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Karasu N, Acer H, Akalin H, Turkgenc B, Demir M, Sahin IO, Gokce N, Gulec A, Ciplakligil A, Sarilar AC, Cuce I, Gumus H, Per H, Canpolat M, Dundar M. Molecular analysis of SMN2, NAIP, and GTF2H2 gene deletions and relationships with clinical subtypes of spinal muscular atrophy. J Neurogenet 2024:1-10. [PMID: 39321203 DOI: 10.1080/01677063.2024.2407332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 09/17/2024] [Indexed: 09/27/2024]
Abstract
SMA (spinal muscular atrophy) is an autosomal recessive neuromuscular disease that causes muscle atrophy and weakness. SMA is diagnosed by a homozygous deletion in exon 7 of the SMN1 gene. However, mutations in genes located in the SMA region, such as SMN2, NAIP, SERF1, and GTF2H2, may also contribute to the severity of the disease. Within our study's scope, 58 SMA patients who applied in 2018-2021 and 40 healthy controls were analyzed. The study retrospectively included the SMN1 and SMN2 copy numbers previously determined by the MLPA method. Then, NAIP gene analyses with the multiplex PCR method and GTF2H2 gene analyses with the RFLP method were performed. There was a significant correlation (p = 0.00001) between SMN2 copy numbers and SMA subtypes. Also, the NAIP gene (p = 0.01) and the GTF2H2 gene (p = 0.0049) revealed a significant difference between healthy and SMA subjects, whereas the SMA subtypes indicated no significant differences. We detected a significant correlation between clinical subtypes and HFMSE scores in 32 pediatric SMA patients compared (p = 0.01). While pediatric patients with GTF2H2 deletions demonstrated higher motor functions, and those with NAIP deletions demonstrated lower motor functions. In this study, we examined the relationship between NAIP and GTF2H2, called SMN region modifier genes, and the clinical severity of the disease in Turkish SMA patients. Despite its small scale, this research will benefit future investigations into the pathogenesis of SMA disease.
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Affiliation(s)
- Nilgun Karasu
- Faculty of Medicine, Department of Medical Genetics, Erciyes University, Kayseri, Turkey
- Faculty of Medicine, Department of Medical Genetics, Uskudar University, Istanbul, Turkey
| | - Hamit Acer
- Department of Pediatric Neurology, Denizli State Hospital, Denizli, Turkey
| | - Hilal Akalin
- Faculty of Medicine, Department of Medical Genetics, Erciyes University, Kayseri, Turkey
| | - Burcu Turkgenc
- Faculty of Medicine, Department of Medical Biology, Uskudar University, Istanbul, Turkey
| | - Mikail Demir
- Faculty of Medicine, Department of Medical Genetics, Erciyes University, Kayseri, Turkey
| | - Izem Olcay Sahin
- Faculty of Medicine, Department of Medical Genetics, Erciyes University, Kayseri, Turkey
| | - Nuriye Gokce
- Faculty of Medicine, Department of Medical Genetics, Erciyes University, Kayseri, Turkey
| | - Ayten Gulec
- Faculty of Medicine, Department of Pediatric Neurology, Erciyes University, Kayseri, Turkey
| | - Asli Ciplakligil
- Faculty of Medicine, Department of Neurology, Erciyes University, Kayseri, Turkey
| | - Ayse Caglar Sarilar
- Faculty of Medicine, Department of Neurology, Erciyes University, Kayseri, Turkey
| | - Isa Cuce
- Faculty of Medicine, Department of Physical Medicine and Rehabilitation, Erciyes University, Kayseri, Turkey
| | - Hakan Gumus
- Faculty of Medicine, Department of Pediatric Neurology, Erciyes University, Kayseri, Turkey
| | - Huseyin Per
- Faculty of Medicine, Department of Pediatric Neurology, Erciyes University, Kayseri, Turkey
| | - Mehmet Canpolat
- Faculty of Medicine, Department of Pediatric Neurology, Erciyes University, Kayseri, Turkey
| | - Munis Dundar
- Faculty of Medicine, Department of Medical Genetics, Erciyes University, Kayseri, Turkey
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Ouyang S, Peng X, Huang W, Bai J, Wang H, Jin Y, Jiao H, Wei M, Ge X, Song F, Qu Y. Association among biomarkers, phenotypes, and motor milestones in Chinese patients with 5q spinal muscular atrophy types 1-3. Front Neurol 2024; 15:1382410. [PMID: 39286802 PMCID: PMC11404040 DOI: 10.3389/fneur.2024.1382410] [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: 02/15/2024] [Accepted: 07/25/2024] [Indexed: 09/19/2024] Open
Abstract
Background Biomarkers can be used to assess the severity of spinal muscular atrophy (5q SMA; SMA). Despite their potential, the relationship between biomarkers and clinical outcomes in SMA remains underexplored. This study aimed to assess the association among biomarkers, phenotypes, and motor milestones in Chinese patients diagnosed with SMA. Methods We collected retrospective clinical and follow-up data of disease-modifying therapy (DMT)-naïve patients with SMA at our center from 2019 to 2021. Four biomarkers were included: survival motor neuron 2 (SMN2) copies, neuronal apoptosis inhibitory protein (NAIP) copies, full-length SMN2 (fl-SMN2), and F-actin bundling protein plastin 3 (PLS3) transcript levels. Data were analyzed and stratified according to SMA subtype. Results Of the 123 patients, 30 were diagnosed with Type 1 (24.3%), 56 with Type 2 (45.5%), and 37 with Type 3 (30.1%). The mortality rate for Type 1 was 50%, with median survival times of 2 and 8 months for types 1a and 1b, respectively. All four biomarkers were correlated with disease severity. Notably, fl-SMN2 transcript levels increased with SMN2 copies and were higher in Type 2b than those in Type 2a (p = 0.028). Motor milestone deterioration was correlated with SMN2 copies, NAIP copies, and fl-SMN2 levels, while PLS3 levels were correlated with standing and walking function. Discussion Our findings suggest that SMN2 copies contribute to survival and that fl-SMN2 may serve as a valuable biomarker for phenotypic variability in SMA Type 2 subtypes. These insights can guide future research and clinical management of SMA.
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Affiliation(s)
- Shijia Ouyang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Xiaoyin Peng
- Department of Neurology, Children's Hospital Affiliated to Capital Institute Pediatrics, Beijing, China
| | - Wenchen Huang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Jinli Bai
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Hong Wang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Yuwei Jin
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Hui Jiao
- Department of Neurology, Children's Hospital Affiliated to Capital Institute Pediatrics, Beijing, China
| | - Maoti Wei
- Center of Clinical Epidemiology, TEDA International Cardiovascular Hospital, Tianjin, China
| | - Xiushan Ge
- Department of Neurology, Children's Hospital Affiliated to Capital Institute Pediatrics, Beijing, China
| | - Fang Song
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Yujin Qu
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
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Wang N, Jiao K, He J, Zhu B, Cheng N, Sun J, Chen L, Chen W, Gong L, Qiao K, Xi J, Wu Q, Zhao C, Zhu W. Diagnosis of Challenging Spinal Muscular Atrophy Cases with Long-Read Sequencing. J Mol Diagn 2024; 26:364-373. [PMID: 38490302 DOI: 10.1016/j.jmoldx.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/17/2024] [Accepted: 02/07/2024] [Indexed: 03/17/2024] Open
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder primarily caused by the deletion or mutation of the survival motor neuron 1 (SMN1) gene. This study assesses the diagnostic potential of long-read sequencing (LRS) in three patients with SMA. For Patient 1, who has a heterozygous SMN1 deletion, LRS unveiled a missense mutation in SMN1 exon 5. In Patient 2, an Alu/Alu-mediated rearrangement covering the SMN1 promoter and exon 1 was identified through a blend of multiplex ligation-dependent probe amplification, LRS, and PCR across the breakpoint. The third patient, born to a consanguineous family, bore four copies of hybrid SMN genes. LRS determined the genomic structures, indicating two distinct hybrids of SMN2 exon 7 and SMN1 exon 8. However, a discrepancy was found between the SMN1/SMN2 ratio interpretations by LRS (0:2) and multiplex ligation-dependent probe amplification (0:4), which suggested a limitation of LRS in SMA diagnosis. In conclusion, this newly adapted long PCR-based third-generation sequencing introduces an additional avenue for SMA diagnosis.
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Affiliation(s)
- Ningning Wang
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Kexin Jiao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jin He
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Bochen Zhu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Nachuan Cheng
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jian Sun
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Lan Chen
- Department of Neurology, Nantong First People's Hospital, Nantong, China
| | - Wanjin Chen
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China
| | - Lingyun Gong
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Kai Qiao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jianying Xi
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Qihan Wu
- Shanghai Ministry of Science and Technology Key Laboratory of Health and Disease Genomics, National Health Commission Key Lab of Reproduction Regulation, Shanghai Institute for Biomedical and Pharmaceutical Technologies, Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Wenhua Zhu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; National Center for Neurological Disorders, Shanghai, China; Huashan Rare Disease Center, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
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Qu Y, Bai J, Jiao H, Qi H, Huang W, OuYang S, Peng X, Jin Y, Wang H, Song F. Variants located in intron 6 of SMN1 lead to misdiagnosis in genetic detection and screening for SMA. Heliyon 2024; 10:e28015. [PMID: 38515714 PMCID: PMC10955315 DOI: 10.1016/j.heliyon.2024.e28015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 02/28/2024] [Accepted: 03/11/2024] [Indexed: 03/23/2024] Open
Abstract
Accurate genetic diagnosis is necessary for guiding the treatment of spinal muscular atrophy (SMA). An updated consensus for the diagnosis and management of SMA was published in 2018. However, clinicians should remain alert to some pitfalls of genetic testing that can occur when following a routine diagnosis. In this study, we report the diagnosis of three unrelated individuals who were initially misdiagnosed as carrying a homozygous deletion of SMN1 exon 7. MLPA (P060 and P021) and qPCR were used to detect the copy number of SMN. SMN1 variants were identified by SMN1 clone and next-generation sequencing (NGS). Transcription of SMN1 variants was detected using qRT-PCR and ex vivo splicing analysis. Among the three individuals, one was identified as a patient with SMA carrying a heterozygous deletion and a pathogenic variant (c.835-17_835-14delCTTT) of SMN1, one was a healthy carrier only carrying a heterozygous deletion of SMN1 exon 7, and the third was a patient with nemaline myopathy 2 carrying a heterozygous deletion of SMN1 exon 7. The misdiagnosis of these individuals was attributed to the presence of the c.835-17_835-14delCTTT or c.835-17C > G variants in SMN1 intron 6, which affect the amplification of SMN1 exon 7 during MLPA-P060 and qPCR testing. However, MLPA-P021 and NGS analyses were unaffected by these variants. These results support that additional detection methods should be employed in cases where the SMN1 copy number is ambiguous to minimize the misdiagnosis of SMA.
