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Sandal S, Verma IC, Mahay SB, Dubey S, Sabharwal RK, Kulshrestha S, Saxena R, Suman P, Kumar P, Puri RD. Next-Generation Sequencing in Unexplained Intellectual Disability. Indian J Pediatr 2024; 91:682-695. [PMID: 37804371 DOI: 10.1007/s12098-023-04820-5] [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: 12/11/2022] [Accepted: 06/23/2023] [Indexed: 10/09/2023]
Abstract
OBJECTIVES To determine the diagnostic yield of next generation sequencing (NGS) in patients with moderate/severe/profound intellectual disability (ID) unexplained by conventional tests and to assess the impact of definitive diagnosis on the clinical management and genetic counselling of these families. METHODS This was a ambi-directional study conducted at Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi. The study comprised 227 patients (prospective cohort - 126, retrospective cohort - 101) in whom NGS based tests were performed. RESULTS The mean age of study cohort was 4.5 ± 4.4 y (2.5 mo to 37.3 y). The male: female ratio was 1.6:1. The overall diagnostic yield of NGS was 53.3% (121/227) with causative variants identified in 84 known ID genes. Autosomal recessive intellectual disability (ARID) (23.3%, 53/227) was the most common followed by autosomal dominant intellectual disability (ADID) (20.7%, 47/227) and X-linked intellectual disability (XLID) (9.2%, 21/227). The diagnostic yield was notably higher for ID plus associated condition group (55.6% vs. 20%) (p = 0.0075, Fisher's exact test) compared to isolated ID group. The impact of diagnosis on active or long-term management was observed in 17/121 (14%) and on reproductive outcomes in 26/121 (21.4%) families. CONCLUSIONS There is paucity of data on molecular genetic spectrum of ID from India. The current study identifies extensive genetic heterogeneity and the impact of NGS in patients with ID unexplained by standard genetic tests. The study identified ARID as the most common cause of ID with additional implications for reproductive outcomes. It reiterates the importance of phenotype in genetic testing.
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Affiliation(s)
- Sapna Sandal
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
| | - Ishwar Chander Verma
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
| | - Sunita Bijarnia Mahay
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
| | - Sudhisha Dubey
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
| | - R K Sabharwal
- Department of Pediatric Neurology, Sir Ganga Ram Hospital, New Delhi, India
| | - Samarth Kulshrestha
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
| | - Renu Saxena
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
| | - Praveen Suman
- Department of Developmental Pediatrics, Sir Ganga Ram Hospital, New Delhi, India
| | - Praveen Kumar
- Department of Pediatric Neurology, Sir Ganga Ram Hospital, New Delhi, India
| | - Ratna Dua Puri
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India.
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2
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Ma H, Zhu L, Yang X, Ao M, Zhang S, Guo M, Dai X, Ma X, Zhang X. Genetic and phenotypic analysis of 225 Chinese children with developmental delay and/or intellectual disability using whole-exome sequencing. BMC Genomics 2024; 25:391. [PMID: 38649797 PMCID: PMC11034079 DOI: 10.1186/s12864-024-10279-1] [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: 10/17/2023] [Accepted: 04/02/2024] [Indexed: 04/25/2024] Open
Abstract
Developmental delay (DD), or intellectual disability (ID) is a very large group of early onset disorders that affects 1-2% of children worldwide, which have diverse genetic causes that should be identified. Genetic studies can elucidate the pathogenesis underlying DD/ID. In this study, whole-exome sequencing (WES) was performed on 225 Chinese DD/ID children (208 cases were sequenced as proband-parent trio) who were classified into seven phenotype subgroups. The phenotype and genomic data of patients with DD/ID were further retrospectively analyzed. There were 96/225 (42.67%; 95% confidence interval [CI] 36.15-49.18%) patients were found to have causative single nucleotide variants (SNVs) and small insertions/deletions (Indels) associated with DD/ID based on WES data. The diagnostic yields among the seven subgroups ranged from 31.25 to 71.43%. Three specific clinical features, hearing loss, visual loss, and facial dysmorphism, can significantly increase the diagnostic yield of WES in patients with DD/ID (P = 0.005, P = 0.005, and P = 0.039, respectively). Of note, hearing loss (odds ratio [OR] = 1.86%; 95% CI = 1.00-3.46, P = 0.046) or abnormal brainstem auditory evoked potential (BAEP) (OR = 1.91, 95% CI = 1.02-3.50, P = 0.042) was independently associated with causative genetic variants in DD/ID children. Our findings enrich the variation spectrums of SNVs/Indels associated with DD/ID, highlight the value genetic testing for DD/ID children, stress the importance of BAEP screen in DD/ID children, and help to facilitate early diagnose, clinical management and reproductive decisions, improve therapeutic response to medical treatment.
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Affiliation(s)
- Heqian Ma
- The School of Public Health, Guilin Medical University, 1 Zhiyuan Road, Lingui District, 541199, Guilin, PR China
| | - Lina Zhu
- Faculty of Pediatrics, The Chinese PLA General Hospital, 100700, Beijing, China
- National Engineering Laboratory for Birth Defects Prevention and Control of Key Technology, 100700, Beijing, China
- Beijing Key Laboratory of Pediatric Organ Failure, 100700, Beijing, China
| | - Xiao Yang
- Faculty of Pediatrics, The Chinese PLA General Hospital, 100700, Beijing, China
- National Engineering Laboratory for Birth Defects Prevention and Control of Key Technology, 100700, Beijing, China
- Beijing Key Laboratory of Pediatric Organ Failure, 100700, Beijing, China
| | - Meng Ao
- The School of Public Health, Guilin Medical University, 1 Zhiyuan Road, Lingui District, 541199, Guilin, PR China
| | - Shunxiang Zhang
- The School of Public Health, Guilin Medical University, 1 Zhiyuan Road, Lingui District, 541199, Guilin, PR China
| | - Meizhen Guo
- The School of Public Health, Guilin Medical University, 1 Zhiyuan Road, Lingui District, 541199, Guilin, PR China
| | - Xuelin Dai
- The School of Public Health, Guilin Medical University, 1 Zhiyuan Road, Lingui District, 541199, Guilin, PR China
| | - Xiuwei Ma
- Faculty of Pediatrics, The Chinese PLA General Hospital, 100700, Beijing, China.
- National Engineering Laboratory for Birth Defects Prevention and Control of Key Technology, 100700, Beijing, China.
- Beijing Key Laboratory of Pediatric Organ Failure, 100700, Beijing, China.
| | - Xiaoying Zhang
- The School of Public Health, Guilin Medical University, 1 Zhiyuan Road, Lingui District, 541199, Guilin, PR China.
- The Guangxi Key Laboratory of Environmental Exposomics and Entire Lifecycle Heath, 1 Zhiyuan Road, Lingui District, 541199, Guilin, PR China.
- Guangxi Health Commission Key Laboratory of Entire Lifecycle Health and Care, 1 Zhiyuan Road, Lingui District, 541199, Guilin, PR China.
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3
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Li J, Wei X, Sun Y, Chen X, Zhang Y, Cui X, Shu J, Li D, Cai C. Phosphoserine aminotransferase deficiency diagnosed by whole-exome sequencing and LC-MS/MS reanalysis: A case report and review of literature. Mol Genet Genomic Med 2024; 12:e2400. [PMID: 38546032 PMCID: PMC10976427 DOI: 10.1002/mgg3.2400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 12/26/2023] [Accepted: 02/05/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND Phosphoserine aminotransferase deficiency (PSATD) is an autosomal recessive disorder associated with hypertonia, psychomotor retardation, and acquired microcephaly. Patients with PSATD have low concentrations of serine in plasma and cerebrospinal fluid. METHODS We reported a 2-year-old female child with developmental delay, dyskinesia, and microcephaly. LC-MS/MS was used to detect amino acid concentration in the blood and whole-exome sequencing (WES) was used to identify the variants. PolyPhen-2 web server and PyMol were used to predict the pathogenicity and changes in the 3D model molecular structure of protein caused by variants. RESULTS WES demonstrated compound heterozygous variants in PSAT1, which is associated with PSATD, with a paternal likely pathogenic variant (c.235G>A, Gly79Arg) and a maternal likely pathogenic variant (c.43G>C, Ala15Pro). Reduced serine concentration in LC-MS/MS further confirmed the diagnosis of PSATD in this patient. CONCLUSIONS Our findings demonstrate the importance of WES combined with LC-MS/MS reanalysis in the diagnosis of genetic diseases and expand the PSAT1 variant spectrum in PSATD. Moreover, we summarize all the cases caused by PSAT1 variants in the literature. This case provides a vital reference for the diagnosis of future cases.
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Affiliation(s)
- Jiaci Li
- Tianjin Children's Hospital (Children's Hospital, Tianjin University)TianjinChina
- Tianjin Pediatric Research InstituteTianjinChina
- Tianjin Key Laboratory of Birth Defects for Prevention and TreatmentTianjinChina
| | - Xinping Wei
- Tianjin Children's Hospital (Children's Hospital, Tianjin University)TianjinChina
- Department of NeurologyTianjin Children's HospitalTianjinChina
| | - Yuchen Sun
- College of Traditional Chinese medicineTianjin University of Traditional Chinese MedicineTianjinChina
| | - Xiaofang Chen
- Tianjin Children's Hospital (Children's Hospital, Tianjin University)TianjinChina
| | - Ying Zhang
- Tianjin Children's Hospital (Children's Hospital, Tianjin University)TianjinChina
- Tianjin Medical UniversityGraduate College of Tianjin Medical UniversityTianjinChina
| | - Xiaoyu Cui
- Tianjin Children's Hospital (Children's Hospital, Tianjin University)TianjinChina
| | - Jianbo Shu
- Tianjin Children's Hospital (Children's Hospital, Tianjin University)TianjinChina
- Tianjin Pediatric Research InstituteTianjinChina
- Tianjin Key Laboratory of Birth Defects for Prevention and TreatmentTianjinChina
| | - Dong Li
- Tianjin Children's Hospital (Children's Hospital, Tianjin University)TianjinChina
- Department of NeurologyTianjin Children's HospitalTianjinChina
| | - Chunquan Cai
- Tianjin Children's Hospital (Children's Hospital, Tianjin University)TianjinChina
- Tianjin Pediatric Research InstituteTianjinChina
- Tianjin Key Laboratory of Birth Defects for Prevention and TreatmentTianjinChina
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4
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Werren EA, LaForce GR, Srivastava A, Perillo DR, Li S, Johnson K, Baris S, Berger B, Regan SL, Pfennig CD, de Munnik S, Pfundt R, Hebbar M, Jimenez-Heredia R, Karakoc-Aydiner E, Ozen A, Dmytrus J, Krolo A, Corning K, Prijoles EJ, Louie RJ, Lebel RR, Le TL, Amiel J, Gordon CT, Boztug K, Girisha KM, Shukla A, Bielas SL, Schaffer AE. TREX tetramer disruption alters RNA processing necessary for corticogenesis in THOC6 Intellectual Disability Syndrome. Nat Commun 2024; 15:1640. [PMID: 38388531 PMCID: PMC10884030 DOI: 10.1038/s41467-024-45948-y] [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: 10/02/2022] [Accepted: 02/07/2024] [Indexed: 02/24/2024] Open
Abstract
THOC6 variants are the genetic basis of autosomal recessive THOC6 Intellectual Disability Syndrome (TIDS). THOC6 is critical for mammalian Transcription Export complex (TREX) tetramer formation, which is composed of four six-subunit THO monomers. The TREX tetramer facilitates mammalian RNA processing, in addition to the nuclear mRNA export functions of the TREX dimer conserved through yeast. Human and mouse TIDS model systems revealed novel THOC6-dependent, species-specific TREX tetramer functions. Germline biallelic Thoc6 loss-of-function (LOF) variants result in mouse embryonic lethality. Biallelic THOC6 LOF variants reduce the binding affinity of ALYREF to THOC5 without affecting the protein expression of TREX members, implicating impaired TREX tetramer formation. Defects in RNA nuclear export functions were not detected in biallelic THOC6 LOF human neural cells. Instead, mis-splicing was detected in human and mouse neural tissue, revealing novel THOC6-mediated TREX coordination of mRNA processing. We demonstrate that THOC6 is required for key signaling pathways known to regulate the transition from proliferative to neurogenic divisions during human corticogenesis. Together, these findings implicate altered RNA processing in the developmental biology of TIDS neuropathology.
