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Akhkiamova M, Polyakov A, Marakhonov A, Voronin S, Saifullina E, Vafina Z, Michalchuk K, Braslavskaya S, Chukhrova A, Ryadninskaya N, Kutsev S, Shchagina O. Rare Variants of the SMN1 Gene Detected during Neonatal Screening. Genes (Basel) 2024; 15:956. [PMID: 39062735 PMCID: PMC11275604 DOI: 10.3390/genes15070956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 07/12/2024] [Accepted: 07/13/2024] [Indexed: 07/28/2024] Open
Abstract
During the expanded neonatal screening program conducted in 2023, we analyzed samples obtained from 1,227,130 out of 1,256,187 newborns in the Russian Federation in order to detect 5q spinal muscular atrophy (5q SMA). Within the 253-sample risk group formed based on the results of the first screening stage, 5 samples showed a discrepancy between the examination results obtained via various screening methods and quantitative MLPA (used as reference). The discrepancy between the results was caused by the presence of either a c.835-18C>T intronic variant or a c.842G>C p.(Arg281Thr) missense variant in the SMN1 gene, both of which are located in the region complementary to the sequences of annealing probes for ligation and real-time PCR. Three newborns had the c.835-18C>T variant in a compound heterozygous state with a deletion of exons 7-8 of the SMN1 gene, one newborn with two copies of the SMN1 gene had the same variant in a heterozygous state, and one newborn had both variants-c.835-18C>T and c.842G>C p.(Arg281Thr)-in a compound heterozygous state. Additional examination was carried out for these variants, involving segregation analysis in families, carriage analysis in population cohorts, and RNA analysis. Based on the obtained results, according to the ACMG criteria, the c.835-18C>T intronic variant should be classified as likely benign, and the c.842G>C p.(Arg281Thr) missense substitution as a variant of uncertain clinical significance. All five probands are under dynamic monitoring. No 5q SMA symptoms were detected in these newborns neonatally or during a 1-year follow-up period.
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Affiliation(s)
- Maria Akhkiamova
- Research Centre for Medical Genetics, Moskvorechie Str., 1, 115522 Moscow, Russia; (A.P.); (A.M.); (S.V.); (K.M.); (S.B.); (A.C.); (N.R.); (S.K.); (O.S.)
| | - Aleksander Polyakov
- Research Centre for Medical Genetics, Moskvorechie Str., 1, 115522 Moscow, Russia; (A.P.); (A.M.); (S.V.); (K.M.); (S.B.); (A.C.); (N.R.); (S.K.); (O.S.)
| | - Andrey Marakhonov
- Research Centre for Medical Genetics, Moskvorechie Str., 1, 115522 Moscow, Russia; (A.P.); (A.M.); (S.V.); (K.M.); (S.B.); (A.C.); (N.R.); (S.K.); (O.S.)
| | - Sergey Voronin
- Research Centre for Medical Genetics, Moskvorechie Str., 1, 115522 Moscow, Russia; (A.P.); (A.M.); (S.V.); (K.M.); (S.B.); (A.C.); (N.R.); (S.K.); (O.S.)
| | - Elena Saifullina
- Bashkir State Medical University, Lenin Str., 3, 450008 Ufa, Russia;
| | - Zulfiia Vafina
- Republic of Tatarstan Ministry of Healthcare Autonomous Public Healthcare, Institution Republic Clinical Hospital, Orenburgskiy Tract Str., 138, 420064 Kazan, Russia;
| | - Kristina Michalchuk
- Research Centre for Medical Genetics, Moskvorechie Str., 1, 115522 Moscow, Russia; (A.P.); (A.M.); (S.V.); (K.M.); (S.B.); (A.C.); (N.R.); (S.K.); (O.S.)
| | - Svetlana Braslavskaya
- Research Centre for Medical Genetics, Moskvorechie Str., 1, 115522 Moscow, Russia; (A.P.); (A.M.); (S.V.); (K.M.); (S.B.); (A.C.); (N.R.); (S.K.); (O.S.)
| | - Alena Chukhrova
- Research Centre for Medical Genetics, Moskvorechie Str., 1, 115522 Moscow, Russia; (A.P.); (A.M.); (S.V.); (K.M.); (S.B.); (A.C.); (N.R.); (S.K.); (O.S.)
| | - Nina Ryadninskaya
- Research Centre for Medical Genetics, Moskvorechie Str., 1, 115522 Moscow, Russia; (A.P.); (A.M.); (S.V.); (K.M.); (S.B.); (A.C.); (N.R.); (S.K.); (O.S.)
| | - Sergey Kutsev
- Research Centre for Medical Genetics, Moskvorechie Str., 1, 115522 Moscow, Russia; (A.P.); (A.M.); (S.V.); (K.M.); (S.B.); (A.C.); (N.R.); (S.K.); (O.S.)
| | - Olga Shchagina
- Research Centre for Medical Genetics, Moskvorechie Str., 1, 115522 Moscow, Russia; (A.P.); (A.M.); (S.V.); (K.M.); (S.B.); (A.C.); (N.R.); (S.K.); (O.S.)
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Wang N, Hu Y, Jiao K, Cheng N, Sun J, Tang J, Song J, Sun C, Wang T, Wang K, Qiao K, Xi J, Zhao C, Yu L, Zhu W. Long-term impact of nusinersen on motor and electrophysiological outcomes in adolescent and adult spinal muscular atrophy: insights from a multicenter retrospective study. J Neurol 2024:10.1007/s00415-024-12567-y. [PMID: 39030456 DOI: 10.1007/s00415-024-12567-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 06/30/2024] [Accepted: 07/05/2024] [Indexed: 07/21/2024]
Abstract
BACKGROUND 5q spinal muscular atrophy (SMA) is a progressive autosomal recessive motor neuron disease. OBJECTIVE We aimed to assess the effects of nusinersen on motor function and electrophysiological parameters in adolescent and adult patients with 5q SMA. METHODS Patients with genetically confirmed 5q SMA were eligible for inclusion, and clinical data were collected at baseline (V1), 63 days (V4), 180 days (V5), and 300 days (V6). The efficacy of nusinersen was monitored by encompassing clinical assessments, including the Revised Upper Limb Module (RULM), Hammersmith Functional Motor Scale Expanded (HFMSE), 6-Minute Walk Test (6MWT), and percent-predicted Forced Vital Capacity in sitting position (FVC%) and Compound Muscle Action Potential (CMAP) amplitude. The patients were divided into "sitter" and "walker" subgroups according to motor function status. RESULTS 54 patients were screened, divided into "sitter" (N = 22) and "walker" (N = 32), with the mean age at baseline of 27.03 years (range 13-53 years). The HFMSE in the walker subgroup increased significantly from baseline to V4 (mean change +2.32-point, P = 0.004), V5 (+3.09, P = 0.004) and V6 (+4.21, P = 0.005). The patients in both the sitter and walker subgroup had no significant changes in mean RULM between V1 and the following time points. Significant increases in CMAP amplitudes were observed in both upper and lower limbs after treatment. Also, patients with RULM ≥ 36 points showed significant CMAP improvements. Our analysis predicted that patients with CMAP amplitudes of trapezius ≥ 1.76 mV were more likely to achieve significant motor function improvements. CONCLUSIONS Nusinersen effectively improves motor function and electrophysiological data in adolescent and adult patients with SMA. This is the first report on the CMAP amplitude changes in the trapezius after treatment in patients with SMA. The CMAP values effectively compensate for the ceiling effect observed in the RULM, suggesting that CMAP could serve as an additional biomarker for evaluating treatment efficacy.
