology, Stanford University Medical Center, Stanford, CA, United States
| | - Darryl C De Vivo
- Departments of Neurology and Pediatrics, Columbia University Irving Medical Center, New York, NY, United States
| | - Janbernd Kirschner
- Clinic for Neuropediatrics and Muscle Disease, University Medical Center Freiburg, Freiburg, Germany
| | - Eugenio Mercuri
- Department of Paediatric Neurology and Nemo Clinical Centre, Catholic University, Rome, Italy
| | - Francesco Muntoni
- Department of Developmental Neuroscience, University College London, London, UK
| | - Perry B Shieh
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Eduardo Tizzano
- Department of Clinical and Molecular Genetics, Hospital Valle Hebron, Barcelona, Spain
| | | | - Susana Quijano-Roy
- Garches Neuromuscular Reference Center (GNMH), APHP Raymond Poincare University Hospital (UVSQ), Garches, France
| | - Kayoko Saito
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo, Japan
| | | | | | - Farid Khan
- AveXis, Inc., Bannockburn, IL, United States
| | | | - Frederick A Anderson
- Center for Outcomes Research, University of Massachusetts Medical School, Worcester, MA, United States
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50
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Wirth B, Karakaya M, Kye MJ, Mendoza-Ferreira N. Twenty-Five Years of Spinal Muscular Atrophy Research: From Phenotype to Genotype to Therapy, and What Comes Next. Annu Rev Genomics Hum Genet 2020; 21:231-261. [PMID: 32004094 DOI: 10.1146/annurev-genom-102319-103602] [Citation(s) in RCA: 119] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Twenty-five years ago, the underlying genetic cause for one of the most common and devastating inherited diseases in humans, spinal muscular atrophy (SMA), was identified. Homozygous deletions or, rarely, subtle mutations of SMN1 cause SMA, and the copy number of the nearly identical copy gene SMN2 inversely correlates with disease severity. SMA has become a paradigm and a prime example of a monogenic neurological disorder that can be efficiently ameliorated or nearly cured by novel therapeutic strategies, such as antisense oligonucleotide or gene replacement therapy. These therapies enable infants to survive who might otherwise have died before the age of two and allow individuals who have never been able to sit or walk to do both. The major milestones on the road to these therapies were to understand the genetic cause and splice regulation of SMN genes, the disease's phenotype-genotype variability, the function of the protein and the main affected cellular pathways and tissues, the disease's pathophysiology through research on animal models, the windows of opportunity for efficient treatment, and how and when to treat patients most effectively.This review aims to bridge our knowledge from phenotype to genotype to therapy, not only highlighting the significant advances so far but also speculating about the future of SMA screening and treatment.
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Affiliation(s)
- Brunhilde Wirth
- Institute of Human Genetics, Center for Molecular Medicine Cologne and Center for Rare Diseases, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany;
| | - Mert Karakaya
- Institute of Human Genetics, Center for Molecular Medicine Cologne and Center for Rare Diseases, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany;
| | - Min Jeong Kye
- Institute of Human Genetics, Center for Molecular Medicine Cologne and Center for Rare Diseases, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany;
| | - Natalia Mendoza-Ferreira
- Institute of Human Genetics, Center for Molecular Medicine Cologne and Center for Rare Diseases, University Hospital of Cologne, University of Cologne, 50931 Cologne, Germany;
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