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Affiliation(s)
- Elizabeth A Werren
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
- Advanced Precision Medicine Laboratory, The Jackson Laboratory for Genomic Medicine, Farmington, CT, 06032, USA
| | - Geneva R LaForce
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Anshika Srivastava
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
- Department of Medical Genetics, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, 226014, India
| | - Delia R Perillo
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Shaokun Li
- Advanced Precision Medicine Laboratory, The Jackson Laboratory for Genomic Medicine, Farmington, CT, 06032, USA
| | - Katherine Johnson
- Advanced Precision Medicine Laboratory, The Jackson Laboratory for Genomic Medicine, Farmington, CT, 06032, USA
| | - Safa Baris
- Division of Pediatric Allergy and Immunology, School of Medicine, Marmara University, Istanbul Jeffrey Modell Diagnostic and Research Center for Primary Immunodeficiencies, The Isil Berat Barlan Center for Translational Medicine, Istanbul, 34722, Turkey
| | - Brandon Berger
- Advanced Precision Medicine Laboratory, The Jackson Laboratory for Genomic Medicine, Farmington, CT, 06032, USA
| | - Samantha L Regan
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Christian D Pfennig
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Sonja de Munnik
- Department of Human Genetics, Radboud University Medical Centre Nijmegen, Nijmegen, 6524, the Netherlands
| | - Rolph Pfundt
- Department of Human Genetics, Radboud University Medical Centre Nijmegen, Nijmegen, 6524, the Netherlands
| | - Malavika Hebbar
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, 98195, Seattle, WA, USA
| | - Raúl Jimenez-Heredia
- Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases, Vienna, 1090, Austria
| | - Elif Karakoc-Aydiner
- Division of Pediatric Allergy and Immunology, School of Medicine, Marmara University, Istanbul Jeffrey Modell Diagnostic and Research Center for Primary Immunodeficiencies, The Isil Berat Barlan Center for Translational Medicine, Istanbul, 34722, Turkey
| | - Ahmet Ozen
- Division of Pediatric Allergy and Immunology, School of Medicine, Marmara University, Istanbul Jeffrey Modell Diagnostic and Research Center for Primary Immunodeficiencies, The Isil Berat Barlan Center for Translational Medicine, Istanbul, 34722, Turkey
| | - Jasmin Dmytrus
- Research Centre for Molecular Medicine of the Austrian Academy of Sciences, Vienna, 1090, Austria
| | - Ana Krolo
- Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases, Vienna, 1090, Austria
| | - Ken Corning
- Greenwood Genetic Center, Greenwood, SC, 29646, USA
| | - E J Prijoles
- Greenwood Genetic Center, Greenwood, SC, 29646, USA
| | | | - Robert Roger Lebel
- Section of Medical Genetics, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
| | - Thuy-Linh Le
- Imagine Institute, INSERM U1163, Paris Cité University, Paris, 75015, France
| | - Jeanne Amiel
- Imagine Institute, INSERM U1163, Paris Cité University, Paris, 75015, France
- Service de Médecine Génomique des Maladies Rares, Hôpital Necker-Enfants Malades, AP-HP, Paris, 75015, France
| | | | - Kaan Boztug
- Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases, Vienna, 1090, Austria
- Research Centre for Molecular Medicine of the Austrian Academy of Sciences, Vienna, 1090, Austria
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, 1090, Austria
- St. Anna Children's Hospital and Children's Cancer Research Institute, Department of Pediatrics, Medical University of Vienna, Vienna, 1090, Austria
| | - Katta M Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Anju Shukla
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Stephanie L Bielas
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
| | - Ashleigh E Schaffer
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
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5
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Kim J, Lee J, Jang DH. Combining chromosomal microarray and clinical exome sequencing for genetic diagnosis of intellectual disability. Sci Rep 2023; 13:22807. [PMID: 38129582 PMCID: PMC10739828 DOI: 10.1038/s41598-023-50285-z] [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: 06/21/2023] [Accepted: 12/18/2023] [Indexed: 12/23/2023] Open
Abstract
Despite the current widespread use of chromosomal microarray analysis (CMA) and exome/genome sequencing for the genetic diagnosis of unexplained intellectual disability (ID) in children, gaining improved diagnostic yields and defined guidelines remains a significant challenge. This is a cohort study of children with unexplained ID. We analyzed the diagnostic yield and its correlation to clinical phenotypes in children with ID who underwent concurrent CMA and clinical exome sequencing (CES). A total of 154 children were included (110 [71.4%] male; mean [SD] age, 51.9 [23.1] months). The overall diagnosis yield was 26.0-33.8%, with CMA contributing 12.3-14.3% and CES contributing 13.6-19.4%, showing no significant difference. The diagnostic rate was significantly higher when gross motor delay (odds ratio, 6.69; 95% CI, 3.20-14.00; P < 0.001), facial dysmorphism (odds ratio, 9.34; 95% CI 4.29-20.30; P < 0.001), congenital structural anomaly (odds ratio 3.62; 95% CI 1.63-8.04; P = 0.001), and microcephaly or macrocephaly (odds ratio 4.87; 95% CI 2.05-11.60; P < 0.001) were presented. Patients with only ID without any other concomitant phenotype (63/154, 40.9%) exhibited a 6.3-11.1% diagnostic rate.
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Affiliation(s)
- Jaewon Kim
- Department of Physical Medicine and Rehabilitation, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Medical Genetics and Rare Disease Center, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Jaewoong Lee
- Department of Laboratory Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Medical Genetics and Rare Disease Center, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Dae-Hyun Jang
- Department of Physical Medicine and Rehabilitation, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
- Medical Genetics and Rare Disease Center, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
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6
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Werren E, LaForce G, Srivastava A, Perillo D, Johnson K, Berger B, Regan S, Pfennig C, Baris S, de Munnik S, Pfundt R, Hebbar M, Jimenez Heredia R, Karakoc-Aydiner E, Ozen A, Dmytrus J, Krolo A, Corning K, Prijoles E, Louie R, Lebel R, Le TL, Amiel J, Gordon C, Boztug K, Girisha K, Shukla A, Bielas S, Schaffer A. Mechanisms of mRNA processing defects in inherited THOC6 intellectual disability syndrome. RESEARCH SQUARE 2023:rs.3.rs-2126145. [PMID: 37720017 PMCID: PMC10503840 DOI: 10.21203/rs.3.rs-2126145/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
THOC6 is the genetic basis of autosomal recessive THOC6 Intellectual Disability Syndrome (TIDS). THOC6 facilitates the formation of the Transcription Export complex (TREX) tetramer, composed of four THO monomers. The TREX tetramer supports mammalian mRNA processing that is distinct from yeast TREX dimer functions. Human and mouse TIDS model systems allow novel THOC6-dependent TREX tetramer functions to be investigated. Biallelic loss-of-functon(LOF) THOC6 variants do not influence the expression and localization of TREX members in human cells, but our data suggests reduced binding affinity of ALYREF. Impairment of TREX nuclear export functions were not detected in cells with biallelic THOC6 LOF. Instead, mRNA mis-splicing was observed in human and mouse neural tissue, revealing novel insights into THOC6-mediated TREX coordination of mRNA processing. We demonstrate that THOC6 is required for regulation of key signaling pathways in human corticogenesis that dictate the transition from proliferative to neurogenic divisions that may inform TIDS neuropathology.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Jasmin Dmytrus
- CeMM Research Centre for Molecular Medicine of the Austrian Academy of Sciences
| | - Ana Krolo
- Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases
| | | | | | | | | | - Thuy-Linh Le
- Imagine Institute, INSERM U1163, Paris Descartes University
| | | | - Christopher Gordon
- Institut National de la Santé et de la Recherche Médicale (INSERM) UMR 1163, Institut Imagine
| | - Kaan Boztug
- Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases
| | - Katta Girisha
- Kasturba Medical College, Manipal, Manipal Academy of Higher Education
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7
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Ballesta-Martínez MJ, Pérez-Fernández V, López-González V, Sánchez-Soler MJ, Serrano-Antón AT, Rodríguez-Peña LI, Barreda-Sánchez M, Armengol-Dulcet L, Guillén-Navarro E. Validation of clinical exome sequencing in the diagnostic procedure of patients with intellectual disability in clinical practice. Orphanet J Rare Dis 2023; 18:201. [PMID: 37480025 PMCID: PMC10362575 DOI: 10.1186/s13023-023-02809-z] [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: 03/07/2023] [Accepted: 07/05/2023] [Indexed: 07/23/2023] Open
Abstract
Intellectual disability (ID) has a prevalence of 1-3% and aproximately 30-50% of ID cases have a genetic cause. Development of next-generation sequencing has shown a high diagnostic potential. The aim of this work was to evaluate the diagnostic yield of clinical exome sequencing in 188 ID patients and the economic impact of its introduction in clinical practice. An analysis of diagnostic yield according to the different clinical variables was performed in order to establish an efficient diagnostic protocol for ID patients. Diagnostic yield of clinical exome sequencing was significant (34%) supporting its utility in diagnosis of ID patients. Wide genetic heterogeneity and predominance of autosomal dominant de novo variants in ID patients were observed. Time to diagnosis was shortened and diagnostic study costs decreased by 62% after implementation of clinical exome sequencing. No association was found between any of the variables analyzed and a higher diagnostic yield; added to the fact that many of the diagnoses weren't clinically detectable, the reduction of time to diagnosis and the economic savings with respect to classical diagnostic studies, strengthen the clinical and economical convenience of early implementation of clinical exome sequencing in the diagnostic workup of ID patients in clinical practice.
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Affiliation(s)
- María Juliana Ballesta-Martínez
- Sección de Genética Médica, Servicio de Pediatría, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain.
- Instituto Murciano de Investigación Biomédica (IMIB), Murcia, Spain.
- Centro de Investigación Biomédica en Red-Enfermedades Raras (CIBERER-Instituto de Salud Carlos III), Madrid, Spain.
| | - Virginia Pérez-Fernández
- Departamento de Ciencias Sociosanitarias-Área de Bioestadística, Facultad de Medicina, Universidad de Murcia, Murcia, Spain
| | - Vanesa López-González
- Sección de Genética Médica, Servicio de Pediatría, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
- Instituto Murciano de Investigación Biomédica (IMIB), Murcia, Spain
- Centro de Investigación Biomédica en Red-Enfermedades Raras (CIBERER-Instituto de Salud Carlos III), Madrid, Spain
| | - María José Sánchez-Soler
- Sección de Genética Médica, Servicio de Pediatría, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
- Instituto Murciano de Investigación Biomédica (IMIB), Murcia, Spain
| | - Ana Teresa Serrano-Antón
- Sección de Genética Médica, Servicio de Pediatría, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
- Instituto Murciano de Investigación Biomédica (IMIB), Murcia, Spain
| | - Lidia Isolina Rodríguez-Peña
- Sección de Genética Médica, Servicio de Pediatría, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
| | | | - Lluís Armengol-Dulcet
- Quantitative Genomic Medicine Laboratories (qGenomics), Esplugues del Llobregat, Catalonia, Spain
| | - Encarna Guillén-Navarro
- Sección de Genética Médica, Servicio de Pediatría, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain.
