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Kakazu J, Walker NL, Babin KC, Trettin KA, Lee C, Sutker PB, Kaye AM, Kaye AD. Risdiplam for the Use of Spinal Muscular Atrophy. Orthop Rev (Pavia) 2021; 13:25579. [PMID: 34745484 DOI: 10.52965/001c.25579] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 07/03/2021] [Indexed: 12/19/2022] Open
Abstract
Spinal muscular atrophy (SMA) is one of the leading causes of death in infants related to the degeneration of neurons. Currently, there are no curative treatment options for SMA, and many options available may not be feasible. This review presents the background, clinical studies, and indications for the use of Risdiplam in treating SMA. SMA causes a decrease in the production of survival motor neuron proteins (SMN) and current treatments target to increase the expression of SMN. Risdiplam is the first and only oral medication to be approved to treat SMA. As an SMN2 splicing modifier, it has provided stronger systemic therapies than previous intrathecal and gene replacement therapies. There have been many efforts to treat SMA with multidisciplinary approaches. These include intrathecal injections to gene replacement therapies. However, these have been faced with limitations such as reaching a good therapeutic dose in systemic tissues, route of administration, and price. Risdiplam is currently the only orally administered drug approved by the FDA for the treatment of SMA. It not only provides a good therapeutic window to systemic tissues but allows for a non-invasive approach in infants. Further investigation and comparison on the safety profile of Risdiplam due to its broader systemic effect should be considered with other available therapies.
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Affiliation(s)
- Juyeon Kakazu
- Georgetown University School of Medicine, Washington DC
| | - Nakoma L Walker
- Louisiana State University Health Sciences Center, Shreveport, LA
| | | | | | - Christopher Lee
- Creighton University School of Medicine-Phoenix Regional Campus, Phoenix, AZ
| | | | - Adam M Kaye
- Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, CA
| | - Alan D Kaye
- Louisiana State University Health Sciences Center, Department of Anesthesiology, New Orleans, LA; Provost, Chief Academic Officer, Vice-Chancellor of Academic Affairs, Professor, Departments of Anesthesiology and Pharmacology, Toxicology, and Neurosciences, LSU Health Shreveport
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2
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Chong LC, Gandhi G, Lee JM, Yeo WWY, Choi SB. Drug Discovery of Spinal Muscular Atrophy (SMA) from the Computational Perspective: A Comprehensive Review. Int J Mol Sci 2021; 22:8962. [PMID: 34445667 PMCID: PMC8396480 DOI: 10.3390/ijms22168962] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 01/27/2021] [Indexed: 01/02/2023] Open
Abstract
Spinal muscular atrophy (SMA), one of the leading inherited causes of child mortality, is a rare neuromuscular disease arising from loss-of-function mutations of the survival motor neuron 1 (SMN1) gene, which encodes the SMN protein. When lacking the SMN protein in neurons, patients suffer from muscle weakness and atrophy, and in the severe cases, respiratory failure and death. Several therapeutic approaches show promise with human testing and three medications have been approved by the U.S. Food and Drug Administration (FDA) to date. Despite the shown promise of these approved therapies, there are some crucial limitations, one of the most important being the cost. The FDA-approved drugs are high-priced and are shortlisted among the most expensive treatments in the world. The price is still far beyond affordable and may serve as a burden for patients. The blooming of the biomedical data and advancement of computational approaches have opened new possibilities for SMA therapeutic development. This article highlights the present status of computationally aided approaches, including in silico drug repurposing, network driven drug discovery as well as artificial intelligence (AI)-assisted drug discovery, and discusses the future prospects.
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Affiliation(s)
- Li Chuin Chong
- Centre for Bioinformatics, School of Data Sciences, Perdana University, Suite 9.2, 9th Floor, Wisma Chase Perdana, Changkat Semantan, Kuala Lumpur 50490, Malaysia; (L.C.C.); (J.M.L.)
| | - Gayatri Gandhi
- Perdana University Graduate School of Medicine, Perdana University, Suite 9.2, 9th Floor, Wisma Chase Perdana, Changkat Semantan, Kuala Lumpur 50490, Malaysia; (G.G.); (W.W.Y.Y.)
