1
|
Brown SM, Ajjarapu AS, Ramachandra D, Blasco-Pérez L, Costa-Roger M, Tizzano EF, Sumner CJ, Mathews KD. Onasemnogene-abeparvovec administration to premature infants with spinal muscular atrophy. Ann Clin Transl Neurol 2024. [PMID: 39342433 DOI: 10.1002/acn3.52213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2024] [Revised: 08/29/2024] [Accepted: 08/30/2024] [Indexed: 10/01/2024] Open
Abstract
Twin girls born at 30 weeks' gestation with spinal muscular atrophy (SMA) received onsasemnogene-abeparvovec (OA) at 3.5 weeks of life. They had no treatment-related adverse events, normal acquisition of motor milestones, and normal neurological examination at 19 months. Genotyping revealed 0 copies of SMN1 and a single, hybrid SMN2 gene containing the positive genetic modifier c.835-44A>G. This was associated with full-length SMN2 blood mRNA expression levels similar to a 2 copy SMA infant. The observed favorable outcomes are likely due to the genetic modifier combined with early drug administration enabled by prematurity.
Collapse
Affiliation(s)
- Stephen M Brown
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Aparna S Ajjarapu
- Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Divya Ramachandra
- Department of Genetics, Advocate Children's Hospital, Oak Lawn, Illinois, USA
| | - Laura Blasco-Pérez
- Department of Clinical and Molecular Genetics and Medicine Genetics Group, VHIR, Hospital Vall d'Hebron, Barcelona, Spain
| | - Mar Costa-Roger
- Department of Clinical and Molecular Genetics and Medicine Genetics Group, VHIR, Hospital Vall d'Hebron, Barcelona, Spain
| | - Eduardo F Tizzano
- Department of Clinical and Molecular Genetics and Medicine Genetics Group, VHIR, Hospital Vall d'Hebron, Barcelona, Spain
| | - Charlotte J Sumner
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Katherine D Mathews
- Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
- Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| |
Collapse
|
2
|
Costa-Roger M, Blasco-Pérez L, Gerin L, Codina-Solà M, Leno-Colorado J, Gómez-García De la Banda M, Garcia-Uzquiano R, Saugier-Veber P, Drunat S, Quijano-Roy S, Tizzano EF. Complex SMN Hybrids Detected in a Cohort of 31 Patients With Spinal Muscular Atrophy. Neurol Genet 2024; 10:e200175. [PMID: 39035824 PMCID: PMC11259531 DOI: 10.1212/nxg.0000000000200175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 06/06/2024] [Indexed: 07/23/2024]
Abstract
Background and Objectives Spinal muscular atrophy (SMA) is a recessive neuromuscular disorder caused by the loss or presence of point pathogenic variants in the SMN1 gene. The main positive modifier of the SMA phenotype is the number of copies of the SMN2 gene, a paralog of SMN1, which only produces around 10%-15% of functional SMN protein. The SMN2 copy number is inversely correlated with phenotype severity; however, discrepancies between the SMA type and the SMN2 copy number have been reported. The presence of SMN2-SMN1 hybrids has been proposed as a possible modifier of SMA disease. Methods We studied 31 patients with SMA, followed at a single center and molecularly diagnosed by Multiplex Ligand-Dependent Probe Amplification (MLPA), with a specific next-generation sequencing protocol to investigate their SMN2 genes in depth. Hybrid characterization also included bioinformatics haplotype phasing and specific PCRs to resolve each SMN2-SMN1 hybrid structure. Results We detected SMN2-SMN1 hybrid genes in 45.2% of the patients (14/31), the highest rate reported to date. This represents a total of 25 hybrid alleles, with 9 different structures, of which only 4 are detectable by MLPA. Of particular interest were 2 patients who presented 4 SMN2-SMN1 hybrid copies each and no pure SMN2 copies, an event reported here for the first time. No clear trend between the presence of hybrids and a milder phenotype was observed, although 5 of the patients with hybrid copies showed a better-than-expected phenotype. The higher hybrid detection rate in our cohort may be due to both the methodology applied, which allows an in-depth characterization of the SMN genes and the ethnicity of the patients, mainly of African origin. Discussion Although hybrid genes have been proposed to be beneficial for patients with SMA, our work revealed great complexity and variability between hybrid structures; therefore, each hybrid structure should be studied independently to determine its contribution to the SMA phenotype. Large-scale studies are needed to gain a better understanding of the function and implications of SMN2-SMN1 hybrid copies, improving genotype-phenotype correlations and prediction of the evolution of patients with SMA.
Collapse
Affiliation(s)
- Mar Costa-Roger
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Laura Blasco-Pérez
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Lorene Gerin
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Marta Codina-Solà
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Jordi Leno-Colorado
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Marta Gómez-García De la Banda
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Rocio Garcia-Uzquiano
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Pascale Saugier-Veber
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Séverine Drunat
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Susana Quijano-Roy
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| | - Eduardo F Tizzano
- From the Medicine Genetics Group (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Vall d'Hebron Research Institute (VHIR); Department of Clinical and Molecular Genetics (M.C.-R., L.B.-P., M.C.-S., J.L.-C., E.F.T.), Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain; Neuromuscular Unit (L.G., M.G.-G.D.B., R.G.-U., P.S.-V., S.D., S.Q.-R.), Pediatric Neurology and ICU Department, Raymond Poincaré Hospital (UVSQ), AP-HP Université Paris-Saclay, Garches; and Laboratoire END-ICAP - UMR 1179 (INSERM/UVSQ) (S.Q.-R.), Equipe 1 Biothérapies des maladies neuromusculaires, Montigny-Le-Bretonneux, France
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Leow DMK, Ng YK, Wang LC, Koh HW, Zhao T, Khong ZJ, Tabaglio T, Narayanan G, Giadone RM, Sobota RM, Ng SY, Teo AKK, Parson SH, Rubin LL, Ong WY, Darras BT, Yeo CJ. Hepatocyte-intrinsic SMN deficiency drives metabolic dysfunction and liver steatosis in spinal muscular atrophy. J Clin Invest 2024; 134:e173702. [PMID: 38722695 PMCID: PMC11178536 DOI: 10.1172/jci173702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 04/25/2024] [Indexed: 06/18/2024] Open
Abstract
Spinal Muscular Atrophy (SMA) is typically characterized as a motor neuron disease, but extra-neuronal phenotypes are present in almost every organ in severely affected patients and animal models. Extra-neuronal phenotypes were previously underappreciated as patients with severe SMA phenotypes usually died in infancy; however, with current treatments for motor neurons increasing patient lifespan, impaired function of peripheral organs may develop into significant future comorbidities and lead to new treatment-modified phenotypes. Fatty liver is seen in SMA animal models , but generalizability to patients and whether this is due to hepatocyte-intrinsic Survival Motor Neuron (SMN) protein deficiency and/or subsequent to skeletal muscle denervation is unknown. If liver pathology in SMA is SMN-dependent and hepatocyte-intrinsic, this suggests SMN repleting therapies must target extra-neuronal tissues and motor neurons for optimal patient outcome. Here we showed that fatty liver is present in SMA and that SMA patient-specific iHeps were susceptible to steatosis. Using proteomics, functional studies and CRISPR/Cas9 gene editing, we confirmed that fatty liver in SMA is a primary SMN-dependent hepatocyte-intrinsic liver defect associated with mitochondrial and other hepatic metabolism implications. These pathologies require monitoring and indicate need for systematic clinical surveillance and additional and/or combinatorial therapies to ensure continued SMA patient health.