- Instituto Murciano de Investigación Biomédica (IMIB), Murcia, Spain.
- Centro de Investigación Biomédica en Red-Enfermedades Raras (CIBERER-Instituto de Salud Carlos III), Madrid, Spain.
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8
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Baalmann N, Spielmann M, Gillessen-Kaesbach G, Hanker B, Schmidt J, Lill CM, Hellenbroich Y, Greiten B, Lohmann K, Trinh J, Hüning I. Phenotypic specificity in patients with neurodevelopmental delay does not correlate with diagnostic yield of trio-exome sequencing. Eur J Med Genet 2023; 66:104774. [PMID: 37120078 DOI: 10.1016/j.ejmg.2023.104774] [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: 10/24/2022] [Revised: 03/12/2023] [Accepted: 04/26/2023] [Indexed: 05/01/2023]
Abstract
In this study, we aimed to examine the diagnostic yield achieved by applying a trio approach in exome sequencing (ES) and the interdependency between the clinical specificity in families with neurodevelopmental delay. Thirty-seven families were recruited and trio-ES as well as three criteria for estimating the clinical phenotypic specificity were suggested and applied to the underaged children. All our patients showed neurodevelopmental delay and most of them a large spectrum of congenital anomalies. Applying the pathogenicity guidelines of the American College of Medical Genetics (ACMG), likely pathogenic (29.7%) and pathogenic variants (8.1%) were found in 40,5% of our index patients. Additionally, we found four variants of uncertain significance (VUS; according to ACMG) and two genes of interest (GOI; going beyond ACMG classification) (GLRA4, NRXN2). Spastic Paraplegia 4 (SPG4) caused by a formerly known SPAST variant was diagnosed in a patient with a complex phenotype, in whom a second genetic disorder may be present. A potential pathogenic variant linked to severe intellectual disability in GLRA4 requires further investigation. No interdependency between the diagnostic yield and the clinical specificity of the phenotypes could be observed. In consequence, trio-ES should be used early in the diagnostic process, independently from the specificity of the patient.
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Affiliation(s)
- Nadja Baalmann
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany.
| | - Malte Spielmann
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany.
| | | | - Britta Hanker
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany.
| | - Julia Schmidt
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany; Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany.
| | - Christina M Lill
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany; Institute of Neurogenetics, University of Lübeck, Lübeck, Germany; Lübeck Interdisciplinary Platform for Genome Analytics, University of Lübeck, Germany; Ageing Epidemiology Research Unit (AGE), School of Public Health, Imperial College London, London, UK.
| | | | - Bianca Greiten
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany.
| | - Katja Lohmann
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.
| | - Joanne Trinh
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.
| | - Irina Hüning
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany.
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9
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Genome-Wide Sequencing Modalities for Children with Unexplained Global Developmental Delay and Intellectual Disabilities—A Narrative Review. CHILDREN 2023; 10:children10030501. [PMID: 36980059 PMCID: PMC10047410 DOI: 10.3390/children10030501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 02/25/2023] [Accepted: 03/01/2023] [Indexed: 03/06/2023]
Abstract
Unexplained global developmental delay (GDD) and intellectual disabilities (ID) together affect nearly 2% of the pediatric population. Establishing an etiologic diagnosis is crucial for disease management, prognostic evaluation, and provision of physical and psychological support for both the patient and the family. Advancements in genome sequencing have allowed rapid accumulation of gene–disorder associations and have accelerated the search for an etiologic diagnosis for unexplained GDD/ID. We reviewed recent studies that utilized genome-wide analysis technologies, and we discussed their diagnostic yield, strengths, and limitations. Overall, exome sequencing (ES) and genome sequencing (GS) outperformed chromosomal microarrays and targeted panel sequencing. GS provides coverage for both ES and chromosomal microarray regions, providing the maximal diagnostic potential, and the cost of ES and reanalysis of ES-negative results is currently still lower than that of GS alone. Therefore, singleton or trio ES is the more cost-effective option for the initial investigation of individuals with GDD/ID in clinical practice compared to a staged approach or GS alone. Based on these updated evidence, we proposed an evaluation algorithm with ES as the first-tier evaluation for unexplained GDD/ID.
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10
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Carter MT, Srour M, Au PYB, Buhas D, Dyack S, Eaton A, Inbar-Feigenberg M, Howley H, Kawamura A, Lewis SME, McCready E, Nelson TN, Vallance H. Genetic and metabolic investigations for neurodevelopmental disorders: position statement of the Canadian College of Medical Geneticists (CCMG). J Med Genet 2023; 60:523-532. [PMID: 36822643 DOI: 10.1136/jmg-2022-108962] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 01/27/2023] [Indexed: 02/25/2023]
Abstract
PURPOSE AND SCOPE The aim of this position statement is to provide recommendations for clinicians regarding the use of genetic and metabolic investigations for patients with neurodevelopmental disorders (NDDs), specifically, patients with global developmental delay (GDD), intellectual disability (ID) and/or autism spectrum disorder (ASD). This document also provides guidance for primary care and non-genetics specialists caring for these patients while awaiting consultation with a clinical geneticist or metabolic specialist. METHODS OF STATEMENT DEVELOPMENT A multidisciplinary group reviewed existing literature and guidelines on the use of genetic and metabolic investigations for the diagnosis of NDDs and synthesised the evidence to make recommendations relevant to the Canadian context. The statement was circulated for comment to the Canadian College of Medical Geneticists (CCMG) membership-at-large and to the Canadian Pediatric Society (Mental Health and Developmental Disabilities Committee); following incorporation of feedback, it was approved by the CCMG Board of Directors on 1 September 2022. RESULTS AND CONCLUSIONS Chromosomal microarray is recommended as a first-tier test for patients with GDD, ID or ASD. Fragile X testing should also be done as a first-tier test when there are suggestive clinical features or family history. Metabolic investigations should be done if there are clinical features suggestive of an inherited metabolic disease, while the patient awaits consultation with a metabolic physician. Exome sequencing or a comprehensive gene panel is recommended as a second-tier test for patients with GDD or ID. Genetic testing is not recommended for patients with NDDs in the absence of GDD, ID or ASD, unless accompanied by clinical features suggestive of a syndromic aetiology or inherited metabolic disease.
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Affiliation(s)
| | - Myriam Srour
- Division of Neurology, McGill University Health Centre, Montreal, Québec, Canada
- Department of Pediatrics, McGill University, Montréal, QC, Canada
| | - Ping-Yee Billie Au
- Department of Medical Genetics, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Daniela Buhas
- Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, McGill University, Montreal, Québec, Canada
- Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Sarah Dyack
- Division of Medical Genetics, IWK Health Centre, Halifax, Nova Scotia, Canada
- Department of Pediatrics, Dalhousie University, Halifax, NS, Canada
| | - Alison Eaton
- Department of Medical Genetics, Stollery Children's Hospital, Edmonton, Alberta, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | - Michal Inbar-Feigenberg
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Heather Howley
- Office of Research Services, CHEO Research Institute, Ottawa, Ontario, Canada
| | - Anne Kawamura
- Division of Developmental Pediatrics, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada
- Department of Paediatrics, University of Toronto, Toronto, ON, Canada
- Mental Health and Developmental Disability Committee, Canadian Pediatric Society, Ottawa, ON, Canada
- Canadian Paediatric Society, Toronto, Ontario, Canada
| | - Suzanne M E Lewis
- Department of Medical Genetics, BC Children's and Women's Hospital, Vancouver, British Columbia, Canada
| | - Elizabeth McCready
- Department of Pathology and Molecular Medicine, McMaster University, McMaster University, Hamilton, ON, Canada, Hamilton, Ontario, Canada
- Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences Centre, Hamilton, ON, Canada
| | - Tanya N Nelson
- Department of Pathology and Laboratory Medicine, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hilary Vallance
- Department of Pathology and Laboratory Medicine, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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11
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Evaluation of Individuals with Non-Syndromic Global Developmental Delay and Intellectual Disability. CHILDREN 2023; 10:children10030414. [PMID: 36979972 PMCID: PMC10047567 DOI: 10.3390/children10030414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/11/2023] [Accepted: 02/16/2023] [Indexed: 02/24/2023]
Abstract
Global Developmental Delay (GDD) and Intellectual Disability (ID) are two of the most common presentations encountered by physicians taking care of children. GDD/ID is classified into non-syndromic GDD/ID, where GDD/ID is the sole evident clinical feature, or syndromic GDD/ID, where there are additional clinical features or co-morbidities present. Careful evaluation of children with GDD and ID, starting with detailed history followed by a thorough examination, remain the cornerstone for etiologic diagnosis. However, when initial history and examination fail to identify a probable underlying etiology, further genetic testing is warranted. In recent years, genetic testing has been shown to be the single most important diagnostic modality for clinicians evaluating children with non-syndromic GDD/ID. In this review, we discuss different genetic testing currently available, review common underlying copy-number variants and molecular pathways, explore the recent evidence and recommendations for genetic evaluation and discuss an approach to the diagnosis and management of children with non-syndromic GDD and ID.
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12
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Miclea D, Osan S, Bucerzan S, Stefan D, Popp R, Mager M, Puiu M, Zimbru C, Chirita-Emandi A, Alkhzouz C. Copy number variation analysis in 189 Romanian patients with global developmental delay/intellectual disability. Ital J Pediatr 2022; 48:207. [PMID: 36585697 PMCID: PMC9801529 DOI: 10.1186/s13052-022-01397-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 12/13/2022] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Developmental delay and intellectual disability represent a common pathology in general population, involving about 3% of the pediatric age population, the genetic etiology being often involved. The aim of this study was to determine the clinically relevant copy number variants in patients diagnosed with global developmental delay/intellectual disability in our population, using the chromosomal microarray analysis. METHODS We analyzed 189 patients diagnosed with global developmental delay/intellectual disability, presented in Clinical Emergency Hospital for Children, Cluj-Napoca. The patients were completely clinically investigated, including dysmorphic and internal malformations evaluation, psychiatric, neuropsychological and metabolic evaluation, standard karyotyping. Genomic analysis was done using chromosomal microarray analysis. RESULTS Pathogenic findings (including uniparental disomy) and variants of unknown significance were detected in 53 of 189 patients (28.04%). Pathogenic copy number variants and uniparental disomy were observed in 35 of 189 patients (18.51%). Two patients presented uniparental disomy for chromosome 15, one with clinical phenotype of Prader-Willi syndrome and the other with clinical phenotype with Angelman syndrome. Within the category of pathogenic findings, the recurrent copy number variants were seen in 21 of 35 patients (60%). CONCLUSIONS The increased percentage of pathogenic structural variants observed in patients with global developmental delay/intellectual disability analyzed by chromosomal microarray technique supports its use in patients with a non-specific phenotype such as these neurodevelopmental disorders. The high percentage of recurrent pathogenic variants between these findings is a finding that support their initial evaluation when a genetic testing algorithm could be a useful option.