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Affiliation(s)
- Ningning Wang
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- National Center for Neurological Disorders (NCND), Shanghai, China
- Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Ying Hu
- Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China
| | - Kexin Jiao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- National Center for Neurological Disorders (NCND), 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 (NCND), 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 (NCND), Shanghai, China
- Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - JinXue Tang
- Qilin District People's Hospital, Qujing, Yunnan Province, China
| | - Jie Song
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- National Center for Neurological Disorders (NCND), Shanghai, China
- Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Chong Sun
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- National Center for Neurological Disorders (NCND), Shanghai, China
- Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Tao Wang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Kai Wang
- Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, China
| | - Kai Qiao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- National Center for Neurological Disorders (NCND), 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 (NCND), Shanghai, China
- Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- National Center for Neurological Disorders (NCND), Shanghai, China
- Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Liqiang Yu
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China.
| | - Wenhua Zhu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
- National Center for Neurological Disorders (NCND), Shanghai, China.
- Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
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Šimić D, Šarić A, Škaričić A, Lehman I, Bunoza B, Rako I, Fumić K. One-Year Pilot Study Results of Newborn Screening for Spinal Muscular Atrophy in the Republic of Croatia. Int J Neonatal Screen 2024; 10:50. [PMID: 39051406 PMCID: PMC11270348 DOI: 10.3390/ijns10030050] [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: 05/29/2024] [Revised: 07/08/2024] [Accepted: 07/08/2024] [Indexed: 07/27/2024] Open
Abstract
Spinal muscular atrophy (SMA) is a neuromuscular and neurodegenerative disease caused by the homozygous deletion of SMN1 exon 7 in 95% of cases. The prognosis for SMA patients has improved with the development of disease-modifying therapies, all of which are available in Croatia. The best treatment outcomes occur when therapy is applied before symptoms appear, making newborn screening (NBS) for SMA a crucial factor. Since SMA NBS is the first genetic test performed in our laboratory, for successful implementation of the program, we had to overcome logistical and organizational issues. Herein, we present the results of the SMA NBS during the one-year pilot project in Croatia and verify the suitability of the Targeted qPCR™ SMA assay for SMA NBS. The pilot project started on 1 March 2023 in the Department for Laboratory Diagnostics of the University Hospital Center Zagreb. A total of 32,655 newborns were tested. Five SMA patients were detected, and their diagnoses were confirmed by the multiplex ligation-dependent probe amplification (MLPA) assay. There have been no false positive or false negative results, to our knowledge so far. The incidence of SMA determined during the pilot study is consistent with the SMA incidence data from other European countries.
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Affiliation(s)
- Darija Šimić
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, 10000 Zagreb, Croatia; (D.Š.); (A.Š.); (A.Š.); (I.R.)
| | - Ana Šarić
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, 10000 Zagreb, Croatia; (D.Š.); (A.Š.); (A.Š.); (I.R.)
| | - Ana Škaričić
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, 10000 Zagreb, Croatia; (D.Š.); (A.Š.); (A.Š.); (I.R.)
| | - Ivan Lehman
- Department of Pediatrics, University Hospital Center Zagreb, 10000 Zagreb, Croatia; (I.L.); (B.B.)
| | - Branka Bunoza
- Department of Pediatrics, University Hospital Center Zagreb, 10000 Zagreb, Croatia; (I.L.); (B.B.)
| | - Ivana Rako
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, 10000 Zagreb, Croatia; (D.Š.); (A.Š.); (A.Š.); (I.R.)
| | - Ksenija Fumić
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, 10000 Zagreb, Croatia; (D.Š.); (A.Š.); (A.Š.); (I.R.)
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Ma K, Zhang K, Chen D, Wang C, Abdalla M, Zhang H, Tian R, Liu Y, Song L, Zhang X, Liu F, Liu G, Wang D. Real-world evidence: Risdiplam in a patient with spinal muscular atrophy type I with a novel splicing mutation and one SMN2 copy. Hum Mol Genet 2024; 33:1120-1130. [PMID: 38520738 PMCID: PMC11190614 DOI: 10.1093/hmg/ddae052] [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: 11/08/2023] [Revised: 03/08/2024] [Accepted: 03/08/2024] [Indexed: 03/25/2024] Open
Abstract
Spinal muscular atrophy (SMA), which results from the deletion or/and mutation in the SMN1 gene, is an autosomal recessive neuromuscular disorder that leads to weakness and muscle atrophy. SMN2 is a paralogous gene of SMN1. SMN2 copy number affects the severity of SMA, but its role in patients treated with disease modifying therapies is unclear. The most appropriate individualized treatment for SMA has not yet been determined. Here, we reported a case of SMA type I with normal breathing and swallowing function. We genetically confirmed that this patient had a compound heterozygous variant: one deleted SMN1 allele and a novel splice mutation c.628-3T>G in the retained allele, with one SMN2 copy. Patient-derived sequencing of 4 SMN1 cDNA clones showed that this intronic single transversion mutation results in an alternative exon (e)5 3' splice site, which leads to an additional 2 nucleotides (AG) at the 5' end of e5, thereby explaining why the patient with only one copy of SMN2 had a mild clinical phenotype. Additionally, a minigene assay of wild type and mutant SMN1 in HEK293T cells also demonstrated that this transversion mutation induced e5 skipping. Considering treatment cost and goals of avoiding pain caused by injections and starting treatment as early as possible, risdiplam was prescribed for this patient. However, the patient showed remarkable clinical improvements after treatment with risdiplam for 7 months despite carrying only one copy of SMN2. This study is the first report on the treatment of risdiplam in a patient with one SMN2 copy in a real-world setting. These findings expand the mutation spectrum of SMA and provide accurate genetic counseling information, as well as clarify the molecular mechanism of careful genotype-phenotype correlation of the patient.
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Affiliation(s)
- Kai Ma
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University, Jingshi road NO. 23976, Jinan, SD 250022, PR China
- Department of neurology, Children’s Hospital Affiliated to Shandong University, Jingshi road NO. 23976, Jinan, SD 250022, PR China
| | - Kaihui Zhang
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University, Jingshi road NO. 23976, Jinan, SD 250022, PR China
| | - Defang Chen
- The Office of operation management committee, Central Hospital Affiliated to Shandong First Medical University, Jiefang road NO. 105, Jinan, SD 250022, PR China
| | - Chuan Wang
- Science, Education and Foreign Affairs Section, Children’s Hospital Affiliated to Shandong University, Jingshi road NO. 23976, Jinan, SD 250022, PR China
| | - Mohnad Abdalla
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University, Jingshi road NO. 23976, Jinan, SD 250022, PR China
| | - Haozheng Zhang
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University, Jingshi road NO. 23976, Jinan, SD 250022, PR China
| | - Rujin Tian
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University, Jingshi road NO. 23976, Jinan, SD 250022, PR China
| | - Yang Liu
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University, Jingshi road NO. 23976, Jinan, SD 250022, PR China
- Ophthalmology department, Children’s Hospital Affiliated to Shandong University, Jingshi road NO. 23976, Jinan, SD 250022, PR China
| | - Li Song
- Pediatric Hematology and Oncology, Children’s Hospital Affiliated to Shandong University, Jingshi road NO. 23976, Jinan, SD 250022, PR China
| | - Xinyi Zhang
- Intensive Care Unit, The Second People’s Hospital of Shandong Province, Duanxing west road NO. 4, Jinan, SD 250022, PR China
| | - Fangfang Liu
- Department of Ultrasound, Central Hospital Affiliated to Shandong First Medical University, Jiefang road NO. 105, Jinan, SD 250022, PR China
| | - Guohua Liu
- Ophthalmology department, Children’s Hospital Affiliated to Shandong University, Jingshi road NO. 23976, Jinan, SD 250022, PR China
| | - Dong Wang
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University, Jingshi road NO. 23976, Jinan, SD 250022, PR China
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Bagga P, Singh S, Ram G, Kapil S, Singh A. Diving into progress: a review on current therapeutic advancements in spinal muscular atrophy. Front Neurol 2024; 15:1368658. [PMID: 38854961 PMCID: PMC11157111 DOI: 10.3389/fneur.2024.1368658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 04/29/2024] [Indexed: 06/11/2024] Open
Abstract
Spinal muscular atrophy (SMA) is an uncommon disorder associated with genes characterized by the gradual weakening and deterioration of muscles, often leading to substantial disability and premature mortality. Over the past decade, remarkable strides have been made in the field of SMA therapeutics, revolutionizing the landscape of patient care. One pivotal advancement is the development of gene-targeted therapies, such as nusinersen, onasemnogene abeparvovec and risdiplam which have demonstrated unprecedented efficacy in slowing disease progression. These therapies aim to address the root cause of SMA by targeting the survival motor neuron (SMN) gene, effectively restoring deficient SMN protein levels. The advent of these innovative approaches has transformed the prognosis for many SMA patients, offering a glimmer of hope where there was once limited therapeutic recourse. Furthermore, the emergence of small molecule compounds and RNA-targeting strategies has expanded the therapeutic arsenal against SMA. These novel interventions exhibit diverse mechanisms of action, including SMN protein stabilization and modulation of RNA splicing, showcasing the multifaceted nature of SMA treatment research. Collective efforts of pharmaceutical industries, research centers, and patient advocacy groups have played an important role in expediting the translation of scientific discoveries into visible clinical benefits. This review not only highlights the remarkable progress achieved in SMA therapeutics but also generates the ray of hope for the ongoing efforts required to enhance accessibility, optimize treatment strategies, rehabilitation (care and therapies) and ultimately pave the way for an improved quality of life for individuals affected by SMA.