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Affiliation(s)
- Yujin Qu
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Jinli Bai
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Hui Jiao
- Department of Neurology, Children’s Hospital Affiliated to Capital Institute of Pediatrics, Beijing, China
| | - Hong Qi
- Prenatal Diagnosis Center, Beijing Haidian District Maternal and Child Health Care Hospital, Beijing, China
| | - Wenchen Huang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Shijia OuYang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Xiaoyin Peng
- Department of Neurology, Children’s Hospital Affiliated to Capital Institute of Pediatrics, Beijing, China
| | - Yuwei Jin
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Hong Wang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Fang Song
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
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Dosi C, Masson R. The impact of three SMN2 gene copies on clinical characteristics and effect of disease-modifying treatment in patients with spinal muscular atrophy: a systematic literature review. Front Neurol 2024; 15:1308296. [PMID: 38487326 PMCID: PMC10937544 DOI: 10.3389/fneur.2024.1308296] [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: 10/06/2023] [Accepted: 02/12/2024] [Indexed: 03/17/2024] Open
Abstract
Objective To review the clinical characteristics and effect of treatment in patients with spinal muscular atrophy (SMA) and three copies of the SMN2 gene. Methods We conducted a literature search in October 2022 to identify English-language clinical research on SMA that included SMN2 copy number according to PRISMA guidelines. Results Our search identified 44 studies examining the impact of three SMN2 copies on clinical characteristics (21 on phenotype, 13 on natural history, and 15 on functional status and other signs/symptoms). In children with type I SMA or presymptomatic infants with an SMN1 deletion, three SMN2 copies was associated with later symptom onset, slower decline in motor function and longer survival compared with two SMN2 copies. In patients with SMA type II or III, three SMN2 copies is associated with earlier symptom onset, loss of ambulation, and ventilator dependence compared with four SMN2 copies. Eleven studies examined treatment effects with nusinersen (nine studies), onasemnogene abeparvovec (one study), and a range of treatments (one study) in patients with three SMN2 copies. In presymptomatic infants, early treatment delayed the onset of symptoms and maintained motor function in those with three SMN2 copies. The impact of copy number on treatment response in symptomatic patients is still unclear. Conclusion SMN2 copy number is strongly correlated with SMA phenotype in patients with SMN1 deletion, while no correlation was found in patients with an SMN1 mutation. Patients with three SMN2 copies show a highly variable clinical phenotype. Early initiation of treatment is highly effective in presymptomatic patients with three SMN2 copies.
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Affiliation(s)
| | - Riccardo Masson
- Fondazione IRCCS Istituto Neurologico Carlo Besta, Developmental Neurology Unit, Milan, Italy
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Abd El Mutaleb ANH, Ibrahim FAR, Megahed FAK, Atta A, Ali BA, Omar TEI, Rashad MM. NAIP Gene Deletion and SMN2 Copy Number as Molecular Tools in Predicting the Severity of Spinal Muscular Atrophy. Biochem Genet 2024:10.1007/s10528-023-10657-6. [PMID: 38388850 DOI: 10.1007/s10528-023-10657-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 12/29/2023] [Indexed: 02/24/2024]
Abstract
Spinal muscular atrophy (SMA) is one of the most prevalent autosomal recessive illnesses with type I being the most severe type. Genomic alterations including survival motor neuron (SMN) copy number as well as deletions in SMN and Neuronal Apoptosis Inhibitory Protein (NAIP) are greatly implicated in the emergence of SMA. However, the association of such alterations with the severity of the disease is yet to be investigated. This study was directed to elucidate the molecular assessment of NAIP and SMN genomic alterations as a useful tool in predicting the severity of SMA among patients. This study included 65 SMA pediatric patients (30 type I and 35 type II) and 65 healthy controls. RFLP-PCR was employed to determine the genetic polymorphisms of the SMN1, SMN2, and NAIP genes. In addition, qRT-PCR was used to identify the expression of the SMN1 and SMN2 genes, and serum levels of creatine kinase were measured using a colorimetric method. DNA sequencing was performed on some samples to detect any single nucleotide polymorphisms in SMN1, SMN2, and NAIP genes. All SMA patients had a homozygous deficiency of SMN1 exon 7. The homozygous deficiency of SMN1 exons 7 and 8, with the deletion of NAIP exon 5 was found among the majority of Type I patients. In contrast, patients with the less severe condition (type II) had SMN1 exons 7 and 8 deleted but did not have any deletions in NAIP, additionally; 65.7% of patients had multiple copies of SMN2. Analysis of NAIP deletion alongside assessing SMN2 copy number might enhance the effectiveness of the diagnosis that can predict severity among Spinal Muscular Atrophy patients.
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Affiliation(s)
| | - Fawziya A R Ibrahim
- Department of Applied Medical Chemistry, Medical Research Institute, University of Alexandria, Alexandria, Egypt.
| | - Fayed A K Megahed
- Department of Nucleic Acid Research, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, Alexandria, Egypt
| | - Ahmed Atta
- Department of Nucleic Acid Research, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, Alexandria, Egypt
| | - Bahy A Ali
- Department of Nucleic Acid Research, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, Alexandria, Egypt
| | - Tarek E I Omar
- Department of Pediatric Neurology, Faculty of Medicine, University of Alexandria, Alexandria, Egypt
| | - Mona M Rashad
- Department of Applied Medical Chemistry, Medical Research Institute, University of Alexandria, Alexandria, Egypt
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Niri F, Nicholls J, Baptista Wyatt K, Walker C, Price T, Kelln R, Hume S, Parboosingh J, Lilley M, Kolski H, Ridsdale R, Muranyi A, Mah JK, Bulman DE. Alberta Spinal Muscular Atrophy Newborn Screening-Results from Year 1 Pilot Project. Int J Neonatal Screen 2023; 9:42. [PMID: 37606479 PMCID: PMC10443376 DOI: 10.3390/ijns9030042] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/17/2023] [Accepted: 07/24/2023] [Indexed: 08/23/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a progressive neuromuscular disease caused by biallelic pathogenic/likely pathogenic variants of the survival motor neuron 1 (SMN1) gene. Early diagnosis via newborn screening (NBS) and pre-symptomatic treatment are essential to optimize health outcomes for affected individuals. We developed a multiplex quantitative polymerase chain reaction (qPCR) assay using dried blood spot (DBS) samples for the detection of homozygous absence of exon 7 of the SMN1 gene. Newborns who screened positive were seen urgently for clinical evaluation. Confirmatory testing by multiplex ligation-dependent probe amplification (MLPA) revealed SMN1 and SMN2 gene copy numbers. Six newborns had abnormal screen results among 47,005 newborns screened during the first year and five were subsequently confirmed to have SMA. Four of the infants received SMN1 gene replacement therapy under 30 days of age. One infant received an SMN2 splicing modulator due to high maternally transferred AAV9 neutralizing antibodies (NAb), followed by gene therapy at 3 months of age when the NAb returned negative in the infant. Early data show that all five infants made excellent developmental progress. Based on one year of data, the incidence of SMA in Alberta was estimated to be 1 per 9401 live births.