| | - Jian Ming Lee
- Centre for Bioinformatics, School of Data Sciences, Perdana University, Suite 9.2, 9th Floor, Wisma Chase Perdana, Changkat Semantan, Kuala Lumpur 50490, Malaysia; (L.C.C.); (J.M.L.)
| | - Wendy Wai Yeng Yeo
- Perdana University Graduate School of Medicine, Perdana University, Suite 9.2, 9th Floor, Wisma Chase Perdana, Changkat Semantan, Kuala Lumpur 50490, Malaysia; (G.G.); (W.W.Y.Y.)
| | - Sy-Bing Choi
- Centre for Bioinformatics, School of Data Sciences, Perdana University, Suite 9.2, 9th Floor, Wisma Chase Perdana, Changkat Semantan, Kuala Lumpur 50490, Malaysia; (L.C.C.); (J.M.L.)
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3
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Noteworthy Professional News. Adv Neonatal Care 2020. [DOI: 10.1097/anc.0000000000000783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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4
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Cavdarli B, Ozturk FN, Guntekin Ergun S, Ergun MA, Dogan O, Percin EF. Intelligent Ratio: A New Method for Carrier and Newborn Screening in Spinal Muscular Atrophy. Genet Test Mol Biomarkers 2020; 24:569-577. [PMID: 32721240 DOI: 10.1089/gtmb.2020.0085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Aim: Spinal muscular atrophy (SMA) is an inherited, autosomal recessive neuromuscular disease that causes high morbidity and mortality. The prevalence is 1-2/100,000, while the incidence is 1/6000-1/10,000 among live births. Due to the high carrier frequency (1/40-1/60) of SMA-associated alleles, screening can prevent new cases. The aim of the current study was to present the development of a new, quantitative, real-time, polymerase chain reaction (PCR)-based screening test that uses an intelligent ratio (IR) for analyses, as well as a comparison of the results with the gold standard. Materials and Methods: Included in the study were 100 patients with various risk genotypes for survivor motor neuron 1 (SMN1) and SMN2 genes whose genetics had been previously investigated using multiplex ligation probe amplification (MLPA). A combination of the 5' nuclease assay and allele-specific PCR was used to quantify the SMN1 deletion mutation with real-time PCR using the FII gene as a reference. All of the optimized standards were adapted to software that provided automated analyses. The approval number of the institutional ethics committee for the study is 2012-KAEK-15/1497. Results: The results of the screening test were completely compatible with the MLPA results; it achieved 100% sensitivity and specificity compared with the gold standard. The use of the IR in the analyses provided a user-independent method that quickly and accurately provided results, regardless of the amount of DNA used of the extraction method. Conclusion: Carrier or newborn screening of SMA is essential in countries that have high rates of consanguineous marriages. The screening test presented in this study that uses FII as a reference gene proved to be low-cost, reliable, applicable, accurate, and amenable to use in an automated system for SMA screening.
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Affiliation(s)
- Busranur Cavdarli
- Department of Medical Genetics, Ankara Numune Training and Research Hospital, Ankara, Turkey
| | - Fatma Nihal Ozturk
- Department of Medical Genetics, Dr Sami Ulus Gynecology Obstetrics and Child Health and Diseases Training and Research Hospital, Ankara, Turkey
| | - Sezen Guntekin Ergun
- Department of Biological Sciences, Molecular Biology and Genetics, Middle East Technical University, Ankara, Turkey
| | - Mehmet Ali Ergun
- Department of Medical Genetics, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Ozlem Dogan
- SNP Biotechnology Ltd., Hacettepe University Technopolis, Ankara, Turkey
| | - Emriye Ferda Percin
- Department of Medical Genetics, Faculty of Medicine, Gazi University, Ankara, Turkey
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Cassandri M, Smirnov A, Novelli F, Pitolli C, Agostini M, Malewicz M, Melino G, Raschellà G. Zinc-finger proteins in health and disease. Cell Death Discov 2017; 3:17071. [PMID: 29152378 PMCID: PMC5683310 DOI: 10.1038/cddiscovery.2017.71] [Citation(s) in RCA: 421] [Impact Index Per Article: 60.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 08/28/2017] [Accepted: 08/29/2017] [Indexed: 02/07/2023] Open
Abstract
Zinc-finger proteins (ZNFs) are one of the most abundant groups of proteins and have a wide range of molecular functions. Given the wide variety of zinc-finger domains, ZNFs are able to interact with DNA, RNA, PAR (poly-ADP-ribose) and other proteins. Thus, ZNFs are involved in the regulation of several cellular processes. In fact, ZNFs are implicated in transcriptional regulation, ubiquitin-mediated protein degradation, signal transduction, actin targeting, DNA repair, cell migration, and numerous other processes. The aim of this review is to provide a comprehensive summary of the current state of knowledge of this class of proteins. Firstly, we describe the actual classification of ZNFs, their structure and functions. Secondly, we focus on the biological role of ZNFs in the development of organisms under normal physiological and pathological conditions.