Collapse
Affiliation(s)
- Damien Meng-Kiat Leow
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Yang Kai Ng
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, Singapore
| | - Loo Chien Wang
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, Singapore
| | - Hiromi W.L. Koh
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, Singapore
| | - Tianyun Zhao
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, Singapore
| | - Zi Jian Khong
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, Singapore
| | - Tommaso Tabaglio
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, Singapore
| | | | - Richard M. Giadone
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge Massachusetts, USA
| | - Radoslaw M. Sobota
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, Singapore
| | - Shi-Yan Ng
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, Singapore
- National Neuroscience Institute, Singapore, Singapore
| | - Adrian Kee Keong Teo
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, Singapore
| | - Simon H. Parson
- Institute of Education in Healthcare and Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, Scotland
| | - Lee L. Rubin
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge Massachusetts, USA
| | - Wei-Yi Ong
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Basil T. Darras
- Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Crystal J.J. Yeo
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, Singapore
- Duke-NUS Medical School, Singapore, Singapore
- National Neuroscience Institute, Singapore, Singapore
- Institute of Education in Healthcare and Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, Scotland
- Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| |
Collapse
|
5
|
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.
Collapse
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.
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Bai J, Qu Y, Huang W, Meng W, Zhan J, Wang H, Hou W, Jin Y, Mao A, Song F. A high-fidelity long-read sequencing-based approach enables accurate and effective genetic diagnosis of spinal muscular atrophy. Clin Chim Acta 2024; 553:117743. [PMID: 38158006 DOI: 10.1016/j.cca.2023.117743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/08/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND We aimed to develop a high-fidelity long-read sequencing (LRS)-based approach to detect SMN gene variants in one step. It is challenging for conventional step-wise methods to simultaneously detect all kinds of variations between homologous SMN1 and SMN2. METHODS In this study, LRS was developed to analyze copy numbers (CNs), full sequences, and structure of SMN1 and SMN2. The results were compared with those from the step-wise methods in 202 samples from 67 families. RESULTS LRS achieved 100% (202/202) and 99.5% (201/202) accuracy for SMN1 and SMN2 CNs, respectively. It corrected SMN1 CNs from MLPA, which was caused by SNVs/indels that located in probe-binding region. LRS identified 23 SNVs/indels distributing throughout SMN1, including c.22dup and c.884A > T in trans-configuration, and a de novo variant c.41_42delinsC for the first time. LRS also identified a SMN2 variant c.346A > G. Moreover, it successfully determined Alu-mediated 8978-bp deletion encompassing exon 2a-5 and 1415-bp deletion disrupting exon 1, and the exact breakpoints of large deletions. Through haplotype-based pedigree trio analysis, LRS identified SMN1 2 + 0 carriers, and determined the distribution of SMN1 and SMN2 on two chromosomes. CONCLUSIONS LRS represents a more comprehensive and accurate diagnosis approach that is beneficial to early treatment and effective management of SMA.
Collapse
Affiliation(s)
- Jinli Bai
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing 100020, China
| | - Yujin Qu
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing 100020, China
| | - Wenchen Huang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing 100020, China
| | - Wanli Meng
- Berry Genomics Corporation, Beijing 102200, China
| | - Jiahan Zhan
- Berry Genomics Corporation, Beijing 102200, China
| | - Hong Wang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing 100020, China
| | - Wenqi Hou
- Berry Genomics Corporation, Beijing 102200, China
| | - Yuwei Jin
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing 100020, China
| | - Aiping Mao
- Berry Genomics Corporation, Beijing 102200, China.
| | - Fang Song
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing 100020, China.
| |
Collapse
|
9
|
Abiusi E, Costa-Roger M, Bertini ES, Tiziano FD, Tizzano EF, Abiusi E, Baranello G, Bertini E, Boemer F, Burghes A, Codina-Solà M, Costa-Roger M, Dangouloff T, Groen E, Gos M, Jędrzejowska M, Kirschner J, Lemmink HH, Müller-Felber W, Ouillade MC, Quijano-Roy S, Rucinski K, Saugier-Veber P, Tiziano FD, Tizzano EF, Wirth B. 270th ENMC International Workshop: Consensus for SMN2 genetic analysis in SMA patients 10-12 March, 2023, Hoofddorp, the Netherlands. Neuromuscul Disord 2024; 34:114-122. [PMID: 38183850 DOI: 10.1016/j.nmd.2023.12.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2024]
Abstract
The 270th ENMC workshop aimed to develop a common procedure to optimize the reliability of SMN2 gene copy number determination and to reinforce collaborative networks between molecular scientists and clinicians. The workshop involved neuromuscular and clinical experts and representatives of patient advocacy groups and industry. SMN2 copy number is currently one of the main determinants for therapeutic decision in SMA patients: participants discussed the issues that laboratories may encounter in this molecular test and the cruciality of the accurate determination, due the implications as prognostic factor in symptomatic patients and in individuals identified through newborn screening programmes. At the end of the workshop, the attendees defined a set of recommendations divided into four topics: SMA molecular prognosis assessment, newborn screening for SMA, SMN2 copies and treatments, and modifiers and biomarkers. Moreover, the group draw up a series of recommendations for the companies manufacturing laboratory kits, that will help to minimize the risk of errors, regardless of the laboratories' expertise.