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Affiliation(s)
- Pankaj Bagga
- School of Bioengineering & Biosciences, Lovely Professional University (LPU), Phagwara, India
| | - Sudhakar Singh
- School of Bioengineering & Biosciences, Lovely Professional University (LPU), Phagwara, India
| | - Gobind Ram
- PG Department of Biotechnology, Layalpur Khalsa College, Jalandhar, India
| | - Subham Kapil
- Department of Zoology, DAV College Jalandhar, Jalandhar, India
| | - Avtar Singh
- School of Electrical Engineering and Computing (SoEEC), Adama Science and Technology University (AS-TU), Adama, Ethiopia
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Aguzzoli Heberle B, Brandon JA, Page ML, Nations KA, Dikobe KI, White BJ, Gordon LA, Fox GA, Wadsworth ME, Doyle PH, Williams BA, Fox EJ, Shantaraman A, Ryten M, Goodwin S, Ghiban E, Wappel R, Mavruk-Eskipehlivan S, Miller JB, Seyfried NT, Nelson PT, Fryer JD, Ebbert MTW. Mapping medically relevant RNA isoform diversity in the aged human frontal cortex with deep long-read RNA-seq. Nat Biotechnol 2024:10.1038/s41587-024-02245-9. [PMID: 38778214 DOI: 10.1038/s41587-024-02245-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 04/15/2024] [Indexed: 05/25/2024]
Abstract
Determining whether the RNA isoforms from medically relevant genes have distinct functions could facilitate direct targeting of RNA isoforms for disease treatment. Here, as a step toward this goal for neurological diseases, we sequenced 12 postmortem, aged human frontal cortices (6 Alzheimer disease cases and 6 controls; 50% female) using one Oxford Nanopore PromethION flow cell per sample. We identified 1,917 medically relevant genes expressing multiple isoforms in the frontal cortex where 1,018 had multiple isoforms with different protein-coding sequences. Of these 1,018 genes, 57 are implicated in brain-related diseases including major depression, schizophrenia, Parkinson's disease and Alzheimer disease. Our study also uncovered 53 new RNA isoforms in medically relevant genes, including several where the new isoform was one of the most highly expressed for that gene. We also reported on five mitochondrially encoded, spliced RNA isoforms. We found 99 differentially expressed RNA isoforms between cases with Alzheimer disease and controls.
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Affiliation(s)
- Bernardo Aguzzoli Heberle
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - J Anthony Brandon
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Madeline L Page
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Kayla A Nations
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Ketsile I Dikobe
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Brendan J White
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Lacey A Gordon
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Grant A Fox
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Mark E Wadsworth
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Patricia H Doyle
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Brittney A Williams
- Department of Pharmacology and Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Edward J Fox
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA
| | | | - Mina Ryten
- UK Dementia Research Institute at The University of Cambridge, Cambridge, UK
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK
- Department of Genetics and Genomic Medicine, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Sara Goodwin
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Elena Ghiban
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Robert Wappel
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | | | - Justin B Miller
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
- Division of Biomedical Informatics, Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY, USA
- Department of Pathology and Laboratory Medicine, University of Kentucky, Lexington, KY, USA
- Microbiology, Immunology and Molecular Genetics, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Nicholas T Seyfried
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA
| | - Peter T Nelson
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - John D Fryer
- Department of Neuroscience, Mayo Clinic, Scottsdale, AZ, USA
| | - Mark T W Ebbert
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA.
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, KY, USA.
- Division of Biomedical Informatics, Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY, USA.
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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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8
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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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9
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Abd El Mutaleb ANH, Ibrahim FAR, Megahed FAK, Atta A, Ali BA, Omar TEI, Rashad MM. NAIP Gene Deletion and SMN2 Copy Number as Molecular Tools in Predicting the Severity of Spinal Muscular Atrophy. Biochem Genet 2024:10.1007/s10528-023-10657-6. [PMID: 38388850 DOI: 10.1007/s10528-023-10657-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 12/29/2023] [Indexed: 02/24/2024]
Abstract
Spinal muscular atrophy (SMA) is one of the most prevalent autosomal recessive illnesses with type I being the most severe type. Genomic alterations including survival motor neuron (SMN) copy number as well as deletions in SMN and Neuronal Apoptosis Inhibitory Protein (NAIP) are greatly implicated in the emergence of SMA. However, the association of such alterations with the severity of the disease is yet to be investigated. This study was directed to elucidate the molecular assessment of NAIP and SMN genomic alterations as a useful tool in predicting the severity of SMA among patients. This study included 65 SMA pediatric patients (30 type I and 35 type II) and 65 healthy controls. RFLP-PCR was employed to determine the genetic polymorphisms of the SMN1, SMN2, and NAIP genes. In addition, qRT-PCR was used to identify the expression of the SMN1 and SMN2 genes, and serum levels of creatine kinase were measured using a colorimetric method. DNA sequencing was performed on some samples to detect any single nucleotide polymorphisms in SMN1, SMN2, and NAIP genes. All SMA patients had a homozygous deficiency of SMN1 exon 7. The homozygous deficiency of SMN1 exons 7 and 8, with the deletion of NAIP exon 5 was found among the majority of Type I patients. In contrast, patients with the less severe condition (type II) had SMN1 exons 7 and 8 deleted but did not have any deletions in NAIP, additionally; 65.7% of patients had multiple copies of SMN2. Analysis of NAIP deletion alongside assessing SMN2 copy number might enhance the effectiveness of the diagnosis that can predict severity among Spinal Muscular Atrophy patients.