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Affiliation(s)
- Matteo Cassandri
- Department of Experimental Medicine and Surgery, University of Rome 'Tor Vergata', Rome 00133, Italy
| | - Artem Smirnov
- Department of Experimental Medicine and Surgery, University of Rome 'Tor Vergata', Rome 00133, Italy
| | - Flavia Novelli
- Department of Experimental Medicine and Surgery, University of Rome 'Tor Vergata', Rome 00133, Italy
| | - Consuelo Pitolli
- Department of Experimental Medicine and Surgery, University of Rome 'Tor Vergata', Rome 00133, Italy
| | - Massimiliano Agostini
- Department of Experimental Medicine and Surgery, University of Rome 'Tor Vergata', Rome 00133, Italy
| | - Michal Malewicz
- Medical Research Council, Toxicology Unit, Leicester University, Leicester LE1 9HN, UK
| | - Gerry Melino
- Department of Experimental Medicine and Surgery, University of Rome 'Tor Vergata', Rome 00133, Italy.,Medical Research Council, Toxicology Unit, Leicester University, Leicester LE1 9HN, UK
| | - Giuseppe Raschellà
- ENEA Research Center Casaccia, Laboratory of Biosafety and Risk Assessment, Via Anguillarese, Rome, Italy
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7
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Van Gronigen Caesar G, Dale JM, Osman EY, Garcia ML, Lorson CL, Schulz LC. Placental development in a mouse model of spinal muscular atrophy. Biochem Biophys Res Commun 2015; 470:82-87. [PMID: 26748185 DOI: 10.1016/j.bbrc.2015.12.120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 12/22/2015] [Indexed: 01/30/2023]
Abstract
Spinal Muscular Atrophy (SMA) is an autosomal recessive disorder, leading to fatal loss of motor neurons. It is caused by loss of function of the SMN gene, which is expressed throughout the body, and there is increasing evidence of dysfunction in non-neuronal tissues. Birthweight is one of most powerful prognostic factors for infants born with SMA, and intrauterine growth restriction is common. In the SMNΔ7 mouse model of SMA, pups with the disease lived 25% longer when their mothers were fed a higher fat, "breeder" diet. The placenta is responsible for transport of nutrients from mother to fetus, and is a major determinant of fetal growth. Thus, the present study tested the hypothesis that placental development is impaired in SMNΔ7 conceptuses. Detailed morphological characterization revealed no defects in SMNΔ7 placental development, and expression of key transcription factors regulating mouse placental development was unaffected. The intrauterine growth restriction observed in SMA infants likely does not result from impaired placental development.
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Affiliation(s)
- Gerialisa Van Gronigen Caesar
- Division of Biological Sciences, University of Missouri, Columbia, MO, USA; Department of Obstetrics, Gynecology and Women's Health, University of Missouri, Columbia, MO, USA
| | - Jeffrey M Dale
- Division of Biological Sciences, University of Missouri, Columbia, MO, USA; Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Erkan Y Osman
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO, USA; Department of Veterinary Pathobiology, University of Missouri, Columbia, MO, USA
| | - Michael L Garcia
- Division of Biological Sciences, University of Missouri, Columbia, MO, USA; Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Christian L Lorson
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO, USA; Department of Veterinary Pathobiology, University of Missouri, Columbia, MO, USA; Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, MO, USA
| | - Laura C Schulz
- Division of Biological Sciences, University of Missouri, Columbia, MO, USA; Department of Obstetrics, Gynecology and Women's Health, University of Missouri, Columbia, MO, USA.
