1
|
Loureiro BMC, de Brito MR, Iwabe C, Dertkigil SSJ, França MC. Quantitative ultrasonography reveals skeletal muscle abnormalities in carriers of DMD pathogenic variants. Muscle Nerve 2024; 69:682-690. [PMID: 38517116 DOI: 10.1002/mus.28086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 03/01/2024] [Accepted: 03/10/2024] [Indexed: 03/23/2024]
Abstract
INTRODUCTION/AIMS Carriers of DMD pathogenic variants may become symptomatic and develop muscle-related manifestations. Despite that, few studies have attempted to characterize changes in the muscles of these carriers using imaging tools, particularly muscle ultrasound (MUS). The aim of this study was to compare lower limb MUS findings in carriers of DMD pathogenic variants (cDMD) vs healthy controls. METHODS Twenty-eight women (15 cDMD and 13 controls) underwent clinical evaluation and MUS. We collected information about muscle-related symptoms and assessed muscle strength. MUS was performed by a single physician (blind to the genetic status of subjects). The following muscles were assessed: rectus femoris, sartorius, tibialis anterior, and medial gastrocnemius. For each site, we computed data on muscle thickness, cross-sectional area, sound attenuation index, and elastography. Between-group comparisons were assessed using nonparametric tests and p-values <.05 were deemed significant. RESULTS None of the subjects had objective muscle weakness, but exercise intolerance/fatigue was reported by four cDMDs and only one control. Regarding MUS, sound attenuation indices were significantly higher among carriers for all muscles tested. Longitudinal and axial deep echo intensities for the rectus femoris and tibialis anterior were also higher in the cDMD group compared with controls. No significant between-group differences were noted for elastography values, muscle area, or mean echo intensities. DISCUSSION cDMD have skeletal muscle abnormalities that can be detected using quantitative MUS. Further studies are needed to determine whether such abnormalities are related to muscle symptoms in these patients.
Collapse
Affiliation(s)
- Bruna Melo Coelho Loureiro
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), São Paulo, Brazil
- Department of Radiology, School of Medical Sciences, University of Campinas (UNICAMP), São Paulo, Brazil
| | - Mariana Rabelo de Brito
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), São Paulo, Brazil
| | - Cristina Iwabe
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), São Paulo, Brazil
| | - Sergio San Juan Dertkigil
- Department of Radiology, School of Medical Sciences, University of Campinas (UNICAMP), São Paulo, Brazil
| | - Marcondes C França
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), São Paulo, Brazil
| |
Collapse
|
2
|
Awano H, Nambu Y, Itoh C, Kida A, Yamamoto T, Lee T, Takeshima Y, Nozu K, Matsuo M. Longitudinal data of serum creatine kinase levels and motor, pulmonary, and cardiac functions in 337 patients with Duchenne muscular dystrophy. Muscle Nerve 2024; 69:604-612. [PMID: 38511270 DOI: 10.1002/mus.28073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 02/15/2024] [Accepted: 02/21/2024] [Indexed: 03/22/2024]
Abstract
INTRODUCTION/AIMS Duchenne muscular dystrophy (DMD) presents with skeletal muscle weakness, followed by cardiorespiratory involvement. The need for longitudinal data regarding DMD that could serve as a control for determining treatment efficacy in clinical trials has increased notably. The present study examined the longitudinal data of Japanese DMD patients collectively and assessed individual patients with pathogenic variants eligible for exon-skipping therapy. METHODS Patients with DMD who visited Kobe University Hospital between March 1991 and March 2019 were enrolled. Data between the patients' first visit until age 20 years were examined. RESULTS Three hundred thirty-seven patients were included. Serum creatine kinase levels showed extremely high values until the age of 6 years and a rapid decline from ages 7-12 years. Both the median 10-m run/walk velocity and rise-from-floor velocity peaked at the age of 4 years and declined with age. The values for respiratory function declined from the age of 11 years. The median left ventricular ejection fraction was >60% until the age of 12 years and rapidly declined from ages 13-15 years. Examination of the relationship between pathogenic variants eligible for exon-skipping therapy and longitudinal data revealed no characteristic findings. DISCUSSION We found that creatine kinase levels and motor, respiratory, and cardiac functions each exhibited various changes over time. These findings provide useful information about the longitudinal data of several outcome measures for patients with DMD not receiving corticosteroids. These data may serve as historical controls in comparing the natural history of DMD patients not on regular steroid use in appropriate clinical trials.
Collapse
Affiliation(s)
- Hiroyuki Awano
- Research Initiative Center, Organization for Research Initiative and Promotion, Tottori University, Yonago, Japan
| | - Yoshinori Nambu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Chieko Itoh
- Division of Rehabilitation Medicine, Kobe University Hospital, Kobe, Japan
| | - Akihiro Kida
- Division of Rehabilitation Medicine, Kobe University Hospital, Kobe, Japan
| | | | - Tomoko Lee
- Department of Pediatrics, Hyogo Medical University, Nishinomiya, Japan
| | | | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Masafumi Matsuo
- Faculty of Health Sciences, Kobe Tokiwa University, Kobe, Japan
| |
Collapse
|
3
|
Pickart AM, Martin AS, Gross BN, Dellefave-Castillo LM, McCallen LM, Nagaraj CB, Rippert AL, Schultz CP, Ulm EA, Armstrong N. Genetic counseling for the dystrophinopathies-Practice resource of the National Society of Genetic Counselors. J Genet Couns 2024. [PMID: 38682751 DOI: 10.1002/jgc4.1892] [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: 05/23/2023] [Revised: 03/06/2024] [Accepted: 03/12/2024] [Indexed: 05/01/2024]
Abstract
The dystrophinopathies encompass the phenotypically variable forms of muscular dystrophy caused by pathogenic variants in the DMD gene. The dystrophinopathies include the most common inherited muscular dystrophy among 46,XY individuals, Duchenne muscular dystrophy, as well as Becker muscular dystrophy and other less common phenotypic variants. With increased access to and utilization of genetic testing in the diagnostic and carrier setting, genetic counselors and clinicians in diverse specialty areas may care for individuals with and carriers of dystrophinopathy. This practice resource was developed as a tool for genetic counselors and other health care professionals to support counseling regarding dystrophinopathies, including diagnosis, health risks and management, psychosocial needs, reproductive options, clinical trials, and treatment. Genetic testing efforts have enabled genotype/phenotype correlation in the dystrophinopathies, but have also revealed unexpected findings, further complicating genetic counseling for this group of conditions. Additionally, the therapeutic landscape for dystrophinopathies has dramatically changed with several FDA-approved therapeutics, an expansive research pathway, and numerous clinical trials. Genotype-phenotype correlations are especially complex and genetic counselors' unique skill sets are useful in exploring and explaining this to families. Given the recent advances in diagnostic testing and therapeutics related to dystrophinopathies, this practice resource is a timely update for genetic counselors and other healthcare professionals involved in the diagnosis and care of individuals with dystrophinopathies.
Collapse
Affiliation(s)
- Angela M Pickart
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Ann S Martin
- Parent Project Muscular Dystrophy, Washington, District of Columbia, USA
| | - Brianna N Gross
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Lisa M Dellefave-Castillo
- Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Leslie M McCallen
- Department of Pediatrics, University of Colorado School of Medicine, Children's Hospital Colorado, Aurora, Colorado, USA
| | - Chinmayee B Nagaraj
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Alyssa L Rippert
- Division of Human Genetics, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | | | - Elizabeth A Ulm
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Niki Armstrong
- Parent Project Muscular Dystrophy, Washington, District of Columbia, USA
| |
Collapse
|
4
|
Smith C, Kitzman JO. Benchmarking splice variant prediction algorithms using massively parallel splicing assays. Genome Biol 2023; 24:294. [PMID: 38129864 PMCID: PMC10734170 DOI: 10.1186/s13059-023-03144-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 12/13/2023] [Indexed: 12/23/2023] Open
Abstract
BACKGROUND Variants that disrupt mRNA splicing account for a sizable fraction of the pathogenic burden in many genetic disorders, but identifying splice-disruptive variants (SDVs) beyond the essential splice site dinucleotides remains difficult. Computational predictors are often discordant, compounding the challenge of variant interpretation. Because they are primarily validated using clinical variant sets heavily biased to known canonical splice site mutations, it remains unclear how well their performance generalizes. RESULTS We benchmark eight widely used splicing effect prediction algorithms, leveraging massively parallel splicing assays (MPSAs) as a source of experimentally determined ground-truth. MPSAs simultaneously assay many variants to nominate candidate SDVs. We compare experimentally measured splicing outcomes with bioinformatic predictions for 3,616 variants in five genes. Algorithms' concordance with MPSA measurements, and with each other, is lower for exonic than intronic variants, underscoring the difficulty of identifying missense or synonymous SDVs. Deep learning-based predictors trained on gene model annotations achieve the best overall performance at distinguishing disruptive and neutral variants, and controlling for overall call rate genome-wide, SpliceAI and Pangolin have superior sensitivity. Finally, our results highlight two practical considerations when scoring variants genome-wide: finding an optimal score cutoff, and the substantial variability introduced by differences in gene model annotation, and we suggest strategies for optimal splice effect prediction in the face of these issues. CONCLUSION SpliceAI and Pangolin show the best overall performance among predictors tested, however, improvements in splice effect prediction are still needed especially within exons.
Collapse
Affiliation(s)
- Cathy Smith
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Jacob O Kitzman
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
- Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
| |
Collapse
|
5
|
Nakamura A, Matsumura T, Ogata K, Mori‐Yoshimura M, Takeshita E, Kimura K, Kawashima T, Tomo Y, Arahata H, Miyazaki D, Takeshima Y, Takahashi T, Ishigaki K, Kuru S, Wakisaka A, Awano H, Funato M, Sato T, Saito Y, Takada H, Sugie K, Kobayashi M, Ozasa S, Fujii T, Maegaki Y, Oi H, Tachimori H, Komaki H. Natural history of Becker muscular dystrophy: a multicenter study of 225 patients. Ann Clin Transl Neurol 2023; 10:2360-2372. [PMID: 37882106 PMCID: PMC10723226 DOI: 10.1002/acn3.51925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 10/02/2023] [Indexed: 10/27/2023] Open
Abstract
OBJECTIVE Becker muscular dystrophy (BMD) is a milder variant of Duchenne muscular dystrophy (DMD), a lethal X-linked muscular disorder. Here, we aim to investigat the clinical involvement of skeletal, respiratory, cardiac, and central nervous systems in patients with BMD, as well as genotype-phenotype relationships. METHODS This nationwide cohort study investigated the clinical manifestations and genotype-phenotype relationships in 225 patients with BMD having in-frame deletion from 22 medical centers. The primary outcome was to elucidate the association of genotype with skeletal muscle, respiratory, cardiac, and central nervous system disorders. Descriptive statistics were used to analyze the data. RESULTS The average age of the subjects was 31.5 (range, 1-81) years. Initial symptoms of BMD were muscular (60%), followed by asymptomatic hypercreatine kinasemia (32.4%) and central nervous system disorders (5.3%). Gait disturbance was observed in 53.8% of patients and the average age at wheelchair introduction was 36.5 years. The ventilator introduction rate was 6.7% at an average age of 36.6 years. More than 30% of patients had an abnormal electrocardiogram and approximately 15% had heart failure symptoms. Cardiac function on echocardiography varied significantly among the patients. The frequencies of seizures and intellectual/developmental disability were 8.0% and 16.9%, respectively. Exon 45-47deletion (del) was the most common (22.6%), followed by exon 45-48del (13.1%). Patients with exon 45-49del patients demonstrated severe skeletal muscle damage. Patients with exon 45-47del and exon 45-55del patients did not require ventilator use. INTERPRETATION The study provides important prognostic information for patients and clinicians to establish therapy plans and to implement preventative medicine.