Collapse
Affiliation(s)
- Emanuela Abiusi
- Section of Genomic Medicine, Department of Public Health and Life Sciences, Università Cattolica del Sacro Cuore, Roma, Italy
| | - Mar Costa-Roger
- Clinical and Molecular Genetics Area, Vall d'Hebron Hospital; Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
| | - Enrico Silvio Bertini
- Research Unit of Neuromuscular Disease, Bambino Gesu’ Children's Hospital, IRCCS, Roma, Italy
| | - Francesco Danilo Tiziano
- Section of Genomic Medicine, Department of Public Health and Life Sciences, Università Cattolica del Sacro Cuore, Roma, Italy
- Complex Unit of Medical Genetics, Fondazione Policlinico Universitario IRCCS “A. Gemelli”, Roma, Italy
| | - Eduardo F Tizzano
- Clinical and Molecular Genetics Area, Vall d'Hebron Hospital; Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
| | - Emanuela Abiusi
- Section of Genomic Medicine, Dept. of Life Sciences and Public Health, Catholic University of the Sacred Heart, Roma, Italy
| | - Giovanni Baranello
- The Dubowitz Neuromuscular Centre, Developmental Neuroscience Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, NIHR Great Ormond Street Hospital Biomedical Research Centre & Great Ormond Street Hospital NHS Foundation Trust, 30 Guilford Street, London WC1N 1EH, UK
| | - Enrico Bertini
- Italy, Research Unit of Neuromuscular Disease, Bambino Gesù Children's Hospital, IRCCS, Roma, Italy
| | - François Boemer
- Biochemical Genetics Lab, Department of Human Genetics, University Hospital, University of Liège, 4000 Liège, Belgium
| | - Arthur Burghes
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Marta Codina-Solà
- Neuromuscular Reference Center, Department of Paediatrics, University Hospital Liege & University of Liege, Belgium
| | - Mar Costa-Roger
- Department of Neurology & Neurosurgery, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Tamara Dangouloff
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Ewout Groen
- Department of Neurology, Medical University of Warsaw, Warsaw, Poland
| | - Monika Gos
- Department of Neuropediatrics and Muscle Disorders, Medical Center University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Maria Jędrzejowska
- Department of Genetics, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands
| | - Janbernd Kirschner
- Centre for Neuromuscular Disorders, Center for Translational Neuro and Behavioral Sciences, Department of Pediatric Neurology, University Duisburg-Essen, 45147 Essen, Germany
| | - Henny H Lemmink
- AFM Téléthon, Évry, France; SMA Europe; European Alliance for Newborn Screening in Spinal Muscular Atrophy
| | - Wolfgang Müller-Felber
- Pediatric Neuromuscular Unit (NEIDF Reference Center at FILNEMUS & Euro-NMD), Child Neurology Department, Raymond Poincaré Hospital (UVSQ), APHP Université Paris Saclay, Garches France
| | - Marie-Christine Ouillade
- Fundacja SMA, Warsaw, Poland; SMA Europe; European Alliance for Newborn Screening in Spinal Muscular Atrophy
| | - Susana Quijano-Roy
- Univ Rouen Normandie, Inserm U1245, Normandie Univ and CHU Rouen, Department of Genetics and Nord/Est/Ile de France Neuromuscular Reference Center, F-76000 Rouen, France
| | - Kacper Rucinski
- Institute of Medical Genomics, Dept. of Life Sciences and Public Health, Catholic University of the Sacred Heart, and Complex Unit of Medical Genetics, Fondazione Policlinico Universitario IRCCS “A. Gemelli”, Roma, Italy
| | - Pascale Saugier-Veber
- Institute of Human Genetics, University Hospital of Cologne, Center for Molecular Medicine, University of Cologne and Center for Rare Diseases Cologne, University Hopsital of Cologne, Cologne, Germany
| | - Francesco Danilo Tiziano
- Institute of Medical Genomics, Dept. of Life Sciences and Public Health, Catholic University of the Sacred Heart, and Complex Unit of Medical Genetics, Fondazione Policlinico Universitario IRCCS “A. Gemelli”, Roma, Italy
| | - Eduardo Fidel Tizzano
- Clinical and Molecular Genetics Area, Vall d'Hebron Hospital; Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
| | - Brunhilde Wirth
- Institute of Human Genetics, University Hospital of Cologne, Center for Molecular Medicine, University of Cologne and Center for Rare Diseases Cologne, University Hopsital of Cologne, Cologne, Germany
| |
Collapse
|
10
|
Pathophysiology and Management of Fatigue in Neuromuscular Diseases. Int J Mol Sci 2023; 24:ijms24055005. [PMID: 36902435 PMCID: PMC10003182 DOI: 10.3390/ijms24055005] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/24/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
Fatigue is a major determinant of quality of life and motor function in patients affected by several neuromuscular diseases, each of them characterized by a peculiar physiopathology and the involvement of numerous interplaying factors. This narrative review aims to provide an overview on the pathophysiology of fatigue at a biochemical and molecular level with regard to muscular dystrophies, metabolic myopathies, and primary mitochondrial disorders with a focus on mitochondrial myopathies and spinal muscular atrophy, which, although fulfilling the definition of rare diseases, as a group represent a representative ensemble of neuromuscular disorders that the neurologist may encounter in clinical practice. The current use of clinical and instrumental tools for fatigue assessment, and their significance, is discussed. A summary of therapeutic approaches to address fatigue, encompassing pharmacological treatment and physical exercise, is also overviewed.
Collapse
|
11
|
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.
Collapse
|
12
|
Vezain M, Thauvin-Robinet C, Vial Y, Coutant S, Drunat S, Urtizberea JA, Rolland A, Jacquin-Piques A, Fehrenbach S, Nicolas G, Lecoquierre F, Saugier-Veber P. Retrotransposon insertion as a novel mutational cause of spinal muscular atrophy. Hum Genet 2023; 142:125-138. [PMID: 36138164 DOI: 10.1007/s00439-022-02473-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 07/15/2022] [Indexed: 01/18/2023]
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder resulting from biallelic alterations of the SMN1 gene: deletion, gene conversion or, in rare cases, intragenic variants. The disease severity is mainly influenced by the copy number of SMN2, a nearly identical gene, which produces only low amounts of full-length (FL) mRNA. Here we describe the first example of retrotransposon insertion as a pathogenic SMN1 mutational event. The 50-year-old patient is clinically affected by SMA type III with a diagnostic odyssey spanning nearly 30 years. Despite a mild disease course, he carries a single SMN2 copy. Using Exome Sequencing and Sanger sequencing, we characterized a SINE-VNTR-Alu (SVA) type F retrotransposon inserted in SMN1 intron 7. Using RT-PCR and RNASeq experiments on lymphoblastoid cell lines, we documented the dramatic decrease of FL transcript production in the patient compared to subjects with the same SMN1 and SMN2 copy number, thus validating the pathogenicity of this SVA insertion. We described the mutant FL-SMN1-SVA transcript characterized by exon extension and showed that it is subject to degradation by nonsense-mediated mRNA decay. The stability of the SMN-SVA protein may explain the mild course of the disease. This observation exemplifies the role of retrotransposons in human genetic disorders.