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Affiliation(s)
| | - Fawziya A R Ibrahim
- Department of Applied Medical Chemistry, Medical Research Institute, University of Alexandria, Alexandria, Egypt.
| | - Fayed A K Megahed
- Department of Nucleic Acid Research, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, Alexandria, Egypt
| | - Ahmed Atta
- Department of Nucleic Acid Research, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, Alexandria, Egypt
| | - Bahy A Ali
- Department of Nucleic Acid Research, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, Alexandria, Egypt
| | - Tarek E I Omar
- Department of Pediatric Neurology, Faculty of Medicine, University of Alexandria, Alexandria, Egypt
| | - Mona M Rashad
- Department of Applied Medical Chemistry, Medical Research Institute, University of Alexandria, Alexandria, Egypt
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10
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Bitetti I, Manna MR, Stella R, Varone A. Motor and neurocognitive profiles of children with symptomatic spinal muscular atrophy type 1 with two copies of SMN2 before and after treatment: a longitudinal observational study. Front Neurol 2024; 15:1326528. [PMID: 38450080 PMCID: PMC10915206 DOI: 10.3389/fneur.2024.1326528] [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: 10/23/2023] [Accepted: 01/30/2024] [Indexed: 03/08/2024] Open
Abstract
Introduction Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by mutations in the survival motor neuron 1 (SMN1) gene. In clinical studies, gene replacement therapy with onasemnogene abeparvovec (formerly AVXS-101, Zolgensma®, Novartis) was efficacious in improving motor functioning in children with SMA. However, its effects on cognitive and language skills are largely unknown. Methods This longitudinal observational study evaluated changes in motor and neurocognitive functioning over a 1-year period after administration of onasemnogene abeparvovec in 12 symptomatic SMA type 1 patients with two copies of SMN2 aged 1.7-52.6 months at administration. Motor functioning was measured using the Children's Hospital of Philadelphia Infant Test for Neuromuscular Disorders (CHOP-INTEND) while neurocognitive assessment was measured using Griffiths III. Motor milestones and language ability were also assessed at each timepoint. Results and discussion Statistically significant increases in median CHOP-INTEND scores from baseline were observed at 1, 3, 6, and 12 months after onasemnogene abeparvovec administration (all p ≤ 0.005). Most (91.7%) patients were able to roll over or sit independently for >1 min at 12 months. Significant increases in the Griffiths III Foundations of Learning, Language and Communication, Eye and Hand Coordination, and Personal-Social-Emotional subscale scores were observed at 12-months, but not in the Gross Motor subscale. Speech and language abilities progressed in most patients. Overall, most patients showed some improvement in cognitive and communication performance after treatment with onasemnogene abeparvovec in addition to significant improvement in motor functioning and motor milestones. Evaluation of neurocognitive function should be considered when assessing the global functioning of patients with SMA.
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Affiliation(s)
- Ilaria Bitetti
- Pediatric Neurology, Santobono-Pausilipon Children's Hospital, Naples, Italy
| | - Maria Rosaria Manna
- Neurorehabilitation Unit, Santobono-Pausilipon Children's Hospital, Naples, Italy
| | - Roberto Stella
- Neurorehabilitation Unit, Santobono-Pausilipon Children's Hospital, Naples, Italy
| | - Antonio Varone
- Pediatric Neurology, Santobono-Pausilipon Children's Hospital, Naples, Italy
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11
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Sonehara S, Bo R, Nambu Y, Iketani K, Lee T, Shimomura H, Ueda M, Takeshima Y, Iijima K, Nozu K, Nishio H, Awano H. Newborn Screening for Spinal Muscular Atrophy: A 2.5-Year Experience in Hyogo Prefecture, Japan. Genes (Basel) 2023; 14:2211. [PMID: 38137033 PMCID: PMC10742789 DOI: 10.3390/genes14122211] [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: 11/20/2023] [Revised: 12/12/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Newborn screening (NBS) for spinal muscular atrophy (SMA) is necessary, as favorable outcomes can be achieved by treatment with disease-modifying drugs in early infancy. Although SMA-NBS has been initiated in Japan, its clinical results have not been fully reported. We report the findings of the initial 2.5 years of a pilot SMA-NBS of approximately 16,000 infants conducted from February 2021 in Hyogo Prefecture, Japan. Clinical data of 17 infants who tested positive were retrospectively obtained from the NBS follow-up centers participating in this multicenter cohort observational study. Genetic testing revealed 14 false positives, and three infants were diagnosed with SMA. Case 1 had two copies of survival motor neuron (SMN) 2 and showed SMA-related symptoms at diagnosis. Case 2 was asymptomatic, with two copies of SMN2. Asymptomatic case 3 had four copies of SMN2 exon 7, including the SMN1/2 hybrid gene. Cases 1 and 2 were treated within 1 month and case 3 at 8 months. All the patients showed improved motor function scores and did not require respiratory support. The identification of infants with SMA via NBS and early treatment improved their motor and respiratory outcomes. Thus, implementation of SMA-NBS at a nationwide scale should be considered.
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Affiliation(s)
- Shoko Sonehara
- Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan; (S.S.); (R.B.); (Y.N.); (K.I.); (K.N.)
| | - Ryosuke Bo
- Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan; (S.S.); (R.B.); (Y.N.); (K.I.); (K.N.)
| | - Yoshinori Nambu
- Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan; (S.S.); (R.B.); (Y.N.); (K.I.); (K.N.)
| | - Kiiko Iketani
- Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan; (S.S.); (R.B.); (Y.N.); (K.I.); (K.N.)
- Hyogo Prefectural Kobe Children’s Hospital, 1-6-7 Minatozimaminami-cho, Chuo-ku, Kobe 650-0047, Japan;
| | - Tomoko Lee
- Department of Pediatrics, Hyogo Medical University, 1-1 Mukogawa-cho, Nishinomiya 663-8501, Japan; (T.L.); (H.S.); (Y.T.)
| | - Hideki Shimomura
- Department of Pediatrics, Hyogo Medical University, 1-1 Mukogawa-cho, Nishinomiya 663-8501, Japan; (T.L.); (H.S.); (Y.T.)
| | - Masaaki Ueda
- Department of Pediatrics, Toyooka Public Hospital, 1094 Tobera, Toyooka 668-8501, Japan;
| | - Yasuhiro Takeshima
- Department of Pediatrics, Hyogo Medical University, 1-1 Mukogawa-cho, Nishinomiya 663-8501, Japan; (T.L.); (H.S.); (Y.T.)
| | - Kazumoto Iijima
- Hyogo Prefectural Kobe Children’s Hospital, 1-6-7 Minatozimaminami-cho, Chuo-ku, Kobe 650-0047, Japan;
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan; (S.S.); (R.B.); (Y.N.); (K.I.); (K.N.)
| | - Hisahide Nishio
- Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe 651-2180, Japan;
| | - Hiroyuki Awano
- Research Initiative Center, Organization for Research Initiative and Promotion, Tottori University, 86 Nishi-cho, Yonago 683-8503, Japan
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12
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Maretina M, Il’ina A, Egorova A, Glotov A, Kiselev A. Development of 2'-O-Methyl and LNA Antisense Oligonucleotides for SMN2 Splicing Correction in SMA Cells. Biomedicines 2023; 11:3071. [PMID: 38002071 PMCID: PMC10669464 DOI: 10.3390/biomedicines11113071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/07/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a devastating neurodegenerative disease caused by mutations in the SMN1 gene. Existing therapies demonstrate positive results on SMA patients but still might be ameliorated in efficacy and price. In the presented study we designed antisense oligonucleotides (AONs), targeting intronic splicing silencer sites, some were modified with 2'-O-methyl, others with LNA. The AONs have been extensively tested in different concentrations, both individually and combined, in order to effectively target the ISS-N1 and A+100G splicing silencer regions in intron 7 of the SMN2 gene. By treating SMA-cultured fibroblasts with certain AONs, we discovered a remarkable increase in the levels of full-length SMN transcripts and the number of nuclear gems. This increase was observed to be dose-dependent and reached levels comparable to those found in healthy cells. When added to cells together, most of the tested molecules showed a remarkable synergistic effect in correcting splicing. Through our research, we have discovered that the impact of oligonucleotides is greatly influenced by their length, sequence, and pattern of modification.