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Affiliation(s)
- Farshad Niri
- Alberta Newborn Screening Laboratory, Alberta Precision Laboratories, Edmonton, AB T6G 2H7, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Jessie Nicholls
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Kelly Baptista Wyatt
- Alberta Newborn Screening Laboratory, Alberta Precision Laboratories, Edmonton, AB T6G 2H7, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Christine Walker
- Alberta Newborn Screening Laboratory, Alberta Precision Laboratories, Edmonton, AB T6G 2H7, Canada
| | - Tiffany Price
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB T3B 6A8, Canada
| | - Rhonda Kelln
- Alberta Newborn Screening Laboratory, Alberta Precision Laboratories, Edmonton, AB T6G 2H7, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Stacey Hume
- Department of Pathology and Laboratory Medicine, University of British Colombia, Vancouver, BC V6H 3N1, Canada
| | - Jillian Parboosingh
- Department of Medical Genetics, University of Calgary, Calgary, AB T2N 4N2, Canada
| | - Margaret Lilley
- Alberta Newborn Screening Laboratory, Alberta Precision Laboratories, Edmonton, AB T6G 2H7, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Hanna Kolski
- Department of Pediatrics, University of Alberta, Edmonton, AB T6G 1C9, Canada
| | - Ross Ridsdale
- Alberta Newborn Screening Laboratory, Alberta Precision Laboratories, Edmonton, AB T6G 2H7, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Andrew Muranyi
- Alberta Newborn Screening Laboratory, Alberta Precision Laboratories, Edmonton, AB T6G 2H7, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Jean K. Mah
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB T3B 6A8, Canada
| | - Dennis E. Bulman
- Alberta Newborn Screening Laboratory, Alberta Precision Laboratories, Edmonton, AB T6G 2H7, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB T3B 6A8, Canada
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de Lima JD, de Paula AGP, Yuasa BS, de Souza Smanioto CC, da Cruz Silva MC, Dos Santos PI, Prado KB, Winter Boldt AB, Braga TT. Genetic and Epigenetic Regulation of the Innate Immune Response to Gout. Immunol Invest 2023; 52:364-397. [PMID: 36745138 DOI: 10.1080/08820139.2023.2168554] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Gout is a disease caused by uric acid (UA) accumulation in the joints, causing inflammation. Two UA forms - monosodium urate (MSU) and soluble uric acid (sUA) have been shown to interact physically with inflammasomes, especially with the nod-like receptor (NLR) family pyrin domain containing 3 (NLRP3), albeit the role of the immune response to UA is poorly understood, given that asymptomatic hyperuricemia does also exist. Macrophage phagocytosis of UA activate NLRP3, lead to cytokines release, and ultimately, lead to chemoattract neutrophils and lymphocytes to the gout flare joint spot. Genetic variants of inflammasome genes and of genes encoding their molecular partners may influence hyperuricemia and gout susceptibility, while also influencing other comorbidities such as metabolic syndrome and cardiovascular diseases. In this review, we summarize the inflammatory responses in acute and chronic gout, specifically focusing on innate immune cell mechanisms and genetic and epigenetic characteristics of participating molecules. Unprecedently, a novel UA binding protein - the neuronal apoptosis inhibitor protein (NAIP) - is suggested as responsible for the asymptomatic hyperuricemia paradox.Abbreviation: β2-integrins: leukocyte-specific adhesion molecules; ABCG2: ATP-binding cassete family/breast cancer-resistant protein; ACR: American college of rheumatology; AIM2: absent in melanoma 2, type of pattern recognition receptor; ALPK1: alpha-protein kinase 1; ANGPTL2: angiopoietin-like protein 2; ASC: apoptosis-associated speck-like protein; BIR: baculovirus inhibitor of apoptosis protein repeat; BIRC1: baculovirus IAP repeat-containing protein 1; BIRC2: baculoviral IAP repeat-containing protein 2; C5a: complement anaphylatoxin; cAMP: cyclic adenosine monophosphate; CARD: caspase activation and recruitment domains; CARD8: caspase recruitment domain-containing protein 8; CASP1: caspase 1; CCL3: chemokine (C-C motif) ligand 3; CD14: cluster of differentiation 14; CD44: cluster of differentiation 44; Cg05102552: DNA-methylation site, usually cytosine followed by guanine nucleotides; contains arbitrary identification code; CIDEC: cell death-inducing DNA fragmentation factor-like effector family; CKD: chronic kidney disease; CNV: copy number variation; CPT1A: carnitine palmitoyl transferase - type 1a; CXCL1: chemokine (CXC motif) ligand 1; DAMPs: damage associated molecular patterns; DC: dendritic cells; DNMT(1): maintenance DNA methyltransferase; eQTL: expression quantitative trait loci; ERK1: extracellular signal-regulated kinase 1; ERK2: extracellular signal-regulated kinase 2; EULAR: European league against rheumatism; GMCSF: granulocyte-macrophage colony-stimulating factor; GWAS: global wide association studies; H3K27me3: tri-methylation at the 27th lysine residue of the histone h3 protein; H3K4me1: mono-methylation at the 4th lysine residue of the histone h3 protein; H3K4me3: tri-methylation at the 4th lysine residue of the histone h3 protein; HOTAIR: human gene located between hoxc11 and hoxc12 on chromosome 12; IκBα: cytoplasmatic protein/Nf-κb transcription inhibitor; IAP: inhibitory apoptosis protein; IFNγ: interferon gamma; IL-1β: interleukin 1 beta; IL-12: interleukin 12; IL-17: interleukin 17; IL18: interleukin 18; IL1R1: interleukin-1 receptor; IL-1Ra: interleukin-1 receptor antagonist; IL-22: interleukin 22; IL-23: interleukin 23; IL23R: interleukin 23 receptor; IL-33: interleukin 33; IL-6: interleukin 6; IMP: inosine monophosphate; INSIG1: insulin-induced gene 1; JNK1: c-jun n-terminal kinase 1; lncRNA: long non-coding ribonucleic acid; LRR: leucine-rich repeats; miR: mature non-coding microRNAs measuring from 20 to 24 nucleotides, animal origin; miR-1: miR followed by arbitrary identification code; miR-145: miR followed by arbitrary identification code; miR-146a: miR followed by arbitrary identification code, "a" stands for mir family; "a" family presents similar mir sequence to "b" family, but different precursors; miR-20b: miR followed by arbitrary identification code; "b" stands for mir family; "b" family presents similar mir sequence to "a" family, but different precursors; miR-221: miR - followed by arbitrary identification code; miR-221-5p: miR followed by arbitrary identification code; "5p" indicates different mature miRNAs generated from the 5' arm of the pre-miRNA hairpin; miR-223: miR followed by arbitrary identification code; miR-223-3p: mir followed by arbitrary identification code; "3p" indicates different mature miRNAs generated from the 3' arm of the pre-miRNA hairpin; miR-22-3p: miR followed by arbitrary identification code, "3p" indicates different mature miRNAs generated from the 3' arm of the pre-miRNA hairpin; MLKL: mixed lineage kinase domain-like pseudo kinase; MM2P: inductor of m2-macrophage polarization; MSU: monosodium urate; mTOR: mammalian target of rapamycin; MyD88: myeloid differentiation primary response 88; n-3-PUFAs: n-3-polyunsaturated fatty-acids; NACHT: acronym for NAIP (neuronal apoptosis inhibitor protein), C2TA (MHC class 2 transcription activator), HET-E (incompatibility locus protein from podospora anserina) and TP1 (telomerase-associated protein); NAIP: neuronal apoptosis inhibitory protein (human); Naip1: neuronal apoptosis inhibitory protein type 1 (murine); Naip5: neuronal apoptosis inhibitory protein type 5 (murine); Naip6: neuronal apoptosis inhibitory protein type 6 (murine); NBD: nucleotide-binding domain; Nek7: smallest NIMA-related kinase; NET: neutrophil extracellular traps; Nf-κB: nuclear factor kappa-light-chain-enhancer of activated b cells; NFIL3: nuclear-factor, interleukin 3 regulated protein; NIIMA: network of immunity in infection, malignancy, and autoimmunity; NLR: nod-like receptor; NLRA: nod-like receptor NLRA containing acidic domain; NLRB: nod-like receptor NLRA containing BIR domain; NLRC: nod-like receptor NLRA containing CARD domain; NLRC4: nod-like receptor family CARD domain containing 4; NLRP: nod-like receptor NLRA containing PYD domain; NLRP1: nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 1; NLRP12: nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 12; NLRP3: nod-like receptor family pyrin domain containing 3; NOD2: nucleotide-binding oligomerization domain; NRBP1: nuclear receptor-binding protein; Nrf2: nuclear factor erythroid 2-related factor 2; OR: odds ratio; P2X: group of membrane ion channels activated by the binding of extracellular; P2X7: p2x purinoceptor 7 gene; p38: member of the mitogen-activated protein kinase family; PAMPs: pathogen associated molecular patters; PBMC: peripheral blood mononuclear cells; PGGT1B: geranylgeranyl transferase type-1 subunit beta; PHGDH: phosphoglycerate dehydrogenase; PI3-K: phospho-inositol; PPARγ: peroxisome proliferator-activated receptor gamma; PPARGC1B: peroxisome proliferative activated receptor, gamma, coactivator 1 beta; PR3: proteinase 3 antigen; Pro-CASP1: inactive precursor of caspase 1; Pro-IL1β: inactive precursor of interleukin 1 beta; PRR: pattern recognition receptors; PYD: pyrin domain; RAPTOR: regulatory associated protein of mTOR complex 1; RAS: renin-angiotensin system; REDD1: regulated in DNA damage and development 1; ROS: reactive oxygen species; rs000*G: single nuclear polymorphism, "*G" is related to snp where replaced nucleotide is guanine, usually preceded by an id number; SLC2A9: solute carrier family 2, member 9; SLC7A11: solute carrier family 7, member 11; SMA: smooth muscular atrophy; Smac: second mitochondrial-derived activator of caspases; SNP: single nuclear polymorphism; Sp3: specificity protein 3; ST2: serum stimulation-2; STK11: serine/threonine kinase 11; sUA: soluble uric acid; Syk: spleen tyrosine kinase; TAK1: transforming growth factor beta activated kinase; Th1: type 1 helper T cells; Th17: type 17 helper T cells; Th2: type 2 helper T cells; Th22: type 22 helper T cells; TLR: tool-like receptor; TLR2: toll-like receptor 2; TLR4: toll-like receptor 4; TNFα: tumor necrosis factor alpha; TNFR1: tumor necrosis factor receptor 1; TNFR2: tumor necrosis factor receptor 2; UA: uric acid; UBAP1: ubiquitin associated protein; ULT: urate-lowering therapy; URAT1: urate transporter 1; VDAC1: voltage-dependent anion-selective channel 1.
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Affiliation(s)
- Jordana Dinorá de Lima
- Microbiology, Parasitology and Pathology Program, Universidade Federal do Parana (UFPR), Curitiba, Brazil
| | | | - Bruna Sadae Yuasa
- Microbiology, Parasitology and Pathology Program, Universidade Federal do Parana (UFPR), Curitiba, Brazil
| | | | - Maria Clara da Cruz Silva
- Microbiology, Parasitology and Pathology Program, Universidade Federal do Parana (UFPR), Curitiba, Brazil
| | | | - Karin Braun Prado
- Genetics Program, Universidade Federal do Parana (UFPR), Curitiba, Brazil
| | - Angelica Beate Winter Boldt
- Program of Internal Medicine, Universidade Federal do Parana (UFPR), Curitiba, Brazil
- Genetics Program, Universidade Federal do Parana (UFPR), Curitiba, Brazil
| | - Tárcio Teodoro Braga
- Microbiology, Parasitology and Pathology Program, Universidade Federal do Parana (UFPR), Curitiba, Brazil
- Biosciences and Biotechnology Program, Instituto Carlos Chagas (ICC), Fiocruz-Parana, Brazil
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9
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Bai J, Qu Y, OuYang S, Jiao H, Wang Y, Li J, Huang W, Zhao Y, Peng X, Wang D, Jin Y, Wang H, Song F. Novel Alu-mediated deletions of the SMN1 gene were identified by ultra-long read sequencing technology in patients with spinal muscular atrophy. Neuromuscul Disord 2023; 33:382-390. [PMID: 37023488 DOI: 10.1016/j.nmd.2023.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 02/20/2023] [Accepted: 03/01/2023] [Indexed: 03/11/2023]
Abstract
Spinal muscular atrophy (SMA) is a neuromuscular disease caused by biallelic variants of the survival motor neuron 1 (SMN1) gene. In this study, our aim was to make a molecular diagnosis in two patients with SMA carrying only one SMN1 copy number. Using ultra-long read sequencing (Ultra-LRS), 1415 bp deletion and 3348 bp deletion of the SMN1 gene were identified in patient 1 and the father of patient 2, respectively. Ultra-LRS revealed two novel deletions, starting from the SMN1 promoter to intron 1. It also accurately provided the location of the deletion breakpoints in the SMN1 gene: chr5 g.70,924,798-70,926,212 for a 1415 bp deletion; chr5 g.70,922,695-70,926,042 for a 3348 bp deletion. By analyzing the breakpoint junctions, we identified that these genomic sequences were composed of Alu sequences, including AluJb, AluYm1, AluSq, and AluYm1, indicating that Alu-mediated rearrangements are a mechanism of SMN1 deletion events. In addition, full-length SMN1 transcripts and SMN protein in patient 1 were significantly decreased (p < 0.01), suggesting that a 1415 bp deletion that included the transcription and translation initiation sites of the SMN1 gene had severe consequences for SMN expression. Ultra-LRS can easily distinguish highly homozygous genes compared to other detection technologies, which is useful for detecting SMN1 intragenic mutations, to quickly discover structural rearrangements and to precisely present the breakpoint positions.