Collapse
Affiliation(s)
- Myriam Vezain
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France
| | - Christel Thauvin-Robinet
- INSERM UMR1231 GAD-Génétique des Anomalies du Développement, Bourgogne Franche-Comté University, F-21000 , Dijon, France.,Genetics Center, Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (TRANSLAD), Dijon-Burgundy University Hospital, F-21000, Dijon, France
| | - Yoann Vial
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France.,Genetics Department, AP-HP, Robert-Debré University Hospital, 48 boulevard Sérurier, 75019 , Paris, France
| | - Sophie Coutant
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France
| | - Séverine Drunat
- INSERM UMR 1141, PROTECT, Paris University, F-75019, Paris, France.,Genetics Department, AP-HP, Robert-Debré University Hospital, F-75019, Paris, France
| | - Jon Andoni Urtizberea
- Myology Institute, AP-HP Pitié-Salpêtrière University Hospital, F-75013, Paris, France
| | - Anne Rolland
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Pediatrics Department, Valence Hospital, 179 boulevard du Maréchal Juin, 26000, Valence, France
| | - Agnès Jacquin-Piques
- Department of Neurology, Clinical Neurophysiology, Competence Center of Neuromuscular Diseases, Dijon-Burgundy University Hospital, F-21000, Dijon, France
| | - Séverine Fehrenbach
- Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France
| | - Gaël Nicolas
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France
| | - François Lecoquierre
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France.,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France
| | - Pascale Saugier-Veber
- INSERM UMR1245, UNIROUEN, Normandie Univ, F-76000, Rouen, France. .,Department of Genetics, FHU G4 Génomique, Rouen University Hospital, F-76000, Rouen, France. .,Laboratoire de Génétique Moléculaire, UFR-Santé, 22 boulevard Gambetta, 76183, Rouen, France.
| |
Collapse
|
13
|
Wu D, Zhang L, Qiang Y, Wang K. Improved detection of SBDS gene mutation by a new method of next-generation sequencing analysis based on the Chinese mutation spectrum. PLoS One 2022; 17:e0269029. [PMID: 36512530 PMCID: PMC9747038 DOI: 10.1371/journal.pone.0269029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 05/13/2022] [Indexed: 12/15/2022] Open
Abstract
Next-generation sequencing (NGS) is a useful molecular diagnostic tool for genetic diseases. However, due to the presence of highly homologous pseudogenes, it is challenging to use short-read NGS for analyzing mutations of the Shwachman-Bodian-Diamond syndrome (SBDS) gene. The SBDS mutation spectrum was analyzed in the Chinese population, which revealed that SBDS variants were primarily from sequence exchange between SBDS and its pseudogene at the base-pair level, predominantly in the coding region and splice junction of exon two. The c.258+2T>C and c.185_184TA>GT variants were the two most common pathogenic SBDS variants in the Chinese population, resulting in a total carrier frequency of 1.19%. When analyzing pathogenic variants in the SBDS gene from the NGS data, the misalignment was identified as a common issue, and there were different probabilities of misalignment for different pathogenic variants. Here, we present a novel mathematical method for identifying pathogenic variants in the SBDS gene from the NGS data, which utilizes read-depth of the paralogous sequence variant (PSV) loci of SBDS and its pseudogene. Combined with PCR and STR orthogonal experiments, SBDS gene mutation analysis results were improved in 40% of clinical samples, and various types of mutations such as homozygous, compound heterozygous, and uniparental diploid were explored. The findings effectively reduce the impact of misalignment in NGS-based SBDS mutation analysis and are helpful for the clinical diagnosis of SBDS-related diseases, the research into population variation, and the carrier screening.
Collapse
Affiliation(s)
- Dong Wu
- Department of Obstetrics and Gynecology, 900 Hospital of the Joint Logistics Team or Dongfang Hospital, Fuzhou, Fujian, People’s Republic of China
| | - Li Zhang
- Fulgent (Fujian) Technologies, Fuzhou, Fujian, People’s Republic of China
| | - Yuzhen Qiang
- Fulgent (Fujian) Technologies, Fuzhou, Fujian, People’s Republic of China
| | - Kaiyu Wang
- Fulgent (Fujian) Technologies, Fuzhou, Fujian, People’s Republic of China
- * E-mail:
| |
Collapse
|
14
|
Abiusi E, Vaisfeld A, Fiori S, Novelli A, Spartano S, Faggiano MV, Giovanniello T, Angeloni A, Vento G, Santoloci R, Gigli F, D'Amico A, Costa S, Porzi A, Panella M, Ticci C, Daniotti M, Sacchini M, Boschi I, Dani C, Agostiniani R, Bertini E, Lanzone A, Lamarca G, Genuardi M, Pane M, Donati MA, Mercuri E, Tiziano FD. Experience of a 2-year spinal muscular atrophy NBS pilot study in Italy: towards specific guidelines and standard operating procedures for the molecular diagnosis. J Med Genet 2022:jmg-2022-108873. [PMID: 36414255 DOI: 10.1136/jmg-2022-108873] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 11/06/2022] [Indexed: 11/23/2022]
Abstract
BACKGROUND Spinal muscular atrophy (SMA) is due to the homozygous absence of SMN1 in around 97% of patients, independent of the severity (classically ranked into types I-III). The high genetic homogeneity, coupled with the excellent results of presymptomatic treatments of patients with each of the three disease-modifying therapies available, makes SMA one of the golden candidates to genetic newborn screening (NBS) (SMA-NBS). The implementation of SMA in NBS national programmes occurring in some countries is an arising new issue that the scientific community has to address. We report here the results of the first Italian SMA-NBS project and provide some proposals for updating the current molecular diagnostic scenario. METHODS The screening test was performed by an in-house-developed qPCR assay, amplifying SMN1 and SMN2. Molecular prognosis was assessed on fresh blood samples. RESULTS We found 15 patients/90885 newborns (incidence 1:6059) having the following SMN2 genotypes: 1 (one patient), 2 (eight patients), 2+c.859G>C variant (one patient), 3 (three patients), 4 (one patient) or 6 copies (one patient). Six patients (40%) showed signs suggestive of SMA at birth. We also discuss some unusual cases we found. CONCLUSION The molecular diagnosis of SMA needs to adapt to the new era of the disease with specific guidelines and standard operating procedures. In detail, SMA diagnosis should be felt as a true medical urgency due to therapeutic implications; SMN2 copy assessment needs to be standardised; commercially available tests need to be improved for higher SMN2 copies determination; and the SMN2 splicing-modifier variants should be routinely tested in SMA-NBS.