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Affiliation(s)
- Marianna Maretina
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (A.E.); (A.G.)
| | - Arina Il’ina
- Faculty of Biology, Saint Petersburg State University, Universitetskaya Embankment 7–9, 199034 Saint Petersburg, Russia;
| | - Anna Egorova
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (A.E.); (A.G.)
| | - Andrey Glotov
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (A.E.); (A.G.)
| | - Anton Kiselev
- Department of Genomic Medicine Named after V.S. Baranov, D.O. Ott Research Institute of Obstetrics, Gynecology and Reproductology, Mendeleevskaya Line 3, 199034 Saint Petersburg, Russia; (M.M.); (A.E.); (A.G.)
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13
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Pajuste FD, Remm M. GeneToCN: an alignment-free method for gene copy number estimation directly from next-generation sequencing reads. Sci Rep 2023; 13:17765. [PMID: 37853040 PMCID: PMC10584998 DOI: 10.1038/s41598-023-44636-z] [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: 05/04/2023] [Accepted: 10/10/2023] [Indexed: 10/20/2023] Open
Abstract
Genomes exhibit large regions with segmental copy number variation, many of which include entire genes and are multiallelic. We have developed a computational method GeneToCN that counts the frequencies of gene-specific k-mers in FASTQ files and uses this information to infer copy number of the gene. We validated the copy number predictions for amylase genes (AMY1, AMY2A, AMY2B) using experimental data from digital droplet PCR (ddPCR) on 39 individuals and observed a strong correlation (R = 0.99) between GeneToCN predictions and experimentally determined copy numbers. An additional validation on FCGR3 genes showed a higher concordance for FCGR3A compared to two other methods, but reduced accuracy for FCGR3B. We further tested the method on three different genomic regions (SMN, NPY4R, and LPA Kringle IV-2 domain). Predicted copy number distributions of these genes in a set of 500 individuals from the Estonian Biobank were in good agreement with the previously published studies. In addition, we investigated the possibility to use GeneToCN on sequencing data generated by different technologies by comparing copy number predictions from Illumina, PacBio, and Oxford Nanopore data of the same sample. Despite the differences in variability of k-mer frequencies, all three sequencing technologies give similar predictions with GeneToCN.
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Affiliation(s)
- Fanny-Dhelia Pajuste
- Institute of Molecular and Cell Biology, University of Tartu, 23 Riia Str., 51010, Tartu, Estonia.
| | - Maido Remm
- Institute of Molecular and Cell Biology, University of Tartu, 23 Riia Str., 51010, Tartu, Estonia
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14
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Angilletta I, Ferrante R, Giansante R, Lombardi L, Babore A, Dell’Elice A, Alessandrelli E, Notarangelo S, Ranaudo M, Palmarini C, De Laurenzi V, Stuppia L, Rossi C. Spinal Muscular Atrophy: An Evolving Scenario through New Perspectives in Diagnosis and Advances in Therapies. Int J Mol Sci 2023; 24:14873. [PMID: 37834320 PMCID: PMC10573646 DOI: 10.3390/ijms241914873] [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: 08/21/2023] [Revised: 09/27/2023] [Accepted: 10/02/2023] [Indexed: 10/15/2023] Open
Abstract
Spinal muscular atrophy (SMA) linked to 5q is a recessive motor neuron disease characterized by progressive and diffuse weakness and muscular atrophy. SMA is the most common neurodegenerative disease in childhood with an incidence of approximately 1 in 6000-10,000 live births, being long considered a leading cause of hereditary mortality in infancy, worldwide. The classification of SMA is based on the natural history of the disease, with a wide clinical spectrum of onset and severity. We are currently in a new therapeutic era, that, thanks to the widespread use of the newly approved disease-modifying therapies and the possibility of an early administration, should lead to a deep change in the clinical scenario and, thus, in the history of SMA. With the aim to achieve a new view of SMA, in this review we consider different aspects of this neuromuscular disease: the historical perspective, the clinical features, the diagnostic process, the psychological outcome, innovation in treatments and therapies, the possibility of an early identification of affected infants in the pre-symptomatic phase through newborn screening programs.
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Affiliation(s)
- Ilaria Angilletta
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (I.A.); (R.F.); (R.G.); (L.L.); (A.D.); (E.A.); (S.N.); (M.R.); (C.P.); (V.D.L.); (L.S.)
- Department of Neurosciences, Imaging and Clinical Sciences, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
| | - Rossella Ferrante
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (I.A.); (R.F.); (R.G.); (L.L.); (A.D.); (E.A.); (S.N.); (M.R.); (C.P.); (V.D.L.); (L.S.)
| | - Roberta Giansante
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (I.A.); (R.F.); (R.G.); (L.L.); (A.D.); (E.A.); (S.N.); (M.R.); (C.P.); (V.D.L.); (L.S.)
| | - Lucia Lombardi
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (I.A.); (R.F.); (R.G.); (L.L.); (A.D.); (E.A.); (S.N.); (M.R.); (C.P.); (V.D.L.); (L.S.)
- Department of Neurosciences, Imaging and Clinical Sciences, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
| | - Alessandra Babore
- Department of Psychological, Health and Territory Sciences, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy;
| | - Anastasia Dell’Elice
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (I.A.); (R.F.); (R.G.); (L.L.); (A.D.); (E.A.); (S.N.); (M.R.); (C.P.); (V.D.L.); (L.S.)
| | - Elisa Alessandrelli
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (I.A.); (R.F.); (R.G.); (L.L.); (A.D.); (E.A.); (S.N.); (M.R.); (C.P.); (V.D.L.); (L.S.)
| | - Stefania Notarangelo
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (I.A.); (R.F.); (R.G.); (L.L.); (A.D.); (E.A.); (S.N.); (M.R.); (C.P.); (V.D.L.); (L.S.)
| | - Marianna Ranaudo
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (I.A.); (R.F.); (R.G.); (L.L.); (A.D.); (E.A.); (S.N.); (M.R.); (C.P.); (V.D.L.); (L.S.)
| | - Claudia Palmarini
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (I.A.); (R.F.); (R.G.); (L.L.); (A.D.); (E.A.); (S.N.); (M.R.); (C.P.); (V.D.L.); (L.S.)
| | - Vincenzo De Laurenzi
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (I.A.); (R.F.); (R.G.); (L.L.); (A.D.); (E.A.); (S.N.); (M.R.); (C.P.); (V.D.L.); (L.S.)
- Department of Innovative Technologies in Medicine and Dentistry, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
| | - Liborio Stuppia
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (I.A.); (R.F.); (R.G.); (L.L.); (A.D.); (E.A.); (S.N.); (M.R.); (C.P.); (V.D.L.); (L.S.)
- Department of Psychological, Health and Territory Sciences, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy;
| | - Claudia Rossi
- Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (I.A.); (R.F.); (R.G.); (L.L.); (A.D.); (E.A.); (S.N.); (M.R.); (C.P.); (V.D.L.); (L.S.)
- Department of Innovative Technologies in Medicine and Dentistry, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
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15
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Fay A. Spinal Muscular Atrophy: A (Now) Treatable Neurodegenerative Disease. Pediatr Clin North Am 2023; 70:963-977. [PMID: 37704354 DOI: 10.1016/j.pcl.2023.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
Spinal muscular atrophy (SMA) is a progressive disease of the lower motor neurons associated with recessive loss of the SMN1 gene, and which leads to worsening weakness and disability, and is fatal in its most severe forms. Over the past six years, three treatments have emerged, two drugs that modify exon splicing and one gene therapy, which have transformed the management of this disease. When treated pre-symptomatically, many children show normal early motor development, and the benefits extend from the newborn period to adulthood. Similar treatment approaches are now under investigation for rare types of SMA associated with genes beyond SMN1.