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10
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Li Y, Wang L, Tan J, Huang M, Wang Y, Shao B, Lv J, Zhang J. Current attitudes toward carrier screening for spinal muscular atrophy among pregnant women in Eastern China. J Genet Couns 2023. [PMID: 36775845 DOI: 10.1002/jgc4.1691] [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: 06/02/2022] [Revised: 01/05/2023] [Accepted: 01/28/2023] [Indexed: 02/14/2023]
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive and often fatal neurological disease. However, very little is known about the attitudes toward SMA carrier screening among Chinese pregnant people. In this study, pregnant women in Eastern China who were undergoing routine chromosomal screening programs were invited to view an educational video about SMA and complete a 26-item survey regarding their attitudes toward SMA screening by scanning a specific quick response code. A total of 1673 questionnaires were collected, and 81.1% of respondents were willing to undergo self-funded screening. If the screening program were included in the medical insurance, 97.8% of respondents were willing to accept screening. The important reasons for supporting SMA screening were a belief that it could help them make better reproductive decisions and avoid having a child with SMA. The key reason for declining SMA screening was not having a family history of genetic diseases. A higher score for SMA genetics knowledge was associated with a greater willingness to undergo SMA screening. We concluded that pregnant women in Eastern China had positive attitudes toward SMA carrier screening. Improving genetic knowledge and including the screening program in medical insurance would support the widespread implementation of SMA carrier screening. Steps should be taken to offer SMA carrier screening along with pre- and posttest education and genetic counseling to raise awareness and reduce misconceptions regarding SMA.
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Affiliation(s)
- Yerong Li
- Department of Prenatal diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Lulu Wang
- Department of Prenatal diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Jianxin Tan
- Department of Prenatal diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Mingtao Huang
- Department of Prenatal diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Yuguo Wang
- Department of Prenatal diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Binbin Shao
- Department of Prenatal diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Juan Lv
- Department of Gynecology, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Jingjing Zhang
- Department of Prenatal diagnosis, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
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11
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Guo W, Meng L, Cao L. Risk factors for recurrent respiratory tract infections and acute respiratory failure in children with spinal muscular atrophy. Pediatr Pulmonol 2023; 58:507-515. [PMID: 36367332 PMCID: PMC10098738 DOI: 10.1002/ppul.26218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 10/19/2022] [Accepted: 10/22/2022] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Assessment of and intervention for sleep-disordered breathing and malnutrition are related to the prevention of recurrent respiratory tract infections (RRTIs) and acute respiratory failure (ARF) in children with spinal muscular atrophy (SMA). However, specific standards for sleep-disordered breathing and malnutrition in the prevention of RRTIs and ARF have not been clarified. PURPOSE The study aimed to identify the risk factors and predictive indices for RRTIs and/or ARF in children with SMA. METHODS In this retrospective study, the differences in clinical characteristics between patients with and without RRTIs and ARF were compared, and binary logistic regression analysis was carried out. The optimal cutoff points for positive predictors were obtained. RESULTS SMA type 1 (odds ratio (OR) = 5.21, 95% confidence interval (CI) 1.50-18.17, p = 0.010) and the apnea-hypopnea index (AHI) (OR = 1.12, 95% CI 1.01-1.24, p = 0.026) were risk factors, while the body mass index z score (BMIz) (OR = 0.65, 95% CI 0.46-0.91, p = 0.013) and mean pulse oxygen saturation (MSpO2 ) (OR = 0.72, 95% CI 0.52-1.00, p = 0.049) were protective factors. A standard consisting of (i) MSpO2 < 96% and (ii) AHI > 10 events/h and/or BMIz < -1 predicted the occurrence of RRTIs and/or ARF in the next year with a sensitivity of 0.513 and a specificity of 0.957. CONCLUSION SMA type 1, BMIz, AHI and MSpO2 should be used to estimate the risk of RRTI and/or ARF in children with SMA. MSpO2 < 96% combined with AHI > 10 events/h or BMIz < -1 should be used as the intervention standard.
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Affiliation(s)
- Wenhui Guo
- Department of Pulmonology, Affiliated Children's HospitalCapital Institute of PediatricsBeijingChina
| | - Linghui Meng
- Center for Evidence‐Based MedicineCapital Institute of PediatricsBeijingChina
| | - Ling Cao
- Department of Pulmonology, Affiliated Children's HospitalCapital Institute of PediatricsBeijingChina
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12
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杨 东. Recent research on the treatment of spinal muscular atrophy. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2022; 24:204-209. [PMID: 35209987 PMCID: PMC8884051 DOI: 10.7499/j.issn.1008-8830.2110041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 12/20/2021] [Indexed: 01/24/2023]
Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease characterized by progressive muscular weakness and atrophy. SMA, as an inherited disease, is the leading cause of death in infants and young children. Rapid progress has been made in the research field of SMA in recent years, and some related treatment drugs have been successfully approved for marketing. This article reviews the recent research advances in the treatment of SMA.
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13
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Butchbach MER. Genomic Variability in the Survival Motor Neuron Genes ( SMN1 and SMN2): Implications for Spinal Muscular Atrophy Phenotype and Therapeutics Development. Int J Mol Sci 2021; 22:ijms22157896. [PMID: 34360669 PMCID: PMC8348669 DOI: 10.3390/ijms22157896] [Citation(s) in RCA: 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.
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Affiliation(s)
- Matthew E. R. Butchbach
- Center for Applied Clinical Genomics, Nemours Children’s Health Delaware, Wilmington, DE 19803, USA;
- Center for Pediatric Research, Nemours Children’s Health Delaware, Wilmington, DE 19803, USA
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
- Department of Pediatrics, Thomas Jefferson University, Philadelphia, PA 19107, USA
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14
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McMillan HJ, Kernohan KD, Yeh E, Amburgey K, Boyd J, Campbell C, Dowling JJ, Gonorazky H, Marcadier J, Tarnopolsky MA, Vajsar J, MacKenzie A, Chakraborty P. Newborn Screening for Spinal Muscular Atrophy: Ontario Testing and Follow-up Recommendations. Can J Neurol Sci 2021; 48:504-511. [PMID: 33059774 DOI: 10.1017/cjn.2020.229] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Spinal muscular atrophy (SMA) is characterized by the progressive loss of motor neurons causing muscle atrophy and weakness. Nusinersen, the first effective SMA therapy was approved by Health Canada in June 2017 and has been added to the provincial formulary of all but one Canadian province. Access to this effective therapy has triggered the inclusion of SMA in an increasing number of Newborn Screening (NBS) programs. However, the range of disease-modifying SMN2 gene copy numbers encountered in survival motor neuron 1 (SMN1)-null individuals means that neither screen-positive definition nor resulting treatment decisions can be determined by SMN1 genotype alone. We outline an approach to this challenge, one that specifically addresses the case of SMA newborns with four copies of SMN2. OBJECTIVES To develop a standardized post-referral evaluation pathway for babies with a positive SMA NBS screen result. METHODS An SMA NBS pilot trial in Ontario using first-tier MassARRAY and second-tier multi-ligand probe amplification (MLPA) was launched in January 2020. Prior to this, Ontario pediatric neuromuscular disease and NBS experts met to review the evidence regarding the diagnosis and treatment of children with SMA as it pertained to NBS. A post-referral evaluation algorithm was developed, outlining timelines for patient retrieval and management. CONCLUSIONS Ontario's pilot NBS program has created a standardized path to facilitate early diagnosis of SMA and initiation of treatment. The goal is to provide timely access to those SMA infants in need of therapy to optimize motor function and prolong survival.