Collapse
Affiliation(s)
- Akinori Nakamura
- Department of NeurologyNHO Matsumoto Medical CenterMatsumotoJapan
| | | | - Katsuhisa Ogata
- Department of NeurologyNHO Higashisaitama National HospitalHasudaJapan
| | - Madoka Mori‐Yoshimura
- Department of NeurologyNational Center Hospital, National Center of Neurology and PsychiatryKodairaJapan
| | - Eri Takeshita
- Department of Child NeurologyNational Center Hospital, National Center of Neurology and PsychiatryKodairaJapan
| | - Koichi Kimura
- Department of Laboratory Medicine/CardiologyThe Institute of Medical Science, The University of TokyoMinato‐kuJapan
| | - Takahiro Kawashima
- Department of Information Medicine, National Center of Neurology and PsychiatryNational Institute of NeuroscienceKodairaJapan
| | - Yui Tomo
- Department of Clinical Data Science, Clinical Research & Education Promotion Division, National Center of Neurology and PsychiatryKodairaJapan
| | - Hajime Arahata
- Department of Neurology, Neuro‐Muscular CenterNHO Omuta National HospitalOmutaJapan
| | - Daigo Miyazaki
- Department of Medicine (Neurology and Rheumatology)Shinshu University School of MedicineMatsumotoJapan
| | - Yasuhiro Takeshima
- Department of PediatricsHyogo Medical University School of MedicineNishinomiyaJapan
| | | | - Keiko Ishigaki
- Department of PediatricsTokyo Women's Medical University School of MedicineShinjuku‐kuJapan
| | - Satoshi Kuru
- Department of NeurologyNHO Suzuka National HospitalSuzukaJapan
| | - Akiko Wakisaka
- Department of PediatricsNHO Iou National HospitalKanazawaJapan
| | - Hiroyuki Awano
- Research Initiative Center, Organization for Research Initiative and PromotionTottori UniversityYonagoJapan
| | - Michinori Funato
- Department of Pediatric NeurologyNHO Nagara Medical CenterNagaraJapan
| | - Tatsuharu Sato
- Department of PediatricsNagasaki University HospitalNagasakiJapan
| | - Yoshiaki Saito
- Department of PediatricsNational Rehabilitation Center for Children with DisabilitiesItabashiJapan
| | - Hiroto Takada
- Department of NeurologyNHO Aomori National HospitalAomoriJapan
| | - Kazuma Sugie
- Department of NeurologyNara Medical University School of MedicineKashiharaJapan
| | - Michio Kobayashi
- Department of NeurologyNHO Akita National HospitalYurihonjoJapan
| | - Shiro Ozasa
- Department of PediatricsKumamoto University HospitalKumamotoJapan
| | - Tatsuya Fujii
- Department of PediatricsShiga Medical Center for ChildrenMoriyamaJapan
| | - Yoshihiro Maegaki
- Division of Child Neurology, Department of Brain and Neurosciences, Faculty of MedicineTottori UniversityYonagoJapan
| | - Hideki Oi
- Department of Clinical Data Science, Clinical Research & Education Promotion Division, National Center of Neurology and PsychiatryKodairaJapan
| | - Hisateru Tachimori
- Department of Information Medicine, National Center of Neurology and PsychiatryNational Institute of NeuroscienceKodairaJapan
- Endowed Course of Health System InnovationKeio University School of MedicineTokyoJapan
| | - Hirofumi Komaki
- Department of Child NeurologyNational Center Hospital, National Center of Neurology and PsychiatryKodairaJapan
| |
Collapse
|
6
|
Dwianingsih EK, Iskandar K, Hapsara S, Ping Liu C, Malueka RG, Gunadi, Matsuo M, Lai PS. Mutation spectrum analysis of DMD gene in Indonesian Duchenne and Becker muscular dystrophy patients. F1000Res 2023; 11:148. [PMID: 38009102 PMCID: PMC10668572 DOI: 10.12688/f1000research.73476.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/13/2023] [Indexed: 11/28/2023] Open
Abstract
Background Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are allelic disorders caused by mutations in the DMD gene. The full mutation spectrum of the DMD gene in Indonesian patients is currently unknown. Mutation-specific therapies are currently being developed, such as exon skipping or stop codon read-through therapy. This study was conducted with the aim of identifying the mutation spectrum of the DMD gene in Indonesia to guide future development and application of feasible therapeutic strategies. Methods This study is a cross sectional study that enrolled 43 male patients with a clinical suspicion of DMD or BMD. Multiplex ligation-dependent probe amplification (MLPA) reaction was performed to screen for the common mutations in the DMD gene. Results Out of 43 subjects, deletions accounted for 69.77% (n=30) cases, while duplications were found in 11.63% (n=5) cases. One novel duplication spanning exons 2 to 62 was identified. Deletion mutations clustered around the distal (66.67%) and proximal (26.67%) hot spot regions of the DMD gene while duplication mutations were observed solely at the proximal region. Two false positive cases of single exon deletion detected through MLPA were attributed to sequence mutations affecting primer ligation sites, confirming the need to validate all single exon deletions when using this screening method. Analysis of available maternal DNA samples showed that the rate of de novo mutations (48.15%) appears higher than expected in this population. Out of 31 patients who were classified as DMD based on clinical and genotype characterizations, 60.47% (n=26) of cases were suitable for exon skipping therapy. Conclusion This is the first comprehensive study showing the feasibility of implementing the MLPA method for routine screening of DMD patients in Indonesia. This is also the first study showing the potential applicability of exon skipping therapy in the majority of DMD cases in the country.
Collapse
Affiliation(s)
- Ery Kus Dwianingsih
- Genetics Working Group, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
- Dr. Sardjito General Hospital, Yogyakarta, 55281, Indonesia
- Department of Anatomical Pathology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
| | - Kristy Iskandar
- Genetics Working Group, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
- Academic Hospital, Universitas Gadjah Mada, Yogyakarta, 55291, Indonesia
- Department of Child Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
| | - Sunartini Hapsara
- Academic Hospital, Universitas Gadjah Mada, Yogyakarta, 55291, Indonesia
- Department of Child Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
| | - Chun Ping Liu
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119228, Singapore
| | - Rusdy Ghazali Malueka
- Genetics Working Group, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
- Dr. Sardjito General Hospital, Yogyakarta, 55281, Indonesia
- Department of Neurology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
| | - Gunadi
- Genetics Working Group, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
- Dr. Sardjito General Hospital, Yogyakarta, 55281, Indonesia
- Pediatric Surgery Division, Department of Surgery, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
| | - Masafumi Matsuo
- KNC Department of Nucleic Acid Drug Discovery, Faculty of Rehabilitation, Kobegakuin University, Kobe, 651-2180, Japan
| | - Poh San Lai
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119228, Singapore
| |
Collapse
|
7
|
Yamamoto T, Nambu Y, Bo R, Morichi S, Yanagiya M, Matsuo M, Awano H. Electrocardiographic R wave amplitude in V6 lead as a predictive marker of cardiac dysfunction in Duchenne muscular dystrophy. J Cardiol 2023; 82:363-370. [PMID: 37481234 DOI: 10.1016/j.jjcc.2023.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 07/11/2023] [Accepted: 07/14/2023] [Indexed: 07/24/2023]
Abstract
PURPOSE Duchenne muscular dystrophy (DMD) is an inherited muscular disease characterized by progressive and fatal muscle weakness. Electrocardiographic (ECG) abnormalities, including abnormal R wave amplitudes are frequently observed in DMD. However, clinical implications of abnormal R wave amplitudes remain unclear. Hence, DMD patients were examined for changes in R wave amplitude over time using synthesized 18-lead ECG and the relationship between R wave amplitude and cardiac function. METHODS The results of 969 ECG examinations of 193 patients with DMD who underwent electrocardiography and echocardiography on the same day were retrospectively reviewed. RESULTS A negative correlation was observed between R wave amplitude and age. Positive correlations between R wave amplitude and left ventricular ejection fraction were observed in leads V4, V5, V6, syn-V7, syn-V8, and syn-V9, with V6 showing the strongest correlation (r = 0.52). Mean R wave amplitude during cardiac dysfunction was lower than that observed with preserved cardiac function in leads V6 to syn-V9. Patients had preserved R wave amplitude up to three years before the onset of cardiac dysfunction, with a sharp decrease two years before cardiac dysfunction in leads V6 to syn-V9. CONCLUSIONS In DMD patients, the R wave amplitude decreases with age. The sharp decline in R amplitude two years before cardiac dysfunction indicates that electrophysiological damage to the myocardium of the left ventricle lateral to the posterior wall precedes the finding of cardiac dysfunction. The R amplitude in V6 of the standard 12-lead ECG is a convenient predictive marker of cardiac dysfunction, similar to that of the 18-lead ECG.
Collapse
Affiliation(s)
| | - Yoshinori Nambu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Ryosuke Bo
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Shotaro Morichi
- Nagahama Institute of Bio-Science and Technology, Nagahama, Japan
| | - Misato Yanagiya
- Nagahama Institute of Bio-Science and Technology, Nagahama, Japan
| | - Masafumi Matsuo
- KNC Department of Nucleic Acid Drug Discovery, Kobe Gakuin University, Japan
| | - Hiroyuki Awano
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan; Organization for Research Initiative and Promotion, Tottori University, Yonago, Japan
| |
Collapse
|
8
|
Imbriano C, Moresi V, Belluti S, Renzini A, Cavioli G, Maretti E, Molinari S. Epitranscriptomics as a New Layer of Regulation of Gene Expression in Skeletal Muscle: Known Functions and Future Perspectives. Int J Mol Sci 2023; 24:15161. [PMID: 37894843 PMCID: PMC10606696 DOI: 10.3390/ijms242015161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 10/09/2023] [Accepted: 10/10/2023] [Indexed: 10/29/2023] Open
Abstract
Epitranscriptomics refers to post-transcriptional regulation of gene expression via RNA modifications and editing that affect RNA functions. Many kinds of modifications of mRNA have been described, among which are N6-methyladenosine (m6A), N1-methyladenosine (m1A), 7-methylguanosine (m7G), pseudouridine (Ψ), and 5-methylcytidine (m5C). They alter mRNA structure and consequently stability, localization and translation efficiency. Perturbation of the epitranscriptome is associated with human diseases, thus opening the opportunity for potential manipulations as a therapeutic approach. In this review, we aim to provide an overview of the functional roles of epitranscriptomic marks in the skeletal muscle system, in particular in embryonic myogenesis, muscle cell differentiation and muscle homeostasis processes. Further, we explored high-throughput epitranscriptome sequencing data to identify RNA chemical modifications in muscle-specific genes and we discuss the possible functional role and the potential therapeutic applications.
Collapse
Affiliation(s)
- Carol Imbriano
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (S.B.); (E.M.)
| | - Viviana Moresi
- Institute of Nanotechnology, National Research Council (CNR-NANOTEC), University of Rome “La Sapienza”, 00181 Rome, Italy;
| | - Silvia Belluti
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (S.B.); (E.M.)
| | - Alessandra Renzini
- Unit of Histology and Medical Embryology, Department of Human Anatomy, Histology, Forensic Medicine and Orthopedics, University of Rome “La Sapienza”, 00161 Rome, Italy; (A.R.); (G.C.)
| | - Giorgia Cavioli
- Unit of Histology and Medical Embryology, Department of Human Anatomy, Histology, Forensic Medicine and Orthopedics, University of Rome “La Sapienza”, 00161 Rome, Italy; (A.R.); (G.C.)
| | - Eleonora Maretti
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (S.B.); (E.M.)
| | - Susanna Molinari
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (S.B.); (E.M.)
| |
Collapse
|
9
|
Garbers TB, Enders M, Neumann P, Ficner R. Crystal structure of Prp16 in complex with ADP. Acta Crystallogr F Struct Biol Commun 2023; 79:200-207. [PMID: 37548918 PMCID: PMC10416764 DOI: 10.1107/s2053230x23005721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 06/29/2023] [Indexed: 08/08/2023] Open
Abstract
DEAH-box helicases play a crucial role in pre-mRNA splicing as they are responsible for major rearrangements of the spliceosome and are involved in various quality-ensuring steps. Prp16 is the driving force during spliceosomal catalysis, remodeling the C state into the C* state. Here, the first crystal structure of Prp16 from Chaetomium thermophilum in complex with ADP is reported at 1.9 Å resolution. Comparison with the other spliceosomal DEAH-box helicases Prp2, Prp22 and Prp43 reveals an overall identical domain architecture. The β-hairpin, which is a structural element of the RecA2 domain, exhibits a unique position, punctuating its flexibility. Analysis of cryo-EM models of spliceosomal complexes containing Prp16 reveals that these models show Prp16 in its nucleotide-free state, rendering the model presented here the first structure of Prp16 in complex with a nucleotide.
Collapse
Affiliation(s)
- Tim Benedict Garbers
- Department of Molecular Structural Biology, Institute of Microbiology and Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Marieke Enders
- Department of Molecular Structural Biology, Institute of Microbiology and Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Piotr Neumann
- Department of Molecular Structural Biology, Institute of Microbiology and Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Ralf Ficner
- Department of Molecular Structural Biology, Institute of Microbiology and Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| |
Collapse
|
10
|
Kekou K, Svingou M, Vogiatzakis N, Nitsa E, Veltra D, Marinakis NM, Tilemis FN, Tzetis M, Mitrakos A, Tsaroucha C, Selenti N, Papadimas GK, Papadopoulos C, Traeger-Synodinos J, Lochmuller H, Sofocleous C. Retrospective analysis of persistent HyperCKemia with or without muscle weakness in a case series from Greece highlights vast DMD variant heterogeneity. Expert Rev Mol Diagn 2023; 23:999-1010. [PMID: 37754746 DOI: 10.1080/14737159.2023.2264181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 09/25/2023] [Indexed: 09/28/2023]
Abstract
BACKGROUND Persistent hyperCKemia results from muscle dysfunction often attributed to genetic alterations of muscle-related genes, such as the dystrophin gene (DMD). Retrospective assessment of findings from DMD analysis, in association with persistent HyperCKemia, was conducted. PATIENTS AND METHODS Evaluation of medical records from 1354 unrelated cases referred during the period 1996-2021. Assessment of data concerning the detection of DMD gene rearrangements and nucleotide variants. RESULTS A total of 730 individuals (657 cases, 569 of Greek and 88 of Albanian origins) were identified, allowing an overall estimation of dystrophinopathy incidence at ~1:3800 live male births. The heterogeneous spectrum of 275 distinct DMD alterations comprised exon(s) deletions/duplications, nucleotide variants, and rare events, such as chromosome translocation {t(X;20)}, contiguous gene deletions, and a fused gene involving the DMD and the DOCK8 genes. Ethnic-specific findings include a common founder variant in exon 36 ('Hellenic' variant). CONCLUSIONS Some 50% of hyperCKemia cases were characterized as dystrophinopathies, highlighting that DMD variants may be considered the most common cause of hyperCKemia in Greece. Delineation of the broad genetic and clinical heterogeneity is fundamental for actionable public health decisions and theragnosis, as well as the establishment of guidelines addressing ethical considerations, especially related to the mild asymptomatic patient subgroup.