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Affiliation(s)
- Diana Miclea
- grid.411040.00000 0004 0571 5814Department of Molecular Sciences, “Iuliu Hatieganu” University of Medicine and Pharmacy, Pasteur Street, No 6, 400349 Cluj-Napoca, Romania ,Emergency Clinical Hospital for Children, Pasteur Street, No 6, 400349 Cluj-Napoca, Romania
| | - Sergiu Osan
- grid.411040.00000 0004 0571 5814Department of Molecular Sciences, “Iuliu Hatieganu” University of Medicine and Pharmacy, Pasteur Street, No 6, 400349 Cluj-Napoca, Romania
| | - Simona Bucerzan
- Emergency Clinical Hospital for Children, Pasteur Street, No 6, 400349 Cluj-Napoca, Romania ,grid.411040.00000 0004 0571 5814Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Delia Stefan
- grid.411040.00000 0004 0571 5814Department of Molecular Sciences, “Iuliu Hatieganu” University of Medicine and Pharmacy, Pasteur Street, No 6, 400349 Cluj-Napoca, Romania
| | - Radu Popp
- grid.411040.00000 0004 0571 5814Department of Molecular Sciences, “Iuliu Hatieganu” University of Medicine and Pharmacy, Pasteur Street, No 6, 400349 Cluj-Napoca, Romania
| | - Monica Mager
- Emergency Clinical Hospital for Children, Pasteur Street, No 6, 400349 Cluj-Napoca, Romania ,grid.411040.00000 0004 0571 5814Department of Neuroscience, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Maria Puiu
- grid.22248.3e0000 0001 0504 4027“Victor Babes” University of Medicine and Pharmacy, Timisoara, Romania
| | - Cristian Zimbru
- grid.6992.40000 0001 1148 0861Polytechnic University, Timisoara, Romania
| | - Adela Chirita-Emandi
- grid.22248.3e0000 0001 0504 4027“Victor Babes” University of Medicine and Pharmacy, Timisoara, Romania
| | - Camelia Alkhzouz
- Emergency Clinical Hospital for Children, Pasteur Street, No 6, 400349 Cluj-Napoca, Romania ,grid.411040.00000 0004 0571 5814Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania
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13
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Five years' experience of the clinical exome sequencing in a Spanish single center. Sci Rep 2022; 12:19209. [PMID: 36357507 PMCID: PMC9649665 DOI: 10.1038/s41598-022-23786-6] [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: 05/19/2022] [Accepted: 11/04/2022] [Indexed: 11/12/2022] Open
Abstract
Nowadays, exome sequencing is a robust and cost-efficient genetic diagnostic tool already implemented in many clinical laboratories. Despite it has undoubtedly improved our diagnostic capacity and has allowed the discovery of many new Mendelian-disease genes, it only provides a molecular diagnosis in up to 25-30% of cases. Here, we comprehensively evaluate the results of a large sample set of 4974 clinical exomes performed in our laboratory over a period of 5 years, showing a global diagnostic rate of 24.62% (1391/4974). For the evaluation we establish different groups of diseases and demonstrate how the diagnostic rate is not only dependent on the analyzed group of diseases (43.12% in ophthalmological cases vs 16.61% in neurological cases) but on the specific disorder (47.49% in retinal dystrophies vs 24.02% in optic atrophy; 18.88% in neuropathies/paraparesias vs 11.43% in dementias). We also detail the most frequent mutated genes within each group of disorders and discuss, on our experience, further investigations and directions needed for the benefit of patients.
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14
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Reitsam NG, Märkl B, Dintner S, Waidhauser J, Vlasenko D, Grosser B. Concurrent loss of MLH1, PMS2 and MSH6 immunoexpression in digestive system cancers indicating a widespread dysregulation in DNA repair processes. Front Oncol 2022; 12:1019798. [PMID: 36387226 PMCID: PMC9643848 DOI: 10.3389/fonc.2022.1019798] [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: 08/15/2022] [Accepted: 10/04/2022] [Indexed: 11/24/2022] Open
Abstract
Immunohistochemical analysis of mismatch repair (MMR) protein expression is widely used to identify tumors with a deficient MMR (dMMR). MMR proteins (MLH1/PMS2 and MSH2/MSH6) work as functional heterodimers, which usually leads to the loss of expression in only one functional MMR heterodimer. Recently, there have been studies showing the simultaneous loss of immunoexpression in proteins of both heterodimers. Yet, this phenomenon has been rarely investigated. In this study, we retrospectively considered cases of different digestive system cancers (gastric cancer, ampullary cancer, small bowel cancer, colorectal cancer), which were immunohistochemically tested for dMMR within a 4-year period at our university hospital (n=352). Of the 103 cases showing dMMR, 5 cases (1.4% of all, 5.1% of dMMR cases) showed a concurrent loss of MLH1, PMS2 and MSH6 immunoexpression, whereas in the other 98 dMMR cases only one MMR heterodimer was affected. MLH1-/PMS2-/MSH6- cancer cases almost arose throughout the entire digestive tract: from the gastric antrum to the left colic flexur. To provide a comprehensive molecular characterization of this MLH1-/PMS2-/MSH6- immunophenotype, tumors were analyzed for microsatellite instability, MLH1 promotor hypermethylation and BRAF exon 15 status. Furthermore, we performed next-generation sequencing focusing on genes related to DNA repair. Here, we could detect pathogenic germline variants as well as multiple sporadic mutations in different genes involved in MMR and homologous recombination repair (HRR) respectively. The affected MMR/HRR-related genes were: ATM, BARD1, BRCA1, CDK12, CHEK1, CHEK2, FANCA, MLH1, MSH6, PALB2, TP53. Considering the biologic function of HRR/MMR proteins as potential drug targets and the low frequency of most of these mutations in digestive system cancers in general, their common occurrence in our MLH1-/PMS2-/MSH6- cases seems to be even more noteworthy, highlighting the need for recognition, awareness and further investigation of this unusual IHC staining pattern.
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Affiliation(s)
- Nic Gabriel Reitsam
- General Pathology and Molecular Diagnostics, Medical Faculty, University of Augsburg, Augsburg, Germany
- *Correspondence: Nic Gabriel Reitsam, ;
| | - Bruno Märkl
- General Pathology and Molecular Diagnostics, Medical Faculty, University of Augsburg, Augsburg, Germany
| | - Sebastian Dintner
- General Pathology and Molecular Diagnostics, Medical Faculty, University of Augsburg, Augsburg, Germany
| | - Johanna Waidhauser
- Department of Hematology and Oncology, University Medical Center Augsburg / University Hospital of Augsburg, Augsburg, Germany
| | - Dmytro Vlasenko
- General, Visceral and Transplantation Surgery, University Hospital of Augsburg, Augsburg, Germany
| | - Bianca Grosser
- General Pathology and Molecular Diagnostics, Medical Faculty, University of Augsburg, Augsburg, Germany
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15
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Chen M, Sun Y, Qian Y, Chen N, Li H, Wang L, Dong M. Case report: FOXP1 syndrome caused by a de novo splicing variant (c.1652+5 G>A) of the FOXP1 gene. Front Genet 2022; 13:926070. [PMID: 35991577 PMCID: PMC9388729 DOI: 10.3389/fgene.2022.926070] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 07/07/2022] [Indexed: 11/30/2022] Open
Abstract
FOXP1 syndrome is a rare neurodevelopmental disorder characterized by global developmental delay, intellectual disability, and language delay, with or without autistic features. Several splicing variants have been reported for this condition, but most of them lack functional evidence, and the actual effects of the sequence changes are still unknown. In this study, a de novo splicing variant (c.1652 + 5 G>A) of the FOXP1 gene was identified in a patient with global developmental delay, mild intellectual disability, speech delay, and autistic features. Assessed by TA-cloning, the variant promoted the skipping of exon 18 and a premature stop codon (p.Asn511*), resulting in a predicted truncated protein. This variant, that is lacking the forkhead-box DNA-binding domain and nuclear localization signal 2, may disrupt the protein function and thus cause FOXP1 syndrome-related symptoms. Our study extends the phenotypic and allelic spectra of the FOXP1 syndrome.
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Affiliation(s)
- Min Chen
- Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yixi Sun
- Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yeqing Qian
- Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Na Chen
- Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Hongge Li
- Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Liya Wang
- Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Minyue Dong
- Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Reproductive Genetics (Zhejiang University), Ministry of Education, Hangzhou, China
- Key Laboratory of Women’s Reproductive Health of Zhejiang Province, Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- *Correspondence: Minyue Dong,
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16
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Diagnostic yield of patients with undiagnosed intellectual disability, global developmental delay and multiples congenital anomalies using karyotype, microarray analysis, whole exome sequencing from Central Brazil. PLoS One 2022; 17:e0266493. [PMID: 35390071 PMCID: PMC8989190 DOI: 10.1371/journal.pone.0266493] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 03/21/2022] [Indexed: 11/19/2022] Open
Abstract
Intellectual Disability (ID) is a neurodevelopmental disorder that affects approximately 3% of children and adolescents worldwide. It is a heterogeneous and multifactorial clinical condition. Several methodologies have been used to identify the genetic causes of ID and in recent years new generation sequencing techniques, such as exome sequencing, have enabled an increase in the detection of new pathogenic variants and new genes associated with ID. The aim of this study was to evaluate exome sequencing with analysis of the ID gene panel as a tool to increase the diagnostic yield of patients with ID/GDD/MCA in Central Brazil, together with karyotype and CMA tests. A retrospective cohort study was carried out with 369 patients encompassing both sexes. Karyotype analysis was performed for all patients. CMA was performed for patients who did not present structural and or numerical alterations in the karyotype. Cases that were not diagnosed after performing karyotyping and CMA were referred for exome sequencing using a gene panel for ID that included 1,252 genes. The karyotype identified chromosomal alterations in 34.7% (128/369). CMA was performed in 83 patients who had normal karyotype results resulting in a diagnostic yield of 21.7% (18/83). Exome sequencing with analysis of the ID gene panel was performed in 19 trios of families that had negative results with previous methodologies. With the ID gene panel analysis, we identified mutations in 63.1% (12/19) of the cases of which 75% (9/12) were pathogenic variants,8.3% (1/12) likely pathogenic and in 16.7% (2/12) it concerned a Variant of Uncertain Significance. With the three methodologies applied, it was possible to identify the genetic cause of ID in 42.3% (156/369) of the patients. In conclusion, our studies show the different methodologies that can be useful in diagnosing ID/GDD/MCA and that whole exome sequencing followed by gene panel analysis, when combined with clinical and laboratory screening, is an efficient diagnostic strategy.
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17
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De Novo ACTG1 Variant Expands the Phenotype and Genotype of Partial Deafness and Baraitser-Winter Syndrome. Int J Mol Sci 2022; 23:ijms23020692. [PMID: 35054877 PMCID: PMC8776155 DOI: 10.3390/ijms23020692] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/02/2022] [Accepted: 01/05/2022] [Indexed: 02/04/2023] Open
Abstract
Actin molecules are fundamental for embryonic structural and functional differentiation; γ-actin is specifically required for the maintenance and function of cytoskeletal structures in the ear, resulting in hearing. Baraitser–Winter Syndrome (B-WS, OMIM #243310, #614583) is a rare, multiple-anomaly genetic disorder caused by mutations in either cytoplasmically expressed actin gene, ACTB (β-actin) or ACTG1 (γ-actin). The resulting actinopathies cause characteristic cerebrofrontofacial and developmental traits, including progressive sensorineural deafness. Both ACTG1-related non-syndromic A20/A26 deafness and B-WS diagnoses are characterized by hypervariable penetrance in phenotype. Here, we identify a 28th patient worldwide carrying a mutated γ-actin ACTG1 allele, with mildly manifested cerebrofrontofacial B-WS traits, hypervariable penetrance of developmental traits and sensorineural hearing loss. This patient also displays brachycephaly and a complete absence of speech faculty, previously unreported for ACTG1-related B-WS or DFNA20/26 deafness, representing phenotypic expansion. The patient’s exome sequence analyses (ES) confirms a de novo ACTG1 variant previously unlinked to the pathology. Additional microarray analysis uncover no further mutational basis for dual molecular diagnosis in our patient. We conclude that γ-actin c.542C > T, p.Ala181Val is a dominant pathogenic variant, associated with mildly manifested facial and cerebral traits typical of B-WS, hypervariable penetrance of developmental traits and sensorineural deafness. We further posit and present argument and evidence suggesting ACTG1-related non-syndromic DFNA20/A26 deafness is a manifestation of undiagnosed ACTG1-related B-WS.