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Affiliation(s)
- Hugh J McMillan
- Children's Hospital of Eastern Ontario Research Institute, Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada
| | - Kristin D Kernohan
- Children's Hospital of Eastern Ontario Research Institute, Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada
- Newborn Screening Ontario, Ottawa, Ontario, Canada
| | - Ed Yeh
- Children's Hospital of Eastern Ontario Research Institute, Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada
- Newborn Screening Ontario, Ottawa, Ontario, Canada
| | - Kim Amburgey
- Hospital for Sick Children, Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Jennifer Boyd
- Hospital for Sick Children, Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Craig Campbell
- Children's Hospital Western Ontario, Department of Pediatrics, Epidemiology and Clinical Neurological Sciences, Schulich School of Medicine, University of Western Ontario, London, Ontario, Canada
| | - James J Dowling
- Hospital for Sick Children, Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Hernan Gonorazky
- Hospital for Sick Children, Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | | | - Mark A Tarnopolsky
- McMaster Children's Hospital, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Jiri Vajsar
- Hospital for Sick Children, Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Alex MacKenzie
- Children's Hospital of Eastern Ontario Research Institute, Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada
| | - Pranesh Chakraborty
- Children's Hospital of Eastern Ontario Research Institute, Department of Pediatrics, University of Ottawa, Ottawa, Ontario, Canada
- Newborn Screening Ontario, Ottawa, Ontario, Canada
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15
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Baranello G, Gorni K, Daigl M, Kotzeva A, Evans R, Hawkins N, Scott DA, Mahajan A, Muntoni F, Servais L. Prognostic Factors and Treatment-Effect Modifiers in Spinal Muscular Atrophy. Clin Pharmacol Ther 2021; 110:1435-1454. [PMID: 33792051 PMCID: PMC9292571 DOI: 10.1002/cpt.2247] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/21/2021] [Indexed: 12/20/2022]
Abstract
Spinal muscular atrophy (SMA) is a rare, progressive neuromuscular disease characterized by loss of motor neurons and muscle atrophy. Untreated infants with type 1 SMA do not achieve major motor milestones, and death from respiratory failure typically occurs before 2 years of age. Individuals with types 2 and 3 SMA exhibit milder phenotypes and have better functional and survival outcomes. Herein, a systematic literature review was conducted to identify factors that influence the prognosis of types 1, 2, and 3 SMA. In untreated infants with type 1 SMA, absence of symptoms at birth, a later symptom onset, and a higher survival of motor neuron 2 (SMN2) copy number are all associated with increased survival. Disease duration, age at treatment initiation, and, to a lesser extent, baseline function were identified as potential treatment‐modifying factors for survival, emphasizing that early treatment with disease‐modifying therapies (DMT) is essential in type 1 SMA. In patients with types 2 and 3 SMA, factors considered prognostic of changes in motor function were SMN2 copy number, age, and ambulatory status. Individuals aged 6–15 years were particularly vulnerable to developing complications (scoliosis and progressive joint contractures) which negatively influence functional outcomes and may also affect the therapeutic response in patients. Age at the time of treatment initiation emerged as a treatment‐effect modifier on the outcome of DMTs. Factors identified in this review should be considered prior to designing or analyzing studies in an SMA population, conducting population matching, or summarizing results from different studies on the treatments for SMA.
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Affiliation(s)
- Giovanni Baranello
- Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health, London, United Kingdom.,Developmental Neurology Unit, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Istituto Neurologico Carlo Besta, Milan, Italy
| | | | | | | | | | | | | | | | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health, London, United Kingdom.,National Institute for Health Research Biomedical Research Centre, University College of London Great Ormond Street Institute of Child Health, Great Ormond Street Hospital National Health Service Trust, London, UK
| | - Laurent Servais
- Division of Child Neurology Reference Center for Neuromuscular Disease, Department of Pediatrics, Centre Hospitalier Régional de Références des Maladies Neuromusculaires, University Hospital Liège & University of La Citadelle, Liège, Belgium.,Department of Paediatrics, Muscular Dystrophy UK Oxford Neuromuscular Centre, University of Oxford, Oxford, UK
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16
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Zhang J, Wang Y, Ma D, Sun Y, Li Y, Yang P, Luo C, Jiang T, Hu P, Xu Z. Carrier Screening and Prenatal Diagnosis for Spinal Muscular Atrophy in 13,069 Chinese Pregnant Women. J Mol Diagn 2020; 22:817-822. [PMID: 32205292 DOI: 10.1016/j.jmoldx.2020.03.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/17/2020] [Accepted: 03/11/2020] [Indexed: 10/24/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a relatively common, life-shortening, autosomal recessive neuromuscular disease. The carrier frequency of SMA ranges from approximately 0.98% to 2.02%, depending on ethnicity. The American College of Medical Genetics has therefore recommended population screening for SMA carrier status, regardless of race or ethnicity. We performed the largest-scale carrier screening for SMA carriers in mainland China. Carrier screening was offered to 36,470 pregnant women between July 2017 and June 2019, of whom 13,069 women accepted the screening program [35.83%; 95% credibility interval (CI), 35.34%-36.33%]. Copy numbers of exons 7 and 8 in the SMN1 gene were detected by real-time quantitative PCR, and the results were confirmed by multiplex ligation-dependent probe amplification. A total of 231 women were identified as carriers (1.77%; 95% CI, 1.56%-2.01%), indicating a carrier prevalence of approximately 1:56 in the population. After detailed genetic counseling, 207 paternal partners were recalled and tested. Both partners were carriers in 10 couples, of whom prenatal diagnosis was implemented in seven, and one fetus was diagnosed with SMA. Carrier screening could provide couples with informed reproductive choices. Our workflow and experience of carrier screening may facilitate the popularization of SMA carrier screening in mainland China.
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Affiliation(s)
- Jingjing Zhang
- Department of Prenatal Diagnosis, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, People's Republic of China
| | - Yuguo Wang
- Department of Prenatal Diagnosis, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, People's Republic of China
| | - Dingyuan Ma
- Department of Prenatal Diagnosis, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, People's Republic of China
| | - Yun Sun
- Department of Prenatal Diagnosis, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, People's Republic of China
| | - Yahong Li
- Department of Prenatal Diagnosis, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, People's Republic of China
| | - Peiying Yang
- Department of Prenatal Diagnosis, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, People's Republic of China
| | - Chunyu Luo
- Department of Prenatal Diagnosis, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, People's Republic of China
| | - Tao Jiang
- Department of Prenatal Diagnosis, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, People's Republic of China
| | - Ping Hu
- Department of Prenatal Diagnosis, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, People's Republic of China.
| | - Zhengfeng Xu
- Department of Prenatal Diagnosis, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, People's Republic of China
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17
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Finkel RS, Day JW, De Vivo DC, Kirschner J, Mercuri E, Muntoni F, Shieh PB, Tizzano E, Desguerre I, Quijano-Roy S, Saito K, Droege M, Dabbous O, Khan F, Renault L, Anderson FA, Servais L. RESTORE: A Prospective Multinational Registry of Patients with Genetically Confirmed Spinal Muscular Atrophy - Rationale and Study Design. J Neuromuscul Dis 2020; 7:145-152. [PMID: 32039859 PMCID: PMC7739962 DOI: 10.3233/jnd-190451] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Background: Dramatic improvements in spinal muscular atrophy (SMA) treatment have changed the prognosis for patients with this disease, leading to important new questions. Gathering representative, real-world data about the long-term efficacy and safety of emerging SMA interventions is essential to document their impact on patients and caregivers. Objectives: This registry will assess outcomes in patients with genetically confirmed SMA and provide information on the effectiveness and long-term safety of approved and emerging treatments. Design and Methods: RESTORE is a prospective, multicenter, multinational observational registry. Patients will be managed according to usual clinical practice. Both newly recruitedSMAtreatment centers and sites involved in existing SMA registries, including iSMAC, Treat-NMD, French SMA Assistance Publique- Hôpitaux de Paris (AP-HP), Cure-SMA, SMArtCARE, will be eligible to participate; de novo; sites already participating in another registry may be included via consortium agreements. Data from patients enrolled in partnering registries will be shared with the RESTORE Registry and data for newly diagnosed patients will be added upon enrollment. Patients will be enrolled over a 5-year period and followed for 15 years or until death. Assessments will include SMA history and treatment, pulmonary, nutritional, and motor milestones, healthcare resource utilization, work productivity, activity impairment, adverse events, quality of life, caregiver burden, and survival. Status: Recruitment started in September 2018. As of January 3, 2020, 64 patients were enrolled at 25 participating sites. Conclusions: The RESTORE Registry has begun recruiting recently diagnosed patients with genetically confirmed SMA, enabling assessment of both short- and long-term patient outcomes.
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Affiliation(s)
- Richard S Finkel
- Department of Pediatrics, Division of Neurology, Nemours Children's Hospital, Orlando, FL, United States
| | - John W Day
- Department of Neurology, Stanford University Medical Center, Stanford, CA, United States
| | - Darryl C De Vivo
- Departments of Neurology and Pediatrics, Columbia University Irving Medical Center, New York, NY, United States
| | - Janbernd Kirschner
- Clinic for Neuropediatrics and Muscle Disease, University Medical Center Freiburg, Freiburg, Germany
| | - Eugenio Mercuri
- Department of Paediatric Neurology and Nemo Clinical Centre, Catholic University, Rome, Italy
| | - Francesco Muntoni
- Department of Developmental Neuroscience, University College London, London, UK
| | - Perry B Shieh
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Eduardo Tizzano
- Department of Clinical and Molecular Genetics, Hospital Valle Hebron, Barcelona, Spain
| | | | - Susana Quijano-Roy
- Garches Neuromuscular Reference Center (GNMH), APHP Raymond Poincare University Hospital (UVSQ), Garches, France
| | - Kayoko Saito
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo, Japan
| | | | | | - Farid Khan
- AveXis, Inc., Bannockburn, IL, United States
| | | | - Frederick A Anderson
- Center for Outcomes Research, University of Massachusetts Medical School, Worcester, MA, United States
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18
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Hassan HA, Zaki MS, Issa MY, El-Bagoury NM, Essawi ML. Genetic pattern of SMN1, SMN2, and NAIP genes in prognosis of SMA patients. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2020. [DOI: 10.1186/s43042-019-0044-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Spinal muscular atrophy (SMA) is the most common autosomal recessive disorder in humans after cystic fibrosis. It is classified into five clinical grades based on age of onset and severity of the disease. Although SMN1 was identified as the SMA disease-determining gene, modifier genes mapped to 5q13 were affirmed to play a crucial role in determination of disease severity and used as a target for SMA therapy. In this study, we determined SMN2 copy number and NAIP deletion status in SMA Egyptian patients with different clinical phenotypes and had homozygous deletion of SMN1. We aimed at finding a prognostic genetic pattern including SMN1, SMN2, and NAIP gene genotypes to determine the clinical SMA type of the patient to help in genetic counseling and prenatal diagnosis.
Results
Copy number variations (CNVs) of exon 7 of SMN2 gene were significantly decreased with the increase in disease severity. Homozygous deletion of exon 5 of NAIP was detected in 60% (12/20) of type I SMA and in 73% (8/11) of type III SMA cases. Combining the data of the SMN2 and NAIP genes showed 8 genotypes. Patients with D2 genotype (0 copies of NAIP and 2 copies of SMN2) were likely to have type I SMA. Type II SMA patients mostly had no homozygous deletion of NAIP and 2 copies of SMN2. However, patients with N3 genotype (> 1 copy of NAIP and 3 copies of SMN2) and patients with D3 genotype (0 copies of NAIP and > 3 copies of SMN2) had type III SMA.