Collapse
Affiliation(s)
- Emanuela Abiusi
- Section of Genomic Medicine, Department of Life Sciences and Public Health, Catholic University of Sacred Heart, Roma, Italy
| | - Alessandro Vaisfeld
- Section of Genomic Medicine, Department of Life Sciences and Public Health, Catholic University of Sacred Heart, Roma, Italy
| | - Stefania Fiori
- Section of Genomic Medicine, Department of Life Sciences and Public Health, Catholic University of Sacred Heart, Roma, Italy
| | - Agnese Novelli
- Section of Genomic Medicine, Department of Life Sciences and Public Health, Catholic University of Sacred Heart, Roma, Italy
| | - Serena Spartano
- Section of Genomic Medicine, Department of Life Sciences and Public Health, Catholic University of Sacred Heart, Roma, Italy
| | - Maria Vittoria Faggiano
- Section of Genomic Medicine, Department of Life Sciences and Public Health, Catholic University of Sacred Heart, Roma, Italy
| | - Teresa Giovanniello
- Department of Experimental Medicine, Newborn Screening Center-Clinical Pathology Unit, Sapienza University of Rome, University Hospital Policlinico Umberto I, Roma, Italy
| | - Antonio Angeloni
- Department of Experimental Medicine, Newborn Screening Center-Clinical Pathology Unit, Sapienza University of Rome, University Hospital Policlinico Umberto I, Roma, Italy
| | - Giovanni Vento
- Section of Pediatrics, Department of Life Sciences and Public Health, Catholic University of Sacred Heart, Roma, Italy.,Neonatology Unit, Fondazione Policlinico Universitario IRCCS "A. Gemelli", Roma, Italy
| | - Roberta Santoloci
- Obstetrics and Gynecology operating Unit, Fondazione Policlinico Universitario IRCCS "A. Gemelli, Roma, Italy
| | - Francesca Gigli
- Neonatology Unit, Fondazione Policlinico Universitario IRCCS "A. Gemelli", Roma, Italy
| | - Adele D'Amico
- Unit of Neuromuscular and Neurodegenerative Disorders, Bambino Gesù Children's Hospital IRCCS, Roma, Italy
| | - Simonetta Costa
- Section of Pediatrics, Department of Life Sciences and Public Health, Catholic University of Sacred Heart, Roma, Italy
| | - Alessia Porzi
- Section of Pediatrics, Department of Life Sciences and Public Health, Catholic University of Sacred Heart, Roma, Italy
| | - Mara Panella
- Obstetrics and Gynecology operating Unit, Fondazione Policlinico Universitario IRCCS "A. Gemelli, Roma, Italy
| | - Chiara Ticci
- Unit of hereditary metabolic and muscular disorders, Meyer Children's University Hospital, Firenze, Italy
| | - Marta Daniotti
- Unit of hereditary metabolic and muscular disorders, Meyer Children's University Hospital, Firenze, Italy
| | - Michele Sacchini
- Unit of hereditary metabolic and muscular disorders, Meyer Children's University Hospital, Firenze, Italy
| | - Ilaria Boschi
- Forensic Medicine operating Unit, Fondazione Policlinico Universitario IRCCS "A. Gemelli", Roma, Italy
| | - Carlo Dani
- Division of Neonatology, Careggi University Hospital of Florence, Florence, Italy.,Department of Neurosciences, University of Florence, Florence, Italy
| | - Rino Agostiniani
- Department of Pediatrics and Neonatology, ASL Toscana Centro, Florence, Italy
| | - Enrico Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, Bambino Gesù Children's Hospital IRCCS, Roma, Italy
| | - Antonio Lanzone
- Obstetrics and Gynecology operating Unit, Fondazione Policlinico Universitario IRCCS "A. Gemelli, Roma, Italy.,Section of Obstetrics and Gynecology, Department of Life Sciences and Public Health, Catholic University of Sacred Heart, Roma, Italy
| | - Giancarlo Lamarca
- Newborn Screening, Clinical Chemistry and Pharmacology Laboratory, Meyer Children's University Hospital, Firenze, Italy
| | - Maurizio Genuardi
- Section of Genomic Medicine, Department of Life Sciences and Public Health, Catholic University of Sacred Heart, Roma, Italy.,Medical Genetics operating Unit, Fondazione Policlinico Universitario IRCCS "A. Gemelli", Roma, Italy
| | - Marika Pane
- Section of Child Psychiatry, Department of Life Sciences and Public Health, Catholic University of Sacred Heart, Roma, Italy.,Child Psychiatry operating Unit, Fondazione Policlinico Universitario IRCCS "A. Gemelli", Roma, Italy
| | - Maria Alice Donati
- Unit of hereditary metabolic and muscular disorders, Meyer Children's University Hospital, Firenze, Italy
| | - Eugenio Mercuri
- Section of Child Psychiatry, Department of Life Sciences and Public Health, Catholic University of Sacred Heart, Roma, Italy.,Child Psychiatry operating Unit, Fondazione Policlinico Universitario IRCCS "A. Gemelli", Roma, Italy
| | - Francesco Danilo Tiziano
- Section of Genomic Medicine, Department of Life Sciences and Public Health, Catholic University of Sacred Heart, Roma, Italy .,Medical Genetics operating Unit, Fondazione Policlinico Universitario IRCCS "A. Gemelli", Roma, Italy
| | | |
Collapse
|
15
|
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.
Collapse
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
| |
Collapse
|
16
|
Deep Molecular Characterization of Milder Spinal Muscular Atrophy Patients Carrying the c.859G>C Variant in SMN2. Int J Mol Sci 2022; 23:ijms23158289. [PMID: 35955418 PMCID: PMC9368089 DOI: 10.3390/ijms23158289] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 02/01/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a severe neuromuscular disorder caused by biallelic loss or pathogenic variants in the SMN1 gene. Copy number and modifier intragenic variants in SMN2, an almost identical paralog gene of SMN1, are known to influence the amount of complete SMN proteins. Therefore, SMN2 is considered the main phenotypic modifier of SMA, although genotype−phenotype correlation is not absolute. We present eleven unrelated SMA patients with milder phenotypes carrying the c.859G>C-positive modifier variant in SMN2. All were studied by a specific NGS method to allow a deep characterization of the entire SMN region. Analysis of two homozygous cases for the variant allowed us to identify a specific haplotype, Smn2-859C.1, in association with c.859G>C. Two other cases with the c.859G>C variant in their two SMN2 copies showed a second haplotype, Smn2-859C.2, in cis with Smn2-859C.1, assembling a more complex allele. We also identified a previously unreported variant in intron 2a exclusively linked to the Smn2-859C.1 haplotype (c.154-1141G>A), further suggesting that this region has been ancestrally conserved. The deep molecular characterization of SMN2 in our cohort highlights the importance of testing c.859G>C, as well as accurately assessing the SMN2 region in SMA patients to gain insight into the complex genotype−phenotype correlations and improve prognostic outcomes.