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18
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Carbillon L, Amarenco B. Corpus callosal agenesis, fetal MRI and molecular genetics. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2022; 59:132. [PMID: 34985820 DOI: 10.1002/uog.24824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 09/24/2021] [Indexed: 06/14/2023]
Affiliation(s)
- L Carbillon
- Assistance Publique - Hôpitaux de Paris, Bondy, France
| | - B Amarenco
- Assistance Publique - Hôpitaux de Paris, Bondy, France
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19
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Smol T, Frénois F, Manouvrier-Hanu S, Petit F, Ghoumid J. Performance of meta-predictors for the classification of MED13L missense variations, implication of raw parameters. Eur J Med Genet 2021; 65:104398. [PMID: 34798324 DOI: 10.1016/j.ejmg.2021.104398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 09/14/2021] [Accepted: 11/13/2021] [Indexed: 11/26/2022]
Abstract
MED13L syndrome is a rare congenital disorder comprising moderate intellectual disability, hypotonia and facial dysmorphism. Whole exome or genome sequencing in patients with non-specific neurodevelopmental disorders leads to identification of an increasing number of MED13L missense variations of unknown signification. The aim of our study was to identify relevant annotation parameters enhancing discrimination between candidate pathogenic or neutral missense variations, and to assess the performance of seven meta-predictor algorithms: BayesDel, CADD, DANN, FATHMM-XF, M-CAP, MISTIC and REVEL for the classification of MED13L missense variants. Significant differences were identified for five parameters: global conservation through verPhyloP and verPhCons scores; physico-chemical difference between amino acids estimated by Grantham scores; conservation of residues between MED13L and MED13 protein; proximity to phosphorylation sites for pathogenic variations. Among the seven selected in-silico tools, BayesDel, REVEL, and MISTIC provided the most interesting performances to discriminate pathogenic from neutral missense variations. Individual gene parameter studies with MED13L have provided expertise on elements of annotation improving meta-predictor choices. The in-silico approach allows us to make valuable hypotheses to predict the involvement of these amino acids in MED13L pathogenic missense variations.
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Affiliation(s)
- Thomas Smol
- Université de Lille, ULR7364 RADEME, F-59000, Lille, France; CHU Lille, Institut de Génétique Médicale, F-59000, Lille, France
| | - Frédéric Frénois
- Université de Lille, ULR7364 RADEME, F-59000, Lille, France; CHU Lille, Clinique de Génétique, Guy Fontaine, F-59000, Lille, France
| | - Sylvie Manouvrier-Hanu
- Université de Lille, ULR7364 RADEME, F-59000, Lille, France; CHU Lille, Clinique de Génétique, Guy Fontaine, F-59000, Lille, France
| | - Florence Petit
- Université de Lille, ULR7364 RADEME, F-59000, Lille, France; CHU Lille, Clinique de Génétique, Guy Fontaine, F-59000, Lille, France
| | - Jamal Ghoumid
- Université de Lille, ULR7364 RADEME, F-59000, Lille, France; CHU Lille, Clinique de Génétique, Guy Fontaine, F-59000, Lille, France.
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20
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de Valles-Ibáñez G, Hildebrand MS, Bahlo M, King C, Coleman M, Green TE, Goldsmith J, Davis S, Gill D, Mandelstam S, Scheffer IE, Sadleir LG. Infantile-onset myoclonic developmental and epileptic encephalopathy: A new RARS2 phenotype. Epilepsia Open 2021; 7:170-180. [PMID: 34717047 PMCID: PMC8886097 DOI: 10.1002/epi4.12553] [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: 05/03/2021] [Revised: 09/29/2021] [Accepted: 10/25/2021] [Indexed: 11/11/2022] Open
Abstract
Recessive variants in RARS2, a nuclear gene encoding a mitochondrial protein, were initially reported in pontocerebellar hypoplasia. Subsequently, a recessive RARS2 early-infantile (<12 weeks) developmental and epileptic encephalopathy was described with hypoglycaemia and lactic acidosis. Here, we describe two unrelated patients with a novel RARS2 phenotype and reanalyse the published RARS2 epilepsy phenotypes and variants. Our novel cases had infantile-onset myoclonic developmental and epileptic encephalopathy, presenting with a progressive movement disorder from 9 months on a background of normal development. Development plateaued and regressed thereafter, with mild to profound impairment. Multiple drug-resistant generalized and focal seizures occurred with episodes of non-convulsive status epilepticus. Seizure types included absence, atonic, myoclonic, and focal seizures. Electroencephalograms showed diffuse slowing, multifocal, and generalised spike-wave activity, activated by sleep. Both patients had compound heterozygous RARS2 variants with likely impact on splicing and transcription. Remarkably, of the now 52 RARS2 variants reported in 54 patients, our reanalysis found that 44 (85%) have been shown to or are predicted to affect splicing or gene expression leading to protein truncation or nonsense-mediated decay. We expand the RARS2 phenotypic spectrum to include infantile encephalopathy and suggest this gene is enriched for pathogenic variants that disrupt splicing.
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Affiliation(s)
| | - Michael S Hildebrand
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia.,Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Melanie Bahlo
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Chontelle King
- Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand
| | - Matthew Coleman
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia.,Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Timothy E Green
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia.,Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - John Goldsmith
- Waikids Paediatric Service, Waikato District Health Board, Hamilton, New Zealand
| | | | - Deepak Gill
- T.Y. Nelson Department of Neurology and Neurosurgery, The Children's Hospital at Westmead, Sydney, New South Wales, Australia
| | - Simone Mandelstam
- Department of Medical Imaging, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Ingrid E Scheffer
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia.,Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Victoria, Australia.,The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia.,Departments of Paediatrics, University of Melbourne, Austin Health and Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Lynette G Sadleir
- Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand
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21
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DFNA20/26 and Other ACTG1-Associated Phenotypes: A Case Report and Review of the Literature. Audiol Res 2021; 11:582-593. [PMID: 34698053 PMCID: PMC8544197 DOI: 10.3390/audiolres11040052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/10/2021] [Accepted: 10/13/2021] [Indexed: 02/08/2023] Open
Abstract
Since the early 2000s, an ever-increasing subset of missense pathogenic variants in the ACTG1 gene has been associated with an autosomal-dominant, progressive, typically post-lingual non-syndromic hearing loss (NSHL) condition designed as DFNA20/26. ACTG1 gene encodes gamma actin, the predominant actin protein in the cytoskeleton of auditory hair cells; its normal expression and function are essential for the stereocilia maintenance. Different gain-of-function pathogenic variants of ACTG1 have been associated with two major phenotypes: DFNA20/26 and Baraitser-Winter syndrome, a multiple congenital anomaly disorder. Here, we report a novel ACTG1 variant [c.625G>A (p. Val209Met)] in an adult patient with moderate-severe NSHL characterized by a downsloping audiogram. The patient, who had a clinical history of slowly progressive NSHL and tinnitus, was referred to our laboratory for the analysis of a large panel of NSHL-associated genes by next generation sequencing. An extensive review of previously reported ACTG1 variants and their associated phenotypes was also performed.
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22
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Abe‐Hatano C, Iida A, Kosugi S, Momozawa Y, Terao C, Ishikawa K, Okubo M, Hachiya Y, Nishida H, Nakamura K, Miyata R, Murakami C, Takahashi K, Hoshino K, Sakamoto H, Ohta S, Kubota M, Takeshita E, Ishiyama A, Nakagawa E, Sasaki M, Kato M, Matsumoto N, Kamatani Y, Kubo M, Takahashi Y, Natsume J, Inoue K, Goto Y. Whole genome sequencing of 45 Japanese patients with intellectual disability. Am J Med Genet A 2021; 185:1468-1480. [PMID: 33624935 PMCID: PMC8247954 DOI: 10.1002/ajmg.a.62138] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/23/2020] [Accepted: 02/06/2021] [Indexed: 02/06/2023]
Abstract
Intellectual disability (ID) is characterized by significant limitations in both intellectual functioning and adaptive behaviors, originating before the age of 18 years. However, the genetic etiologies of ID are still incompletely elucidated due to the wide range of clinical and genetic heterogeneity. Whole genome sequencing (WGS) has been applied as a single-step clinical diagnostic tool for ID because it detects genetic variations with a wide range of resolution from single nucleotide variants (SNVs) to structural variants (SVs). To explore the causative genes for ID, we employed WGS in 45 patients from 44 unrelated Japanese families and performed a stepwise screening approach focusing on the coding variants in the genes. Here, we report 12 pathogenic and likely pathogenic variants: seven heterozygous variants of ADNP, SATB2, ANKRD11, PTEN, TCF4, SPAST, and KCNA2, three hemizygous variants of SMS, SLC6A8, and IQSEC2, and one homozygous variant in AGTPBP1. Of these, four were considered novel. Furthermore, a novel 76 kb deletion containing exons 1 and 2 in DYRK1A was identified. We confirmed the clinical and genetic heterogeneity and high frequency of de novo causative variants (8/12, 66.7%). This is the first report of WGS analysis in Japanese patients with ID. Our results would provide insight into the correlation between novel variants and expanded phenotypes of the disease.
