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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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2
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Ponomarev AS, Chulpanova DS, Yanygina LM, Solovyeva VV, Rizvanov AA. Emerging Gene Therapy Approaches in the Management of Spinal Muscular Atrophy (SMA): An Overview of Clinical Trials and Patent Landscape. Int J Mol Sci 2023; 24:13743. [PMID: 37762045 PMCID: PMC10530942 DOI: 10.3390/ijms241813743] [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: 06/30/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a rare autosomal recessive neuromuscular disease that is characterized by progressive muscle atrophy (degeneration), including skeletal muscles in charge of the ability to move. SMA is caused by defects in the SMN1 gene (Survival of Motor Neuron 1) which encodes a protein crucial for the survival and functionality of neuron cells called motor neurons. Decreased level of functioning SMN protein leads to progressive degeneration of alpha-motor neurons performing muscular motility. Over the past decade, many strategies directed for SMN-level-restoration emerged, such as gene replacement therapy (GRT), CRISPR/Cas9-based gene editing, usage of antisense oligonucleotides and small-molecule modulators, and all have been showing their perspectives in SMA therapy. In this review, modern SMA therapy strategies are described, making it a valuable resource for researchers, clinicians and everyone interested in the progress of therapy of this serious disorder.
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Affiliation(s)
| | | | | | | | - Albert A. Rizvanov
- Institute of Fundamental Medicine and Biology, Kazan Federal University, 420008 Kazan, Russia; (A.S.P.); (D.S.C.); (L.M.Y.); (V.V.S.)
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3
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Babić M, Banović M, Berečić I, Banić T, Babić Leko M, Ulamec M, Junaković A, Kopić J, Sertić J, Barišić N, Šimić G. Molecular Biomarkers for the Diagnosis, Prognosis, and Pharmacodynamics of Spinal Muscular Atrophy. J Clin Med 2023; 12:5060. [PMID: 37568462 PMCID: PMC10419842 DOI: 10.3390/jcm12155060] [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: 06/25/2023] [Revised: 07/24/2023] [Accepted: 07/30/2023] [Indexed: 08/13/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a progressive degenerative illness that affects 1 in every 6 to 11,000 live births. This autosomal recessive disorder is caused by homozygous deletion or mutation of the SMN1 gene (survival motor neuron). As a backup, the SMN1 gene has the SMN2 gene, which produces only 10% of the functional SMN protein. Nusinersen and risdiplam, the first FDA-approved medications, act as SMN2 pre-mRNA splicing modifiers and enhance the quantity of SMN protein produced by this gene. The emergence of new therapies for SMA has increased the demand for good prognostic and pharmacodynamic (response) biomarkers in SMA. This article discusses current molecular diagnostic, prognostic, and pharmacodynamic biomarkers that could be assessed in SMA patients' body fluids. Although various proteomic, genetic, and epigenetic biomarkers have been explored in SMA patients, more research is needed to uncover new prognostic and pharmacodynamic biomarkers (or a combination of biomarkers).
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Affiliation(s)
- Marija Babić
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
| | - Maria Banović
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
| | - Ivana Berečić
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
| | - Tea Banić
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
| | - Mirjana Babić Leko
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
| | - Monika Ulamec
- Department of Pathology, University Clinical Hospital Sestre Milosrdnice Zagreb, 10000 Zagreb, Croatia
- Department of Pathology, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
| | - Alisa Junaković
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
| | - Janja Kopić
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
| | - Jadranka Sertić
- Department of Medical Chemistry and Biochemistry, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
- Department of Laboratory Diagnostics, University Hospital Centre Zagreb, 10000 Zagreb, Croatia
| | - Nina Barišić
- Department of Pediatrics, University Hospital Centre Zagreb, 10000 Zagreb, Croatia
| | - Goran Šimić
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
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4
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Belančić A, Strbad T, Kučan Štiglić M, Vitezić D. Effectiveness of Nusinersen in Type 1, 2 and 3 Spinal Muscular Atrophy: Croatian Real-World Data. J Clin Med 2023; 12:2839. [PMID: 37109175 PMCID: PMC10142582 DOI: 10.3390/jcm12082839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/05/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