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Eissa NR, Hassan HA, Senousy SM, Soliman HN, Essawi ML. SMA carrier testing using Real-time PCR as a potential preconception screening tool. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2022. [DOI: 10.1186/s43042-022-00233-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background
SMA is a neuromuscular genetic disorder causing irreversible degeneration of the anterior horn cells of lower motor neurons. According to the age of onset and severity of the condition, it is classified into 5 subtypes. SMA carrier’s frequency worldwide is 1:40–80. We used quantitative real-time PCR to determine the copy number of the disease-determining SMN1 gene by rapid and reliable assays. We studied the SMN1 gene copy number in Egyptian sample of 115 individuals, as well as in 10 SMA families.
Results
Our results showed that 57.4% of the couples with the previous history of an affected family members were carriers. On the individual level, carriers of single SMN1 gene copy rate are much higher than the previously reported frequency rates. The effect of consanguineous marriages appears evident in SMA as an autosomal recessive disorder.
Conclusions
In conclusion, the carrier frequency detected in our cohort was high, which possibly corresponds with the worldwide report of SMA as a leading genetic cause of death among infants. Considering the high rate of consanguinity in developing countries confirms the importance of national SMA carrier screening in Egypt. The qPCR carrier screening test is a rapid-cost effective test that can detect approximately 90% of carriers. A population-based preconception prenatal screening for couples will also help reduce the disease burden.
Collapse
|
19
|
Three years pilot of spinal muscular atrophy newborn screening turned into official program in Southern Belgium. Sci Rep 2021; 11:19922. [PMID: 34620959 PMCID: PMC8497564 DOI: 10.1038/s41598-021-99496-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 09/27/2021] [Indexed: 11/23/2022] Open
Abstract
Three new therapies for spinal muscular atrophy (SMA) have been approved by the United States Food and Drug Administration and the European Medicines Agency since 2016. Although these new therapies improve the quality of life of patients who are symptomatic at first treatment, administration before the onset of symptoms is significantly more effective. As a consequence, newborn screening programs have been initiated in several countries. In 2018, we launched a 3-year pilot program to screen newborns for SMA in the Belgian region of Liège. This program was rapidly expanding to all of Southern Belgium, a region of approximately 55,000 births annually. During the pilot program, 136,339 neonates were tested for deletion of exon 7 of SMN1, the most common cause of SMA. Nine SMA cases with homozygous deletion were identified through this screen. Another patient was identified after presenting with symptoms and was shown to be heterozygous for the SMN1 exon 7 deletion and a point mutation on the opposite allele. These ten patients were treated. The pilot program has now successfully transitioned into the official neonatal screening program in Southern Belgium. The lessons learned during implementation of this pilot program are reported.
Collapse
|
20
|
Abiusi E, Infante P, Cagnoli C, Lospinoso Severini L, Pane M, Coratti G, Pera MC, D'Amico A, Diano F, Novelli A, Spartano S, Fiori S, Baranello G, Moroni I, Mora M, Pasanisi MB, Pocino K, Le Pera L, D'Amico D, Travaglini L, Ria F, Bruno C, Locatelli D, Bertini ES, Morandi LO, Mercuri E, Di Marcotullio L, Tiziano FD. SMA-miRs (miR-181a-5p, -324-5p, and -451a) are overexpressed in spinal muscular atrophy skeletal muscle and serum samples. eLife 2021; 10:68054. [PMID: 34542403 PMCID: PMC8486378 DOI: 10.7554/elife.68054] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 09/13/2021] [Indexed: 12/24/2022] Open
Abstract
Background: Spinal muscular atrophy (SMA) is a neuromuscular disorder characterized by the degeneration of the second motor neuron. The phenotype ranges from very severe to very mild forms. All patients have the homozygous loss of the SMN1 gene and a variable number of SMN2 (generally 2–4 copies), inversely related to the severity. The amazing results of the available treatments have made compelling the need of prognostic biomarkers to predict the progression trajectories of patients. Besides the SMN2 products, few other biomarkers have been evaluated so far, including some miRs. Methods: We performed whole miRNome analysis of muscle samples of patients and controls (14 biopsies and 9 cultures). The levels of muscle differentially expressed miRs were evaluated in serum samples (51 patients and 37 controls) and integrated with SMN2 copies, SMN2 full-length transcript levels in blood and age (SMA-score). Results: Over 100 miRs were differentially expressed in SMA muscle; 3 of them (hsa-miR-181a-5p, -324-5p, -451a; SMA-miRs) were significantly upregulated in the serum of patients. The severity predicted by the SMA-score was related to that of the clinical classification at a correlation coefficient of 0.87 (p<10-5). Conclusions: miRNome analyses suggest the primary involvement of skeletal muscle in SMA pathogenesis. The SMA-miRs are likely actively released in the blood flow; their function and target cells require to be elucidated. The accuracy of the SMA-score needs to be verified in replicative studies: if confirmed, its use could be crucial for the routine prognostic assessment, also in presymptomatic patients. Funding: Telethon Italia (grant #GGP12116).
Collapse
Affiliation(s)
- Emanuela Abiusi
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università cattolica del Sacro Cuore, Roma, Italy
| | - Paola Infante
- Center For Life Nano Science@Sapienza, Istituto Italiano di Tecnologia; Department of Molecular Medicine, Università degli Studi di Roma "La Sapienza", Roma, Italy, Roma, Italy
| | - Cinzia Cagnoli
- Clinical and Experimental Epileptology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy, Roma, Italy
| | | | - Marika Pane
- Pediatric Neurology, Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy.,Centro Clinico Nemo, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Roma, Italy
| | - Giorgia Coratti
- Centro Clinico Nemo, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Roma, Italy
| | - Maria Carmela Pera
- Centro Clinico Nemo, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Roma, Italy
| | - Adele D'Amico
- Unit of Neuromuscular and Neurodegenerative Disorders, Dept. Neurosciences, Bambino Gesu' Children's Hospital IRCCS, Roma, Italy
| | - Federica Diano
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università cattolica del Sacro Cuore, Roma, Italy
| | - Agnese Novelli
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università cattolica del Sacro Cuore, Roma, Italy
| | - Serena Spartano
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università cattolica del Sacro Cuore, Roma, Italy
| | - Stefania Fiori
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università cattolica del Sacro Cuore, Roma, Italy
| | - Giovanni Baranello
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Isabella Moroni
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Marina Mora
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Maria Barbara Pasanisi
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Krizia Pocino
- Department of Medical and Surgical Sciences, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Roma, Italy
| | - Loredana Le Pera
- Bioenergetics and Molecular Biotechnologies (IBIOM), CNR-Institute of Biomembranes, Bari, Italy.,CNR-Institute of Molecular Biology and Pathology (IBPM), Rome, Italy
| | - Davide D'Amico
- Amazentis SA, EPFL Innovation Park, Losanne, Switzerland
| | - Lorena Travaglini