Collapse
Affiliation(s)
- Kyriaki Kekou
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Maria Svingou
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Nikos Vogiatzakis
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Evangelia Nitsa
- Postgraduate Program in Biostatistics School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Danai Veltra
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- St. Sophia's Children's Hospital, Research University Institute for the Study and Prevention of Genetic and Malignant Disease of Childhood, National and Kapodistrian University of Athens, Athens, Greece
| | - Nikolaos M Marinakis
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- St. Sophia's Children's Hospital, Research University Institute for the Study and Prevention of Genetic and Malignant Disease of Childhood, National and Kapodistrian University of Athens, Athens, Greece
| | - Faidon-Nikolaos Tilemis
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Maria Tzetis
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Anastasios Mitrakos
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- St. Sophia's Children's Hospital, Research University Institute for the Study and Prevention of Genetic and Malignant Disease of Childhood, National and Kapodistrian University of Athens, Athens, Greece
| | - Charalambia Tsaroucha
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Nicoletta Selenti
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Giorgos-Konstantinos Papadimas
- Department of Neurology, Eginition Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Constantinos Papadopoulos
- Department of Neurology, Eginition Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Joanne Traeger-Synodinos
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Hanns Lochmuller
- Department of Neuropediatrics and Muscle Disorders, Medical Center - University of Freiburg, Freiburg, Germany
- Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Children's Hospital of Eastern Ontario Research Institute; Division of Neurology, Department of Medicine, The Ottawa Hospital, Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada
| | - Christalena Sofocleous
- Laboratory of Medical Genetics, St. Sophia's Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| |
Collapse
|
11
|
Tang F, Xiao Y, Zhou C, Zhang H, Wang J, Zeng Y. NGS-based targeted sequencing identified six novel variants in patients with Duchenne/Becker muscular dystrophy from southwestern China. BMC Med Genomics 2023; 16:121. [PMID: 37254189 DOI: 10.1186/s12920-023-01556-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 05/22/2023] [Indexed: 06/01/2023] Open
Abstract
BACKGROUND At present, Multiplex ligation-dependent probe amplification (MLPA) and exome sequencing are common gene detection methods in patients with Duchenne muscular dystrophy or Becker muscular dystrophy (DMD/BMD), but they can not cover the whole-genome sequence of the DMD gene. In this study, the whole genome capture of the DMD gene and next-generation sequencing (NGS) technology were used to detect the patients with DMD/BMD in Southwest China, to clarify the application value of this technology and further study the gene variant spectrum. METHODS From 2017 to 2020, 51 unrelated patients with DMD/BMD in southwestern China were clinically diagnosed at West China Second University Hospital of Sichuan University (Chengdu, China). The whole-genome of the DMD gene was captured from the peripheral blood of all patients, and next-generation sequencing was performed. Large copy number variants (CNVs) in the exon regions of the DMD gene were verified through MLPA, and small variations (such as single nucleotide variation and < 50 bp fragment insertions/deletions) were validated using Sanger sequencing. RESULTS Among the 51 patients, 49 (96.1% [49/51]) had pathogenic or likely pathogenic variants in the DMD gene. Among the 49 positive samples, 17 patients (34.7% [17/49]) had CNVs in the exon regions and 32 patients (65.3% [32/49]) had small variations. A total of six novel variants were identified: c.10916_10917del, c.1790T>A, c.1842del, c.5015del, c.5791_5792insCA, and exons 38-50 duplication. CONCLUSIONS Pathogenic or likely pathogenic variants of the DMD gene were detected in 49 patients (96.1% [49/51]), of which 6 variants (12.2% [6/49]) had not been previously reported. This study confirmed the value of NGS-based targeted sequencing for the DMD gene expanding the spectrum of variants in DMD, which may provide effective genetic counseling and prenatal diagnosis for families.
Collapse
Affiliation(s)
- Feng Tang
- Department of Medical Genetics, West China Second University Hospital of Sichuan University, Chengdu, People's Republic of China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, Sichuan, People's Republic of China
| | - Yuanyuan Xiao
- Department of Medical Genetics, West China Second University Hospital of Sichuan University, Chengdu, People's Republic of China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, Sichuan, People's Republic of China
| | - Cong Zhou
- Department of Medical Genetics, West China Second University Hospital of Sichuan University, Chengdu, People's Republic of China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, Sichuan, People's Republic of China
| | - Haixia Zhang
- Department of Medical Genetics, West China Second University Hospital of Sichuan University, Chengdu, People's Republic of China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, Sichuan, People's Republic of China
| | - Jing Wang
- Department of Medical Genetics, West China Second University Hospital of Sichuan University, Chengdu, People's Republic of China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, Sichuan, People's Republic of China
| | - Yang Zeng
- Department of Medical Genetics, West China Second University Hospital of Sichuan University, Chengdu, People's Republic of China.
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, Sichuan, People's Republic of China.
| |
Collapse
|
12
|
Eisen B, Binah O. Modeling Duchenne Muscular Dystrophy Cardiomyopathy with Patients' Induced Pluripotent Stem-Cell-Derived Cardiomyocytes. Int J Mol Sci 2023; 24:ijms24108657. [PMID: 37240001 DOI: 10.3390/ijms24108657] [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: 04/20/2023] [Revised: 05/05/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked progressive muscle degenerative disease caused by mutations in the dystrophin gene, resulting in death by the end of the third decade of life at the latest. A key aspect of the DMD clinical phenotype is dilated cardiomyopathy, affecting virtually all patients by the end of the second decade of life. Furthermore, despite respiratory complications still being the leading cause of death, with advancements in medical care in recent years, cardiac involvement has become an increasing cause of mortality. Over the years, extensive research has been conducted using different DMD animal models, including the mdx mouse. While these models present certain important similarities to human DMD patients, they also have some differences which pose a challenge to researchers. The development of somatic cell reprograming technology has enabled generation of human induced pluripotent stem cells (hiPSCs) which can be differentiated into different cell types. This technology provides a potentially endless pool of human cells for research. Furthermore, hiPSCs can be generated from patients, thus providing patient-specific cells and enabling research tailored to different mutations. DMD cardiac involvement has been shown in animal models to include changes in gene expression of different proteins, abnormal cellular Ca2+ handling, and other aberrations. To gain a better understanding of the disease mechanisms, it is imperative to validate these findings in human cells. Furthermore, with the recent advancements in gene-editing technology, hiPSCs provide a valuable platform for research and development of new therapies including the possibility of regenerative medicine. In this article, we review the DMD cardiac-related research performed so far using human hiPSCs-derived cardiomyocytes (hiPSC-CMs) carrying DMD mutations.
Collapse
Affiliation(s)
- Binyamin Eisen
- Cardiac Research Laboratory, Department of Physiology, Biophysics and Systems Biology, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Ofer Binah
- Cardiac Research Laboratory, Department of Physiology, Biophysics and Systems Biology, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| |
Collapse
|
13
|
Smith C, Kitzman JO. Benchmarking splice variant prediction algorithms using massively parallel splicing assays. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.04.539398. [PMID: 37205456 PMCID: PMC10187268 DOI: 10.1101/2023.05.04.539398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Background Variants that disrupt mRNA splicing account for a sizable fraction of the pathogenic burden in many genetic disorders, but identifying splice-disruptive variants (SDVs) beyond the essential splice site dinucleotides remains difficult. Computational predictors are often discordant, compounding the challenge of variant interpretation. Because they are primarily validated using clinical variant sets heavily biased to known canonical splice site mutations, it remains unclear how well their performance generalizes. Results We benchmarked eight widely used splicing effect prediction algorithms, leveraging massively parallel splicing assays (MPSAs) as a source of experimentally determined ground-truth. MPSAs simultaneously assay many variants to nominate candidate SDVs. We compared experimentally measured splicing outcomes with bioinformatic predictions for 3,616 variants in five genes. Algorithms' concordance with MPSA measurements, and with each other, was lower for exonic than intronic variants, underscoring the difficulty of identifying missense or synonymous SDVs. Deep learning-based predictors trained on gene model annotations achieved the best overall performance at distinguishing disruptive and neutral variants. Controlling for overall call rate genome-wide, SpliceAI and Pangolin also showed superior overall sensitivity for identifying SDVs. Finally, our results highlight two practical considerations when scoring variants genome-wide: finding an optimal score cutoff, and the substantial variability introduced by differences in gene model annotation, and we suggest strategies for optimal splice effect prediction in the face of these issues. Conclusion SpliceAI and Pangolin showed the best overall performance among predictors tested, however, improvements in splice effect prediction are still needed especially within exons.
Collapse
Affiliation(s)
- Cathy Smith
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Jacob O. Kitzman
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| |
Collapse
|
14
|
Newborn screening and genomic analysis of duchenne muscular dystrophy in Henan, China. Clin Chim Acta 2023; 539:90-96. [PMID: 36516925 DOI: 10.1016/j.cca.2022.11.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 11/23/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Duchenne Muscular Dystrophy (DMD) is a rare disorder caused by mutations in the dystrophin gene. Recent availability in treatment for DMD raised the need of early screening in our center, but newborn screening (NBS) for DMD has not been carried out in Henan Province. OBJECTIVES To determine an optimal cutoff value through the quantitative determination of the creatine kinase isoform MM (CK-MM) concentration dried blood spot (DBS) to identify male DMD, and to evaluate assess the detection rate and mutation spectrum of DMD in Henan, China. METHODS The CK-MM level in DBS was measured using with a GSP® neonatal creatine kinase -MM kit from 13,110 male newborns to establish the cut-off value for CK-MM. Multiplex ligation-dependent probe amplification (MLPA) were carried out for infants with elevated CK levels to detect DMD gene deletions/ duplications, NGS and sanger sequencing were then applied to exclude MLPA-negative samples to single-nucleotide variants. Phenotype-genotype correlations were analyzed using REVEL For novel missense mutations. RESULTS Statistical analysis of CK-MM value of the 13,110 neonates suggested that the cut-off value may be set as 472 ng/mL. 3 cases of DMD were screened among 13,110 newborns, all of whom had CK-MM levels >600 ng/mL. We detected 4 rare variants in DMD gene, including 2 exon deletions (deletion of exon 52 and deletion from exon 3 to exon 7) and 2 point variants (c.9568C>T and c.4030C>T). Two cases were all exon deletions, one case was compound heterozygous variants. CONCLUSIONS The estimated incidence of male neonatal DMD was 1:4,370 in Henan province. NBS is of great value to the early intervention and treatment of the disease, and is fundamental to support public health decision-making. The experience from this study provided a model that will allow further expansion and facilitate establishment a universal public health screening in Henan hospital systems.
Collapse
|
15
|
Viggiano E, Picillo E, Passamano L, Onore ME, Piluso G, Scutifero M, Torella A, Nigro V, Politano L. Spectrum of Genetic Variants in the Dystrophin Gene: A Single Centre Retrospective Analysis of 750 Duchenne and Becker Patients from Southern Italy. Genes (Basel) 2023; 14:214. [PMID: 36672955 PMCID: PMC9859256 DOI: 10.3390/genes14010214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/29/2022] [Accepted: 01/11/2023] [Indexed: 01/18/2023] Open
Abstract
Dystrophinopathies are X-linked recessive muscle disorders caused by mutations in the dystrophin (DMD) gene that include deletions, duplications, and point mutations. Correct diagnosis is important for providing adequate patient care and family planning, especially at this time when mutation-specific therapies are available. We report a large single-centre study on the spectrum of DMD gene variants observed in 750 patients analyzed for suspected Duchenne (DMD) or Becker (BMD) muscular dystrophy, over the past 30 years, at the Cardiomyology and Medical Genetics of the University of Campania. We found 534 (71.21%) large deletions, 73 (9.73%) large duplications, and 112 (14.93%) point mutations, of which 44 (5.9%) were small ins/del causing frame-shifts, 57 (7.6%) nonsense mutations, 8 (1.1%) splice site and 3 (0.4%) intronic mutations, and 31 (4.13%) non mutations. Moreover, we report the prevalence of the different types of mutations in patients with DMD and BMD according to their decade of birth, from 1930 to 2020, and correlate the data to the different techniques used over the years. In the most recent decades, we observed an apparent increase in the prevalence of point mutations, probably due to the use of Next-Generation Sequencing (NGS). In conclusion, in southern Italy, deletions are the most frequent variation observed in DMD and BMD patients followed by point mutations and duplications, as elsewhere in the world. NGS was useful to identify point mutations in cases of strong suspicion of DMD/BMD negative on deletions/duplications analyses. In the era of personalized medicine and availability of new causative therapies, a collective effort is necessary to enable DMD and BMD patients to have timely genetic diagnoses and avoid late implementation of standard of care and late initiation of appropriate treatment.
Collapse
Affiliation(s)
- Emanuela Viggiano
- Department of Prevention, Hygiene and Public Health Service, ASL Roma 2, 00157 Rome, Italy
| | - Esther Picillo
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Luigia Passamano
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Maria Elena Onore
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Giulio Piluso
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Marianna Scutifero
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Annalaura Torella
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Vincenzo Nigro
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
- Telethon Institute of Genetics and Medicine, 80078 Pozzuoli, Italy
| | - Luisa Politano
- Cardiomyology and Medical Genetics, Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| |
Collapse
|
16
|
Kim H, Shim Y, Lee TG, Won D, Choi JR, Shin S, Lee ST. Copy-number analysis by base-level normalization: An intuitive visualization tool for evaluating copy number variations. Clin Genet 2023; 103:35-44. [PMID: 36152294 DOI: 10.1111/cge.14236] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 09/19/2022] [Accepted: 09/20/2022] [Indexed: 12/13/2022]
Abstract
Next-generation sequencing (NGS) facilitates comprehensive molecular analyses that help with diagnosing unsolved disorders. In addition to detecting single-nucleotide variations and small insertions/deletions, bioinformatics tools can identify copy number variations (CNVs) in NGS data, which improves the diagnostic yield. However, due to the possibility of false positives, subsequent confirmation tests are generally performed. Here, we introduce Copy-number Analysis by BAse-level NormAlization (CABANA), a visualization tool that allows users to intuitively identify candidate CNVs using the normalized single-base-level read depth calculated from NGS data. To demonstrate how CABANA works, NGS data were obtained from 474 patients with neuromuscular disorders. CNVs were screened using a conventional bioinformatics tool, ExomeDepth, and then we normalized and visualized those data at the single-base level using CABANA, followed by manual inspection by geneticists to filter out false positives and determine candidate CNVs. In doing so, we identified 31 candidate CNVs (7%) in 474 patients and subsequently confirmed all of them to be true using multiplex ligation-dependent probe amplification. The performance of CABANA was deemed acceptable by comparing its diagnostic yield with previous data about neuromuscular disorders. Despite some limitations, we expect CABANA to help researchers accurately identify CNVs and reduce the need for subsequent confirmation testing.