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Affiliation(s)
- Alex Fay
- University of California, San Francisco, 1875 4th Street., Suite 5A, San Francisco, CA 94158, USA.
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16
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Alghamdi A, AlDossary S, Abdulaziz Alabdulqader W, Amer F, Ali M, Almomen M, Alghamdi F. Identifying Clinical and Genetic Characteristics of Spinal Muscular Atrophy Patients and Families in Saudi Arabia. Cureus 2023; 15:e46452. [PMID: 37927698 PMCID: PMC10623204 DOI: 10.7759/cureus.46452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2023] [Indexed: 11/07/2023] Open
Abstract
INTRODUCTION Spinal muscular atrophy (SMA) is an inherited, neuromuscular disease characterized by the deterioration of spinal motor neurons, causing progressive muscular atrophy and weakening. It is an autosomal recessive disease with the mutation of the survival motor neuron 1 (SMN1) gene as a hallmark. Evidence suggests that the SMN2 gene modulates the severity of the disease. SMA is classified based on the maximum motor function achieved. This study aims to describe the genetic makeup and characteristics of an SMA cohort in the Kingdom of Saudi Arabia (KSA). METHODS Data from families presenting with SMA children was collected between January 2018 and December 2020. Blood samples were collected from patients and family members. Genetic testing for SMA and mutations was performed at a European central lab. RESULTS AND DISCUSSION Seventeen families were enrolled in the study, including 52 children. Among 34 parents, 28 were carriers with heterozygous deletion (82.3%), one (2.9%) had no deletion detected by multiplex ligation-dependent probe amplification (MLPA) but had point mutation by sequencing, one (2.9%) had homozygous deletion and was symptomatic, three (8.8%) had no deletion or point mutation and were presumed to have 2+0, and one (2.9%) was not tested. CONCLUSION This study provides insight into the carrier mutational analysis of families with SMA disease manifestations in KSA. Further studies are needed to understand the burden and impact of SMA among the Saudi population.
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Affiliation(s)
- Alaa Alghamdi
- Primary Care and Population Health, King Fahad University Hospital, Dammam, SAU
| | - Shaikhah AlDossary
- Primary Care and Population Health, University College London, London, GBR
| | | | - Fawzia Amer
- Pediatric Neurology, King Fahad Specialist Hospital, Dammam, SAU
- Pediatric Neurology and Metabolic, Cairo University Children Hospital, Cairo, EGY
| | - Mona Ali
- Neurology, Neuroscience Center, King Fahad Specialist Hospital, Dammam, SAU
| | - Momen Almomen
- Pediatric Neurology, King Fahad Specialist Hospital, Dammam, SAU
| | - Fouad Alghamdi
- Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Dammam, SAU
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Votsi C, Koutsou P, Ververis A, Georghiou A, Nicolaou P, Tanteles G, Christodoulou K. Spinal muscular atrophy type I associated with a novel SMN1 splicing variant that disrupts the expression of the functional transcript. Front Neurol 2023; 14:1241195. [PMID: 37799281 PMCID: PMC10548546 DOI: 10.3389/fneur.2023.1241195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 08/31/2023] [Indexed: 10/07/2023] Open
Abstract
Introduction Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder caused by pathogenic variants in the SMN1 gene. The majority of SMA patients harbor a homozygous deletion of SMN1 exon 7 (95%). Heterozygosity for a conventional variant and a deletion is rare (5%) and not easily detected, due to the highly homologous SMN2 gene interference. SMN2 mainly produces a truncated non-functional protein (SMN-d7) instead of the full-length functional (SMN-FL). We hereby report a novel SMN1 splicing variant in an infant with severe SMA. Methods MLPA was used for SMN1/2 exon dosage determination. Sanger sequencing approaches and long-range PCR were employed to search for an SMN1 variant. Conventional and improved Real-time PCR assays were developed for the qualitative and quantitative SMN1/2 RNA analysis. Results The novel SMN1 splice-site variant c.835-8_835-5delinsG, was identified in compound heterozygosity with SMN1 exons 7/8 deletion. RNA studies revealed complete absence of SMN1 exon 7, thus confirming a disruptive effect of the variant on SMN1 splicing. No expression of the functional SMN1-FL transcript, remarkable expression of the SMN1-d7 and increased levels of the SMN2-FL/SMN2-d7 transcripts were observed. Discussion We verified the occurrence of a non-deletion SMN1 variant and supported its pathogenicity, thus expanding the SMN1 variants spectrum. We discuss the updated SMA genetic findings in the Cypriot population, highlighting an increased percentage of intragenic variants compared to other populations.
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Affiliation(s)
- Christina Votsi
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Pantelitsa Koutsou
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Antonis Ververis
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Anthi Georghiou
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Paschalis Nicolaou
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - George Tanteles
- Clinical Genetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Kyproula Christodoulou
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
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18
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Bitetti I, Lanzara V, Margiotta G, Varone A. Onasemnogene abeparvovec gene replacement therapy for the treatment of spinal muscular atrophy: a real-world observational study. Gene Ther 2023; 30:592-597. [PMID: 35606491 PMCID: PMC10457192 DOI: 10.1038/s41434-022-00341-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 04/22/2022] [Accepted: 05/06/2022] [Indexed: 11/08/2022]
Abstract
Spinal muscular atrophy (SMA) is a genetically inherited recessive neuromuscular disease that causes muscular atrophy and weakness. Onasemnogene abeparvovec (formerly AVXS-101, Zolgensma®, Novartis) is a targeted therapy approved to treat patients with SMA in >40 countries worldwide. This study describes the clinical efficacy and tolerability of gene replacement therapy with onasemnogene abeparvovec over a 3-month period in 9 SMA type 1 patients aged 1.7-48 months, with 7 patients on stable nusinersen (i.e., had received all four nusinersen loading doses before inclusion in this study). Liver function (alanine aminotransferase, aspartate aminotransferase, total bilirubin), troponin I, platelet counts, creatinine levels, and motor function (CHOP-INTEND) were monitored. For the seven patients on stable nusinersen, the median baseline CHOP-INTEND score increased significantly during nusinersen treatment (Wilcoxon signed-rank test p = 0.018) and at 3 months after switching to onasemnogene abeparvovec (Wilcoxon signed-rank test p = 0.0467). We also identified two patients who responded poorly to nusinersen but showed the largest increase in baseline CHOP-INTEND scores at 1 and 3 months after switching, which could suggest that poor responders to nusinersen may respond favorably to onasemnogene abeparvovec. No unknown adverse events occurred. One patient developed moderate/severe thrombocytopenia 1 week after onasemnogene abeparvovec administration that resolved after treatment. Our study suggests the possibility of a change in the dynamic of CHOP-INTEND for patients who respond poorly to nusinersen after switching therapy to onasemnogene abeparvovec. Alternatively, patient age at treatment initiation may impact the response to onasemnogene abeparvovec. Testing in larger patient populations must be undertaken to assess the plausibility of these hypotheses.