- Unit of Neuromuscular and Neurodegenerative Disorders, Dept. Neurosciences, Bambino Gesu' Children's Hospital IRCCS, Roma, Italy
| | - Francesco Ria
- Department of Translational Medicine and Surgery, Section of General Pathology, Università Cattolica del Sacro Cuore, Roma, Italy.,Fondazione Policlinico Universitario A. Gemelli - IRCCS, Rome, Italy
| | - Claudio Bruno
- Center of Translational and Experimental Myology, IRCCS Istituto Giannina Gaslini, Genova, Italy
| | - Denise Locatelli
- Clinical and Experimental Epileptology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy, Roma, Italy
| | - Enrico Silvio Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, Dept. Neurosciences, Bambino Gesu' Children's Hospital IRCCS, Roma, Italy
| | - Lucia Ovidia Morandi
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Eugenio Mercuri
- Pediatric Neurology, Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Rome, Italy.,Centro Clinico Nemo, Fondazione Policlinico Universitario A. Gemelli IRCCS-Università Cattolica del Sacro Cuore, Roma, Italy
| | - Lucia Di Marcotullio
- Department of Molecular Medicine, Università degli Studi di Roma "La Sapienza", Roma, Italy.,Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Department of Molecular Medicine, Sapienza University, Rome, Italy
| | - Francesco Danilo Tiziano
- Department of Life Sciences and Public Health, Section of Genomic Medicine, Università cattolica del Sacro Cuore, Roma, Italy.,Unit of Medical Genetics, Department of Laboratory science and Infectious Diseases, Fondazione Policlinico Universitario IRCCS "A. Gemelli", Rome, Italy
| |
Collapse
|
21
|
The Importance of Digging into the Genetics of SMN Genes in the Therapeutic Scenario of Spinal Muscular Atrophy. Int J Mol Sci 2021; 22:ijms22169029. [PMID: 34445733 PMCID: PMC8396600 DOI: 10.3390/ijms22169029] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/13/2021] [Accepted: 08/19/2021] [Indexed: 12/12/2022] Open
Abstract
After 26 years of discovery of the determinant survival motor neuron 1 and the modifier survival motor neuron 2 genes (SMN1 and SMN2, respectively), three SMN-dependent specific therapies are already approved by FDA and EMA and, as a consequence, worldwide SMA patients are currently under clinical investigation and treatment. Bi-allelic pathogenic variants (mostly deletions) in SMN1 should be detected in SMA patients to confirm the disease. Determination of SMN2 copy number has been historically employed to correlate with the phenotype, predict disease evolution, stratify patients for clinical trials and to define those eligible for treatment. In view that discordant genotype-phenotype correlations are present in SMA, besides technical issues with detection of SMN2 copy number, we have hypothesized that copy number determination is only the tip of the iceberg and that more deepen studies of variants, sequencing and structures of the SMN2 genes are necessary for a better understanding of the disease as well as to investigate possible influences in treatment responses. Here, we highlight the importance of a comprehensive approach of SMN1 and SMN2 genetics with the perspective to apply for better prediction of SMA in positive neonatal screening cases and early diagnosis to start treatments.
Collapse
|
22
|
Baker MW, Mochal ST, Dawe SJ, Wiberley-Bradford AE, Cogley MF, Zeitler BR, Piro ZD, Harmelink MM, Kwon JM. Newborn screening for spinal muscular atrophy: The Wisconsin first year experience. Neuromuscul Disord 2021; 32:135-141. [PMID: 35120759 DOI: 10.1016/j.nmd.2021.07.398] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 07/10/2021] [Accepted: 07/20/2021] [Indexed: 11/27/2022]
Abstract
Spinal muscular atrophy was recently added to the Wisconsin newborn screening panel. Here we report our screening methods, algorithm, and outcomes. A multiplex real-time PCR assay was used to identify newborns with homozygous SMN1 exon 7 deletion, and those newborns' specimens further underwent a droplet digital PCR assay for SMN2 copy number assessment. An independent dried blood spot specimen was collected and tested to confirm the initial screening results for SMN1 and SMN2. From October 15, 2019 to October 14, 2020, a total of 60,984 newborns were screened for spinal muscular atrophy. Six newborns screened positive for and were confirmed to have spinal muscular atrophy, making the Wisconsin spinal muscular atrophy birth prevalence 1 in 10,164. Of these six infants, two have two copies of SMN2, two have three copies of SMN2, and two have four copies of SMN2. Five newborns received Zolgensma therapy, and one newborn received Spinraza therapy. Our screening method's positive predictive value is 100%. This comprehensive approach, providing both timely SMN2 information and SMN1 and SMN2 confirmation as parts of the algorithm for spinal muscular atrophy newborn screening, facilitated timely clinical follow-up, family counseling, and treatment planning.
Collapse
Affiliation(s)
- Mei W Baker
- Newborn Screening Laboratory, Wisconsin State Laboratory of Hygiene, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; Genetics and Metabolism Division, Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States.
| | - Sean T Mochal
- Newborn Screening Laboratory, Wisconsin State Laboratory of Hygiene, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States
| | - Sandra J Dawe
- Office of Information Systems, Wisconsin State Laboratory of Hygiene University of Wisconsin School of Medicine and Public Health, Madison, WI, United States
| | - Amy E Wiberley-Bradford
- Newborn Screening Laboratory, Wisconsin State Laboratory of Hygiene, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States
| | - Michael F Cogley
- Newborn Screening Laboratory, Wisconsin State Laboratory of Hygiene, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States
| | - Bethany R Zeitler
- Newborn Screening Laboratory, Wisconsin State Laboratory of Hygiene, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States
| | - Zachary D Piro
- Newborn Screening Laboratory, Wisconsin State Laboratory of Hygiene, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States
| | - Mathew M Harmelink
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Jennifer M Kwon
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States
| |
Collapse
|
23
|
Butchbach MER. Genomic Variability in the Survival Motor Neuron Genes ( SMN1 and SMN2): Implications for Spinal Muscular Atrophy Phenotype and Therapeutics Development. Int J Mol Sci 2021; 22:ijms22157896. [PMID: 34360669 PMCID: PMC8348669 DOI: 10.3390/ijms22157896] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/14/2021] [Accepted: 07/21/2021] [Indexed: 02/07/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a leading genetic cause of infant death worldwide that is characterized by loss of spinal motor neurons leading to muscle weakness and atrophy. SMA results from the loss of survival motor neuron 1 (SMN1) gene but retention of its paralog SMN2. The copy numbers of SMN1 and SMN2 are variable within the human population with SMN2 copy number inversely correlating with SMA severity. Current therapeutic options for SMA focus on increasing SMN2 expression and alternative splicing so as to increase the amount of SMN protein. Recent work has demonstrated that not all SMN2, or SMN1, genes are equivalent and there is a high degree of genomic heterogeneity with respect to the SMN genes. Because SMA is now an actionable disease with SMN2 being the primary target, it is imperative to have a comprehensive understanding of this genomic heterogeneity with respect to hybrid SMN1–SMN2 genes generated by gene conversion events as well as partial deletions of the SMN genes. This review will describe this genetic heterogeneity in SMA and its impact on disease phenotype as well as therapeutic efficacy.