Conclusion
SMN2 and NAIP are the most important modifier genes whose copy numbers can affect the severity of SMA. We concluded that the combination of modifier genes to provide prognostic genetic pattern for phenotype determination is preferable than using CNVs of exon 7 of SMN2 gene only. CNVs of exon 7 of SMN2 are of high importance to predict patients’ response to genetic therapy. On the other hand, deletion of exon5 of NAIP gene alone is not a sufficient predictor of SMA severity.
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19
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Zhang Y, He J, Zhang Y, Li L, Tang X, Wang L, Guo J, Jin C, Tighe S, Zhang Y, Zhu Y, Zhu B. The analysis of the association between the copy numbers of survival motor neuron gene 2 and neuronal apoptosis inhibitory protein genes and the clinical phenotypes in 40 patients with spinal muscular atrophy: Observational study. Medicine (Baltimore) 2020; 99:e18809. [PMID: 32011487 PMCID: PMC7220227 DOI: 10.1097/md.0000000000018809] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In this article, the correlation between the copy number of survival motor neuron 2 (SMN2) gene, neuronal apoptosis inhibitory protein (NAIP), and the phenotype of spinal muscular atrophy patients were analyzed.Forty patients with spinal muscular atrophy (SMA) were included in the study at the Department of Medical Genetics of the First People's Hospital and the Department of Neurology of the Second People's Hospital in Yunnan Province from January 2012 to September 2018. Multiplex ligation-dependent probe amplification assay was performed to determine the copy numbers of SMN2 and NAIP genes. Statistical analysis was performed to determine the correlation between copy numbers of the SMN2 and NAIP genes and the clinical phenotypes of SMA.Our results show that among the 40 SMA patients, there were 13 type I cases, 16 type II cases and 11 type III cases. A total of 37 patients possessed a homozygous deletion of SMN1 exons 7 and 8, while the other 3 SMA patients possessed a single copy of SMN1 exon 8. There was no correlation between SMA subtypes and the deletion types of SMN1 exon 7 and 8 (P = .611). The percentage of 2, 3, and 4 copies of SMN2 exon 7 was 25.0%, 62.5%, and 12.5%, respectively. The percentage of 0, 1, and 2 copies of NAIP exon 5 was 10%, 57.5%, and 32.5%, respectively. The distributions of SMN2 and NAIP copy numbers among various SMA types were significantly different (all P < .05). Five combined SMN1-SMN2-NAIP genotypes were detected, of which 0-3-1 genotype had the highest proportion than the others, accounting for 42.5%. The copy number of SMN2 and NAIP gene had synergistic effect on SMA phenotype. The combined SMN1-SMN2-NAIP genotypes with fewer copies were associated with earlier onset age, higher mortality, and smaller average age at death in SMA patients.Therefore, we conclude that the copy number variance of SMN2 and NAIP is correlated with the SMA phenotype. Analysis of the copy number structure of the SMN1-SMN2-NAIP gene is helpful for SMA typing, disease prognosis prediction, and genetic counseling.
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Affiliation(s)
- Yinhong Zhang
- Department of Medical Genetics, The First People's Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology
- Faculty of Life Science and Biotechnology, Kunming University of Science and Technology
| | - Jing He
- Department of Medical Genetics, The First People's Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology
| | - Yunqian Zhang
- Department of Neurology, The Second People's Hospital of Yunnan Province
| | - Li Li
- Faculty of Life Science and Biotechnology, Kunming University of Science and Technology
- Department of Pediatrics, The First People's Hospital of Yunnan Province, Kunming, Yunnan, China
| | - Xinhua Tang
- Department of Medical Genetics, The First People's Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology
| | - Lei Wang
- Department of Medical Genetics, The First People's Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology
| | - Jingjing Guo
- Department of Medical Genetics, The First People's Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology
| | - Chanchan Jin
- Department of Medical Genetics, The First People's Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology
| | - Sean Tighe
- Tissue Tech, Inc., Ocular Surface Center, and Ocular Surface Research & Education Foundation, Miami, FL
| | - Yuan Zhang
- Tissue Tech, Inc., Ocular Surface Center, and Ocular Surface Research & Education Foundation, Miami, FL
| | - Yingting Zhu
- Tissue Tech, Inc., Ocular Surface Center, and Ocular Surface Research & Education Foundation, Miami, FL
| | - Baosheng Zhu
- Department of Medical Genetics, The First People's Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology
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20
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Zhang YH, Zhang YQ, Zhu BS, He J, Wang L, Tang XH, Guo JJ, Jin CC, Chen H, Zhang J, Zhang JM, Li L. [Association of copy number of SMN1 and SMN2 with clinical phenotypes in children with spinal muscular atrophy]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2019; 21:239-243. [PMID: 30907347 PMCID: PMC7389366 DOI: 10.7499/j.issn.1008-8830.2019.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/10/2019] [Indexed: 06/09/2023]
Abstract
OBJECTIVE To study the association of copy number of SMN1 and SMN2 with clinical phenotypes in children with spinal muscular atrophy (SMA). METHODS A total of 45 children with SMA were enrolled. Multiplex ligation-dependent probe amplification was used to measure the gene copy numbers of SMN1 and SMN2. The association of copy number of SMN1 and SMN2 with clinical phenotypes was analyzed. RESULTS Of the 45 children with SMA, 42 (93%) had a homozygous deletion of SMN1 exons 7 and 8, and 3 (7%) had a deletion of SMN1 exon 7 alone. No association was found between SMA clinical types and the deletion types of SMN1 exons 7 and 8 (P>0.05). There was a significant difference in the distribution of SMN2 gene copy numbers between the children with SMA and the healthy children (P<0.05). The children with SMA usually had two or three copies of SMN2 gene, while the healthy children usually had one or two copies of SMN2 gene. There was a significant difference in the distribution of SMN2 copy numbers among the children with different SMA clinical types (P<0.05). The children with two copies of SMN2 gene had a significantly lower age of onset than those with three or four copies. Most of the children with type I SMA had two or three copies of SMN2 gene. Most of the children with type II SMA had three copies of SMN2 gene. Most of the children with type III SMA had three or four copies of SMN2 gene. Children with a higher copy number of SMN2 gene tended to have an older age of onset and better motor function and clinical outcome, and there was a significant association between SMN2 gene copy number and clinical outcome (P<0.05). CONCLUSIONS The SMN2 gene can reduce the severity of SMA via the dosage compensation effect. SMN2 copy number is associated with the phenotype of SMA, and therefore, it can be used to predict disease severity.
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Affiliation(s)
- Yin-Hong Zhang
- Genetic Diagnosis Center, Affiliated Hospital of Kunming University of Science and Technology, Kunming 650032, China.
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21
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Bai J, Qu Y, Cao Y, Yang L, Ge L, Jin Y, Wang H, Song F. The SMN1 common variant c.22 dupA in Chinese patients causes spinal muscular atrophy by nonsense-mediated mRNA decay in humans. Gene 2017; 644:49-55. [PMID: 29080838 DOI: 10.1016/j.gene.2017.10.048] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 09/28/2017] [Accepted: 10/16/2017] [Indexed: 11/18/2022]
Abstract
Spinal muscular atrophy (SMA) is a common autosomal recessive neuromuscular disorder that is mostly caused by homozygous deletion of the SMN1 gene. Approximately 5%-10% of SMA patients are believed to have SMN1 variants. c.22 dupA (p.Ser8lysfs*23) has been identified as the most frequent variant in the Chinese SMA population and to be associated with a severe phenotype. However, the exact molecular mechanism of the variant on the pathogenesis of SMA is unclear. We observed that SMN1 mRNA and the SMN protein in the peripheral blood cells of a patient with c.22 dupA were lower than those of controls. The aim of this study is to investigate whether nonsense-mediated mRNA decay (NMD) plays a role in the mechanism of the c.22 dupA variant of the SMN1 gene as it causes SMA. Two lymphoblasts cell lines from two patients (patient 1 and 2) with the c.22 dupA, and one dermal fibroblasts cell line from patient 2 were included in our study. Two-stage validation of the NMD mechanism was supplied. We first measured the changes in the transcript levels of the SMN1 gene by real-time quantitative PCR after immortalized B-lymphoblasts and dermal fibroblasts cells of the SMA patients were treated with inhibitors of the NMD pathway, including puromycin and cyclohemide. Next, lentivirus-mediated knockdown of the key NMD factor-Up-frameshift protein 1 (UPF1)-was performed in the fibroblasts cell line to further clarify whether the variant led to NMD, as UPF1 recognizes abnormally terminated transcripts as NMD substrates during translation. SC35 1.7-kb transcripts, a physiological NMD substrate was determined to be a NMD positive gene in our experiments. The two inhibitors resulted in a dramatic escalation of the levels of the full-length SMN1 (fl-SMN1) transcripts. Additionally, the SC35 1.7-kb mRNA levels were also increased, suggesting that NMD pathway is suppressed by the two inhibitors. For the 3 cell lines, the fold increase of the SMN1 transcript levels of cycloheximide ranged from 2.5±0.4 to 8.3±0.1, 1.9±0.2 to 5.0±0.7 and 2.2±0.1 to 4.9±0.2 for two lymphoblastoid cell lines and one fibroblasts cell line, respectively. For these cell lines, the fold increases of the SMN1 transcript levels of puromycin were as follows: 5.5±0.2 to 19.5±4.0, 3.1±0.3 to 9.9±1.8 and 1.5±0.2 to 6.5±0.5. Meanwhile, the SC35 1.7-kb transcript levels were markedly increased in all 3 cell lines. In addition, lentivirus-mediated UPF1 knockdown lead to a reduction of the UPF1 protein level to 22.5% compared to the negative control lentivirus. Additionally, knockdown of the UPF1 gene also promoted mRNA expression of the SC35 1.7kb and fl-SMN1 genes. The increases of the SMN1 and SC35 1.7-kb mRNA levels reached about 4- and 6.5-fold in fibroblasts derived from the patient 2, respectively. Altogether, our study provides the first evidence that the c.22 dupA variant in the SMN1 gene triggers NMD. SMA pathogenesis in the patient is associated with mRNA degradation of SMN1, but not the truncated SMN protein.