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8
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Kaczmarek A, Schneider S, Wirth B, Riessland M. Investigational therapies for the treatment of spinal muscular atrophy. Expert Opin Investig Drugs 2015; 24:867-81. [DOI: 10.1517/13543784.2015.1038341] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Anna Kaczmarek
- 1University of Cologne, Institute of Human Genetics, Kerpener Str. 34, Cologne 50931, Germany ;
- 2University of Cologne, Institute for Genetics, Cologne, Germany
- 3University of Cologne, Center for Molecular Medicine Cologne, Cologne, Germany
| | - Svenja Schneider
- 1University of Cologne, Institute of Human Genetics, Kerpener Str. 34, Cologne 50931, Germany ;
- 2University of Cologne, Institute for Genetics, Cologne, Germany
- 3University of Cologne, Center for Molecular Medicine Cologne, Cologne, Germany
| | - Brunhilde Wirth
- 1University of Cologne, Institute of Human Genetics, Kerpener Str. 34, Cologne 50931, Germany ;
- 2University of Cologne, Institute for Genetics, Cologne, Germany
- 3University of Cologne, Center for Molecular Medicine Cologne, Cologne, Germany
| | - Markus Riessland
- 1University of Cologne, Institute of Human Genetics, Kerpener Str. 34, Cologne 50931, Germany ;
- 2University of Cologne, Institute for Genetics, Cologne, Germany
- 3University of Cologne, Center for Molecular Medicine Cologne, Cologne, Germany
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9
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Abstract
In humans, assembly of spliceosomal snRNPs (small nuclear ribonucleoproteins) begins in the cytoplasm where the multi-protein SMN (survival of motor neuron) complex mediates the formation of a seven-membered ring of Sm proteins on to a conserved site of the snRNA (small nuclear RNA). The SMN complex contains the SMN protein Gemin2 and several additional Gemins that participate in snRNP biosynthesis. SMN was first identified as the product of a gene found to be deleted or mutated in patients with the neurodegenerative disease SMA (spinal muscular atrophy), the leading genetic cause of infant mortality. In the present study, we report the solution structure of Gemin2 bound to the Gemin2-binding domain of SMN determined by NMR spectroscopy. This complex reveals the structure of Gemin2, how Gemin2 binds to SMN and the roles of conserved SMN residues near the binding interface. Surprisingly, several conserved SMN residues, including the sites of two SMA patient mutations, are not required for binding to Gemin2. Instead, they form a conserved SMN/Gemin2 surface that may be functionally important for snRNP assembly. The SMN-Gemin2 structure explains how Gemin2 is stabilized by SMN and establishes a framework for structure-function studies to investigate snRNP biogenesis as well as biological processes involving Gemin2 that do not involve snRNP assembly.
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10
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Leyenaar J, Camfield P, Camfield C. A schematic approach to hypotonia in infancy. Paediatr Child Health 2011; 10:397-400. [PMID: 19668647 DOI: 10.1093/pch/10.7.397] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Hypotonia may be the presenting sign for many systemic diseases and diseases of the nervous system. The present paper discusses a rational, simple and accurate diagnostic approach to hypotonia in infancy, illustrated by the case of a five-month-old infant girl recently referred to the IWK Health Centre in Halifax, Nova Scotia. Key points in the history and physical examination are outlined to allow a tailored investigation both for the patient and for other hypotonic infants. A discussion of an important neuromuscular disease, diagnosed in the present patient, concludes the paper.
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Affiliation(s)
- Joanna Leyenaar
- Department of Pediatrics, Dalhousie University, IWK Health Centre, Halifax, Nova Scotia
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11
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Burnett BG, Crawford TO, Sumner CJ. Emerging treatment options for spinal muscular atrophy. Curr Treat Options Neurol 2011; 11:90-101. [PMID: 19210911 DOI: 10.1007/s11940-009-0012-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The motor neuron disease spinal muscular atrophy (SMA) is one of the leading genetic killers of infants worldwide. SMA is caused by mutation of the survival motor neuron 1 (SMN1) gene and deficiency of the survival motor neuron (SMN) protein. All patients retain one or more copies of the SMN2 gene, which (by producing a small amount of the SMN protein) rescues embryonic lethality and modifies disease severity. Rapid progress continues in dissecting the cellular functions of the SMN protein, but the mechanisms linking SMN deficiency with dysfunction and loss of functioning motor units remain poorly defined. Clinically, SMA should to be distinguished from other neuromuscular disorders, and the diagnosis can be readily confirmed with genetic testing. Quality of life and survival of SMA patients are improved with aggressive supportive care including optimized respiratory and nutritional care and management of scoliosis and contractures. Because SMA is caused by inadequate amounts of SMN protein, one aim of current SMA therapeutics development is to increase SMN protein levels in SMA patients by activating SMN2 gene expression and/or increasing levels of full-length SMN2 transcripts. Several potential therapeutic compounds are currently being studied in clinical trials in SMA patients.