(1) Background: To investigate the real-world effectiveness and safety profile of nusinersen in Croatian paediatric and adult spinal muscular atrophy (SMA) patients. (2) Methods: A retrospective and anonymous collection of relevant demographic and clinical data for all Croatian SMA patients treated with nusinersen and reimbursed by the Croatian Health Insurance Fund (CHIF) between April 2018 and February 2022 was performed through searching the CHIF database and studying the associated reimbursement documentation. All patients who received at least one dose of nusinersen were included in the baseline clinical-demographic overview and safety analysis, whereas only subjects who had completed six doses were included in the effectiveness analysis. (3) Results: Fifty-two patients [61.5% male; median age 13.4 (0.1-51.1) yr.] received nusinersen treatment. In SMA type 1 and type 3 paediatric patients, statistically significant motor function improvement (CHOP INTEND 10.8 ± 10.3 vs. 20.0 ± 15.8, p = 0.003; HFMSE 49.6 ± 7.9 vs. 53.1 ± 7.7, p = 0.008; respectively) was achieved immediately after 4 loading doses of nusinersen and remained statistically significant onwards. Average improvements in HFMSE motor performance in SMA type 2 patients after four, five, and six doses of nusinersen were +6.0, +10.5, and +11.0 points, respectively. In SMA type 3 adult patients, no significant improvement in RHS motor performance or the 6-Minute Walk Test (MWT) was demonstrated. During the study period, 437 doses were administered without any new safety concerns appearing. (4) Conclusions: Our RWD findings indicate that nusinersen is an effective and safe treatment in a heterogeneous group of paediatric patients with all types of SMA; however, no significant benefit (but only RHS and 6MWT maintenance) was demonstrated in SMA type 3 patients who started nusinersen after >18 years of age.
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Affiliation(s)
- Andrej Belančić
- Department of Clinical Pharmacology, Clinical Hospital Centre Rijeka, 51000 Rijeka, Croatia;
- Department of Basic and Clinical Pharmacology with Toxicology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia
| | - Tea Strbad
- Croatian Health Insurance Fund, 10000 Zagreb, Croatia;
| | - Marta Kučan Štiglić
- Primorje-Gorski Kotar County Community Health Centre, 51000 Rijeka, Croatia;
| | - Dinko Vitezić
- Department of Clinical Pharmacology, Clinical Hospital Centre Rijeka, 51000 Rijeka, Croatia;
- Department of Basic and Clinical Pharmacology with Toxicology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia
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Mansouri V, Heidari M, Bemanalizadeh M, Azizimalamiri R, Nafissi S, Akbari MG, Barzegar M, Moayedi AR, Badv RS, Mohamadi M, Tavasoli AR, Amirsalari S, Khajeh A, Inaloo S, Fatehi F, Hosseinpour S, Babaei M, Hosseini SA, Mahdi Hosseiny SM, Fayyazi A, Hosseini F, Toosi MB, Khosroshahi N, Ghabeli H, Biglari HN, Kakhki SK, Mirlohi SH, Bidabadi E, Mohammadi B, Omrani A, Sedighi M, Vafaee-Shahi M, Rasulinezhad M, Hoseini SM, Movahedinia M, Rezaei Z, Karimi P, Farshadmoghadam H, Anvari S, Yaghini O, Nasiri J, Zamani G, Ashrafi MR. The First Report of Iranian Registry of Patients with Spinal Muscular Atrophy. J Neuromuscul Dis 2023; 10:211-225. [PMID: 36776076 DOI: 10.3233/jnd-221614] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
BACKGROUND Insufficient amounts of survival motor neuron protein is leading to one of the most disabling neuromuscular diseases, spinal muscular atrophy (SMA). Before the current study, the detailed characteristics of Iranian patients with SMA had not been determined. OBJECTIVE To describe the key demographic, clinical, and genetic characteristics of patients with SMA registered in the Iranian Registry of SMA (IRSMA). METHODS IRSMA has been established since 2018, and the demographic, clinical, and genetic characteristics of patients with SMA were recorded according to the methods of treat neuromuscular disease (TREAT-NMD) project. RESULTS By October 1, 2022, 781 patients with 5q SMA were registered. Of them, 164 patients died, the majority of them had SMA type 1 and died during the first 20 months of life. The median survival of patients with type 1 SMA was 23 months. The consanguinity rate in 617 alive patients was 52.4%, while merely 24.8% of them had a positive family history. The most common type of SMA in live patients was type 3. Morbidities were defined as having scoliosis (44.1%), wheelchair dependency (36.8%), tube feeding (8.1%), and requiring mechanical ventilation (9.9%). Most of the registered patients had a homozygous deletion of SMN1, while the frequency of patients with higher copy numbers of SMN2, was less in more severe types of the disease. Earlier onset of the disease was significantly seen in patients with lower copy numbers of SMN2. The neuronal apoptosis inhibitory protein (NAIP) gene deletion was associated with a higher incidence of more severe types of SMA, higher dependency on ventilators, tube feeding, and earlier onset of the disease. CONCLUSIONS The IRSMA is the first established Iranian nationwide registry of patients with SMA. Using this registry, decision-makers, researchers, and practitioners can precisely understand the epidemiology, characteristics, and genetics of patients with SMA in Iran.