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Affiliation(s)
- Ilaria Bitetti
- Pediatric Neurology, Santobono-Pausilipon Children's Hospital, Naples, Italy.
| | - Valentina Lanzara
- Pediatric Neurology, Santobono-Pausilipon Children's Hospital, Naples, Italy
| | - Giovanna Margiotta
- Department of Pharmacy, Santobono-Pausilipon Children's Hospital, Naples, Italy
| | - Antonio Varone
- Pediatric Neurology, Santobono-Pausilipon Children's Hospital, Naples, Italy
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19
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Lumpkin CJ, Harris AW, Connell AJ, Kirk RW, Whiting JA, Saieva L, Pellizzoni L, Burghes AHM, Butchbach MER. Evaluation of the orally bioavailable 4-phenylbutyrate-tethered trichostatin A analogue AR42 in models of spinal muscular atrophy. Sci Rep 2023; 13:10374. [PMID: 37365234 PMCID: PMC10293174 DOI: 10.1038/s41598-023-37496-0] [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: 09/07/2022] [Accepted: 06/22/2023] [Indexed: 06/28/2023] Open
Abstract
Proximal spinal muscular atrophy (SMA) is a leading genetic cause for infant death in the world and results from the selective loss of motor neurons in the spinal cord. SMA is a consequence of low levels of SMN protein and small molecules that can increase SMN expression are of considerable interest as potential therapeutics. Previous studies have shown that both 4-phenylbutyrate (4PBA) and trichostatin A (TSA) increase SMN expression in dermal fibroblasts derived from SMA patients. AR42 is a 4PBA-tethered TSA derivative that is a very potent histone deacetylase inhibitor. SMA patient fibroblasts were treated with either AR42, AR19 (a related analogue), 4PBA, TSA or vehicle for 5 days and then immunostained for SMN localization. AR42 as well as 4PBA and TSA increased the number of SMN-positive nuclear gems in a dose-dependent manner while AR19 did not show marked changes in gem numbers. While gem number was increased in AR42-treated SMA fibroblasts, there were no significant changes in FL-SMN mRNA or SMN protein. The neuroprotective effect of this compound was then assessed in SMNΔ7 SMA (SMN2+/+;SMNΔ7+/+;mSmn-/-) mice. Oral administration of AR42 prior to disease onset increased the average lifespan of SMNΔ7 SMA mice by ~ 27% (20.1 ± 1.6 days for AR42-treated mice vs. 15.8 ± 0.4 days for vehicle-treated mice). AR42 treatment also improved motor function in these mice. AR42 treatment inhibited histone deacetylase (HDAC) activity in treated spinal cord although it did not affect SMN protein expression in these mice. AKT and GSK3β phosphorylation were both significantly increased in SMNΔ7 SMA mouse spinal cords. In conclusion, presymptomatic administration of the HDAC inhibitor AR42 ameliorates the disease phenotype in SMNΔ7 SMA mice in a SMN-independent manner possibly by increasing AKT neuroprotective signaling.
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Affiliation(s)
- Casey J Lumpkin
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Ashlee W Harris
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA
| | - Andrew J Connell
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA
| | - Ryan W Kirk
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA
| | - Joshua A Whiting
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA
| | - Luciano Saieva
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Livio Pellizzoni
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
- Department of Neurology, Columbia University, New York, NY, USA
- Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, USA
| | - Arthur H M Burghes
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Matthew E R Butchbach
- Division of Neurology, Nemours Children's Hospital Delaware, 4462 E400 DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE, 19803, USA.
- Department of Biological Sciences, University of Delaware, Newark, DE, USA.
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
- Department of Pediatrics, Thomas Jefferson University, Philadelphia, PA, USA.
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20
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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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21
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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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22
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Butchbach MER, Scott RC. Biological networks and complexity in early-onset motor neuron diseases. Front Neurol 2022; 13:1035406. [PMID: 36341099 PMCID: PMC9634177 DOI: 10.3389/fneur.2022.1035406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 10/10/2022] [Indexed: 11/16/2022] Open
Abstract
Motor neuron diseases (MNDs) are neuromuscular disorders where the spinal motor neurons-either the cell bodies themselves or their axons-are the primary cells affected. To date, there are 120 different genes that are lost or mutated in pediatric-onset MNDs. Most of these childhood-onset disorders, aside from spinal muscular atrophy (SMA), lack viable therapeutic options. Previous research on MNDs has focused on understanding the pathobiology of a single, specific gene mutation and targeting therapies to that pathobiology. This reductionist approach has yielded therapeutic options for a specific disorder, in this case SMA. Unfortunately, therapies specific for SMA have not been effective against other pediatric-onset MNDs. Pursuing the same approach for the other defined MNDs would require development of at least 120 independent treatments raising feasibility issues. We propose an alternative to this this type of reductionist approach by conceptualizing MNDs in a complex adaptive systems framework that will allow identification of common molecular and cellular pathways which form biological networks that are adversely affected in early-onset MNDs and thus MNDs with similar phenotypes despite diverse genotypes. This systems biology approach highlights the complexity and self-organization of the motor system as well as the ways in which it can be affected by these genetic disorders. Using this integrated approach to understand early-onset MNDs, we would be better poised to expand the therapeutic repertoire for multiple MNDs.
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Affiliation(s)
- Matthew E. R. Butchbach
- Division of Neurology, Nemours Children's Hospital Delaware, Wilmington, DE, United States,Department of Pediatrics, Thomas Jefferson University, Philadelphia, PA, United States,Department of Biological Sciences, University of Delaware, Newark, DE, United States,*Correspondence: Matthew E. R. Butchbach
| | - Rod C. Scott
- Division of Neurology, Nemours Children's Hospital Delaware, Wilmington, DE, United States,Department of Pediatrics, Thomas Jefferson University, Philadelphia, PA, United States,Department of Psychological and Brain Sciences, University of Delaware, Newark, DE, United States,Neurosciences Unit, Institute of Child Health, University College London, London, United Kingdom,Rod C. Scott
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23
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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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Qiu J, Wu L, Qu R, Jiang T, Bai J, Sheng L, Feng P, Sun J. History of development of the life-saving drug “Nusinersen” in spinal muscular atrophy. Front Cell Neurosci 2022; 16:942976. [PMID: 36035257 PMCID: PMC9414009 DOI: 10.3389/fncel.2022.942976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 07/20/2022] [Indexed: 11/21/2022] Open
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive disorder with an incidence of 1/6,000–1/10,000 and is the leading fatal disease among infants. Previously, there was no effective treatment for SMA. The first effective drug, nusinersen, was approved by the US FDA in December 2016, providing hope to SMA patients worldwide. The drug was introduced in the European Union in 2017 and China in 2019 and has so far saved the lives of several patients in most parts of the world. Nusinersen are fixed sequence antisense oligonucleotides with special chemical modifications. The development of nusinersen progressed through major scientific discoveries in medicine, genetics, biology, and other disciplines, wherein several scientists have made substantial contributions. In this article, we will briefly describe the pathogenesis and therapeutic strategies of SMA, summarize the timeline of important scientific findings during the development of nusinersen in a detailed, scientific, and objective manner, and finally discuss the implications of the development of nusinersen for SMA research.
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Affiliation(s)
- Jiaying Qiu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, China
- Department of Prenatal Screening and Diagnosis Center, Affiliated Maternity and Child Health Care Hospital of Nantong University, Nantong, China
| | - Liucheng Wu
- Laboratory Animal Center, Nantong University, Nantong, China
| | - Ruobing Qu
- Biomedical Polymers Laboratory, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, China
| | - Tao Jiang
- Institute of Neuroscience, Soochow University, Suzhou, China
| | - Jialin Bai
- College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Lei Sheng
- Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Pengchao Feng
- Nanjing Antisense Biopharmaceutical Co., Ltd, Nanjing, China
| | - Junjie Sun
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, China
- *Correspondence: Junjie Sun
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25
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Pinto A, Cunha C, Chaves R, Butchbach MER, Adega F. Comprehensive In Silico Analysis of Retrotransposon Insertions within the Survival Motor Neuron Genes Involved in Spinal Muscular Atrophy. BIOLOGY 2022; 11:824. [PMID: 35741345 PMCID: PMC9219815 DOI: 10.3390/biology11060824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 05/19/2022] [Accepted: 05/25/2022] [Indexed: 11/16/2022]
Abstract
Transposable elements (TEs) are interspersed repetitive and mobile DNA sequences within the genome. Better tools for evaluating TE-derived sequences have provided insights into the contribution of TEs to human development and disease. Spinal muscular atrophy (SMA) is an autosomal recessive motor neuron disease that is caused by deletions or mutations in the Survival Motor Neuron 1 (SMN1) gene but retention of its nearly perfect orthologue SMN2. Both genes are highly enriched in TEs. To establish a link between TEs and SMA, we conducted a comprehensive, in silico analysis of TE insertions within the SMN1/2 loci of SMA, carrier and healthy genomes. We found an Alu insertion in the promoter region and one L1 element in the 3'UTR that may play an important role in alternative promoter as well as in alternative transcriptional termination. Additionally, several intronic Alu repeats may influence alternative splicing via RNA circularization and causes the presence of new alternative exons. These Alu repeats present throughout the genes are also prone to recombination events that could lead to SMN1 exons deletions and, ultimately, SMA. TE characterization of the SMA genomic region could provide for a better understanding of the implications of TEs on human disease and genomic evolution.