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Affiliation(s)
- Barrington G Burnett
- Charlotte J. Sumner, MD 600 North Wolfe Street, Meyer 5-119b, Baltimore, MD 21287, USA.
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12
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Bollag L, Kent C, Richebé P, Landau R. Anesthetic management of spinal muscle atrophy type II in a parturient. Local Reg Anesth 2011; 4:15-20. [PMID: 22915887 PMCID: PMC3417967 DOI: 10.2147/lra.s17089] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
We report the peripartum management of a 30-year-old wheelchair-bound nullipara woman with spinal muscular atrophy (SMA) type II, including severe restrictive lung disease and Harrington rods. At 38 weeks gestation, she was admitted for an induction of labor with neuraxial analgesia, but she subsequently had to be delivered via cesarean section under general anesthesia. We describe the anesthetic implications of SMA on labor and delivery management and review the available literature.
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Affiliation(s)
- Laurent Bollag
- Department of Anesthesiology and Pain Medicine, University of Washington Medical Center, Seattle, WA, USA
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13
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14
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Abstract
Spinal muscular atrophy is an autosomal recessive neurodegenerative disease characterised by degeneration of spinal cord motor neurons, atrophy of skeletal muscles, and generalised weakness. It is caused by homozygous disruption of the survival motor neuron 1 (SMN1) gene by deletion, conversion, or mutation. Although no medical treatment is available, investigations have elucidated possible mechanisms underlying the molecular pathogenesis of the disease. Treatment strategies have been developed to use the unique genomic structure of the SMN1 gene region. Several candidate treatment agents have been identified and are in various stages of development. These and other advances in medical technology have changed the standard of care for patients with spinal muscular atrophy. In this Seminar, we provide a comprehensive review that integrates clinical manifestations, molecular pathogenesis, diagnostic strategy, therapeutic development, and evidence from clinical trials.
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Affiliation(s)
- Mitchell R Lunn
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
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Petrone A, Pavone M, Testa MBC, Petreschi F, Bertini E, Cutrera R. Noninvasive Ventilation in Children with Spinal Muscular Atrophy Types 1 and 2. Am J Phys Med Rehabil 2007; 86:216-21. [PMID: 17314706 DOI: 10.1097/phm.0b013e31802ef774] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Our aim was to assess the efficacy of noninvasive ventilation (NIV) for the treatment of thoracoabdominal asynchrony during sleep in children with spinal muscular atrophy (SMA) types 1 and 2. DESIGN Nine subjects underwent assessment for sleep apnea/hypopnea index (AHI), mean oxyhemoglobin saturation (SpO2), oxygen desaturation index, transcutaneous carbon dioxide tension (tcpCO2), and mean phase angle during sleep as a measure of thoracoabdominal coordination. A second sleep study was performed with use of NIV. RESULTS The nine patients (7 mos of age, range 2-33) had a baseline AHI of 2.1 events per hour (range 0.5-55.8), oxygen desaturation index of 3.7 events per hour (range 1.6-46.1), mean tcpCO2 of 46 mm Hg (range 37-60), and phase angle of 127 degrees (range 72.7-151.7). Comparing baseline and NIV sleep studies, we found significant improvement in oxygen desaturation index (P < 0.010), mean tcpCO2 (P < 0.001), and phase angle (P < 0.001). For five patients, phase-angle improvement became significant when using high-span bilevel positive airway pressure (PAP). CONCLUSIONS NIV improved sleep breathing parameters and thoracoabdominal coordination during sleep in SMA types 1 and 2. Phase-angle improvement correlated with bilevel PAP pressures. Phase angle may be useful for the evaluation and monitoring of therapeutic interventions such as NIV.