Collapse
Affiliation(s)
- Hongkyung Kim
- Department of Laboratory Medicine, Yonsei University College of Medicine, Severance Hospital, Seoul, Republic of Korea
| | - Yeeun Shim
- Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, Republic of Korea
| | - Taek Gyu Lee
- Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, Republic of Korea
| | - Dongju Won
- Department of Laboratory Medicine, Yonsei University College of Medicine, Severance Hospital, Seoul, Republic of Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Yonsei University College of Medicine, Severance Hospital, Seoul, Republic of Korea.,Dxome Co. Ltd, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - Saeam Shin
- Department of Laboratory Medicine, Yonsei University College of Medicine, Severance Hospital, Seoul, Republic of Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Yonsei University College of Medicine, Severance Hospital, Seoul, Republic of Korea.,Dxome Co. Ltd, Seongnam-si, Gyeonggi-do, Republic of Korea
| |
Collapse
|
17
|
Cell-Based and Gene-Based Therapy Approaches in Neuro-orthopedic Disorders: a Literature Review. REGENERATIVE ENGINEERING AND TRANSLATIONAL MEDICINE 2022. [DOI: 10.1007/s40883-022-00284-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
18
|
Zinina E, Bulakh M, Chukhrova A, Ryzhkova O, Sparber P, Shchagina O, Polyakov A, Kutsev S. Specificities of the DMD Gene Mutation Spectrum in Russian Patients. Int J Mol Sci 2022; 23:ijms232112710. [PMID: 36361501 PMCID: PMC9658738 DOI: 10.3390/ijms232112710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/19/2022] [Accepted: 10/20/2022] [Indexed: 11/07/2022] Open
Abstract
Duchenne/Becker muscular dystrophy (DMD/BMD) is the most common form of muscular dystrophy, accounting for over 50% of all cases. In this regard, in Russia we carry out a program of selective screening for DMD/BMD, which mainly involves male patients. The main inclusion criteria are an increase in the level of creatine phosphokinase (>2000 U/L) or an established clinical diagnosis. At the first stage of screening, patients are scanned for extended deletions and duplications in the DMD gene using multiplex ligase-dependent probe amplification (MLPA SALSA P034 and P035 DMD probemix, MRC-Holland). The second stage is the search for small mutations using a custom NGS panel, which includes 31 genes responsible for various forms of limb-girdle muscular dystrophy. In a screening of 1025 families with a referral Duchenne/Becker diagnosis, pathogenic and likely pathogenic variants in the DMD gene were found in 788 families (in 76.9% of cases). In the current study, we analyzed the mutation spectrum of the DMD gene in Russian patients and noted certain differences between the examined cohort and the multi-ethnic cohort. The analysis of the DMD gene mutation spectrum is essential for patients with DMD/BMD because the exact mutation type determines the application of a specific therapeutic method.
Collapse
|
19
|
Abdelhalim H, Berber A, Lodi M, Jain R, Nair A, Pappu A, Patel K, Venkat V, Venkatesan C, Wable R, Dinatale M, Fu A, Iyer V, Kalove I, Kleyman M, Koutsoutis J, Menna D, Paliwal M, Patel N, Patel T, Rafique Z, Samadi R, Varadhan R, Bolla S, Vadapalli S, Ahmed Z. Artificial Intelligence, Healthcare, Clinical Genomics, and Pharmacogenomics Approaches in Precision Medicine. Front Genet 2022; 13:929736. [PMID: 35873469 PMCID: PMC9299079 DOI: 10.3389/fgene.2022.929736] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 05/25/2022] [Indexed: 12/13/2022] Open
Abstract
Precision medicine has greatly aided in improving health outcomes using earlier diagnosis and better prognosis for chronic diseases. It makes use of clinical data associated with the patient as well as their multi-omics/genomic data to reach a conclusion regarding how a physician should proceed with a specific treatment. Compared to the symptom-driven approach in medicine, precision medicine considers the critical fact that all patients do not react to the same treatment or medication in the same way. When considering the intersection of traditionally distinct arenas of medicine, that is, artificial intelligence, healthcare, clinical genomics, and pharmacogenomics—what ties them together is their impact on the development of precision medicine as a field and how they each contribute to patient-specific, rather than symptom-specific patient outcomes. This study discusses the impact and integration of these different fields in the scope of precision medicine and how they can be used in preventing and predicting acute or chronic diseases. Additionally, this study also discusses the advantages as well as the current challenges associated with artificial intelligence, healthcare, clinical genomics, and pharmacogenomics.
Collapse
Affiliation(s)
- Habiba Abdelhalim
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Asude Berber
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Mudassir Lodi
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Rihi Jain
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Achuth Nair
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Anirudh Pappu
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Kush Patel
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Vignesh Venkat
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Cynthia Venkatesan
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Raghu Wable
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Matthew Dinatale
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Allyson Fu
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Vikram Iyer
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Ishan Kalove
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Marc Kleyman
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Joseph Koutsoutis
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - David Menna
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Mayank Paliwal
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Nishi Patel
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Thirth Patel
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Zara Rafique
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Rothela Samadi
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Roshan Varadhan
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Shreyas Bolla
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Sreya Vadapalli
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States
| | - Zeeshan Ahmed
- Rutgers Institute for Health, Health Care Policy and Aging Research, Rutgers University, New Brunswick, NJ, United States.,Department of Medicine, Rutgers Robert Wood Johnson Medical School, Rutgers Biomedical and Health Sciences, New Brunswick, NJ, United States
| |
Collapse
|
20
|
Cohen G, Asor AS, Ben-Shahar S, Goldfarb-Yaacobi R, Kaiser M, Rosenfeld R, Vinovezky M, Irge D, Furman Y, Reiss D, Litz-Philipsborn S, Sukenik-Halevy R. Large scale population screening for Duchenne muscular dystrophy - Predictable and unpredictable challenges. Prenat Diagn 2022; 42:1162-1172. [PMID: 35751502 PMCID: PMC9546335 DOI: 10.1002/pd.6201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 06/05/2022] [Accepted: 06/21/2022] [Indexed: 11/10/2022]
Abstract
Objective Large deletions and duplications account for 65%–80% of pathogenic Duchenne muscular dystrophy (DMD) variants. A nationwide carrier screening for DMD was initiated in Israel in 2020. We assessed the carrier rate and spectrum of variants detected in a cohort of women screened for DMD carrier status and analyzed screening efficacy and challenges related to DMD population screening. Methods A cohort of 12,362 women were tested at a single institute using multiplex ligation‐dependent probe amplification based copy number analysis of the 79 DMD exons. Consecutive sequencing of the primer region was performed when a single exon deletion was suspected. Results Deletions involving multiple exons were detected in seven cases and duplications involving multiple exons were found in four. Of these, nine were pathogenic based on previous reports and familial segregation testing, translating to a carrier rate of 1:1374. A family history was reported in three cases. Single exon deletions were suspected in 81 cases; further sequencing detected a single nucleotide variant affecting probe hybridization. These cases clustered according to ethnic origin. Discussion Population screening for DMD has a significant yield. Most carriers did not report a family history of dystrophinopathies. Screening should be adjusted for methodological limitations. Some cases may require extensive genetic counseling and work‐up.
What's already known about this topic?
Deletions and duplications account for 65%–80% of pathogenic Duchenne muscular dystrophy (DMD) variants. About two‐thirds of DMD pathogenic variants are inherited from a female carrier. A nationwide carrier screening for DMD was initiated in Israel in 2020.
What does this study add?
The carrier rate among 12,362 women tested for deletions and duplications in the DMD gene was 1:1374. Screening should be adjusted for methodological limitations and may require extensive genetic counseling and work‐up.
Collapse
Affiliation(s)
- Gal Cohen
- Meir Medical Center, Kfar Saba, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Atalia Shtorch Asor
- Meir Medical Center, Kfar Saba, Israel.,Genetics Institute, Meir Medical Center, Kfar Saba, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shay Ben-Shahar
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Clalit Innovation division, Clalit Health System, Tel Aviv, Israel
| | - Racheli Goldfarb-Yaacobi
- Meir Medical Center, Kfar Saba, Israel.,Genetics Institute, Meir Medical Center, Kfar Saba, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | | | | | | | - Dana Irge
- Meir Medical Center, Kfar Saba, Israel.,Genetics Institute, Meir Medical Center, Kfar Saba, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yael Furman
- Meir Medical Center, Kfar Saba, Israel.,Genetics Institute, Meir Medical Center, Kfar Saba, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Dafni Reiss
- Meir Medical Center, Kfar Saba, Israel.,Genetics Institute, Meir Medical Center, Kfar Saba, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shira Litz-Philipsborn
- Meir Medical Center, Kfar Saba, Israel.,Genetics Institute, Meir Medical Center, Kfar Saba, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Rivka Sukenik-Halevy
- Meir Medical Center, Kfar Saba, Israel.,Genetics Institute, Meir Medical Center, Kfar Saba, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
21
|
Waldrop MA, Moore SA, Mathews KD, Darbro BW, Medne L, Finkel R, Connolly AM, Crawford TO, Drachman D, Wein N, Habib AA, Krzesniak-Swinarska MA, Zaidman CM, Collins JJ, Jokela M, Udd B, Day JW, Ortiz-Guerrero G, Statland J, Butterfield RJ, Dunn DM, Weiss RB, Flanigan KM. Intron mutations and early transcription termination in Duchenne and Becker muscular dystrophy. Hum Mutat 2022; 43:511-528. [PMID: 35165973 PMCID: PMC9901284 DOI: 10.1002/humu.24343] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 02/05/2022] [Accepted: 02/07/2022] [Indexed: 11/11/2022]
Abstract
DMD pathogenic variants for Duchenne and Becker muscular dystrophy are detectable with high sensitivity by standard clinical exome analyses of genomic DNA. However, up to 7% of DMD mutations are deep intronic and analysis of muscle-derived RNA is an important diagnostic step for patients who have negative genomic testing but abnormal dystrophin expression in muscle. In this study, muscle biopsies were evaluated from 19 patients with clinical features of a dystrophinopathy, but negative clinical DMD mutation analysis. Reverse transcription-polymerase chain reaction or high-throughput RNA sequencing methods identified 19 mutations with one of three pathogenic pseudoexon types: deep intronic point mutations, deletions or insertions, and translocations. In association with point mutations creating intronic splice acceptor sites, we observed the first examples of DMD pseudo 3'-terminal exon mutations causing high efficiency transcription termination within introns. This connection between splicing and premature transcription termination is reminiscent of U1 snRNP-mediating telescripting in sustaining RNA polymerase II elongation across large genes, such as DMD. We propose a novel classification of three distinct types of mutations identifiable by muscle RNA analysis, each of which differ in potential treatment approaches. Recognition and appropriate characterization may lead to therapies directed toward full-length dystrophin expression for some patients.
Collapse
Affiliation(s)
- Megan A. Waldrop
- The Center for Gene Therapy, Nationwide Children’s Hospital, Columbus, OH 43205,Department of Neurology, The Ohio State University, Columbus, OH 43205,Department of Pediatrics, The Ohio State University, Columbus, OH 43205
| | - Steven A. Moore
- Department of Pathology, The University of Iowa, Iowa City, IA, 52242
| | | | | | - Livja Medne
- Children’s Hospital of Philadelphia, Philadelphia, PA 19104
| | | | - Anne M. Connolly
- Department of Neurology, Washington University, Saint Louis, MO 63110
| | | | | | - Nicolas Wein
- The Center for Gene Therapy, Nationwide Children’s Hospital, Columbus, OH 43205
| | | | | | - Craig M. Zaidman
- Department of Neurology, Washington University, Saint Louis, MO 63110
| | - James J. Collins
- Department of Pediatric Neurology, Mercy Hospitals, Springfield, MO 65804
| | - Manu Jokela
- Neuromuscular Research Center, Tampere University Hospital and University of Tampere, Tampere, Finland,Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland
| | - Bjarne Udd
- Neuromuscular Research Center, Tampere University Hospital and University of Tampere, Tampere, Finland
| | - John W. Day
- Department of Neurology, University of Minnesota Medical Center, Minneapolis, MN 55454
| | | | - Jeff Statland
- Department of Neurology, University of Kansas, Kansas City, KS
| | - Russell J. Butterfield
- Department of Pediatrics, The University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Diane M. Dunn
- Department of Human Genetics, The University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Robert B. Weiss
- Department of Pediatrics, The University of Utah School of Medicine, Salt Lake City, UT 84112,Department of Human Genetics, The University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Kevin M. Flanigan
- The Center for Gene Therapy, Nationwide Children’s Hospital, Columbus, OH 43205,Department of Neurology, The Ohio State University, Columbus, OH 43205,Department of Pediatrics, The Ohio State University, Columbus, OH 43205
| |
Collapse
|
22
|
Genetic Analysis of Forty MLPA-Negative Duchenne Muscular Dystrophy Patients by Whole-Exome Sequencing. J Mol Neurosci 2022; 72:1098-1107. [PMID: 35218518 DOI: 10.1007/s12031-022-01980-5] [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: 12/18/2021] [Accepted: 01/26/2022] [Indexed: 10/19/2022]
Abstract
This manuscript aimed to determine the underlying point mutations causing Duchenne muscular dystrophy (DMD) in a heterogeneous group of Iranian patients, who are clinically suspected. Whole-exome sequencing was utilized to detect disease-causing variants in 40 MLPA-negative DMD patients. Disease-causing variants were detected in the DMD gene in 36/40 of the patients (90%), and 4/40 of them (10%) remained undiagnosed. WES analysis revealed that nonsense variant was the most common type in our study (23/36 of the cases). Besides, 12/36 of the cases had frameshift variant, and one of the patients had a likely pathogenic splice variant in the DMD gene. Carrier testing revealed that 21/40 of the mothers had the identified variant. Therefore, most variants were inherited (58.3%), while 19/40 were de novo (41. 7%). The present study has demonstrated the importance of performing WES to detect disease-causing point mutations in MLPA-negative DMD patients and to identify carrier females. Due to regulatory challenges, the clinical development of therapeutic approaches is time-consuming and may not be available to all patients shortly. Therefore, it appears that the techniques used to accurately detect disease-causing variants in carrier mothers are a more efficient solution to prevent the increased prevalence of DMD.