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Affiliation(s)
- Vahid Mansouri
- Gene Therapy Research Center, Digestive Diseases Research Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Morteza Heidari
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Maryam Bemanalizadeh
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran.,Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Reza Azizimalamiri
- Department of Pediatric Neurology, Golestan, Medical, Educational, and Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Shahriar Nafissi
- Neurology Department, Shariati Hospital, Iranian Neuromuscular Research Center (INMRC), Tehran University of Medical Sciences, Tehran, Iran
| | - Masood Ghahvechi Akbari
- Physical Medicine and Rehabilitation Department, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Barzegar
- Pediatric Health Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ali Reza Moayedi
- Department of Pediatric Neurology, Children's Hospital, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - Reza Shervin Badv
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahmood Mohamadi
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali Reza Tavasoli
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Susan Amirsalari
- New Hearing Technologies Research Center, Baqiatallah University of Medical Sciences, Tehran, Iran
| | - Ali Khajeh
- Department of Pediatrics, Children and Adolescent Health Research Center, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Soroor Inaloo
- Neonatal Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Farzad Fatehi
- Neurology Department, Shariati Hospital, Iranian Neuromuscular Research Center (INMRC), Tehran University of Medical Sciences, Tehran, Iran
| | - Sareh Hosseinpour
- Department of Pediatrics, Division of Pediatric Neurology, Vali-e-Asr Hospital, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Meisam Babaei
- Department of Pediatrics, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Seyed Ahmad Hosseini
- Department of Pediatrics, Taleghani Children's Hospital, Golestan University of Medical Sciences, Gorgan, Iran
| | | | - Afshin Fayyazi
- Department of Pediatric Neurology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Firoozeh Hosseini
- Department of Pediatric Neurology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mehran Beiraghi Toosi
- Department of Pediatric Neurology, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Nahid Khosroshahi
- Department of Pediatrics, Division of Pediatric Neurology, Bahrami Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Homa Ghabeli
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Habibeh Nejad Biglari
- Department of Pediatrics, School of Medicine, Afzalipour Hospital, Kerman University of Medical Sciences, Kerman, Iran
| | - Simin Khayatzadeh Kakhki
- Department of Pediatrics, Division of Pediatric Neurology, Bahrami Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Seyed Hossein Mirlohi
- Pediatric respiratory and sleep medicine research center, children's medical center, Tehran University of Medical sciences, Tehran, Iran
| | | | - Bahram Mohammadi
- Department of Pediatrics, Yasuj University of Medical Sciences, Yasuj, Iran
| | - Abdolmajid Omrani
- Department of Pediatrics, Faculty of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Mostafa Sedighi
- Department of Neurology, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | | | - Maryam Rasulinezhad
- Pediatric Neurology Department, Iran University of Medical Sciences, Tehran, Iran
| | - Seyyed Mohamad Hoseini
- Department of Pediatrics, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Mojtaba Movahedinia
- Department of Pediatrics, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Zahra Rezaei
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Parviz Karimi
- Department of Pediatric Diseases, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran
| | - Hossein Farshadmoghadam
- Department of Pediatrics, Children Growth Research Centre, Research Institute for Prevention of Non-Communicable Disease, Qazvin University of Medical Science, Qazvin, Iran
| | - Saeed Anvari
- Department of Pediatrics, Division of Pediatric Neurology, Milad Hospital, Social Security Organisation, Tehran, Iran
| | - Omid Yaghini
- Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Jafar Nasiri
- Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Gholamreza Zamani
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahmoud Reza Ashrafi
- Department of Pediatrics, Division of Pediatric Neurology, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran.,Pediatric Cell and Gene Therapy Research Center (PCGTRC), Tehran University of Medical Sciences, Tehran, Iran