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Affiliation(s)
- Albino Petrone
- Respiratory Unit, Bambino Gesù Children Hospital, Research Institute, Rome, Italy
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Doran B, Gherbesi N, Hendricks G, Flavell RA, Davis RJ, Gangwani L. Deficiency of the zinc finger protein ZPR1 causes neurodegeneration. Proc Natl Acad Sci U S A 2006; 103:7471-5. [PMID: 16648254 PMCID: PMC1464363 DOI: 10.1073/pnas.0602057103] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mutations that cause reduced expression of the full-length Survival Motor Neurons (SMN) protein are a major cause of spinal muscular atrophy (SMA), a disease characterized by degeneration of the alpha-motor neurons in the anterior horn of the spinal cord. The severity of SMA may be influenced by the actions of modifier genes. One potential modifier gene is represented by ZPR1, which is down-regulated in patients with SMA and encodes a zinc finger protein that interacts with complexes formed by SMN. To test the functional significance of ZPR1 gene down-regulation, we examined a mouse model with targeted ablation of the Zpr1 gene. We report that ZPR1-deficient mice exhibit axonal pathology and neurodegeneration. These data identify ZPR1 deficiency as a contributing factor in neurodegenerative disorders.
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Affiliation(s)
| | | | | | - Richard A. Flavell
- Howard Hughes Medical Institute and Section of Immunobiology, Yale University School of Medicine, New Haven, CT 06520
| | - Roger J. Davis
- *Program in Molecular Medicine
- Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, MA 01605; and
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Singh Roy N, Nakano T, Xuing L, Kang J, Nedergaard M, Goldman SA. Enhancer-specified GFP-based FACS purification of human spinal motor neurons from embryonic stem cells. Exp Neurol 2005; 196:224-34. [PMID: 16198339 DOI: 10.1016/j.expneurol.2005.06.021] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2005] [Revised: 06/09/2005] [Accepted: 06/29/2005] [Indexed: 12/23/2022]
Abstract
Human embryonic stem (hES) cells may generate all major somatic cell types, yet no neuronal subtype has yet been specifically generated in useful purity from hES culture. We report here the selective induction and isolation of functional spinal motor neurons (MNs) from human ES cells. hES cells of the H1 line were transfected with plasmids encoding GFP placed under the control of an MN-specifying enhancer within the 5'-regulatory region of the gene encoding the transcription factor Hb9 and treated with sonic hedgehog (Shh) and retinoic acid (RA). As MNs were induced under the influence of Shh and RA, they activated Hb9-driven GFP expression, permitting their isolation by fluorescence-activated cell sorting (FACS). The MNs thereby generated and isolated became cholinergic and achieved functional maturation in vitro, as evidenced by their fast sodium currents and action potentials on whole-cell patch-clamp and alpha-bungarotoxin-identified clustering of AChR receptors on co-cultured skeletal myoblasts. The serial combination of these two approaches, motor neuron phenotypic induction followed by Hb9 enhancer-based FACS, permitted the high-efficiency induction and isolation of functional motor neurons from hES cells. These results suggest the utility of promoter/enhancer-based FACS for the isolation of specific phenotypes from hES cell populations as a means of purifying clinically appropriate vectors for cell therapy.
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Affiliation(s)
- Neeta Singh Roy
- Department of Neurology, Cornell University Medical College, NYC, NY 10021, USA.