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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
| | - YanYan Cao
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing 100020, China
| | - Lan Yang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing 100020, China
| | - Lin Ge
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing 100020, China
| | - YuWei Jin
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing 100020, China
| | - Hong Wang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing 100020, China
| | - Fang Song
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing 100020, China.
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22
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Ahn EJ, Yum MS, Kim EH, Yoo HW, Lee BH, Kim GH, Ko TS. Genotype-Phenotype Correlation of SMN1 and NAIP Deletions in Korean Patients with Spinal Muscular Atrophy. J Clin Neurol 2016; 13:27-31. [PMID: 27730768 PMCID: PMC5242148 DOI: 10.3988/jcn.2017.13.1.27] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 06/02/2016] [Accepted: 06/02/2016] [Indexed: 01/27/2023] Open
Abstract
Background and Purpose Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease characterized by progressive muscle weakness and atrophy. Most SMA patients have a homozygous deletion in survival of motor neuron 1 (SMN1) gene, and neuronal apoptosis inhibitory protein (NAIP) gene is considered a phenotype modifier. We investigated the genotype-phenotype correlation of SMN1 and NAIP deletions in Korean SMA patients. Methods Thirty-three patients (12 males and 21 females) treated at the Asan Medical Center between 1999 and 2013 were analyzed retrospectively. The polymerase chain reaction (PCR), restriction-fragment-length polymorphism analysis, and multiplex PCR were used to detect deletions in SMN1 (exons 7 and 8) and NAIP (exons 4 and 5). We reviewed clinical presentations and outcomes and categorized the patients into three clinical types. NAIP deletion-driven differences between the two genotypes were analyzed. Results Deletion analysis identified homozygous deletions of SMN1 exons 7 and 8 in 30 patients (90.9%). Among these, compared with patients without an NAIP deletion, those with an NAIP deletion showed a significantly lower age at symptom onset (1.9±1.7 months vs. 18.4±20.4 months, mean±SD; p=0.007), more frequent type 1 phenotype (6/6 vs. 8/24, p=0.005), and worse outcomes, with early death or a requirement for ventilator support (4/4 vs. 2/12, p=0.008). Conclusions Homozygous deletion in SMN1 and a concurrent NAIP deletion were associated with an early onset, severe hypotonia, and worse outcome in SMA patients. Deletion analysis of NAIP and SMN1 can help to accurately predict prognostic outcomes in SMA.
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Affiliation(s)
- Eun Ji Ahn
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea
| | - Mi Sun Yum
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea
| | - Eun Hee Kim
- Department of Pediatrics, CHA Gangnam Medical Center, CHA University, Seoul, Korea
| | - Han Wook Yoo
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea.,Department of Medical Genetics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea
| | - Beom Hee Lee
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea.,Department of Medical Genetics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea
| | - Gu Hwan Kim
- Department of Medical Genetics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea
| | - Tae Sung Ko
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea.
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23
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Liu Z, Zhang P, He X, Liu S, Tang S, Zhang R, Wang X, Tan J, Peng B, Jiang L, Hong S, Zou L. New multiplex real-time PCR approach to detect gene mutations for spinal muscular atrophy. BMC Neurol 2016; 16:141. [PMID: 27534852 PMCID: PMC4989483 DOI: 10.1186/s12883-016-0651-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 07/29/2016] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Spinal muscular atrophy (SMA) is the most common autosomal recessive disease in children, and the diagnosis is complicated and difficult, especially at early stage. Early diagnosis of SMA is able to improve the outcome of SMA patients. In our study, Real-time PCR was developed to measure the gene mutation or deletion of key genes for SMA and to further analyse genotype-phenotype correlation. METHODS The multiple real-time PCR for detecting the mutations of survival of motor neuron (SMN), apoptosis inhibitory protein (NAIP) and general transcription factor IIH, polypeptide 2 gene (GTF2H2) was established and confirmed by DNA sequencing and multiplex ligation-dependent probe amplification (MLPA). The diagnosis and prognosis of 141 hospitalized children, 100 normal children and further 2000 cases of dry blood spot (DBS) samples were analysed by this multiple real-time PCR. RESULTS The multiple real-time PCR was established and the accuracy of it to detect the mutations of SMN, NAIP and GTF2H2 was at least 98.8 % comparing with DNA sequencing and MLPA. Among 141 limb movement disorders children, 75 cases were SMA. 71 cases of SMA (94.67 %) were with SMN c.840 mutation, 9 cases (12 %) with NAIP deletion and 3 cases (4 %) with GTF2H2 deletion. The multiple real-time PCR was able to diagnose and predict the prognosis of SMA patients. Simultaneously, the real-time PCR was applied to detect trace DNA from DBS and able to make an early diagnosis of SMA. CONCLUSION The clinical and molecular characteristics of SMA in Southwest of China were presented. Our work provides a novel way for detecting SMA in children by using real-time PCR and the potential usage in newborn screening for early diagnosis of SMA.
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Affiliation(s)
- Zhidai Liu
- Center for Clinical Molecular Medicine, Children's Hospital, Chongqing Medical University, 136 Zhongshan Er Road, Yuzhong District, Chongqing, 400014, China.,Ministry of Education Key Laboratory of Development and Disorders, Children's Hospital, Chongqing Medical University, Yuzhong District, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Children's Hospital, Chongqing Medical University, Chongqing, China
| | - Penghui Zhang
- Center for Clinical Laboratory, Children's Hospital, Chongqing Medical University, Yuzhong District, Chongqing, China.,Ministry of Education Key Laboratory of Development and Disorders, Children's Hospital, Chongqing Medical University, Yuzhong District, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Children's Hospital, Chongqing Medical University, Chongqing, China
| | - Xiaoyan He
- Center for Clinical Molecular Medicine, Children's Hospital, Chongqing Medical University, 136 Zhongshan Er Road, Yuzhong District, Chongqing, 400014, China.,Ministry of Education Key Laboratory of Development and Disorders, Children's Hospital, Chongqing Medical University, Yuzhong District, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Children's Hospital, Chongqing Medical University, Chongqing, China
| | - Shan Liu
- Center for Clinical Molecular Medicine, Children's Hospital, Chongqing Medical University, 136 Zhongshan Er Road, Yuzhong District, Chongqing, 400014, China.,Ministry of Education Key Laboratory of Development and Disorders, Children's Hospital, Chongqing Medical University, Yuzhong District, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Children's Hospital, Chongqing Medical University, Chongqing, China
| | - Shi Tang
- Center for Clinical Molecular Medicine, Children's Hospital, Chongqing Medical University, 136 Zhongshan Er Road, Yuzhong District, Chongqing, 400014, China.,Ministry of Education Key Laboratory of Development and Disorders, Children's Hospital, Chongqing Medical University, Yuzhong District, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Children's Hospital, Chongqing Medical University, Chongqing, China
| | - Rong Zhang
- Center for Clinical Molecular Medicine, Children's Hospital, Chongqing Medical University, 136 Zhongshan Er Road, Yuzhong District, Chongqing, 400014, China.,Ministry of Education Key Laboratory of Development and Disorders, Children's Hospital, Chongqing Medical University, Yuzhong District, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Children's Hospital, Chongqing Medical University, Chongqing, China
| | - Xinbin Wang
- Center for Clinical Molecular Medicine, Children's Hospital, Chongqing Medical University, 136 Zhongshan Er Road, Yuzhong District, Chongqing, 400014, China.,Ministry of Education Key Laboratory of Development and Disorders, Children's Hospital, Chongqing Medical University, Yuzhong District, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Children's Hospital, Chongqing Medical University, Chongqing, China
| | - Junjie Tan
- Center for Clinical Molecular Medicine, Children's Hospital, Chongqing Medical University, 136 Zhongshan Er Road, Yuzhong District, Chongqing, 400014, China.,Ministry of Education Key Laboratory of Development and Disorders, Children's Hospital, Chongqing Medical University, Yuzhong District, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Children's Hospital, Chongqing Medical University, Chongqing, China
| | - Bin Peng
- Department of Health Statistics, School of Public Health, Chongqing Medical University, Yuzhong District, Chongqing, China
| | - Li Jiang
- Department of Neurology, Children's Hospital, Chongqing Medical University, Yuzhong District, Chongqing, China.,Ministry of Education Key Laboratory of Development and Disorders, Children's Hospital, Chongqing Medical University, Yuzhong District, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Children's Hospital, Chongqing Medical University, Chongqing, China
| | - Siqi Hong
- Department of Neurology, Children's Hospital, Chongqing Medical University, Yuzhong District, Chongqing, China.,Ministry of Education Key Laboratory of Development and Disorders, Children's Hospital, Chongqing Medical University, Yuzhong District, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Children's Hospital, Chongqing Medical University, Chongqing, China
| | - Lin Zou
- Center for Clinical Molecular Medicine, Children's Hospital, Chongqing Medical University, 136 Zhongshan Er Road, Yuzhong District, Chongqing, 400014, China. .,Ministry of Education Key Laboratory of Development and Disorders, Children's Hospital, Chongqing Medical University, Yuzhong District, Chongqing, China. .,Key Laboratory of Pediatrics in Chongqing, Children's Hospital, Chongqing Medical University, Chongqing, China.