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Alternative Splicing Role in New Therapies of Spinal Muscular Atrophy. Genes (Basel) 2021; 12:genes12091346. [PMID: 34573328 PMCID: PMC8468182 DOI: 10.3390/genes12091346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/24/2021] [Accepted: 08/25/2021] [Indexed: 11/17/2022] Open
Abstract
It has been estimated that 80% of the pre-mRNA undergoes alternative splicing, which exponentially increases the flow of biological information in cellular processes and can be an attractive therapeutic target. It is a crucial mechanism to increase genetic diversity. Disturbed alternative splicing is observed in many disorders, including neuromuscular diseases and carcinomas. Spinal Muscular Atrophy (SMA) is an autosomal recessive neurodegenerative disease. Homozygous deletion in 5q13 (the region coding for the motor neuron survival gene (SMN1)) is responsible for 95% of SMA cases. The nearly identical SMN2 gene does not compensate for SMN loss caused by SMN1 gene mutation due to different splicing of exon 7. A pathologically low level of survival motor neuron protein (SMN) causes degeneration of the anterior horn cells in the spinal cord with associated destruction of α-motor cells and manifested by muscle weakness and loss. Understanding the regulation of the SMN2 pre-mRNA splicing process has allowed for innovative treatment and the introduction of new medicines for SMA. After describing the concept of splicing modulation, this review will cover the progress achieved in this field, by highlighting the breakthrough accomplished recently for the treatment of SMA using the mechanism of alternative splicing.
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Sharifi Z, Taheri M, Fallah MS, Abiri M, Golnabi F, Bagherian H, Zeinali R, Farahzadi H, Alborji M, Tehrani PG, Amini M, Asnavandi S, Hashemi M, Forouzesh F, Zeinali S. Comprehensive Mutation Analysis and Report of 12 Novel Mutations in a Cohort of Patients with Spinal Muscular Atrophy in Iran. J Mol Neurosci 2021; 71:2281-2298. [PMID: 33481221 DOI: 10.1007/s12031-020-01789-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 12/30/2020] [Indexed: 12/17/2022]
Abstract
Spinal muscular atrophies (SMAs) are a heterogeneous group of neuromuscular diseases characterized by loss of motor neurons, muscle weakness, hypotonia and muscle atrophy, with different modes of inheritance; however, the survival motor neuron 1 (SMN1) gene is predominantly involved. The aims of the current study were to clarify the genetic basis of SMA and determine the mutation spectrum of SMN1 and other associated genes, in order to provide molecular information for more accurate diagnosis and future prospects for treatment. We performed a comprehensive analysis of 5q SMA in 1765 individuals including 528 patients from 432 unrelated families with at least one child with suspected clinical presentation of SMA. Copy number variations of the SMN1 and SMN2 genes and linkage analysis were performed using multiplex ligation-dependent probe amplification (MLPA) and short tandem repeat (STR) markers linked to the SMN1 gene. Cases without mutation in the SMA locus on 5q were analyzed for the DNAJB2, IGHMBP2, SIGMAR1 and PLEKHG5 genes using linked STR markers. Sanger sequencing of whole genes was performed for cases with homozygous haplotypes. Whole-genome sequencing (WGS) and whole-exome analysis was conducted for some of the remaining cases. Mutations in the SMN1 gene were identified in 287 (66.43%) families including 269 patients (62.26%) with homozygous deletion of the entire SMN1 gene. Only one of the patients had a homozygous point mutation in the SMN1 gene. Among the remaining families, three families showed mutations in either the DNAJB2, SIGMAR1 or PLEKHG5 genes, which were linked using STR analysis and Sanger sequencing. From 10 families who underwent WGS, we found six homozygous point mutations in six families for either the TNNT1, TPM3, TTN, SACS or COL6A2 genes. Two mutations in the PLA2G6 gene were also found in another patient as compound heterozygous. This rather large cohort allowed us to identify genotype patterns in Iranian 5q SMA patients. The process of identifying 11 mutations (9 novel) in 9 different genes among non-5q SMA patients shows the diversity of genes involved in non-5q SMA in Iranians. Genotyping of patients with SMA is essential for prenatal and preimplantation genetic diagnosis (PGD), and may be very helpful for guiding treatment, with the advent of new, more effective, albeit very expensive, therapies. Also, combining linkage analysis was shown to be beneficial in many ways, including sample authenticity and segregation analysis, and for ruling out maternal cell contamination during prenatal diagnosis (PND).