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Affiliation(s)
- Chihiro Abe‐Hatano
- Department of Mental Retardation and Birth Defect ResearchNational Institute of Neuroscience, National Center of Neurology and PsychiatryTokyoJapan
- Department of PediatricsNagoya University Graduate School of MedicineAichiJapan
| | - Aritoshi Iida
- Medical Genome CenterNational Center of Neurology and PsychiatryTokyoJapan
| | - Shunichi Kosugi
- Laboratory for Statistical and Translational GeneticsRIKEN Center for Integrative Medical SciencesKanagawaJapan
| | - Yukihide Momozawa
- Laboratory for Genotyping DevelopmentRIKEN Center for Integrative Medical SciencesKanagawaJapan
| | - Chikashi Terao
- Laboratory for Statistical and Translational GeneticsRIKEN Center for Integrative Medical SciencesKanagawaJapan
- Clinical Research CenterShizuoka General HospitalShizuokaJapan
- The Department of Applied GeneticsThe School of Pharmaceutical Sciences, University of ShizuokaShizuokaJapan
| | - Keiko Ishikawa
- Medical Genome CenterNational Center of Neurology and PsychiatryTokyoJapan
| | - Mariko Okubo
- Department of Child NeurologyNational Center Hospital, National Center of Neurology and PsychiatryTokyoJapan
| | - Yasuo Hachiya
- Department of NeuropediatricsTokyo Metropolitan Neurological HospitalTokyoJapan
| | - Hiroya Nishida
- Department of NeuropediatricsTokyo Metropolitan Neurological HospitalTokyoJapan
| | - Kazuyuki Nakamura
- Department of PediatricsYamagata University Faculty of MedicineYamagataJapan
| | - Rie Miyata
- Department of PediatricsTokyo‐Kita Medical CenterTokyoJapan
| | - Chie Murakami
- Department of PediatricsKitakyusyu Children's Rehabilitation CenterFukuokaJapan
| | - Kan Takahashi
- Department of PediatricsOme Municipal General HospitalTokyoJapan
| | - Kyoko Hoshino
- Department of PediatricsMinami Wakayama Medical CenterWakayamaJapan
| | - Haruko Sakamoto
- Department of NeonatologyJapanese Red Cross Osaka HospitalOsakaJapan
| | - Sayaka Ohta
- Division of NeurologyNational Center for Child Health and DevelopmentTokyoJapan
| | - Masaya Kubota
- Division of NeurologyNational Center for Child Health and DevelopmentTokyoJapan
| | - Eri Takeshita
- Department of Child NeurologyNational Center Hospital, National Center of Neurology and PsychiatryTokyoJapan
| | - Akihiko Ishiyama
- Department of Child NeurologyNational Center Hospital, National Center of Neurology and PsychiatryTokyoJapan
| | - Eiji Nakagawa
- Department of Child NeurologyNational Center Hospital, National Center of Neurology and PsychiatryTokyoJapan
| | - Masayuki Sasaki
- Department of Child NeurologyNational Center Hospital, National Center of Neurology and PsychiatryTokyoJapan
| | - Mitsuhiro Kato
- Department of PediatricsYamagata University Faculty of MedicineYamagataJapan
- Department of PediatricsShowa University School of MedicineTokyoJapan
| | - Naomichi Matsumoto
- Department of Human GeneticsYokohama City University Graduate School of MedicineKanagawaJapan
| | - Yoichiro Kamatani
- Laboratory for Statistical and Translational GeneticsRIKEN Center for Integrative Medical SciencesKanagawaJapan
- Department of Computational Biology and Medical SciencesGraduate School of Frontier Sciences, The University of TokyoTokyoJapan
| | - Michiaki Kubo
- Laboratory for Genotyping DevelopmentRIKEN Center for Integrative Medical SciencesKanagawaJapan
| | - Yoshiyuki Takahashi
- Department of PediatricsNagoya University Graduate School of MedicineAichiJapan
| | - Jun Natsume
- Department of PediatricsNagoya University Graduate School of MedicineAichiJapan
| | - Ken Inoue
- Department of Mental Retardation and Birth Defect ResearchNational Institute of Neuroscience, National Center of Neurology and PsychiatryTokyoJapan
| | - Yu‐Ichi Goto
- Department of Mental Retardation and Birth Defect ResearchNational Institute of Neuroscience, National Center of Neurology and PsychiatryTokyoJapan
- Medical Genome CenterNational Center of Neurology and PsychiatryTokyoJapan
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23
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Towards a Change in the Diagnostic Algorithm of Autism Spectrum Disorders: Evidence Supporting Whole Exome Sequencing as a First-Tier Test. Genes (Basel) 2021; 12:genes12040560. [PMID: 33921431 PMCID: PMC8068856 DOI: 10.3390/genes12040560] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/02/2021] [Accepted: 04/07/2021] [Indexed: 12/20/2022] Open
Abstract
Autism spectrum disorder (ASD) is a prevalent and extremely heterogeneous neurodevelopmental disorder (NDD) with a strong genetic component. In recent years, the clinical relevance of de novo mutations to the aetiology of ASD has been demonstrated. Current guidelines recommend chromosomal microarray (CMA) and a FMR1 testing as first-tier tests, but there is increasing evidence that support the use of NGS for the diagnosis of NDDs. Specifically in ASD, it has not been extensively evaluated and, thus, we performed and compared the clinical utility of CMA, FMR1 testing, and/or whole exome sequencing (WES) in a cohort of 343 ASD patients. We achieved a global diagnostic rate of 12.8% (44/343), the majority of them being characterised by WES (33/44; 75%) compared to CMA (9/44; 20.4%) or FMR1 testing (2/44; 4.5%). Taking into account the age at which genetic testing was carried out, we identified a causal genetic alteration in 22.5% (37/164) of patients over 5 years old, but only in 3.9% (7/179) of patients under this age. Our data evidence the higher diagnostic power of WES compared to CMA in the study of ASD and support the implementation of WES as a first-tier test for the genetic diagnosis of this disorder, when there is no suspicion of fragile X syndrome.
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24
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Mary L, Nourisson E, Feger C, Laugel V, Chaigne D, Keren B, Afenjar A, Billette T, Trost D, Cieuta-Walti C, Gerard B, Piton A, Schaefer E. Pathogenic variants in KCNQ2 cause intellectual deficiency without epilepsy: Broadening the phenotypic spectrum of a potassium channelopathy. Am J Med Genet A 2021; 185:1803-1815. [PMID: 33754465 DOI: 10.1002/ajmg.a.62181] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 01/19/2021] [Accepted: 03/11/2021] [Indexed: 12/22/2022]
Abstract
High-throughput sequencing (HTS) improved the molecular diagnosis in individuals with intellectual deficiency (ID) and helped to broaden the phenotype of previously known disease-causing genes. We report herein four unrelated patients with isolated ID, carriers of a likely pathogenic variant in KCNQ2, a gene usually implicated in benign familial neonatal seizures (BFNS) or early onset epileptic encephalopathy (EOEE). Patients were diagnosed by targeted HTS or exome sequencing. Pathogenicity of the variants was assessed by multiple in silico tools. Patients' ID ranged from mild to severe with predominance of speech disturbance and autistic features. Three of the four variants disrupted the same amino acid. Compiling all the pathogenic variants previously reported, we observed a strong overlap between variants causing EOEE, isolated ID, and BFNS and an important intra-familial phenotypic variability, although missense variants in the voltage-sensing domain and the pore are significantly associated to EOEE (p < 0.01, Fisher test). Thus, pathogenic variants in KCNQ2 can be associated with isolated ID. We did not highlight strong related genotype-phenotype correlations in KCNQ2-related disorders. A second genetic hit, a burden of rare variants, or other extrinsic factors may explain such a phenotypic variability. However, it is of interest to study encephalopathy genes in non-epileptic ID patients.
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Affiliation(s)
- Laura Mary
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Elsa Nourisson
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Claire Feger
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Vincent Laugel
- Service de Neuropédiatrie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Denys Chaigne
- Service de Neuropédiatrie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Boris Keren
- Département de Génétique, Centre de Référence des Déficiences Intellectuelles de Causes Rares, Groupe de Recherche Clinique "Déficiences Intellectuelles et Autisme," Université Pierre et Marie Curie, Hôpital de la Pitié-Salpêtrière, Paris, France.,Institut du Cerveau et de la Moelle Épinière, Sorbonne Universités, Université Pierre et Marie Curie (Université Paris 06), UMRS 1127, INSERM U 1127, CNRS UMR 7225, Paris, France
| | - Alexandra Afenjar
- Centre de Référence Déficiences Intellectuelles de Causes Rares, Département de Génétique et Embryologie Médicale, Hôpital Trousseau, Sorbonne Universités, Paris, France
| | - Thierry Billette
- Assistance Publique-Hôpitaux de Paris, Service de Neuropédiatrie, Hôpital Armand Trousseau, Paris, France
| | | | | | - Bénédicte Gerard
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Amélie Piton
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.,Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR-7104, Inserm U964, Université de Strasbourg, Strasbourg, France
| | - Elise Schaefer
- Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, Institut de Génétique Médicale d'Alsace, Strasbourg, France
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25
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Carter MT, Cloutier M, Tsampalieros A, Webster R. Genetic and metabolic investigations for individuals with neurodevelopmental disorders: A survey of Canadian geneticists' practices. Am J Med Genet A 2021; 185:1757-1766. [PMID: 33720531 DOI: 10.1002/ajmg.a.62167] [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: 10/13/2020] [Revised: 01/15/2021] [Accepted: 02/26/2021] [Indexed: 11/06/2022]
Abstract
Neurodevelopmental disorders (NDDs) are genetically heterogeneous. There are many possible etiological investigations for NDDs, and a lack of clear and current guidelines for such testing. Here we characterize the practices of genetic and metabolic physicians in Canada as it pertains to etiological investigation of patients with NDDs, by means of an online questionnaire. The survey response rate was 30% (n = 46). The most commonly ordered first-line tests for patients with non-syndromic NDDs are chromosomal microarray (98%) and Fragile X testing (85%). The most commonly ordered second-line test for non-syndromic NDDs is a multi-gene panel (78%) or exome sequencing (29%). Biochemical screening is ordered as a first line test by 33% of respondents, second line by 31%, and rarely or never by 36% of respondents. Those respondents with metabolics fellowship training were more likely to order biochemical screening than those without. The number of years of clinical experience generally did not affect the types of tests ordered. For patients with NDDs, test-ordering practice among Canadian clinical geneticists is highly variable, in particular with respect to biochemical screening and use of next-generation sequencing technologies. Evidence-based guidelines should be developed to facilitate best practices in Canada.
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26
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Wei H, Lai A, Tan ES, Koh MJA, Ng I, Ting TW, Thomas T, Cham B, Lim JY, Kam S, Goh CYJ, Lin G, Brett M, Chan D, Jamuar SS, Tan EC. Genetic landscape of congenital disorders in patients from Southeast Asia: results from sequencing using a gene panel for Mendelian phenotypes. Arch Dis Child 2021; 106:38-43. [PMID: 32978145 DOI: 10.1136/archdischild-2020-319177] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 07/24/2020] [Accepted: 08/30/2020] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To test the utility and diagnostic yield of a medical-exome gene panel for identifying pathogenic variants in Mendelian disorders. METHODS Next-generation sequencing was performed with the TruSight One gene panel (targeting 4813 genes) followed by MiSeq sequencing on 216 patients who presented with suspected genetic disorders as assessed by their attending physicians. RESULTS There were 56 pathogenic and 36 likely pathogenic variants across 57 genes identified in 87 patients. Causal mutations were more likely to be truncating and from patients with a prior clinical diagnosis. Another 18 promising variants need further evaluation for more evidence to meet the requirement for potential upgrade to pathogenic. Forty-five of the 92 clinically significant variants were novel. CONCLUSION The 40.3% positive yield compares favourably with similar studies using either this panel or whole exome sequencing, demonstrating that large gene panels could be a good alternative to whole exome sequencing for quick genetic confirmation of Mendelian disorders.