Collapse
|
23
|
Yamaguchi H, Awano H, Yamamoto T, Nambu Y, Iijima K. Serum Cardiac Troponin I is a Candidate Biomarker for Cardiomyopathy in Duchenne and Becker Muscular Dystrophies. Muscle Nerve 2022; 65:521-530. [PMID: 35174514 DOI: 10.1002/mus.27522] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 02/04/2022] [Accepted: 02/12/2022] [Indexed: 11/07/2022]
Abstract
INTRODUCTION/AIMS Serum cardiac troponin I (cTnI), its relation to cardiomyopathy, and the contribution of the ACTN3 genotype to serum levels of cTnI in Duchenne and Becker muscular dystrophy (DMD and BMD) remain unknown. This study aimed to reveal the characteristics of cTnI, assess whether cTnI is a biomarker for cardiomyopathy in these dystrophinopathies, and evaluate the contribution of the ACTN3 genotype to the serum levels of cTnI in DMD patients. METHODS Serum cTnI values obtained from 127 DMD and 47 BMD patients were retrospectively analyzed. The relationship between cTnI and echocardiography data or the ACTN3 XX genotype was assessed. RESULTS The cTnI levels and proportion of patients with abnormal cTnI levels were significantly higher among DMD patients than BMD, especially in the second decade of life. In DMD, the cTnI level reached a maximum at 13 years, and left ventricular ejection fraction (LVEF) became abnormal approximately 1 year subsequently. In BMD, the cTnI level peaked at the age of 14 years, and LVEF became abnormal 3 years later. Decreased LVEF was observed after cTnI elevation in both populations. cTnI levels by age in DMD patients with the ACTN3 XX genotype tended to increase significantly and early. DISCUSSION Myocardial injury indicated by cTnI elevation was more common and severe in DMD patients. cTnI elevation preceding cardiac dysfunction may represent an early phase of cardiomyopathy progression and may be a biomarker for early detection of cardiomyopathy in these dystrophinopathies. The ACTN3 XX genotype may be a risk factor for early myocardial injury. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Hiroshi Yamaguchi
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Hiroyuki Awano
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | | | - Yoshinori Nambu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kazumoto Iijima
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan.,Director, Hyogo Prefectural Kobe Children's Hospital, Kobe, Japan
| |
Collapse
|
24
|
Keegan NP, Wilton SD, Fletcher S. Analysis of Pathogenic Pseudoexons Reveals Novel Mechanisms Driving Cryptic Splicing. Front Genet 2022; 12:806946. [PMID: 35140743 PMCID: PMC8819188 DOI: 10.3389/fgene.2021.806946] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 12/09/2021] [Indexed: 12/16/2022] Open
Abstract
Understanding pre-mRNA splicing is crucial to accurately diagnosing and treating genetic diseases. However, mutations that alter splicing can exert highly diverse effects. Of all the known types of splicing mutations, perhaps the rarest and most difficult to predict are those that activate pseudoexons, sometimes also called cryptic exons. Unlike other splicing mutations that either destroy or redirect existing splice events, pseudoexon mutations appear to create entirely new exons within introns. Since exon definition in vertebrates requires coordinated arrangements of numerous RNA motifs, one might expect that pseudoexons would only arise when rearrangements of intronic DNA create novel exons by chance. Surprisingly, although such mutations do occur, a far more common cause of pseudoexons is deep-intronic single nucleotide variants, raising the question of why these latent exon-like tracts near the mutation sites have not already been purged from the genome by the evolutionary advantage of more efficient splicing. Possible answers may lie in deep intronic splicing processes such as recursive splicing or poison exon splicing. Because these processes utilize intronic motifs that benignly engage with the spliceosome, the regions involved may be more susceptible to exonization than other intronic regions would be. We speculated that a comprehensive study of reported pseudoexons might detect alignments with known deep intronic splice sites and could also permit the characterisation of novel pseudoexon categories. In this report, we present and analyse a catalogue of over 400 published pseudoexon splice events. In addition to confirming prior observations of the most common pseudoexon mutation types, the size of this catalogue also enabled us to suggest new categories for some of the rarer types of pseudoexon mutation. By comparing our catalogue against published datasets of non-canonical splice events, we also found that 15.7% of pseudoexons exhibit some splicing activity at one or both of their splice sites in non-mutant cells. Importantly, this included seven examples of experimentally confirmed recursive splice sites, confirming for the first time a long-suspected link between these two splicing phenomena. These findings have the potential to improve the fidelity of genetic diagnostics and reveal new targets for splice-modulating therapies.
Collapse
Affiliation(s)
- Niall P. Keegan
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, Australia
- Centre for Neuromuscular and Neurological Disorders, Perron Institute for Neurological and Translational Science, The University of Western Australia, Perth, WA, Australia
- *Correspondence: Niall P. Keegan,
| | - Steve D. Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, Australia
- Centre for Neuromuscular and Neurological Disorders, Perron Institute for Neurological and Translational Science, The University of Western Australia, Perth, WA, Australia
| | - Sue Fletcher
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Perth, WA, Australia
- Centre for Neuromuscular and Neurological Disorders, Perron Institute for Neurological and Translational Science, The University of Western Australia, Perth, WA, Australia
| |
Collapse
|
25
|
Ma YL, Zhang WH, Chen GH, Song LF, Wang Y, Yuan RL, Wang Y, Cheng XY. Walking alone milestone combined reading-frame rule improves early prediction of Duchenne muscular dystrophy. Front Pediatr 2022; 10:985878. [PMID: 36034570 PMCID: PMC9417149 DOI: 10.3389/fped.2022.985878] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 07/22/2022] [Indexed: 12/05/2022] Open
Abstract
OBJECTIVE To explore the potential of walking alone milestone combined reading-frame rule to improve the early diagnosis of Duchenne muscular dystrophy (DMD). METHOD To retrospectively describe the genotype and phenotype of Duchenne and Becker muscular dystrophies (BMD) patients with deletions and duplicates in the dystrophin gene. The sensitivity and specificity of the reading frame rule were calculated and compared to that of the combined reading frame rule and walking alone milestone. The diagnostic coincidence rate of two different methods was analyzed. RESULT One hundred sixty-nine male DMD/BMD patients were enrolled, including 17 cases of BMD and 152 cases of DMD. The diagnostic coincidence rate, diagnostic sensitivity, and specificity of the reading-frame rule for DMD/BMD were 85.2, 86.8, and 70.59%, respectively. The sensitivity and specificity of the reading frame principle combined with the walking alone milestone for DMD/BMD were 96.05 and 70.59%, respectively. The diagnostic coincidence rate increased to 93.49%, significantly different from that predicted by reading- frame rule (P < 0.05). CONCLUSION The reading-frame rule combined with the walking alone milestone significantly improved the early diagnosis rate of DMD.
Collapse
Affiliation(s)
- Yan-Li Ma
- Department of Neonatology, The First Affiliated Hospital of Zheng Zhou University, Zhengzhou, China.,Department of Neurology, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, China
| | - Wei-Hua Zhang
- Department of Neurology, Beijing Children's Hospital, Beijing, China
| | - Guo-Hong Chen
- Department of Neurology, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, China
| | - Li-Fang Song
- Department of Neurology, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, China
| | - Yuan Wang
- Department of Neurology, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, China
| | - Rui-Li Yuan
- Department of Neurology, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, China
| | - Ying Wang
- Department of Neurology, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, China
| | - Xiu-Yong Cheng
- Department of Neonatology, The First Affiliated Hospital of Zheng Zhou University, Zhengzhou, China
| |
Collapse
|
26
|
Liu W, Shi X, Li Y, Qiao F, Wu Y. The identification of a novel splicing mutation in the DMD gene of a Chinese family. Clin Case Rep 2021; 9:e05166. [PMID: 34938549 PMCID: PMC8659554 DOI: 10.1002/ccr3.5166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/25/2021] [Accepted: 11/05/2021] [Indexed: 11/14/2022] Open
Abstract
The proband is a five-year-old boy diagnosed with Duchenne muscular dystrophy (DMD) by clinical manifestations and laboratory examination, but clinical phenotype of his parents is normal. In the study, his mother had a second pregnancy, and they went to obstetrics for genetic counseling to make informed reproductive choices.
Collapse
Affiliation(s)
- Wanlu Liu
- Department of Obstetrics and GynecologyTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Xinwei Shi
- Department of Obstetrics and GynecologyTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Yuqi Li
- Department of Obstetrics and GynecologyTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Fuyuan Qiao
- Department of Obstetrics and GynecologyTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Yuanyuan Wu
- Department of Obstetrics and GynecologyTongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| |
Collapse
|
27
|
Kim MJ, Lee S, Yun H, Cho SI, Kim B, Lee JS, Chae JH, Sun C, Park SS, Seong MW. Consistent count region-copy number variation (CCR-CNV): an expandable and robust tool for clinical diagnosis of copy number variation at the exon level using next-generation sequencing data. Genet Med 2021; 24:663-672. [PMID: 34906491 DOI: 10.1016/j.gim.2021.10.025] [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: 10/29/2021] [Accepted: 10/29/2021] [Indexed: 11/29/2022] Open
Abstract
PURPOSE Despite the importance of exonic copy number variations (CNVs) in human genetic diseases, reliable next-generation sequencing-based methods for detecting them are unavailable. We developed an expandable and robust exonic CNV detection tool called consistent count region (CCR)-CNV. METHODS In total, about 1000 samples of the truth set were used for validating CCR-CNV. We compared CCR-CNV performance with 2 well-known CNV tools. Finally, to overcome the limitations of CCR-CNV, we devised a combined approach. RESULTS The mean sensitivity and specificity of CCR-CNV alone were above 95%, which was superior to that of other CNV tools, such as DECoN and Atlas-CNV. However, low covered region and positive predictive value and high false discovery rate act as obstacles to its use in clinical settings. The combined approach showed much improved performance than CCR-CNV alone. CONCLUSION In this study, we present a novel diagnostic tool that allows the identification of exonic CNVs with high confidence using various reagents and clinical next-generation sequencing platforms. We validated this method using the largest multiple ligation-dependent probe amplification-confirmed data set, including sufficient copy normal control data. The approach, combined with existing CNV tools, allows the implementation of CCR-CNV in clinical settings.
Collapse
Affiliation(s)
- Man Jin Kim
- Department of Genomic Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea; Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Sungyoung Lee
- Department of Genomic Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea; Center for Precision Medicine, Seoul National University Hospital, Seoul, Korea
| | - Hongseok Yun
- Department of Genomic Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea; Center for Precision Medicine, Seoul National University Hospital, Seoul, Korea
| | - Sung Im Cho
- Center for Precision Medicine, Seoul National University Hospital, Seoul, Korea
| | - Boram Kim
- Center for Precision Medicine, Seoul National University Hospital, Seoul, Korea
| | - Jee-Soo Lee
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Jong Hee Chae
- Department of Genomic Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea; Department of Pediatrics, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | | | - Sung Sup Park
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Moon-Woo Seong
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
| |
Collapse
|
28
|
Prenatal Diagnosis of Dystrophinopathy and Cytogenetic Analysis in 303 Chinese Families. MATERNAL-FETAL MEDICINE 2021. [DOI: 10.1097/fm9.0000000000000089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|
29
|
Chen Y, Zhu Y, Zhou Y, Zeng J. Becker muscular dystrophy with dilated cardiomyopathy: A case report. Clin Case Rep 2021; 9:e04777. [PMID: 34567552 PMCID: PMC8449112 DOI: 10.1002/ccr3.4777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/12/2021] [Accepted: 08/22/2021] [Indexed: 11/10/2022] Open
Abstract
Becker muscular dystrophy (BMD) complicated with DCM is rare in our daily clinical practice. BMD serves an etiology for heart failure patients due to DCM. Multidisciplinary management is required in this case.
Collapse
Affiliation(s)
- Yongliang Chen
- Center of Cooperative Postgraduate Cultivation in Xiangtan Central HospitalUniversity of South ChinaXiangtanChina
- Department of CardiologyXiangtan Central HospitalXiangtanChina
| | - Yunlong Zhu
- Department of CardiologyXiangtan Central HospitalXiangtanChina
| | - Yuying Zhou
- Center of Cooperative Postgraduate Cultivation in Xiangtan Central HospitalUniversity of South ChinaXiangtanChina
- Department of CardiologyXiangtan Central HospitalXiangtanChina
| | - Jianping Zeng
- Center of Cooperative Postgraduate Cultivation in Xiangtan Central HospitalUniversity of South ChinaXiangtanChina
- Department of CardiologyXiangtan Central HospitalXiangtanChina
| |
Collapse
|
30
|
Guevara-Fujita ML, Huaman-Dianderas F, Obispo D, Sánchez R, Barrenechea V, Rojas-Málaga D, Estrada-Cuzcano A, Trubnykova M, Cornejo-Olivas M, Marca V, Gallardo B, Dueñas-Roque M, Protzel A, Castañeda C, Abarca H, Celis L, La Serna-Infantes J, Fujita R. MLPA followed by target-NGS to detect mutations in the dystrophin gene of Peruvian patients suspected of DMD/DMB. Mol Genet Genomic Med 2021; 9:e1759. [PMID: 34327855 PMCID: PMC8457708 DOI: 10.1002/mgg3.1759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/09/2021] [Accepted: 07/08/2021] [Indexed: 11/11/2022] Open
Abstract
Background We report the molecular analysis of the DMD gene in a group of Peruvian patients with Duchenne/Becker dystrophinopathy. This is the first study to thoroughly characterize mutations in this population. Methods We used the combination of multiplex ligation‐dependent probe amplification (MLPA) and sequencing analysis of the DMD gene. We recruited Peruvian patients in 2 years from reference national hospitals. We performed DNA tests in 152 patients, checking first exon deletion/duplication by MLPA, and subsequently, if negative, samples were sequenced to detect point mutations. Results The average age for diagnosis was 9.8 years, suggesting a delay for timely diagnosis and care. We found causal DMD mutations in 125 patients: 72 (57.6%) exon deletions/duplications (41.6% deletions, 16.0% duplications), and 53 (42.4%) point mutations (27.2% nonsense, 9.6% small indels, and 5.6% splice site). Conclusion Due to our genetic background, we expected a higher number of novel and recurrent causal mutations in our sample. Results showed 16% of novel mutations, similar to other well‐studied populations.