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Affiliation(s)
- Zohreh Sharifi
- Department of Genetics, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.,Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | - Mohammad Taheri
- Urogenital Stem Cell Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad-Sadegh Fallah
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | - Maryam Abiri
- Department of Medical Genetics and Molecular Biology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Golnabi
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | - Hamideh Bagherian
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | - Razieh Zeinali
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | - Hossein Farahzadi
- Proteomics Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Marjan Alborji
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | | | - Masoume Amini
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | - Sadaf Asnavandi
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran
| | - Mehrdad Hashemi
- Department of Genetics, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Flora Forouzesh
- Department of Genetics, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Sirous Zeinali
- Dr. Zeinali's Medical Genetics Laboratory, Kawsar Human Genetics Research Center, Tehran, Iran. .,Department of Molecular Medicine, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
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8
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Zhang Y, He J, Zhang Y, Li L, Tang X, Wang L, Guo J, Jin C, Tighe S, Zhang Y, Zhu Y, Zhu B. The analysis of the association between the copy numbers of survival motor neuron gene 2 and neuronal apoptosis inhibitory protein genes and the clinical phenotypes in 40 patients with spinal muscular atrophy: Observational study. Medicine (Baltimore) 2020; 99:e18809. [PMID: 32011487 PMCID: PMC7220227 DOI: 10.1097/md.0000000000018809] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In this article, the correlation between the copy number of survival motor neuron 2 (SMN2) gene, neuronal apoptosis inhibitory protein (NAIP), and the phenotype of spinal muscular atrophy patients were analyzed.Forty patients with spinal muscular atrophy (SMA) were included in the study at the Department of Medical Genetics of the First People's Hospital and the Department of Neurology of the Second People's Hospital in Yunnan Province from January 2012 to September 2018. Multiplex ligation-dependent probe amplification assay was performed to determine the copy numbers of SMN2 and NAIP genes. Statistical analysis was performed to determine the correlation between copy numbers of the SMN2 and NAIP genes and the clinical phenotypes of SMA.Our results show that among the 40 SMA patients, there were 13 type I cases, 16 type II cases and 11 type III cases. A total of 37 patients possessed a homozygous deletion of SMN1 exons 7 and 8, while the other 3 SMA patients possessed a single copy of SMN1 exon 8. There was no correlation between SMA subtypes and the deletion types of SMN1 exon 7 and 8 (P = .611). The percentage of 2, 3, and 4 copies of SMN2 exon 7 was 25.0%, 62.5%, and 12.5%, respectively. The percentage of 0, 1, and 2 copies of NAIP exon 5 was 10%, 57.5%, and 32.5%, respectively. The distributions of SMN2 and NAIP copy numbers among various SMA types were significantly different (all P < .05). Five combined SMN1-SMN2-NAIP genotypes were detected, of which 0-3-1 genotype had the highest proportion than the others, accounting for 42.5%. The copy number of SMN2 and NAIP gene had synergistic effect on SMA phenotype. The combined SMN1-SMN2-NAIP genotypes with fewer copies were associated with earlier onset age, higher mortality, and smaller average age at death in SMA patients.Therefore, we conclude that the copy number variance of SMN2 and NAIP is correlated with the SMA phenotype. Analysis of the copy number structure of the SMN1-SMN2-NAIP gene is helpful for SMA typing, disease prognosis prediction, and genetic counseling.