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Affiliation(s)
- Heming Wei
- KK Research Centre, KK Women's & Children's Hospital, Singapore
| | - Angeline Lai
- Paediatric Academic Clinical Programme, SingHealth Duke-NUS Graduate Medical School, Singapore.,Genetics Service, KK Women's & Children's Hospital, Singapore
| | - Ee Shien Tan
- Paediatric Academic Clinical Programme, SingHealth Duke-NUS Graduate Medical School, Singapore.,Genetics Service, KK Women's & Children's Hospital, Singapore
| | - Mark Jean Aan Koh
- Paediatric Academic Clinical Programme, SingHealth Duke-NUS Graduate Medical School, Singapore.,Dermatology Service, KK Women's & Children's Hospital, Singapore
| | - Ivy Ng
- Paediatric Academic Clinical Programme, SingHealth Duke-NUS Graduate Medical School, Singapore.,Genetics Service, KK Women's and Children's Hospital, Singapore
| | - Teck Wah Ting
- Paediatric Academic Clinical Programme, SingHealth Duke-NUS Graduate Medical School, Singapore.,Genetics Service, KK Women's and Children's Hospital, Singapore
| | - Terrence Thomas
- Paediatric Academic Clinical Programme, SingHealth Duke-NUS Graduate Medical School, Singapore.,Neurology Service, KK Women's & Children's Hospital, Singapore
| | - Breana Cham
- Genetics Service, KK Women's & Children's Hospital, Singapore
| | - Jiin Ying Lim
- Genetics Service, KK Women's & Children's Hospital, Singapore
| | - Sylvia Kam
- Genetics Service, KK Women's & Children's Hospital, Singapore
| | | | - Grace Lin
- KK Research Centre, KK Women's & Children's Hospital, Singapore
| | - Maggie Brett
- KK Research Centre, KK Women's & Children's Hospital, Singapore
| | - Derrick Chan
- Paediatric Academic Clinical Programme, SingHealth Duke-NUS Graduate Medical School, Singapore.,Neurology Service, KK Women's & Children's Hospital, Singapore
| | - Saumya Shekhar Jamuar
- Paediatric Academic Clinical Programme, SingHealth Duke-NUS Graduate Medical School, Singapore.,Genetics Service, KK Women's & Children's Hospital, Singapore
| | - Ene-Choo Tan
- KK Research Centre, KK Women's & Children's Hospital, Singapore .,Paediatric Academic Clinical Programme, SingHealth Duke-NUS Graduate Medical School, Singapore
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27
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Lin L, Zhang Y, Pan H, Wang J, Qi Y, Ma Y. Clinical and genetic characteristics and prenatal diagnosis of patients presented GDD/ID with rare monogenic causes. Orphanet J Rare Dis 2020; 15:317. [PMID: 33176815 PMCID: PMC7656751 DOI: 10.1186/s13023-020-01599-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/26/2020] [Indexed: 12/18/2022] Open
Abstract
Background Global developmental delay/intellectual disability (GDD/ID), used to be named as mental retardation (MR), is one of the most common phenotypes in neurogenetic diseases. In this study, we described the diagnostic courses, clinical and genetic characteristics and prenatal diagnosis of a cohort with patients presented GDD/ID with monogenic causes, from the perspective of a tertiary genetic counseling and prenatal diagnostic center. Method We retrospectively analyzed the diagnostic courses, clinical characteristics, and genetic spectrum of patients presented GDD/ID with rare monogenic causes. We also conducted a follow-up study on prenatal diagnosis in these families. Pathogenicity of variants was interpreted by molecular geneticists and clinicians according to the guidelines of the American College of Medical Genetics and Genomics (ACMG). Results Among 81 patients with GDD/ID caused by rare monogenic variants it often took 0.5–4.5 years and 2–8 referrals to obtain genetic diagnoses. Devlopmental delay typically occurred before 3 years of age, and patients usually presented severe to profound GDD/ID. The most common co-existing conditions were epilepsy (58%), microcephaly (21%) and facial anomalies (17%). In total, 111 pathogenic variants were found in 62 different genes among the 81 pedigrees, and 56 variants were novel. The most common inheritance patterns in this outbred Chinese population were autosomal dominant (AD; 47%), following autosomal recessive (AR; 37%), and X-linked (XL; 16%). SCN2A, SHANK3 and STXBP1 were important causal genes. Hot-spot variants were rarely found. By the follow-up, 33 affected families, including 15, 13 and 5 families inherited in AR, AD and XL modes respectively, had undergone prenatal diagnosis. And the recurrence rates are 26.7%, 15.4% and 20% for families inherited in AR, AD, and XL patterns. Conclusion Patients presented with GDD/ID caused by rare single gene variants are characterized by early onset, relatively severe symptoms and great clinical variability and genetic heterogeneity. Timely referrals to genetic counseling and prenatal diagnostic laboratories are important for affected families planning to have additional children.
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Affiliation(s)
- Liling Lin
- Department of Central Laboratory, Peking University First Hospital, No. 8, Xishiku Street, Xicheng District, Beijing, 100034, China
| | - Ying Zhang
- Department of Central Laboratory, Peking University First Hospital, No. 8, Xishiku Street, Xicheng District, Beijing, 100034, China
| | - Hong Pan
- Department of Central Laboratory, Peking University First Hospital, No. 8, Xishiku Street, Xicheng District, Beijing, 100034, China
| | - Jingmin Wang
- Department of Pediatrics, Peking University First Hospital, No. 8, Xishiku Street, Xicheng District, Beijing, 100034, China
| | - Yu Qi
- Department of Central Laboratory, Peking University First Hospital, No. 8, Xishiku Street, Xicheng District, Beijing, 100034, China
| | - Yinan Ma
- Department of Central Laboratory, Peking University First Hospital, No. 8, Xishiku Street, Xicheng District, Beijing, 100034, China.
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28
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Khan MI, Latif M, Saif M, Ahmad H, Khan AU, Naseer MI, Hussain HMJ, Jelani M. Whole exome sequencing identified a novel missense alteration in CC2D2A causing Joubert syndrome 9 in a Pakhtun family. J Gene Med 2020; 23:e3279. [PMID: 32989887 DOI: 10.1002/jgm.3279] [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: 04/15/2020] [Revised: 09/21/2020] [Accepted: 09/21/2020] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Joubert syndrome (JBTS) is a heterogenous disorder characterized by intellectual disability, developmental delays, molar tooth sign in brain imaging, hypotonia, ocular motor apraxia and overlapping features of ciliopathies. There are 36 clinical subtypes of JBTS, with an equal number of genes known so far for this phenotype. METHODS Whole exome sequencing (WES) and Sanger sequencing were performed for the molecular diagnosis of a Pakhtun family affected with Joubert syndrome type 9 (JBTS9). RESULTS A novel homozygous missense variant (c.4417C>G; Pro1473Ala) in exon 34 was identified in coiled-coil and C2 domains-containing the protein 2A (CC2D2A; NM_001080522) gene. The variant co-segregated in autosomal recessive fashion within the family and was not found in 200 ethnically matched unaffected individuals. In silico analyses supported the pathogenic effect of the altered CC2D2A protein. CONCLUSIONS To the best of our knowledge, this is the first report of CC2D2A alteration co-segragating with a JBTS9 phenotype in a Pakhtun family from Pakistan. Our findings broaden the pathogenic spectrum of JBTS9, adding a novel variant to CC2D2A variation pool. WES analysis is a successful molecular diagnostic tool for rare genetic disorders, especially in those populations where the marriage of cousins is more frequent. Efficient and accurate genetic testing and counselling of the affected families are helpful for patient management and for reducing the disease burden in future generations.
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Affiliation(s)
- Muhammad Ismail Khan
- Department of Zoology, Islamia College Peshawar, Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Muhammad Latif
- Centre for Genetics and Inherited Diseases (CGID), Taibah University, Al-Madinah, Al-Munawwarah, Saudi Arabia
| | - Maria Saif
- Centre for Omic Sciences, Islamia College Peshawar, Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Hilal Ahmad
- Centre for Omic Sciences, Islamia College Peshawar, Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Atta Ullah Khan
- Department of Medicine, Pak International Medical College Phase 5, Hayatabad Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Muhammad Imran Naseer
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah, Saudi Arabia.,Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Musharraf Jelani
- Centre for Omic Sciences, Islamia College Peshawar, Peshawar, Khyber Pakhtunkhwa, Pakistan
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Gieldon L, Mackenroth L, Kahlert AK, Lemke JR, Porrmann J, Schallner J, von der Hagen M, Markus S, Weidensee S, Novotna B, Soerensen C, Klink B, Wagner J, Tzschach A, Jahn A, Kuhlee F, Hackmann K, Schrock E, Di Donato N, Rump A. Correction: Diagnostic value of partial exome sequencing in developmental disorders. PLoS One 2020; 15:e0239959. [PMID: 32970766 PMCID: PMC7514079 DOI: 10.1371/journal.pone.0239959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
[This corrects the article DOI: 10.1371/journal.pone.0201041.].
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Melas M, Subbiah S, Saadat S, Rajurkar S, McDonnell KJ. The Community Oncology and Academic Medical Center Alliance in the Age of Precision Medicine: Cancer Genetics and Genomics Considerations. J Clin Med 2020; 9:E2125. [PMID: 32640668 PMCID: PMC7408957 DOI: 10.3390/jcm9072125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 06/28/2020] [Accepted: 07/02/2020] [Indexed: 12/15/2022] Open
Abstract
Recent public policy, governmental regulatory and economic trends have motivated the establishment and deepening of community health and academic medical center alliances. Accordingly, community oncology practices now deliver a significant portion of their oncology care in association with academic cancer centers. In the age of precision medicine, this alliance has acquired critical importance; novel advances in nucleic acid sequencing, the generation and analysis of immense data sets, the changing clinical landscape of hereditary cancer predisposition and ongoing discovery of novel, targeted therapies challenge community-based oncologists to deliver molecularly-informed health care. The active engagement of community oncology practices with academic partners helps with meeting these challenges; community/academic alliances result in improved cancer patient care and provider efficacy. Here, we review the community oncology and academic medical center alliance. We examine how practitioners may leverage academic center precision medicine-based cancer genetics and genomics programs to advance their patients' needs. We highlight a number of project initiatives at the City of Hope Comprehensive Cancer Center that seek to optimize community oncology and academic cancer center precision medicine interactions.
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Affiliation(s)
- Marilena Melas
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children’s Hospital, Columbus, OH 43205, USA;
| | - Shanmuga Subbiah
- Department of Medical Oncology and Therapeutics Research, City of Hope Comprehensive Cancer Center, Glendora, CA 91741, USA;
| | - Siamak Saadat
- Department of Medical Oncology and Therapeutics Research, City of Hope Comprehensive Cancer Center, Colton, CA 92324, USA;
| | - Swapnil Rajurkar
- Department of Medical Oncology and Therapeutics Research, City of Hope Comprehensive Cancer Center, Upland, CA 91786, USA;
| | - Kevin J. McDonnell
- Department of Medical Oncology and Therapeutics Research, City of Hope Comprehensive Cancer Center and Beckman Research Institute, Duarte, CA 91010, USA
- Center for Precision Medicine, City of Hope Comprehensive Cancer Center, Duarte, CA 91010, USA
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Han JY, Lee IG. Genetic tests by next-generation sequencing in children with developmental delay and/or intellectual disability. Clin Exp Pediatr 2020; 63:195-202. [PMID: 32024334 PMCID: PMC7303420 DOI: 10.3345/kjp.2019.00808] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 10/24/2019] [Indexed: 02/07/2023] Open
Abstract
Developments in next-generation sequencing (NGS) techogies have assisted in clarifying the diagnosis and treatment of developmental delay/intellectual disability (DD/ID) via molecular genetic testing. Advances in DNA sequencing technology have not only allowed the evolution of targeted panels but also, and more currently enabled genome-wide analyses to progress from research era to clinical practice. Broad acceptance of accuracy- guided targeted gene panel, whole-exome sequencing (WES), and whole-genome sequencing (WGS) for DD/ID need prospective analyses of the increasing cost-effectiveness versus conventional genetic testing. Choosing the appropriate sequencing method requires individual planning. Data are required to guide best-practice recommendations for genomic testing, regarding various clinical phenotypes in an etiologic approach. Targeted panel testing may be recommended as a first-tier testing approach for children with DD/ID. Family-based trio testing by WES/WGS can be used as a second test for DD/ ID in undiagnosed children who previously tested negative on a targeted panel. The role of NGS in molecular diagnostics, treatment, prediction of prognosis will continue to increase further in the coming years. Given the rapid pace of changes in the past 10 years, all medical providers should be aware of the changes in the transformative genetics field.
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Affiliation(s)
- Ji Yoon Han
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - In Goo Lee
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea
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Stojanovic JR, Miletic A, Peterlin B, Maver A, Mijovic M, Borlja N, Dimitrijevic B, Soldatovic I, Cuturilo G. Diagnostic and Clinical Utility of Clinical Exome Sequencing in Children With Moderate and Severe Global Developmental Delay / Intellectual Disability. J Child Neurol 2020; 35:116-131. [PMID: 31623504 DOI: 10.1177/0883073819879835] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Clinical exome sequencing is currently being used in diagnostics of various genetic disorders, but studies supporting its application in clinical setting are scarce. The aim of this study was to establish diagnostic and clinical utility of clinical exome sequencing in patients with moderate and severe global developmental delay/intellectual disability. Clinical diagnosis was made in 49 of 88 investigated patients, with overall diagnostic yield of 55.7%. Molecular findings are characterized in detail, including the impact of newly made diagnosis on clinical management. Several previously unreported genotype-phenotype correlations and 33 novel variants are described. Genetic and clinical data were shared through publicly available database. In conclusion, clinical exome sequencing allows identification of causative variants in a significant proportion of patients in investigated clinical subgroup. Compared to whole exome sequencing, it shows similar diagnostic and clinical utility with reduced costs, which could be of particular importance for institutions with limited resources.