Collapse
Affiliation(s)
- María Luisa Guevara-Fujita
- Centro de Genética y Biología Molecular, Instituto de Investigación, Facultad de Medicina Humana, Universidad de San Martín de Porres, Lima, Peru
| | - Francia Huaman-Dianderas
- Centro de Genética y Biología Molecular, Instituto de Investigación, Facultad de Medicina Humana, Universidad de San Martín de Porres, Lima, Peru
| | - Daisy Obispo
- Centro de Genética y Biología Molecular, Instituto de Investigación, Facultad de Medicina Humana, Universidad de San Martín de Porres, Lima, Peru
| | - Rodrigo Sánchez
- Centro de Genética y Biología Molecular, Instituto de Investigación, Facultad de Medicina Humana, Universidad de San Martín de Porres, Lima, Peru
| | - Victor Barrenechea
- Centro de Genética y Biología Molecular, Instituto de Investigación, Facultad de Medicina Humana, Universidad de San Martín de Porres, Lima, Peru
| | - Diana Rojas-Málaga
- Centro de Genética y Biología Molecular, Instituto de Investigación, Facultad de Medicina Humana, Universidad de San Martín de Porres, Lima, Peru.,Laboratório de Genética Molecular, Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Rio Grande do Sul, Brazil
| | - Alejandro Estrada-Cuzcano
- Centro de Genética y Biología Molecular, Instituto de Investigación, Facultad de Medicina Humana, Universidad de San Martín de Porres, Lima, Peru.,Paris-Saclay Institute of Neuroscience, CERTO-Retina France, CNRS, Université Paris-Saclay, Orsay, 91405, France
| | - Milana Trubnykova
- Servicio de Genética y Errores Innatos del Metabolismo del Instituto Nacional de Salud del Niño, Lima, Peru
| | - Mario Cornejo-Olivas
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima, Peru.,Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Victoria Marca
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima, Peru
| | - Bertha Gallardo
- Servicio de Genética y Errores Innatos del Metabolismo del Instituto Nacional de Salud del Niño, Lima, Peru
| | | | - Ana Protzel
- Hospital Nacional Edgardo Rebagliati Martins, EsSalud, Lima, Peru
| | | | - Hugo Abarca
- Servicio de Genética y Errores Innatos del Metabolismo del Instituto Nacional de Salud del Niño, Lima, Peru
| | - Luis Celis
- Servicio de Genética, Instituto de Salud del Niño San Borja, Lima, Peru
| | | | - Ricardo Fujita
- Centro de Genética y Biología Molecular, Instituto de Investigación, Facultad de Medicina Humana, Universidad de San Martín de Porres, Lima, Peru
| |
Collapse
|
31
|
Santin R, Vieira IA, Nunes JC, Benevides ML, Quadros F, Brusius-Facchin AC, Macedo G, Bertoni APS. A novel DMD intronic alteration: a potentially disease-causing variant of an intermediate muscular dystrophy phenotype. ACTA MYOLOGICA : MYOPATHIES AND CARDIOMYOPATHIES : OFFICIAL JOURNAL OF THE MEDITERRANEAN SOCIETY OF MYOLOGY 2021; 40:93-100. [PMID: 34355126 PMCID: PMC8290513 DOI: 10.36185/2532-1900-048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 06/24/2021] [Indexed: 06/13/2023]
Abstract
Pathogenic germline variants in DMD gene, which encodes the well-known cytoskeletal protein named dystrophin, are associated with a wide range of dystrophinopathies disorders, such as Duchenne muscular dystrophy (DMD, severe form), Becker muscular dystrophy (BMD, mild form) and intermediate muscular dystrophy (IMD). Muscle biopsy, immunohistochemistry, molecular (multiplex ligation-dependent probe amplification (MLPA)/next-generation sequencing (NGS) and Sanger methods) and in silico analyses were performed in order to identify alterations in DMD gene and protein in a patient with a clinical manifestation and with high creatine kinase levels. Herein, we described a previously unreported intronic variant in DMD and reduced dystrophin staining in the muscle biopsy. This novel DMD variant allele, c.9649+4A>T that was located in a splice donor site within intron 66. Sanger sequencing analysis from maternal DNA showed the presence of both variant c.9649+4A>T and wild-type (WT) DMD alleles. Different computational tools suggested that this nucleotide change might affect splicing through a WT donor site disruption, occurring in an evolutionarily conserved region. Indeed, we observed that this novel variant, could explain the reduced dystrophin protein levels and discontinuous sarcolemmal staining in muscle biopsy, which suggests that c.9649+4A>T allele may be re-classified as pathogenic in the future. Our data show that the c.9649+4A>T intronic sequence variant in the DMD gene may be associated with an IMD phenotype and our findings reinforce the importance of a more precise diagnosis combining muscle biopsy, molecular techniques and comprehensive in silico approaches in the clinical cases with negative results for conventional genetic analysis.
Collapse
Affiliation(s)
- Ricardo Santin
- Santa Casa de Misericórdia de Porto Alegre, (ISCMPA), Porto Alegre, Rio Grande do Sul, Brazil
| | - Igor Araujo Vieira
- Programa de Pós Graduação em Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil
- Laboratório de Medicina Genômica, Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Rio Grande do Sul, Brazil
| | - Jean Costa Nunes
- Neurodiagnostic Brazil - Floranópolis, Santa Catarina (SC), Brazil
- Departmento de Patologia, Universidade Federal de Santa Catarina (UFSC), Hospital Polydoro Ernani de São Thiago, SC, Brazil
| | - Maria Luiza Benevides
- Departmento de Neurologia, Hospital Governador Celso Ramos, Santa Catarina (SC), Brazil
| | - Fernanda Quadros
- Santa Casa de Misericórdia de Porto Alegre, (ISCMPA), Porto Alegre, Rio Grande do Sul, Brazil
| | - Ana Carolina Brusius-Facchin
- Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Rio Grande do Sul, Brazil
| | - Gabriel Macedo
- Laboratório de Medicina Genômica, Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Rio Grande do Sul, Brazil
- Programa de Medicina Personalizada, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Rio Grande do Sul, Brazil
| | - Ana Paula Santin Bertoni
- Departamento de Ciências Básicas da Saúde and Laboratório de Biologia Celular, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil
| |
Collapse
|
32
|
Lee T, Tokunaga S, Taniguchi N, Misaki M, Shimomura H, Nishino I, Itoh K, Takeshima Y. Underlying diseases in sporadic presentation of high creatine kinase levels in girls. Clin Chim Acta 2021; 519:198-203. [PMID: 33965408 DOI: 10.1016/j.cca.2021.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/02/2021] [Accepted: 05/04/2021] [Indexed: 11/19/2022]
Abstract
BACKGROUND Persistent creatine kinase (CK) elevation can occur due to various conditions. Identifying the causes of hyperCKemia is crucial for enabling appropriate follow-up and care. Girls with elevated CK levels may be carriers of Duchenne/Becker muscular dystrophy (DMD/BMD), making diagnosis more difficult than that in boys. This study aimed to elucidate the underlying causes of high CK levels in girls. METHODS Fourteen girls (seven symptomatic, seven asymptomatic) with persistently elevated CK levels but without a family history of muscle diseases were referred to our hospital between April 2014 and August 2018. Muscle biopsy and/or genetic analysis were conducted for diagnoses. RESULTS Among the symptomatic girls, six (85.7%) had muscular dystrophy (five DMD/BMD carriers, and one sarcoglycanopathy [limb-girdle muscular dystrophy: LGMDR4]), and one had dermatomyositis. Among the asymptomatic girls, four (57.1%) had muscular dystrophy (three DMD/BMD carriers, and one calpainopathy [LGMDR1]), and three were undiagnosed. CONCLUSION Our results indicate that muscular dystrophy, including DMD/BMD carriers, must be considered in girls with highperCKemia regardless of symptoms presentation, and in symptomatic girls with dermatomyositis. Investigations in girls with hyperCKemia should be performed under proper ethical considerations. Further research is necessary to develop a diagnostic strategy for girls with hyperCKemia.
Collapse
Affiliation(s)
- Tomoko Lee
- Department of Pediatrics, Hyogo College of Medicine, Nishinomiya, Japan.
| | - Sachi Tokunaga
- Department of Pediatrics, Hyogo College of Medicine, Nishinomiya, Japan
| | - Naoko Taniguchi
- Department of Pediatrics, Hyogo College of Medicine, Nishinomiya, Japan
| | - Maiko Misaki
- Department of Pediatrics, Hyogo College of Medicine, Nishinomiya, Japan
| | - Hideki Shimomura
- Department of Pediatrics, Hyogo College of Medicine, Nishinomiya, Japan
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Kyoko Itoh
- Department of Pathology and Applied Neurobiology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan
| | | |
Collapse
|
33
|
Prenatal diagnosis of de novo DMD duplication by multiplex ligation-dependent probe amplification (MLPA) after noninvasive prenatal screening (NIPS) at 11 gestational weeks. Taiwan J Obstet Gynecol 2021; 60:570-573. [PMID: 33966752 DOI: 10.1016/j.tjog.2021.03.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2020] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE Dystrophinopathy is an X-linked recessive muscular dystrophy caused by mutations in the DMD gene. Herein we describe the prenatal detection of DMD gene mutations in a patient with no family history, by multiplex ligation-dependent probe amplification (MLPA) after noninvasive prenatal screening (NIPS). CASE REPORT A 41-year-old woman underwent NIPS owing to an advanced maternal age. A copy number variation was detected in the maternal X chromosome, and uninformative results were obtained for the fetal sex chromosomes. Following amniocentesis, a duplication was identified in exons 1-29 of the dystrophin gene by MLPA. After interviewing her family members it was confirmed that the patient is a de novo carrier of DMD duplications, and her daughter is a carrier of the same mutation. CONCLUSION his is the first case report to describe the prenatal diagnosis of duplications in the DMD gene by MLPA following NIPS in a patient with no family history.
Collapse
|
34
|
Geng C, Tong Y, Zhang S, Ling C, Wu X, Wang D, Dai Y. Sequence and Structure Characteristics of 22 Deletion Breakpoints in Intron 44 of the DMD Gene Based on Long-Read Sequencing. Front Genet 2021; 12:638220. [PMID: 34211494 PMCID: PMC8240811 DOI: 10.3389/fgene.2021.638220] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 03/29/2021] [Indexed: 12/27/2022] Open
Abstract
Purpose: Exon deletions make up to 80% of mutations in the DMD gene, which cause Duchenne and Becker muscular dystrophy. Exon 45-55 regions were reported as deletion hotspots and intron 44 harbored more than 25% of deletion start points. We aimed to investigate the fine structures of breakpoints in intron 44 to find potential mechanisms of large deletions in intron 44. Methods: Twenty-two dystrophinopathy patients whose deletion started in intron 44 were sequenced using long-read sequencing of a DMD gene capture panel. Sequence homology, palindromic sequences, and polypyrimidine sequences were searched at the breakpoint junctions. RepeatMasker was used to analyze repetitive elements and Mfold was applied to predict secondary DNA structure. Results: With a designed DMD capture panel, 22 samples achieved 2.25 gigabases and 1.28 million reads on average. Average depth was 308× and 99.98% bases were covered at least 1×. The deletion breakpoints in intron 44 were scattered and no breakpoints clustered in any region less than 500 bp. A total of 72.7% of breakpoints located in distal 100 kb of intron 44 and more repetitive elements were found in this region. Microhomologies of 0–1 bp were found in 36.4% (8/22) of patients, which corresponded with non-homologous end-joining. Microhomologies of 2–20 bp were found in 59.1% (13/22) of patients, which corresponded with microhomology-mediated end-joining. Moreover, a 7 bp insertion was found in one patient, which might be evidence of aberrant replication origin firing. Palindromic sequences, polypyrimidine sequences, and small hairpin loops were found near several breakpoint junctions. No evidence of large hairpin loop formation in deletion root sequences was observed. Conclusion: This study was the first to explore possible mechanisms underlying exon deletions starting from intron 44 of the DMD gene based on long-read sequencing. Diverse mechanisms might be associated with deletions in the DMD gene.
Collapse
Affiliation(s)
- Chang Geng
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Yuanren Tong
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | | | - Chao Ling
- Laboratory of Clinical Genetics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Xin Wu
- GrandOmics Biosciences, Beijing, China
| | | | - Yi Dai
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| |
Collapse
|
35
|
Abreu NJ, Waldrop MA. Overview of gene therapy in spinal muscular atrophy and Duchenne muscular dystrophy. Pediatr Pulmonol 2021; 56:710-720. [PMID: 32886442 DOI: 10.1002/ppul.25055] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/25/2020] [Accepted: 08/27/2020] [Indexed: 12/12/2022]
Abstract
Both 5q-linked spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD) are fatal monogenic neuromuscular disorders caused by loss-of-function mutations. SMA is an autosomal recessive disorder affecting motor neurons that is typically caused by homozygous whole-gene deletions of SMN1. DMD is an X-linked recessive muscle disease most often due to exon deletions, but also duplications and smaller sized variants within the DMD gene. Gene replacement therapy offers the opportunity to correct the underlying genetic defect by the introduction of a functional gene. We review the transformative work from clinical trials to United States Food and Drug Administration approval of onasemnogene abeparvovec-xioi in SMA and its application in clinical practice and the early results of microdystrophin delivery in DMD. We also review the introduction of antisense oligonucleotides to alter pre-messenger RNA splicing to promote exon inclusion (as in nusinersen in SMA) or exclusion (as in eteplirsen in DMD) into neuromuscular therapeutics. There are multiple promising novel genetically mediated therapies on the horizon, which in aggregate point towards a hopeful future for individuals with SMA and DMD.
Collapse
Affiliation(s)
- Nicolas J Abreu
- Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Megan A Waldrop
- Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, Ohio, USA.,Departments of Pediatrics and Neurology, Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| |
Collapse
|
36
|
A Genotype-Phenotype Correlation Study of Exon Skip-Equivalent In-Frame Deletions and Exon Skip-Amenable Out-of-Frame Deletions across the DMD Gene to Simulate the Effects of Exon-Skipping Therapies: A Meta-Analysis. J Pers Med 2021; 11:jpm11010046. [PMID: 33466756 PMCID: PMC7830903 DOI: 10.3390/jpm11010046] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 01/16/2023] Open
Abstract
Dystrophinopathies are caused by mutations in the DMD gene. Out-of-frame deletions represent most mutational events in severe Duchenne muscular dystrophy (DMD), while in-frame deletions typically lead to milder Becker muscular dystrophy (BMD). Antisense oligonucleotide-mediated exon skipping converts an out-of-frame transcript to an in-frame one, inducing a truncated but partially functional dystrophin protein. The reading frame rule, however, has many exceptions. We thus sought to simulate clinical outcomes of exon-skipping therapies for DMD exons from clinical data of exon skip-equivalent in-frame deletions, in which the expressed quasi-dystrophins are comparable to those resulting from exon-skipping therapies. We identified a total of 1298 unique patients with exon skip-equivalent mutations in patient registries and the existing literature. We classified them into skip-equivalent deletions of each exon and statistically compared the ratio of DMD/BMD and asymptomatic individuals across the DMD gene. Our analysis identified that five exons are associated with significantly milder phenotypes than all other exons when corresponding exon skip-equivalent in-frame deletion mutations occur. Most exon skip-equivalent in-frame deletions were associated with a significantly milder phenotype compared to corresponding exon skip-amenable out-of-frame mutations. This study indicates the importance of genotype-phenotype correlation studies in the rational design of exon-skipping therapies.