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Affiliation(s)
- Yinhong Zhang
- Department of Medical Genetics, The First People's Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology
- Faculty of Life Science and Biotechnology, Kunming University of Science and Technology
| | - Jing He
- Department of Medical Genetics, The First People's Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology
| | - Yunqian Zhang
- Department of Neurology, The Second People's Hospital of Yunnan Province
| | - Li Li
- Faculty of Life Science and Biotechnology, Kunming University of Science and Technology
- Department of Pediatrics, The First People's Hospital of Yunnan Province, Kunming, Yunnan, China
| | - Xinhua Tang
- Department of Medical Genetics, The First People's Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology
| | - Lei Wang
- Department of Medical Genetics, The First People's Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology
| | - Jingjing Guo
- Department of Medical Genetics, The First People's Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology
| | - Chanchan Jin
- Department of Medical Genetics, The First People's Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology
| | - Sean Tighe
- Tissue Tech, Inc., Ocular Surface Center, and Ocular Surface Research & Education Foundation, Miami, FL
| | - Yuan Zhang
- Tissue Tech, Inc., Ocular Surface Center, and Ocular Surface Research & Education Foundation, Miami, FL
| | - Yingting Zhu
- Tissue Tech, Inc., Ocular Surface Center, and Ocular Surface Research & Education Foundation, Miami, FL
| | - Baosheng Zhu
- Department of Medical Genetics, The First People's Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology
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Maeda K, Chong PF, Yamashita F, Akamine S, Kawakami S, Saito K, Takahata Y, Kira R. Global Central Nervous System Atrophy in Spinal Muscular Atrophy Type 0. Ann Neurol 2019; 86:801-802. [DOI: 10.1002/ana.25596] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 08/16/2019] [Accepted: 08/16/2019] [Indexed: 11/11/2022]
Affiliation(s)
- Kenichi Maeda
- Department of Pediatric NeurologyFukuoka Children's Hospital Fukuoka
| | - Pin Fee Chong
- Department of Pediatric NeurologyFukuoka Children's Hospital Fukuoka
| | - Fumiya Yamashita
- Department of Pediatric NeurologyFukuoka Children's Hospital Fukuoka
| | - Satoshi Akamine
- Department of Pediatric NeurologyFukuoka Children's Hospital Fukuoka
| | - Saori Kawakami
- Department of Pediatric NeurologyFukuoka Children's Hospital Fukuoka
| | - Kayoko Saito
- Institute of Medical GeneticsTokyo Women's Medical University Tokyo
| | - Yasushi Takahata
- Department of NeonatologyFukuoka Children's Hospital Fukuoka Japan
| | - Ryutaro Kira
- Department of Pediatric NeurologyFukuoka Children's Hospital Fukuoka
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10
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Zhang YH, Zhang YQ, Zhu BS, He J, Wang L, Tang XH, Guo JJ, Jin CC, Chen H, Zhang J, Zhang JM, Li L. [Association of copy number of SMN1 and SMN2 with clinical phenotypes in children with spinal muscular atrophy]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2019; 21:239-243. [PMID: 30907347 PMCID: PMC7389366 DOI: 10.7499/j.issn.1008-8830.2019.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/10/2019] [Indexed: 06/09/2023]
Abstract
OBJECTIVE To study the association of copy number of SMN1 and SMN2 with clinical phenotypes in children with spinal muscular atrophy (SMA). METHODS A total of 45 children with SMA were enrolled. Multiplex ligation-dependent probe amplification was used to measure the gene copy numbers of SMN1 and SMN2. The association of copy number of SMN1 and SMN2 with clinical phenotypes was analyzed. RESULTS Of the 45 children with SMA, 42 (93%) had a homozygous deletion of SMN1 exons 7 and 8, and 3 (7%) had a deletion of SMN1 exon 7 alone. No association was found between SMA clinical types and the deletion types of SMN1 exons 7 and 8 (P>0.05). There was a significant difference in the distribution of SMN2 gene copy numbers between the children with SMA and the healthy children (P<0.05). The children with SMA usually had two or three copies of SMN2 gene, while the healthy children usually had one or two copies of SMN2 gene. There was a significant difference in the distribution of SMN2 copy numbers among the children with different SMA clinical types (P<0.05). The children with two copies of SMN2 gene had a significantly lower age of onset than those with three or four copies. Most of the children with type I SMA had two or three copies of SMN2 gene. Most of the children with type II SMA had three copies of SMN2 gene. Most of the children with type III SMA had three or four copies of SMN2 gene. Children with a higher copy number of SMN2 gene tended to have an older age of onset and better motor function and clinical outcome, and there was a significant association between SMN2 gene copy number and clinical outcome (P<0.05). CONCLUSIONS The SMN2 gene can reduce the severity of SMA via the dosage compensation effect. SMN2 copy number is associated with the phenotype of SMA, and therefore, it can be used to predict disease severity.
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Affiliation(s)
- Yin-Hong Zhang
- Genetic Diagnosis Center, Affiliated Hospital of Kunming University of Science and Technology, Kunming 650032, China.