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Affiliation(s)
| | - Aleksandra Miletic
- University Children's Hospital, Department of Clinical Genetics, Belgrade, Serbia
| | - Borut Peterlin
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Ales Maver
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Marija Mijovic
- University Children's Hospital, Department of Clinical Genetics, Belgrade, Serbia
| | | | | | - Ivan Soldatovic
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Goran Cuturilo
- University Children's Hospital, Department of Clinical Genetics, Belgrade, Serbia.,Faculty of Medicine, University of Belgrade, Belgrade, Serbia
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Abicht A, Neuhann T, Mehnert L, Rost I, Reis A, Zweier C, Holinski-Feder E. Diagnostik seltener Erkrankungen mit „next generation sequencing“ – angekommen oder abgewehrt? MED GENET-BERLIN 2019. [DOI: 10.1007/s11825-019-00258-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Zusammenfassung
In der genetischen Diagnostik geht der Weg von Einzelgenanalysen hin zu Genpanelanalysen, insbesondere bei seltenen genetischen Erkrankungen. Im Juli 2016 wurde mit einer Änderung des EBM (Einheitlicher Bewertungsmaßstab) die Möglichkeit geschaffen, bei Patienten mit seltenen Erkrankungen im Rahmen der gesetzlichen Krankenversicherung genetische Analysen mittels „next generation sequencing“ (NGS) zu erbringen. Allerdings wurde die Mutationssuche in mehr als 25 Kilobasen (kb) kodierender Sequenz unter einen Genehmigungsvorbehalt durch die Krankenkassen gestellt und im zeitlichen Verlauf durch einen Abrechnungsausschluss zur Analyse einzelner oder weniger Gene mit einem Analyseumfang von weniger als 25 kb weiter eingeschränkt.
Aus Diagnostiklaboren des bayerischen Landesverbandes des BVDH (Berufsverband Deutscher Humangenetiker e. V.) berichten wir über die Erfahrungen, die mit Antragstellung, Widerspruchsverfahren, Genehmigungsquote, Ablehnungsgründen und diagnostischem Outcome bei der Analyse großer Genpanels im Rahmen seltener Erkrankungen gewonnen wurden. Im Erhebungszeitraum von 7 Quartalen wurden in vier Laboren insgesamt 314 Gutachten zur Begründung eines Antrags nach GOP 11514 erstellt, die alle durch den MDK begutachtet wurden. 71 % der Anträge wurden abgelehnt. Insgesamt 95 Anträge (29 %) wurden genehmigt, teilweise allerdings erst nach bis zu 5 Widersprüchen. Die Ablehnungen wurden sowohl mit sozialmedizinischen als auch mit formalen Argumenten begründet, wobei in den meisten Fällen eine als fehlend angesehene therapeutische Relevanz als sozialmedizinisches Argument aufgeführt wurde. Durch die genehmigten umfassenden NGS-Analysen konnte bei über 30 % der untersuchten Patienten eine genetische Diagnose gestellt werden, die in zwei Drittel der Fälle behandlungsrelevant war.
Zusammenfassend stehen der Genehmigungsvorbehalt einer NGS-Analyse nach GOP 11514 und die damit aufgebauten Widerstände einer medizinisch notwendigen und sinnvollen Diagnostik in der Versorgung von Patienten mit seltenen Erkrankungen im Wege.
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Affiliation(s)
- Angela Abicht
- 1 grid.491982.f 0000 0000 9738 9673 MGZ – Medizinisch Genetisches Zentrum Bayerstr. 3–5 80335 München Deutschland
| | - Teresa Neuhann
- 1 grid.491982.f 0000 0000 9738 9673 MGZ – Medizinisch Genetisches Zentrum Bayerstr. 3–5 80335 München Deutschland
| | | | - Imma Rost
- 3 Zentrum für Humangenetik und Laboratoriumsdiagnostik Martinsried Deutschland
| | - André Reis
- 4 grid.5330.5 0000 0001 2107 3311 Humangenetisches Institut, Universitätsklinikum Erlangen Friedrich-Alexander-Universität Erlangen-Nürnberg Erlangen Deutschland
| | - Christiane Zweier
- 4 grid.5330.5 0000 0001 2107 3311 Humangenetisches Institut, Universitätsklinikum Erlangen Friedrich-Alexander-Universität Erlangen-Nürnberg Erlangen Deutschland
| | - Elke Holinski-Feder
- 1 grid.491982.f 0000 0000 9738 9673 MGZ – Medizinisch Genetisches Zentrum Bayerstr. 3–5 80335 München Deutschland
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Yamamoto T, Imaizumi T, Yamamoto-Shimojima K, Lu Y, Yanagishita T, Shimada S, Chong PF, Kira R, Ueda R, Ishiyama A, Takeshita E, Momosaki K, Ozasa S, Akiyama T, Kobayashi K, Oomatsu H, Kitahara H, Yamaguchi T, Imai K, Kurahashi H, Okumura A, Oguni H, Seto T, Okamoto N. Genomic backgrounds of Japanese patients with undiagnosed neurodevelopmental disorders. Brain Dev 2019; 41:776-782. [PMID: 31171384 DOI: 10.1016/j.braindev.2019.05.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 05/08/2019] [Accepted: 05/21/2019] [Indexed: 01/07/2023]
Abstract
BACKGROUND Recently, many genes related to neurodevelopmental disorders have been identified by high-throughput genomic analysis; however, a comprehensive understanding of the mechanism underlying neurodevelopmental disorders remains to be established. To further understand these underlying mechanisms, we performed a comprehensive genomic analysis of patients with undiagnosed neurodevelopmental disorders. METHODS Genomic analysis using next-generation sequencing with a targeted panel was performed for a total of 133 Japanese patients (male/female, 81/52) with previously undiagnosed neurodevelopmental disorders, including developmental delay (DD), intellectual disability (ID), autism spectrum disorder (ASD), and epilepsy. Genomic copy numbers were also analyzed using the eXome Hidden Markov Model (XHMM). RESULTS Thirty-nine patients (29.3%) exhibited pathogenic or likely pathogenic findings with single-gene variants or chromosomal aberrations. Among them, 20 patients were presented here. Pathogenic or likely pathogenic variants were identified in 18 genes, including ACTG1, CACNA1A, CHD2, CDKL5, DNMT3A, EHMT1, GABRB3, GABRG2, GRIN2B, KCNQ3, KDM5C, MED13L, SCN2A, SHANK3, SMARCA2, STXBP1, SYNGAP1, and TBL1XR1. CONCLUSION A diagnostic yield of 29.3% in this study was nearly the same as that previously reported from other countries. Thus, we suggest that there is no difference in genomic backgrounds in Japanese patients with undiagnosed neurodevelopmental disabilities. Although most of the patients possessed de novo variants, one of the patients showed an X-linked inheritance pattern. As X-linked recessive disorders exhibit the possibility of recurrent occurrence in the family, comprehensive molecular diagnosis is important for genetic counseling.
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Affiliation(s)
- Toshiyuki Yamamoto
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo, Japan; Tokyo Women's Medical University Institute of Integrated Medical Sciences, Tokyo, Japan.
| | - Taichi Imaizumi
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo, Japan; Department of Pediatrics, St. Mariannna University School of Medicine, Kawasaki, Japan
| | - Keiko Yamamoto-Shimojima
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo, Japan; Tokyo Women's Medical University Institute of Integrated Medical Sciences, Tokyo, Japan
| | - Yongping Lu
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo, Japan
| | - Tomoe Yanagishita
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo, Japan; Department of Pediatrics, Tokyo Women's Medical University, Tokyo, Japan
| | - Shino Shimada
- Department of Pediatrics, Tokyo Women's Medical University, Tokyo, Japan
| | - Pin Fee Chong
- Department of Pediatric Neurology, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Ryutaro Kira
- Department of Pediatric Neurology, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Riyo Ueda
- Department of Child Neurology, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Akihiko Ishiyama
- Department of Child Neurology, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Eri Takeshita
- Department of Child Neurology, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Ken Momosaki
- Department of Pediatrics, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Shiro Ozasa
- Department of Pediatrics, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Tomoyuki Akiyama
- Department of Child Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Katsuhiro Kobayashi
- Department of Child Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Hiroo Oomatsu
- Department of Pediatrics, National Epilepsy Center, NHO Shizuoka Institute of Epilepsy and Neurological Disorders, Japan
| | - Hikaru Kitahara
- Department of Pediatrics, National Epilepsy Center, NHO Shizuoka Institute of Epilepsy and Neurological Disorders, Japan
| | - Tokito Yamaguchi
- Department of Pediatrics, National Epilepsy Center, NHO Shizuoka Institute of Epilepsy and Neurological Disorders, Japan
| | - Katsumi Imai
- Department of Pediatrics, National Epilepsy Center, NHO Shizuoka Institute of Epilepsy and Neurological Disorders, Japan
| | | | - Akihisa Okumura
- Department of Pediatrics, Aichi Medical University, Nagakute, Japan
| | - Hirokazu Oguni
- Department of Pediatrics, Tokyo Women's Medical University, Tokyo, Japan
| | - Toshiyuki Seto
- Department of Pediatrics, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Nobuhiko Okamoto
- Department of Medical Genetics, Osaka Women's and Children's Hospital, Izumi, Japan
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Pekeles H, Accogli A, Boudrahem-Addour N, Russell L, Parente F, Srour M. Diagnostic Yield of Intellectual Disability Gene Panels. Pediatr Neurol 2019; 92:32-36. [PMID: 30581057 DOI: 10.1016/j.pediatrneurol.2018.11.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 11/06/2018] [Accepted: 11/07/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Recent technological advances have improved the understanding and identification of the genetic basis of intellectual disability (ID) and global developmental delay (GDD). Next-generation sequencing panels of ID genes are now available for clinical testing; however, their overall yield in clinical practice has not yet been investigated. AIM We determined the diagnostic yield of ID gene panels in a clinical setting and explored whether any clinical features are associated with an increased diagnostic yield. METHODS We performed a systematic retrospective chart review of all patients with ID/GDD who underwent an ID gene panel between April 2014 and July 2017 at our institution. Chi-square analysis assessed whether any specific clinical features were significantly associated with a positive diagnostic yield. RESULTS Forty-eight subjects (18 females, 30 males; median age: 7.5 years) were included. Consanguinity was present in 17%, autism in 38%, seizures in 42%, nonspecific dysmorphic features in 67%, and abnormalities on neurological examination in 56%; furthermore, 29% of the cohort was nonverbal and 4% was nonambulatory. Four different gene panels were used. The diagnostic yield was 21% (10/48) overall, and 38% with the more recent trio-based panel. Eight of 10 patients had de novo pathogenic dominant mutations, one had an inherited pathogenic autosomal dominant mutation, and one had compound heterozygous pathogenic recessive mutations. No clinical feature was significantly associated with an increased diagnostic yield. CONCLUSIONS Our study suggests that ID gene panels have a high yield and are a valuable diagnostic tool in the evaluation of children with ID/GDD.
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Affiliation(s)
| | - Andrea Accogli
- Division of Pediatric Neurology, Departments of Pediatrics and Neurology & Neurosurgery, McGill University, Montreal, Canada; Scientific Institute for Research and Healthcare, Istituto Giannina Gaslini, Genova, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, and Maternal and Children's Sciences, Università degli Studi di Genova, Italy
| | - Nassima Boudrahem-Addour
- Child Health and Human Development Program, McGill University Health Center (MUHC) Research Institute, Montreal, Canada
| | - Laura Russell
- Division of Medical Genetics, Department of Medicine, McGill University, Montreal, Canada
| | - Fabienne Parente
- Division of Medical Genetics, Department of Medicine, McGill University, Montreal, Canada
| | - Myriam Srour
- Division of Pediatric Neurology, Departments of Pediatrics and Neurology & Neurosurgery, McGill University, Montreal, Canada.
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