Collapse
Affiliation(s)
- Matthew E. R. Butchbach
- Center for Applied Clinical Genomics, Nemours Children’s Health Delaware, Wilmington, DE 19803, USA;
- Center for Pediatric Research, Nemours Children’s Health Delaware, Wilmington, DE 19803, USA
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
- Department of Pediatrics, Thomas Jefferson University, Philadelphia, PA 19107, USA
| |
Collapse
|
24
|
Kumar B, Barton S, Kordowska J, Eaton RB, Counihan AM, Hale JE, Comeau AM. Novel Modification of a Confirmatory SMA Sequencing Assay that Can Be Used to Determine SMN2 Copy Number. Int J Neonatal Screen 2021; 7:ijns7030047. [PMID: 34449530 PMCID: PMC8395917 DOI: 10.3390/ijns7030047] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/11/2021] [Accepted: 07/16/2021] [Indexed: 01/04/2023] Open
Abstract
Promising treatments for spinal muscular atrophy (SMA), the leading genetic cause of infant mortality, prompted calls for inclusion in newborn screening (NBS). In January 2018, the New England Newborn Screening Program (NENSP) began statewide screening for SMA using a tiered algorithm looking for the absence of SMN1 Exon 7. When results from the first and second tier needed reconciliation, we developed and validated a third tier DNA sequencing assay to ensure the presence or absence of SMN1 Exon 7. All nine infants referred to specialty centers through NBS showed single base substitution of c.840C>T, and were confirmed to have SMA. Further, a minor sequencing protocol modification allowed the estimation of SMN2 copy number in SMA affected patients; we developed and validated a copy-number assay yielding 100% match with seven previously characterized specimens of SMA patients. All nine SMA-affected infants found through NBS were also assayed for SMN2 copy number. Results were comparable but not 100% matched with those that were reported by independent diagnostic laboratories. In conclusion, a sequencing protocol confirms NBS findings from real-time qPCR, and its modified application allows NBS programs that have sequencing capabilities to provide SMN2 copy numbers without the need for additional instrumentation.
Collapse
Affiliation(s)
- Binod Kumar
- New England Newborn Screening Program, University of Massachusetts Medical School, Worcester, MA 01605, USA; (S.B.); (J.K.); (R.B.E.); (A.M.C.); (J.E.H.); (A.M.C.)
- Division of Genetics, Department of Pediatrics, University of Massachusetts Medical School, Worcester, MA 01605, USA
- Correspondence: ; Tel.: +1-774-455-4657
| | - Samantha Barton
- New England Newborn Screening Program, University of Massachusetts Medical School, Worcester, MA 01605, USA; (S.B.); (J.K.); (R.B.E.); (A.M.C.); (J.E.H.); (A.M.C.)
| | - Jolanta Kordowska
- New England Newborn Screening Program, University of Massachusetts Medical School, Worcester, MA 01605, USA; (S.B.); (J.K.); (R.B.E.); (A.M.C.); (J.E.H.); (A.M.C.)
| | - Roger B. Eaton
- New England Newborn Screening Program, University of Massachusetts Medical School, Worcester, MA 01605, USA; (S.B.); (J.K.); (R.B.E.); (A.M.C.); (J.E.H.); (A.M.C.)
- Division of Genetics, Department of Pediatrics, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Anne M. Counihan
- New England Newborn Screening Program, University of Massachusetts Medical School, Worcester, MA 01605, USA; (S.B.); (J.K.); (R.B.E.); (A.M.C.); (J.E.H.); (A.M.C.)
| | - Jaime E. Hale
- New England Newborn Screening Program, University of Massachusetts Medical School, Worcester, MA 01605, USA; (S.B.); (J.K.); (R.B.E.); (A.M.C.); (J.E.H.); (A.M.C.)
| | - Anne Marie Comeau
- New England Newborn Screening Program, University of Massachusetts Medical School, Worcester, MA 01605, USA; (S.B.); (J.K.); (R.B.E.); (A.M.C.); (J.E.H.); (A.M.C.)
- Division of Genetics, Department of Pediatrics, University of Massachusetts Medical School, Worcester, MA 01605, USA
| |
Collapse
|
25
|
Blasco-Pérez L, Paramonov I, Leno J, Bernal S, Alias L, Fuentes-Prior P, Cuscó I, Tizzano EF. Beyond copy number: A new, rapid, and versatile method for sequencing the entire SMN2 gene in SMA patients. Hum Mutat 2021; 42:787-795. [PMID: 33739559 PMCID: PMC8252042 DOI: 10.1002/humu.24200] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 01/13/2021] [Accepted: 03/11/2021] [Indexed: 01/16/2023]
Abstract
Spinal muscular atrophy (SMA) is caused by bi‐allelic loss or pathogenic variants in the SMN1 gene. SMN2, the highly homologous copy of SMN1, is considered the major phenotypic modifier of the disease. Determination of SMN2 copy number is essential to establish robust genotype–phenotype correlations and predict disease evolution, to stratify patients for clinical trials, as well as to define those eligible for treatment. Discordant genotype–phenotype correlations are not uncommon in SMA, some of which are due to intragenic SMN2 variants that may influence the amount of complete SMN transcripts and, therefore, of full‐length SMN protein. Detection of these variants is crucial to predict SMA phenotypes in the present scenario of therapeutic advances and with the perspective of SMA neonatal screening and early diagnosis to start treatments. Here, we present a novel, affordable, and versatile method for complete sequencing of the SMN2 gene based on long‐range polymerase chain reaction and next‐generation sequencing. The method was validated by analyzing samples from 53 SMA patients who lack SMN1, allowing to characterize paralogous, rare variants, and single‐nucleotide polymorphisms of SMN2 as well as SMN2–SMN1 hybrid genes. The method identifies partial deletions and can be adapted to determine rare pathogenic variants in patients with at least one SMN1 copy.
Collapse
Affiliation(s)
- Laura Blasco-Pérez
- Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.,Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Barcelona, Spain
| | - Ida Paramonov
- Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.,Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Barcelona, Spain
| | - Jordi Leno
- Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.,Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Barcelona, Spain
| | - Sara Bernal
- Genetics Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER)
| | - Laura Alias
- Genetics Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER)
| | - Pablo Fuentes-Prior
- Molecular Bases of Disease, Biomedical Research Institute Sant Pau (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Ivon Cuscó
- Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.,Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER)
| | - Eduardo F Tizzano
- Medicine Genetics Group, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain.,Department of Clinical and Molecular Genetics, Hospital Vall d'Hebron, Barcelona, Spain
| |
Collapse
|