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11
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Zhang YH, Zhang YQ, Zhu BS, He J, Wang L, Tang XH, Guo JJ, Jin CC, Chen H, Zhang J, Zhang JM, Li L. [Association of copy number of SMN1 and SMN2 with clinical phenotypes in children with spinal muscular atrophy]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2019; 21:239-243. [PMID: 30907347 PMCID: PMC7389366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/10/2019] [Indexed: 11/12/2023]
Abstract
OBJECTIVE To study the association of copy number of SMN1 and SMN2 with clinical phenotypes in children with spinal muscular atrophy (SMA). METHODS A total of 45 children with SMA were enrolled. Multiplex ligation-dependent probe amplification was used to measure the gene copy numbers of SMN1 and SMN2. The association of copy number of SMN1 and SMN2 with clinical phenotypes was analyzed. RESULTS Of the 45 children with SMA, 42 (93%) had a homozygous deletion of SMN1 exons 7 and 8, and 3 (7%) had a deletion of SMN1 exon 7 alone. No association was found between SMA clinical types and the deletion types of SMN1 exons 7 and 8 (P>0.05). There was a significant difference in the distribution of SMN2 gene copy numbers between the children with SMA and the healthy children (P<0.05). The children with SMA usually had two or three copies of SMN2 gene, while the healthy children usually had one or two copies of SMN2 gene. There was a significant difference in the distribution of SMN2 copy numbers among the children with different SMA clinical types (P<0.05). The children with two copies of SMN2 gene had a significantly lower age of onset than those with three or four copies. Most of the children with type I SMA had two or three copies of SMN2 gene. Most of the children with type II SMA had three copies of SMN2 gene. Most of the children with type III SMA had three or four copies of SMN2 gene. Children with a higher copy number of SMN2 gene tended to have an older age of onset and better motor function and clinical outcome, and there was a significant association between SMN2 gene copy number and clinical outcome (P<0.05). CONCLUSIONS The SMN2 gene can reduce the severity of SMA via the dosage compensation effect. SMN2 copy number is associated with the phenotype of SMA, and therefore, it can be used to predict disease severity.
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Affiliation(s)
- Yin-Hong Zhang
- Genetic Diagnosis Center, Affiliated Hospital of Kunming University of Science and Technology, Kunming 650032, China.
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Verhaart IEC, Robertson A, Wilson IJ, Aartsma-Rus A, Cameron S, Jones CC, Cook SF, Lochmüller H. Prevalence, incidence and carrier frequency of 5q-linked spinal muscular atrophy - a literature review. Orphanet J Rare Dis 2017; 12:124. [PMID: 28676062 PMCID: PMC5496354 DOI: 10.1186/s13023-017-0671-8] [Citation(s) in RCA: 336] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 06/13/2017] [Indexed: 12/14/2022] Open
Abstract
Spinal muscular atrophy linked to chromosome 5q (SMA) is a recessive, progressive, neuromuscular disorder caused by bi-allelic mutations in the SMN1 gene, resulting in motor neuron degeneration and variable presentation in relation to onset and severity. A prevalence of approximately 1-2 per 100,000 persons and incidence around 1 in 10,000 live births have been estimated with SMA type I accounting for around 60% of all cases. Since SMA is a relatively rare condition, studies of its prevalence and incidence are challenging. Most published studies are outdated and therefore rely on clinical rather than genetic diagnosis. Furthermore they are performed in small cohorts in small geographical regions and only study European populations. In addition, the heterogeneity of the condition can lead to delays and difficulties in diagnosing the condition, especially outside of specialist clinics, and contributes to the challenges in understanding the epidemiology of the disease. The frequency of unaffected, heterozygous carriers of the SMN1 mutations appears to be higher among Caucasian and Asian populations compared to the Black (Sub-Saharan African ancestry) population. However, carrier frequencies cannot directly be translated into incidence and prevalence, as very severe (death in utero) and very mild (symptom free in adults) phenotypes carrying bi-allelic SMN1 mutations exist, and their frequency is unknown. More robust epidemiological data on SMA covering larger populations based on accurate genetic diagnosis or newborn screening would be helpful to support planning of clinical studies, provision of care and therapies and evaluation of outcomes.
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Affiliation(s)
- Ingrid E. C. Verhaart
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Agata Robertson
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Ian J. Wilson
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Annemieke Aartsma-Rus
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Shona Cameron
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | | | | | - Hanns Lochmüller
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
- John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ UK
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