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24
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Qu YJ, Bai JL, Cao YY, Wang H, Jin YW, Du J, Ge XS, Zhang WH, Li Y, He SX, Song F. Mutation Spectrum of the Survival of Motor Neuron 1 and Functional Analysis of Variants in Chinese Spinal Muscular Atrophy. J Mol Diagn 2016; 18:741-752. [PMID: 27425821 DOI: 10.1016/j.jmoldx.2016.05.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Revised: 04/22/2016] [Accepted: 05/10/2016] [Indexed: 11/28/2022] Open
Abstract
Proximal spinal muscular atrophy (SMA) is a common fatal autosomal recessive disorder caused by deletion or mutation of the survival of motor neuron 1 (SMN1). Here, we studied SMA molecular pathology in 653 Chinese patients and found approximately 88.2% with homozygous SMN1 exon 7 deletion and 6.3% with heterozygous exon 7 loss using multiplex ligation-dependent probe amplification. SMN1 variants were detected in 34 patients with heterozygous SMN1 loss by clone sequencing. In 27 of them, 15 variants were identified: five were unreported novel variants [c.-7_9del(p.0), p.Tyr109Cys, p.Ile249Tyrfs*16, p.Tyr272Trpfs*35, and c.835-5T>G], five were previously found only in Chinese patients (p.Ser8Lysfs*23, p.Gln14*, p.Val19Glyfs*21, p.Leu228*, and p.Tyr277Cys), and five were reported in other populations [p.Ala2Gly, p.Gln15*, p.Glu134Lys, p.Ser230Leu, and c.863G>T (r.835_*3del, p.Gly279Glufs*5)]. Variants p.Ser8Lysfs*23 and p.Leu228* were the most common in Chinese SMA. Five variants (p.Ser8Lysfs*23, p.Gln14*, p.Gln15*, p.Val19Glyfs*21, and p.Leu228*) resulted in premature stop codons, likely causing SMN1 mRNA nonsense-mediated decay. The novel variant c.-7_9del (p.0) caused deletion of the translation start codon (AUG), resulting in full-length SMN protein loss. The novel variant c.835-5T>G, located in a splice site, resulted in 90% exon 7 skipping. Our study could facilitate early diagnosis for SMA patients in mutation detection and revealed the specific mutation spectrum of SMN1 in Chinese SMA and high genetic heterogeneity in subtle variants observed between patients from China and Caucasians.
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Affiliation(s)
- Yu-Jin Qu
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Jin-Li Bai
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Yan-Yan Cao
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Hong Wang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Yu-Wei Jin
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Juan Du
- Children's Hospital Affiliated Capital Institute of Pediatrics, Beijing, China
| | - Xiu-Shan Ge
- Children's Hospital Affiliated Capital Institute of Pediatrics, Beijing, China
| | - Wen-Hui Zhang
- Children's Hospital Affiliated Capital Institute of Pediatrics, Beijing, China
| | - Yan Li
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Sheng-Xi He
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Fang Song
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China.
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Qu YJ, Bai JL, Cao YY, Zhang WH, Wang H, Jin YW, Song F. A rare variant (c.863G>T) in exon 7 of SMN1 disrupts mRNA splicing and is responsible for spinal muscular atrophy. Eur J Hum Genet 2016; 24:864-70. [PMID: 26419278 PMCID: PMC4867452 DOI: 10.1038/ejhg.2015.213] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 08/10/2015] [Accepted: 08/25/2015] [Indexed: 11/08/2022] Open
Abstract
Proximal spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder caused by deletion or mutation of SMN1 (survival motor neuron 1). SMN exon 7 splicing is regulated by a number of exonic and intronic regulatory sequences and the trans-factors that bind them. Variants located in or near these regulated regions should be evaluated to determine their effect on splicing. We identified the rare variant c.863G>T (r.835_*3del, p.Gly279Glufs*5) in exon 7 of SMN1 in three patients affected with type I or type II SMA. Most of the SMN1 transcripts exhibited complete loss of exon 7 in vivo. The ex vivo splicing assay demonstrated that the variant disrupts inclusion of exon 7 (~85%) in the SMN1 mRNA; replacement with various bases yielded a variety of splicing effects in SMN1 and SMN2 pre-mRNA. The c.863G>T (r.835_*3del, p.Gly279Glufs*5) variant is located in a region that includes binding sites for multiple splicing factors including Tra2β1. Thus, the variant disrupts Tra2β1 binding, but does not affect binding of hnRNP A1. These findings demonstrate how rare variants influence pre-mRNA splicing of SMN and reveal the functional influence of c.863G>T (r.835_*3del, p.Gly279Glufs*5) variant in patients with SMA.
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Affiliation(s)
- Yu-jin Qu
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, P.R. China
| | - Jin-li Bai
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, P.R. China
| | - Yan-yan Cao
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, P.R. China
| | - Wen-hui Zhang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, P.R. China
| | - Hong Wang
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, P.R. China
| | - Yu-wei Jin
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, P.R. China
| | - Fang Song
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, P.R. China
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26
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Butchbach MER. Copy Number Variations in the Survival Motor Neuron Genes: Implications for Spinal Muscular Atrophy and Other Neurodegenerative Diseases. Front Mol Biosci 2016; 3:7. [PMID: 27014701 PMCID: PMC4785180 DOI: 10.3389/fmolb.2016.00007] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 02/25/2016] [Indexed: 12/11/2022] Open
Abstract
Proximal spinal muscular atrophy (SMA), a leading genetic cause of infant death worldwide, is an early-onset, autosomal recessive neurodegenerative disease characterized by the loss of spinal α-motor neurons. This loss of α-motor neurons is associated with muscle weakness and atrophy. SMA can be classified into five clinical grades based on age of onset and severity of the disease. Regardless of clinical grade, proximal SMA results from the loss or mutation of SMN1 (survival motor neuron 1) on chromosome 5q13. In humans a large tandem chromosomal duplication has lead to a second copy of the SMN gene locus known as SMN2. SMN2 is distinguishable from SMN1 by a single nucleotide difference that disrupts an exonic splice enhancer in exon 7. As a result, most of SMN2 mRNAs lack exon 7 (SMNΔ7) and produce a protein that is both unstable and less than fully functional. Although only 10–20% of the SMN2 gene product is fully functional, increased genomic copies of SMN2 inversely correlates with disease severity among individuals with SMA. Because SMN2 copy number influences disease severity in SMA, there is prognostic value in accurate measurement of SMN2 copy number from patients being evaluated for SMA. This prognostic value is especially important given that SMN2 copy number is now being used as an inclusion criterion for SMA clinical trials. In addition to SMA, copy number variations (CNVs) in the SMN genes can affect the clinical severity of other neurological disorders including amyotrophic lateral sclerosis (ALS) and progressive muscular atrophy (PMA). This review will discuss how SMN1 and SMN2 CNVs are detected and why accurate measurement of SMN1 and SMN2 copy numbers is relevant for SMA and other neurodegenerative diseases.
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Affiliation(s)
- Matthew E R Butchbach
- Center for Applied Clinical Genomics, Nemours Biomedical Research, Nemours Alfred I. duPont Hospital for ChildrenWilmington, DE, USA; Center for Pediatric Research, Nemours Biomedical Research, Nemours Alfred I. duPont Hospital for ChildrenWilmington, DE, USA; Department of Biological Sciences, University of DelawareNewark, DE, USA; Department of Pediatrics, Thomas Jefferson UniversityPhiladelphia, PA, USA
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27
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Fang P, Li L, Zeng J, Zhou WJ, Wu WQ, Zhong ZY, Yan TZ, Xie JS, Huang J, Lin L, Zhao Y, Xu XM. Molecular characterization and copy number of SMN1, SMN2 and NAIP in Chinese patients with spinal muscular atrophy and unrelated healthy controls. BMC Musculoskelet Disord 2015; 16:11. [PMID: 25888055 PMCID: PMC4328246 DOI: 10.1186/s12891-015-0457-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 01/12/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Spinal muscular atrophy (SMA) is caused by SMN1 dysfunction, and the copy number of SMN2 and NAIP can modify the phenotype of SMA. The aim of this study was to analyze the copy numbers and gene structures of SMA-related genes in Chinese SMA patients and unrelated healthy controls. METHODS Forty-two Chinese SMA patients and two hundred and twelve unrelated healthy Chinese individuals were enrolled in our study. The copy numbers and gene structures of SMA-related genes were measured by MLPA assay. RESULTS We identified a homozygous deletion of SMN1 in exons 7 and 8 in 37 of 42 patients (88.1%); the other 5 SMA patients (11.9%) had a single copy of SMN1 exon 8. The proportions of the 212 unrelated healthy controls with different copy numbers for the normal SMN1 gene were 1 copy in 4 individuals (1.9%), 2 copies in 203 (95.7%) and 3 copies in 5 (2.4%). Three hybrid SMN genes and five genes that lack partial sequences were found in SMA patients and healthy controls. Distributions of copy numbers for normal SMN2 and NAIP were significantly different (P < 0.001) in people with and without SMA. CONCLUSION The copy numbers and gene structures of SMA-related genes were different in Chinese SMA patients and healthy controls.
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Affiliation(s)
- Ping Fang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Avenue North1838, Guangzhou, Guangdong, People's Republic of China.
| | - Liang Li
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Avenue North1838, Guangzhou, Guangdong, People's Republic of China.
| | - Jian Zeng
- Department of Clinical Laboratory, The Fuzhou General Hospital, Nanjing Military Command, Fuzhou, Fujian, People's Republic of China.
| | - Wan-Jun Zhou
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Avenue North1838, Guangzhou, Guangdong, People's Republic of China.
| | - Wei-Qing Wu
- Prenatal Diagnosis Center, Shenzhen Maternity and Child Healthcare Hospital, Shenzhen, Guangdong, People's Republic of China.
| | - Ze-Yan Zhong
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Avenue North1838, Guangzhou, Guangdong, People's Republic of China.
| | - Ti-Zhen Yan
- Liuzhou Key Laboratory of birth defects prevention and control, Liuzhou Municipal Maternity and Child Healthcare Hospital, Liuzhou, Guangxi, People's Republic of China.
| | - Jian-Sheng Xie
- Prenatal Diagnosis Center, Shenzhen Maternity and Child Healthcare Hospital, Shenzhen, Guangdong, People's Republic of China.
| | - Jing Huang
- The Third Affiliated Hospital of Southern Medical University, Guangzhou, Guangdong, People's Republic of China.
| | - Li Lin
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Avenue North1838, Guangzhou, Guangdong, People's Republic of China.
| | - Ying Zhao
- Prenatal Diagnostic Center, Dongguan Maternal and Children Health Hospital, Dongguan, Guangdong, People's Republic of China.
| | - Xiang-Min Xu
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Avenue North1838, Guangzhou, Guangdong, People's Republic of China.
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