Collapse
|
37
|
Zimowski JG, Purzycka J, Pawelec M, Ozdarska K, Zaremba J. Small mutations in Duchenne/Becker muscular dystrophy in 164 unrelated Polish patients. J Appl Genet 2021; 62:289-295. [PMID: 33420945 DOI: 10.1007/s13353-020-00605-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 12/09/2020] [Accepted: 12/22/2020] [Indexed: 10/22/2022]
Abstract
In the 164 patients with Duchenne/Becker muscular dystrophy, we found 142 different small mutations including 51 novel mutations not listed in the LOVD, the UMD-DMD, the ClinVar, and the HGMD databases. Among all mutations, nonsense mutations occurred in 45.7%, frameshift mutations in 32.9%, and splicing mutations in 19.5%. Small mutations were distributed throughout the whole dystrophin gene. Splicing mutations were twice more common in BMD patients than in DMD patients. Eighty-two percent of mothers of the males affected with DMD/BMD were found to be carriers of small mutations.
Collapse
Affiliation(s)
- Janusz G Zimowski
- Department of Genetics, Institute of Psychiatry and Neurology, 02-957, Sobieskiego 9, Warsaw, Poland. .,, Warsaw, Poland.
| | - Joanna Purzycka
- Department of Genetics, Institute of Psychiatry and Neurology, 02-957, Sobieskiego 9, Warsaw, Poland
| | - Magdalena Pawelec
- Department of Genetics, Institute of Psychiatry and Neurology, 02-957, Sobieskiego 9, Warsaw, Poland
| | - Katarzyna Ozdarska
- Department of Genetics, Institute of Psychiatry and Neurology, 02-957, Sobieskiego 9, Warsaw, Poland
| | - Jacek Zaremba
- Department of Genetics, Institute of Psychiatry and Neurology, 02-957, Sobieskiego 9, Warsaw, Poland
| |
Collapse
|
38
|
Nassoro DD, Torres L, Marando R, Mboma L, Mushi S, Habakkuk Mwakyula I. A child with duchenne muscular dystrophy: A case report of a rare diagnosis among Africans. Clin Case Rep 2020; 8:2654-2660. [PMID: 33363799 PMCID: PMC7752564 DOI: 10.1002/ccr3.3254] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 07/20/2020] [Accepted: 07/22/2020] [Indexed: 01/14/2023] Open
Abstract
In Africa, lack of awareness and low index of suspicion of rare diseases like dystrophinopathies, directly or indirectly, contributes to the increased morbidity and mortality. Therefore, even though the data on prevalence is limited, we need to have a high degree of suspicion in patients presenting with suggestive clinical features.
Collapse
Affiliation(s)
- David D. Nassoro
- Department of Internal MedicineMbeya Zonal Referral HospitalMbeyaTanzania
- Department of Internal MedicineThe University of Dar es SalaamMbeya College of Health and Allied SciencesMbeyaTanzania
| | - Liset Torres
- Department of PathologyMbeya Zonal Referral HospitalMbeyaTanzania
- Department of PathologyThe University of Dar es SalaamMbeya College of Health and Allied SciencesMbeyaTanzania
| | - Rehema Marando
- Department of Pediatrics and Child HealthMbeya Zonal Referral HospitalMbeyaTanzania
- Department of Pediatrics and Child HealthThe University of Dar es SalaamMbeya College of Health and Allied SciencesMbeyaTanzania
| | - Lazaro Mboma
- Department of SurgeryMbeya Zonal Referral HospitalMbeyaTanzania
- Department of SurgeryThe University of Dar es SalaamMbeya College of Health and Allied SciencesMbeyaTanzania
| | - Seraphine Mushi
- Department of PhysiotherapyMbeya Zonal Referral HospitalMbeyaTanzania
| | - Issakwisa Habakkuk Mwakyula
- Department of Internal MedicineMbeya Zonal Referral HospitalMbeyaTanzania
- Department of Internal MedicineThe University of Dar es SalaamMbeya College of Health and Allied SciencesMbeyaTanzania
| |
Collapse
|
39
|
Abstract
The DMD gene is the largest in the human genome, with a total intron content exceeding 2.2Mb. In the decades since DMD was discovered there have been numerous reported cases of pseudoexons (PEs) arising in the mature DMD transcripts of some individuals, either as the result of mutations or as low-frequency errors of the spliceosome. In this review, I collate from the literature 58 examples of DMD PEs and examine the diversity and commonalities of their features. In particular, I note the high frequency of PEs that arise from deep intronic SNVs and discuss a possible link between PEs induced by distal mutations and the regulation of recursive splicing.
Collapse
Affiliation(s)
- Niall P Keegan
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University and Perron Institute, Perth, Australia
| |
Collapse
|
40
|
Joynt AT, Evans TA, Pellicore MJ, Davis-Marcisak EF, Aksit MA, Eastman AC, Patel SU, Paul KC, Osorio DL, Bowling AD, Cotton CU, Raraigh KS, West NE, Merlo CA, Cutting GR, Sharma N. Evaluation of both exonic and intronic variants for effects on RNA splicing allows for accurate assessment of the effectiveness of precision therapies. PLoS Genet 2020; 16:e1009100. [PMID: 33085659 PMCID: PMC7605713 DOI: 10.1371/journal.pgen.1009100] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 11/02/2020] [Accepted: 09/08/2020] [Indexed: 12/21/2022] Open
Abstract
Elucidating the functional consequence of molecular defects underlying genetic diseases enables appropriate design of therapeutic options. Treatment of cystic fibrosis (CF) is an exemplar of this paradigm as the development of CFTR modulator therapies has allowed for targeted and effective treatment of individuals harboring specific genetic variants. However, the mechanism of these drugs limits effectiveness to particular classes of variants that allow production of CFTR protein. Thus, assessment of the molecular mechanism of individual variants is imperative for proper assignment of these precision therapies. This is particularly important when considering variants that affect pre-mRNA splicing, thus limiting success of the existing protein-targeted therapies. Variants affecting splicing can occur throughout exons and introns and the complexity of the process of splicing lends itself to a variety of outcomes, both at the RNA and protein levels, further complicating assessment of disease liability and modulator response. To investigate the scope of this challenge, we evaluated splicing and downstream effects of 52 naturally occurring CFTR variants (exonic = 15, intronic = 37). Expression of constructs containing select CFTR intronic sequences and complete CFTR exonic sequences in cell line models allowed for assessment of RNA and protein-level effects on an allele by allele basis. Characterization of primary nasal epithelial cells obtained from individuals harboring splice variants corroborated in vitro data. Notably, we identified exonic variants that result in complete missplicing and thus a lack of modulator response (e.g. c.2908G>A, c.523A>G), as well as intronic variants that respond to modulators due to the presence of residual normally spliced transcript (e.g. c.4242+2T>C, c.3717+40A>G). Overall, our data reveals diverse molecular outcomes amongst both exonic and intronic variants emphasizing the need to delineate RNA, protein, and functional effects of each variant in order to accurately assign precision therapies. Genetic variants that impact pre-mRNA splicing are a common cause of genetic disease and have varying downstream molecular consequences. As a result, precision therapies that function at the protein level are not always effective for these variants and thus careful assessment is necessary. Here we evaluate RNA-level effects of 52 variants in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and show that study of splicing and its consequences allows for more accurate assignment of precision therapies.
Collapse
Affiliation(s)
- Anya T. Joynt
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Taylor A. Evans
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Matthew J. Pellicore
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Emily F. Davis-Marcisak
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Melis A. Aksit
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Alice C. Eastman
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Shivani U. Patel
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins Hospital, Baltimore, Maryland, United States of America
| | - Kathleen C. Paul
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Derek L. Osorio
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Alyssa D. Bowling
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Calvin U. Cotton
- Departments of Pediatrics, Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Karen S. Raraigh
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Natalie E. West
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins Hospital, Baltimore, Maryland, United States of America
| | - Christian A. Merlo
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins Hospital, Baltimore, Maryland, United States of America
| | - Garry R. Cutting
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (GRC); (NS)
| | - Neeraj Sharma
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (GRC); (NS)
| |
Collapse
|
41
|
Nagai M, Awano H, Yamamoto T, Bo R, Matsuo M, Iijima K. The ACTN3 577XX Null Genotype Is Associated with Low Left Ventricular Dilation-Free Survival Rate in Patients with Duchenne Muscular Dystrophy. J Card Fail 2020; 26:841-848. [DOI: 10.1016/j.cardfail.2020.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 07/09/2020] [Accepted: 08/06/2020] [Indexed: 11/28/2022]
|
42
|
Tong YR, Geng C, Guan YZ, Zhao YH, Ren HT, Yao FX, Ling C, Wang DC, Chen L, Cui LY, Zhang SY, Dai Y. A Comprehensive Analysis of 2013 Dystrophinopathies in China: A Report From National Rare Disease Center. Front Neurol 2020; 11:572006. [PMID: 33101180 PMCID: PMC7554367 DOI: 10.3389/fneur.2020.572006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/24/2020] [Indexed: 12/17/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive neuromuscular disorders caused by mutations in DMD. A high-quality database of DMD/BMD is essential not only for clinical practice but also for fundamental research. Here, we aimed to build the largest Chinese national dystrophinopathy database using the National Rare Diseases Registry System of China. Peking Union Medical College Hospital (PUMCH) was the National Rare Diseases Center of China. This research involved 2013 patients with dystrophinopathies, whose diagnoses were confirmed; they were registered and followed up at PUMCH from March 2011 to December 2018. Family history, clinical signs, and treatment data were reported for patients with DMD and BMD at different rates. All six serum biochemical indexes could accurately distinguish between DMD and BMD patients. Copy number variations were the most frequent mutation type (79.2% in DMD and 84.3% in BMD), of which large deletions accounted for 88.4 and 88.6%, large duplications accounted for 11.6 and 11.4% in DMD and BMD, respectively. An exon deletion hotspot, located in exons 45-54, was observed in DMD, and intron 44 was the most frequent deletion starting point (26.5%). Duplication and single nucleotide variations appeared to be uniformly distributed among all exons. Eleven patients were identified to have ultrarare mutation types. Eleven other patients suffered from two separate mutations simultaneously, some of which may have taken place via dependent mechanisms. Thus, we have established the largest hospital-based Chinese dystrophinopathy database via the National Rare Diseases Registry System. This study provides valuable information for further diagnostic and therapeutic studies of dystrophinopathy.
Collapse
Affiliation(s)
- Yuan-Ren Tong
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Chang Geng
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yu-Zhou Guan
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yan-Huan Zhao
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Hai-Tao Ren
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Feng-Xia Yao
- Laboratory of Clinical Genetics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Chao Ling
- Laboratory of Clinical Genetics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Dan-Chen Wang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Lin Chen
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Li-Ying Cui
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Shu-Yang Zhang
- Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yi Dai
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| |
Collapse
|
43
|
Population-Wide Duchenne Muscular Dystrophy Carrier Detection by CK and Molecular Testing. BIOMED RESEARCH INTERNATIONAL 2020; 2020:8396429. [PMID: 33029525 PMCID: PMC7537677 DOI: 10.1155/2020/8396429] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/27/2020] [Accepted: 09/03/2020] [Indexed: 01/28/2023]
Abstract
Carrier screening of Duchenne muscular dystrophy (DMD) has not been widely evaluated. To identify definite DMD female carriers prior to or in early pregnancy, we studied a large population of reproductive age females and provided informed reproductive options to DMD carriers. 37268 females were recruited from the Hangzhou Family Planning Publicity and Technology Guidance Station/Hangzhou Health Service Center for Children and Women, Hangzhou, China, between October 10, 2017, and December 16, 2018. CK activity was measured with follow-up serum DMD genetic testing in subjects with hyperCKemia, defined as CK > 200 U/L. The calculated upper reference limit (97.5th percentile) of serum creatine kinase (CK) for females aged 20-50 years in this study was near the reference limit recommended by the manufacturer (200 U/L), above which was defined as hyperCKemia. 427 females (1.2%) harbored initially elevated CK, among which 281 females (response rate of 65.8%) accepted CK retesting. DMD genetic testing was conducted on 62 subjects with sustained serum CK > 200 U/L and 16 females with a family history of DMD. Finally, 6 subjects were confirmed to be DMD definite carriers. The estimated DMD female carrier rate in this study was 1 : 4088 (adjusting for response rate), an underestimated rate, since only 50% to 70% of DMD female carriers manifest elevated serum CK, and carriers in this study may have been missed due to lack of follow-up or inability to detect all DMD pathogenic variants by current genetic testing.
Collapse
|
44
|
Torella A, Zanobio M, Zeuli R, del Vecchio Blanco F, Savarese M, Giugliano T, Garofalo A, Piluso G, Politano L, Nigro V. The position of nonsense mutations can predict the phenotype severity: A survey on the DMD gene. PLoS One 2020; 15:e0237803. [PMID: 32813700 PMCID: PMC7437896 DOI: 10.1371/journal.pone.0237803] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/03/2020] [Indexed: 12/23/2022] Open
Abstract
A nonsense mutation adds a premature stop signal that hinders any further translation of a protein-coding gene, usually resulting in a null allele. To investigate the possible exceptions, we used the DMD gene as an ideal model. First, because dystrophin absence causes Duchenne muscular dystrophy (DMD), while its reduction causes Becker muscular dystrophy (BMD). Second, the DMD gene is X-linked and there is no second allele that can interfere in males. Third, databases are accumulating reports on many mutations and phenotypic data. Finally, because DMD mutations may have important therapeutic implications. For our study, we analyzed large databases (LOVD, HGMD and ClinVar) and literature and revised critically all data, together with data from our internal patients. We totally collected 2593 patients. Positioning these mutations along the dystrophin transcript, we observed a nonrandom distribution of BMD-associated mutations within selected exons and concluded that the position can be predictive of the phenotype. Nonsense mutations always cause DMD when occurring at any point in fifty-one exons. In the remaining exons, we found milder BMD cases due to early 5’ nonsense mutations, if reinitiation can occur, or due to late 3’ nonsense when the shortened product retains functionality. In the central part of the gene, all mutations in some in-frame exons, such as in exons 25, 31, 37 and 38 cause BMD, while mutations in exons 30, 32, 34 and 36 cause DMD. This may have important implication in predicting the natural history and the efficacy of therapeutic use of drug-stimulated translational readthrough of premature termination codons, also considering the action of internal natural rescuers. More in general, our survey confirm that a nonsense mutation should be not necessarily classified as a null allele and this should be considered in genetic counselling.