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Affiliation(s)
- Albano Pinto
- Laboratory of Cytogenomics and Animal Genomics (CAG), Department of Genetics and Biotechnology (DGB), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal; (A.P.); (C.C.); (R.C.)
- BioISI-Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, 1749-016 Lisbon, Portugal
| | - Catarina Cunha
- Laboratory of Cytogenomics and Animal Genomics (CAG), Department of Genetics and Biotechnology (DGB), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal; (A.P.); (C.C.); (R.C.)
- BioISI-Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, 1749-016 Lisbon, Portugal
| | - Raquel Chaves
- Laboratory of Cytogenomics and Animal Genomics (CAG), Department of Genetics and Biotechnology (DGB), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal; (A.P.); (C.C.); (R.C.)
- BioISI-Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, 1749-016 Lisbon, Portugal
| | - Matthew E. R. Butchbach
- Division of Neurology, Nemours Children’s Hospital Delaware, Wilmington, DE 19803, USA;
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
- Department of Pediatrics, Sidney Kimmel College of Medicine, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Filomena Adega
- Laboratory of Cytogenomics and Animal Genomics (CAG), Department of Genetics and Biotechnology (DGB), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal; (A.P.); (C.C.); (R.C.)
- BioISI-Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, 1749-016 Lisbon, Portugal
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Hu L, Mao S, Lin L, Bai G, Liu B, Mao J. Stress granules in the spinal muscular atrophy and amyotrophic lateral sclerosis: The correlation and promising therapy. Neurobiol Dis 2022; 170:105749. [PMID: 35568100 DOI: 10.1016/j.nbd.2022.105749] [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: 01/22/2022] [Revised: 03/27/2022] [Accepted: 05/05/2022] [Indexed: 10/18/2022] Open
Abstract
Increasing genetic and biochemical evidence has broadened our view of the pathomechanisms that lead to Spinal muscular atrophy (SMA) and Amyotrophic lateral sclerosis (ALS), two fatal neurodegenerative diseases with similar symptoms and causes. Stress granules are dynamic cytosolic storage hubs for mRNAs in response to stress exposures, that are evolutionarily conserved cytoplasmic RNA granules in somatic cells. A lot of previous studies have shown that the impaired stress granules are crucial events in SMA/ALS pathogenesis. In this review, we described the key stress granules related RNA binding proteins (SMN, TDP-43, and FUS) involved in SMA/ALS, summarized the reported mutations in these RNA binding proteins involved in SMA/ALS pathogenesis, and discussed the mechanisms through which stress granules dynamics participate in the diseases. Meanwhile, we described the applications and limitation of current therapies targeting SMA/ALS. We futher proposed the promising targets on stress granules in the future therapeutic interventions of SMA/ALS.
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Affiliation(s)
- LiDan Hu
- the Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou 310052, China.
| | - Shanshan Mao
- the Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou 310052, China
| | - Li Lin
- the Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou 310052, China
| | - Guannan Bai
- the Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou 310052, China
| | - Bingjie Liu
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jianhua Mao
- the Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou 310052, China
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Caracterización clínica y funcional de pacientes con atrofia muscular espinal en el centro-occidente colombiano. BIOMÉDICA 2022; 42:89-99. [PMID: 35866733 PMCID: PMC9410705 DOI: 10.7705/biomedica.6178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Indexed: 11/21/2022]
Abstract
Introducción. La atrofia muscular espinal es una enfermedad neurodegenerativa huérfana de origen genético que afecta las neuronas motoras del asta anterior de la médula espinal, y produce atrofia y debilidad muscular. En Colombia, son pocos los estudios publicados sobre la enfermedad y no hay ninguno con análisis funcional. Objetivo. Caracterizar clínica y funcionalmente una serie de casos de atrofia muscular espinal del centro-occidente colombiano. Materiales y métodos. Se hizo un estudio descriptivo transversal, entre el 2007 y el 2020, de pacientes con diagnóstico clínico y molecular de atrofia muscular espinal que consultaron en el centro de atención. La evaluación funcional se realizó con las escalas Hammersmith y Chop Intend. En la sistematización de los datos, se empleó el programa Epi-Info, versión 7.0. Resultados. Se analizaron 14 pacientes: 8 mujeres y 6 hombres. La atrofia muscular espinal más prevalente fue la de tipo II, la cual se presentó en 10 casos. Se encontró variabilidad fenotípica en términos de funcionalidad en algunos pacientes con atrofia muscular espinal de tipo II, cinco de los cuales lograron alcanzar la marcha. La estimación de la supervivencia fue de 28,6 años. Conclusiones. Los hallazgos en el grupo de pacientes analizados evidenciaron que los puntajes de la escala de Hammersmith revisada y expandida, concordaron con la gravedad de la enfermedad.
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Tan C, Yan Y, Guo N, Wang F, Wang S, Zhu L, Wang Y, Ma Y, Guo Y. Single-Tube Multiplex Digital Polymerase Chain Reaction Assay for Molecular Diagnosis and Prediction of Severity of Spinal Muscular Atrophy. Anal Chem 2022; 94:3517-3525. [PMID: 35137581 DOI: 10.1021/acs.analchem.1c04403] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease characterized by the degeneration of motor neurons and progressive muscle atrophy. Accurate detection of SMN1 and SMN2 copy numbers is essential for SMA diagnosis, carrier screening, disease severity prediction, therapy, and prognosis. However, a method for SMN1 and SMN2 copy number determination that is simultaneously accurate, simple, rapid, multitargeted, and applicable to various samples has not previously been reported. Here, we developed a single-tube multiplex digital polymerase chain reaction (dPCR) assay for simultaneous determination of the copy numbers of SMN1 exons 7 and 8 and SMN2 exons 7 and 8. A total of 317 clinical samples, including peripheral blood, amniotic fluid, chorionic villus, buccal swabs, and dried blood spots, were collected to evaluate the performance of this dPCR-based assay. The test results were accurate for all the clinical samples. Our assay is accurate, rapid, easy to handle, and applicable to many types of samples and uses a small amount of DNA; it is a powerful tool for SMA molecular diagnosis, large-scale screening, and disease severity assessment.
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Affiliation(s)
- Chianru Tan
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Yousheng Yan
- Prenatal Diagnostic Center, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing 100026, China
| | - Na Guo
- TargetingOne Corporation, Beijing 100190, China
| | - Fang Wang
- TargetingOne Corporation, Beijing 100190, China
| | - Songtao Wang
- Department of Central Laboratory, Peking University First Hospital, Beijing 100034, China
| | | | - Yipeng Wang
- Prenatal Diagnostic Center, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing 100026, China
| | - Yinan Ma
- Department of Central Laboratory, Peking University First Hospital, Beijing 100034, China
| | - Yong Guo
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
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