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Testa MBC, Pavone M, Bertini E, Petrone A, Pagani M, Cutrera R. Sleep-Disordered Breathing in Spinal Muscular Atrophy Types 1 and 2. Am J Phys Med Rehabil 2005; 84:666-70. [PMID: 16141743 DOI: 10.1097/01.phm.0000176362.24957.77] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Our aim was to assess the respiratory pattern during sleep in patients affected by spinal muscular atrophy types 1 and 2 and to compare their apnea-hypopnea indices with those of controls. DESIGN All consecutively referred patients underwent polysomnography. Sleep stages were defined as either wake, quiet sleep (QS), or active sleep (AS). As measures of thoracoabdominal coordination, we measured: phase angle during QS and AS (Ph Angle QS and AS), phase relation during inspiration and expiration during QS and AS: (Ph RIB QS, Ph RIB AS, Ph REB QS; Ph REB AS) and the apnea-hypopnea index. RESULTS The 14 consecutively referred infants and small children (age, 11.7 +/- 11.4 mos) showed a higher apnea-hypopnea index (P < 0.001), Ph Angle QS (P < 0.001), Ph Angle AS (P < 0.001), Ph RIB QS (P < 0.001), Ph RIB AS (P < 0.001), Ph REB QS (P < 0.001), and Ph REB AS (P < 0.001) compared with 28 healthy controls (age, 10.1 +/- 8.9 mos). CONCLUSIONS Patients affected by types 1 and 2 spinal muscular atrophy had significantly higher apnea-hypopnea indices than controls. Thoracoabdominal asynchrony was present during the inspiratory and expiratory phases in both quiet and active sleep. Measures of thoracoabdominal coordination may be useful for the evaluation and monitoring of therapeutic interventions for these patients.
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Kesari A, Rennert H, Leonard DGB, Mittal B. SMN1 dosage analysis in spinal muscular atrophy from India. BMC MEDICAL GENETICS 2005; 6:22. [PMID: 15910686 PMCID: PMC1174872 DOI: 10.1186/1471-2350-6-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2004] [Accepted: 05/23/2005] [Indexed: 11/18/2022]
Abstract
Background Spinal muscular atrophy (SMA) represents the second most common fatal autosomal recessive disorder after cystic fibrosis. Due to the high carrier frequency, the burden of this genetic disorder is very heavy in developing countries like India. As there is no cure or effective treatment, genetic counseling becomes very important in disease management. SMN1 dosage analysis results can be utilized for identifying carriers before offering prenatal diagnosis in the context of genetic counseling. Methods In the present study we analyzed the carrier status of parents and sibs of proven SMA patients. In addition, SMN1 copy number was determined in suspected SMA patients and parents of children with a clinical diagnosis of SMA. Results wenty nine DNA samples were analyzed by quantitative PCR to determine the number of SMN1 gene copies present, and 17 of these were found to have one SMN1 gene copy. The parents of confirmed SMA patients were found to be obligate carriers of the disease. Dosage analysis was useful in ruling out clinical suspicion of SMA in four patients. In a family with history of a deceased floppy infant and two abortions, both parents were found to be carriers of SMA and prenatal diagnosis could be offered in future pregnancies. Conclusion SMN1 copy number analysis is an important parameter for identification of couples at risk for having a child affected with SMA and reduces unwarranted prenatal diagnosis for SMA. The dosage analysis is also useful for the counseling of clinically suspected SMA with a negative diagnostic SMA test.
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Affiliation(s)
- Akanchha Kesari
- Department of Genetics, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow-14, U.P, India
- Current Address- Center for Genetic Medicine, Children's National Medical Center Washington- DC. USA
| | - Hanna Rennert
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia USA
| | - Debra GB Leonard
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia USA
- Department of Pathology and Laboratory Medicine, Newyork Presbyterian Hospital, Cornell Campus, Newyork USA
| | - Balraj Mittal
- Department of Genetics, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow-14, U.P, India
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Kesari A, Rennert H, Leonard DGB, Phadke SR, Mittal B. Prenatal diagnosis of spinal muscular atrophy: Indian scenario. Prenat Diagn 2005; 25:641-4. [PMID: 16049987 DOI: 10.1002/pd.1212] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVES To study the psychosocial issues associated with prenatal diagnosis of SMA in India and the use of SMN1 copy number analysis for carrier detection prior to offering prenatal diagnosis. METHODS Homozygous deletion of SMN1 gene was done by PCR-RFLP. Copy number analysis of SMN1 gene was performed by quantitative PCR. RESULTS We report our experience of eight cases of prenatal diagnosis for SMA and the use of carrier detection prior to offering prenatal diagnosis. Quantitative PCR results show that SMN1 copy number analysis is useful to identify couples at risk. CONCLUSION Case analyses depict unique psychosocial issues associated with prenatal diagnosis of SMA from India.
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Affiliation(s)
- Akanchha Kesari
- Department of Genetics, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
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