Collapse
Affiliation(s)
- Annalaura Torella
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Mariateresa Zanobio
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
| | - Roberta Zeuli
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
| | | | - Marco Savarese
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
- Folkhälsan Research Center, Medicum, University of Helsinki, Helsinki, Finland
| | - Teresa Giugliano
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
| | - Arcomaria Garofalo
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
| | - Giulio Piluso
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
| | - Luisa Politano
- Dipartimento di Medicina Sperimentale, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
| | - Vincenzo Nigro
- Dipartimento di Medicina di Precisione, Università degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- * E-mail:
| |
Collapse
|
45
|
Zhu Y, Yang L, Ma T, Lu Y, Tao D, Liu Y, Ma Y. Identification of two rare mutations c.1318G>A and c.6438+2T>G in a Chinese DMD family as genetic markers. Genes Genomics 2020; 42:1067-1074. [PMID: 32725577 DOI: 10.1007/s13258-020-00975-z] [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: 03/03/2020] [Accepted: 07/15/2020] [Indexed: 02/05/2023]
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD) is a fatal X-linked recessive disorder with no effective treatment, which underscores the importance of avoiding the birth of children with DMD by identifying pathogenic mutations and obtaining an accurate prenatal diagnosis. OBJECTIVE The objective of this study was to analyze the genetic defect of a Chinese family where all male patients have died of DMD. METHODS Multiplex ligation dependent probe analysis (MLPA) and next-generation sequencing (NGS) were employed to detect DMD mutations. The candidate mutations were then validated by Sanger sequencing. In vitro splicing assay was further conducted to examine the potential effect of the novel DMD splice site mutation on splicing. RESULTS We found that two rare DMD mutations c.1318G>A and c.6438+2T>G passed from generation to generation among female carriers and they may be used as genetic markers in the Chinese DMD family. In vitro splicing assay further revealed that the novel classical splice site mutation c.6438+2T>G gave rise to a new donor splice site, which resulted in a frame shift of the transcripts and a premature termination at position 2159 in exon 45 (p.Y2144Nfs*16). CONCLUSION We found that two co-inherited mutations passed from generation to generation in female carriers and they may be used as genetic markers in the Chinese DMD family. Our findings not only expanded the DMD mutation spectrum, but also provided an important basis for identifying of female carriers and avoiding the birth of affected male children in this DMD family.
Collapse
Affiliation(s)
- Yingchuan Zhu
- Department of Medical Genetics, West China Medical School, West China Hospital, Sichuan University, 1st Keyuan 4 Lu, High-Tech Zone, Chengdu, 610041, Sichuan, China
| | - Lijun Yang
- Department of Medical Genetics, West China Medical School, West China Hospital, Sichuan University, 1st Keyuan 4 Lu, High-Tech Zone, Chengdu, 610041, Sichuan, China
| | - Tengjiao Ma
- Department of Medical Genetics, West China Medical School, West China Hospital, Sichuan University, 1st Keyuan 4 Lu, High-Tech Zone, Chengdu, 610041, Sichuan, China
| | - Yilu Lu
- Department of Medical Genetics, West China Medical School, West China Hospital, Sichuan University, 1st Keyuan 4 Lu, High-Tech Zone, Chengdu, 610041, Sichuan, China
| | - Dachang Tao
- Department of Medical Genetics, West China Medical School, West China Hospital, Sichuan University, 1st Keyuan 4 Lu, High-Tech Zone, Chengdu, 610041, Sichuan, China
| | - Yunqiang Liu
- Department of Medical Genetics, West China Medical School, West China Hospital, Sichuan University, 1st Keyuan 4 Lu, High-Tech Zone, Chengdu, 610041, Sichuan, China
| | - Yongxin Ma
- Department of Medical Genetics, West China Medical School, West China Hospital, Sichuan University, 1st Keyuan 4 Lu, High-Tech Zone, Chengdu, 610041, Sichuan, China.
| |
Collapse
|
46
|
Expectations and anxieties of Duchenne muscular dystrophy patients and their families during the first-in-human clinical trial of NS-065/NCNP-01. Brain Dev 2020; 42:348-356. [PMID: 31992520 DOI: 10.1016/j.braindev.2020.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 12/18/2019] [Accepted: 01/06/2020] [Indexed: 11/20/2022]
Abstract
Duchenne muscular dystrophy (DMD) is a recessive X-linked genetic disease caused by a mutation in the dystrophin gene. The new drug NS-065/NCNP-01 utilizing exon-skipping therapy targeting specific deletions has been used in a first-in-human trial for the treatment of DMD. We surveyed 10 pairs of DMD participants and their parents within this clinical trial via an iPad survey form and through interviews regarding their understanding of the trial, expectations, anxieties, and reasons for participating in the trial. Approximately half of the participants actively decided to participate of their own volition, and none considered quitting the trial. This indicates that participants participated more positively in this clinical trial than previously expected. However, some potential concerns were also revealed, with one being that the desire to please those around them might be more important to the DMD participants than the effects of the drug. Another issue is the possibility of biased information originating from the study subjects' parents; while seven out of 10 of the parents told their children that the study drug might work, only four of these parents also explained that it might not work. Only two study participants received an explanation concerning the drug's side effects from their parents. This result implies that caution should be taken when family expectations are high, and there is a possibility that subjects will be given biased information from their parents.
Collapse
|
47
|
Yang YM, Yan K, Liu B, Chen M, Wang LY, Huang YZ, Qian YQ, Sun YX, Li HG, Dong MY. Comprehensive genetic diagnosis of patients with Duchenne/Becker muscular dystrophy (DMD/BMD) and pathogenicity analysis of splice site variants in the DMD gene. J Zhejiang Univ Sci B 2020; 20:753-765. [PMID: 31379145 DOI: 10.1631/jzus.b1800541] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are caused by mutations in the DMD gene. The aim of this study is to identify pathogenic DMD variants in probands and reduce the risk of recurrence of the disease in affected families. Variations in 100 unrelated DMD/BMD patients were detected by multiplex ligation-dependent probe amplification (MLPA) and next-generation sequencing (NGS). Pathogenic variants in DMD were successfully identified in all cases, and 11 of them were novel. The most common mutations were intragenic deletions (69%), with two hotspots located in the 5' end (exons 2-19) and the central of the DMD gene (exons 45-55), while point mutations were observed in 22% patients. Further, c.1149+1G>A and c.1150-2A>G were confirmed by hybrid minigene splicing assay (HMSA). This two splice site mutations would lead to two aberrant DMD isoforms which give rise to severely truncated protein. Therefore, the clinical use of MLPA, NGS, and HMSA is an effective strategy to identify variants. Importantly, eight embryos were terminated pregnancies according to prenatal diagnosis and a healthy boy was successfully delivered by preimplantation genetic diagnosis (PGD). Early and accurate genetic diagnosis is essential for prenatal diagnosis/PGD to reduce the risk of recurrence of DMD in affected families.
Collapse
Affiliation(s)
- Yan-Mei Yang
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Kai Yan
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Bei Liu
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Min Chen
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Li-Ya Wang
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Ying-Zhi Huang
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Ye-Qing Qian
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Yi-Xi Sun
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Hong-Ge Li
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| | - Min-Yue Dong
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China.,Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou 310006, China.,Key Laboratory of Women's Reproductive Health of Zhejiang Province, Hangzhou 310006, China
| |
Collapse
|
48
|
Shariati G, Shakerian S, Mohammadi Anaie M, Abdorasouli N, Nanvazadeh F, Sedaghat A, Sedighi M, Saberi A. Deletion and duplication mutations spectrum in Duchenne muscular dystrophy in the southwest of Iran. Meta Gene 2020. [DOI: 10.1016/j.mgene.2019.100641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
|
49
|
Mercuri E, Muntoni F, Osorio AN, Tulinius M, Buccella F, Morgenroth LP, Gordish-Dressman H, Jiang J, Trifillis P, Zhu J, Kristensen A, Santos CL, Henricson EK, McDonald CM, Desguerre I. Safety and effectiveness of ataluren: comparison of results from the STRIDE Registry and CINRG DMD Natural History Study. J Comp Eff Res 2020; 9:341-360. [PMID: 31997646 PMCID: PMC7610147 DOI: 10.2217/cer-2019-0171] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Aim: Strategic Targeting of Registries and International Database of Excellence (STRIDE) is an ongoing, multicenter registry providing real-world evidence regarding ataluren use in patients with nonsense mutation Duchenne muscular dystrophy (nmDMD). We examined the effectiveness of ataluren + standard of care (SoC) in the registry versus SoC alone in the Cooperative International Neuromuscular Research Group (CINRG) Duchenne Natural History Study (DNHS), DMD genotype–phenotype/–ataluren benefit correlations and ataluren safety. Patients & methods: Propensity score matching was performed to identify STRIDE and CINRG DNHS patients who were comparable in established disease progression predictors (registry cut-off date, 9 July 2018). Results & conclusion: Kaplan–Meier analyses demonstrated that ataluren + SoC significantly delayed age at loss of ambulation and age at worsening performance in timed function tests versus SoC alone (p ≤ 0.05). There were no DMD genotype–phenotype/ataluren benefit correlations. Ataluren was well tolerated. These results indicate that ataluren + SoC delays functional milestones of DMD progression in patients with nmDMD in routine clinical practice. ClinicalTrials.gov identifier: NCT02369731. ClinicalTrials.gov identifier: NCT02369731.
Collapse
Affiliation(s)
- Eugenio Mercuri
- Department of Pediatric Neurology, Catholic University, Rome, Italy.,Centro Clinico Nemo, Policlinico Universitario A Gemelli IRCCS, Rome, Italy
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre & MRC Centre for Neuromuscular Diseases, University College London, Institute of Child Health & Great Ormond Street Hospital for Children Foundation Trust, 30 Guildford Street, London, WC1N 1EH, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, Great Ormond Street Institute of Child Health, University College London, Great Ormond Street Hospital Trust, London, UK
| | - Andrés Nascimento Osorio
- Hospital Sant Joan de Déu Unidad de Patología Neuromuscular, Universidad de Barcelona, CIBERER, ISCIII, Barcelona, Spain
| | - Már Tulinius
- Department of Pediatrics, Gothenburg University, Queen Silvia Children's Hospital, Gothenburg, Sweden
| | | | - Lauren P Morgenroth
- Therapeutic Research in Neuromuscular Disorders Solutions, Pittsburgh, PA, USA
| | - Heather Gordish-Dressman
- Center for Genetic Medicine, Children's National Health System & the George Washington, Washington, DC, USA
| | - Joel Jiang
- PTC Therapeutics Inc., South Plainfield, NJ 07080-2449, USA
| | | | - Jin Zhu
- PTC Therapeutics Inc., South Plainfield, NJ 07080-2449, USA
| | | | | | - Erik K Henricson
- University of California Davis School of Medicine, Davis, CA, USA
| | - Craig M McDonald
- University of California Davis School of Medicine, Davis, CA, USA
| | - Isabelle Desguerre
- APHP Necker - Enfants Malades Hospital, Paris V Descartes University, Neuromuscular Network FILNEMUS, Paris, France
| | | | | |
Collapse
|
50
|
Fujiwara T, Takeda N, Ishii S, Morita H, Komuro I. Unique Mechanism by Which TGFBR1 Variants Cause 2 Distinct System Diseases - Loeys-Dietz Syndrome and Multiple Self-Healing Squamous Epithelioma. Circ Rep 2019; 1:487-492. [PMID: 33693090 PMCID: PMC7897567 DOI: 10.1253/circrep.cr-19-0098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Variant types and sites in a single gene could influence the age of onset, severity, and pattern of affected organs of the genetic disease, such as in Marfan syndrome (MFS)-causing
FBN1, and understanding the genotype-phenotype relationship could aid in determining the treatment strategy. In contrast, completely distinct system and/or organ diseases induced by 1 gene mutation have been rarely reported. Transforming growth factor-β (TGF-β) type I receptor-encoding
TGFBR1
is such a gene, causing Loeys-Dietz syndrome (LDS) closely related to MFS, and also multiple self-healing squamous epithelioma (MSSE) without clinical overlap. The detailed mechanisms underlying this effect, however, remain elusive. We recently reported the significance of 2 distinct intronic variants (c.973+1G>A and c.806-2A>C) of
TGFBR1, which were both predicted to mediate in-frame exon 5 skipping but caused LDS and MSSE, respectively. On ex vivo minigene splicing assay analysis we demonstrated that 2 different cryptic splice sites were activated, and in-frame and out-of-frame transcripts were produced in LDS and MSSE, respectively, supporting the previously proposed but not yet approved mechanism that loss-of-function and haploinsufficiency-causing variants in serine/threonine kinase domains induce LDS and MSSE, respectively. In this review, we briefly summarize the recent findings and unresolved problems for the pathogenesis of LDS, including the TGF-β signaling paradox: most variants have been verified or predicted to be loss of function in vitro, but these variants enhanced TGF-β signaling in vivo.
Collapse
Affiliation(s)
- Takayuki Fujiwara
- Department of Cardiovascular Medicine, The University of Tokyo Hospital Tokyo Japan.,Department of Therapeutic Strategy for Heart Failure, Graduate School of Medicine, The University of Tokyo Tokyo Japan
| | - Norifumi Takeda
- Department of Cardiovascular Medicine, The University of Tokyo Hospital Tokyo Japan
| | - Satoshi Ishii
- Department of Cardiovascular Medicine, The University of Tokyo Hospital Tokyo Japan
| | - Hiroyuki Morita
- Department of Cardiovascular Medicine, The University of Tokyo Hospital Tokyo Japan
| | - Issei Komuro
- Department of Cardiovascular Medicine, The University of Tokyo Hospital Tokyo Japan
| |
Collapse
|