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Kim SH, Seo J, Kwon SS, Teng LY, Won D, Shin S, Lee JS, Lee ST, Choi JR, Kang HC. Common genes and recurrent causative variants in 957 Asian patients with pediatric epilepsy. Epilepsia 2024; 65:766-778. [PMID: 38073125 DOI: 10.1111/epi.17857] [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: 08/14/2023] [Revised: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 12/23/2023]
Abstract
OBJECTIVE We aimed to identify common genes and recurrent causative variants in a large group of Asian patients with different epilepsy syndromes and subgroups. METHODS Patients with unexplained pediatric-onset epilepsy were identified from the in-house Severance Neurodevelopmental Disorders and Epilepsy Database. All patients underwent either exome sequencing or multigene panels from January 2017 to December 2019, at Severance Children's Hospital in Korea. Clinical data were extracted from the medical records. RESULTS Of the 957 patients studied, 947 (99.0%) were Korean and 570 were male (59.6%). The median age at testing was 4.91 years (interquartile range, 1.53-9.39). The overall diagnostic yield was 32.4% (310/957). Clinical exome sequencing yielded a diagnostic rate of 36.9% (134/363), whereas the epilepsy panel yielded a diagnostic rate of 29.9% (170/569). Diagnostic yield differed across epilepsy syndromes. It was high in Dravet syndrome (87.2%, 41/47) and early infantile developmental epileptic encephalopathy (60.7%, 17/28), but low in West syndrome (21.8%, 34/156) and myoclonic-atonic epilepsy (4.8%, 1/21). The most frequently implicated genes were SCN1A (n = 49), STXBP1 (n = 15), SCN2A (n = 14), KCNQ2 (n = 13), CDKL5 (n = 11), CHD2 (n = 9), SLC2A1 (n = 9), PCDH19 (n = 8), MECP2 (n = 6), SCN8A (n = 6), and PRRT2 (n = 5). The recurrent genetic abnormalities included 15q11.2 deletion/duplication (n = 9), Xq28 duplication (n = 5), PRRT2 deletion (n = 4), MECP2 duplication (n = 3), SCN1A, c.2556+3A>T (n = 3), and 2q24.3 deletion (n = 3). SIGNIFICANCE Here we present the results of a large-scale study conducted in East Asia, where we identified several common genes and recurrent variants that varied depending on specific epilepsy syndromes. The overall genetic landscape of the Asian population aligns with findings from other populations of varying ethnicities.
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Affiliation(s)
- Se Hee Kim
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, South Korea
- Department of Pediatrics, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, South Korea
| | - Jieun Seo
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Soon Sung Kwon
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Lip-Yuen Teng
- Pediatric Neurology Unit, Department of Pediatrics, Hospital Tunku Azizah, Kuala Lumpur, Malaysia
| | - DongJu Won
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Saeam Shin
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Joon Soo Lee
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, South Korea
- Department of Pediatrics, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, South Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Hoon-Chul Kang
- Division of Pediatric Neurology, Epilepsy Research Institute, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, South Korea
- Department of Pediatrics, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, South Korea
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Jo YH, Choi SH, Yoo HW, Kwak MJ, Park KH, Kong J, Lee YJ, Nam SO, Lee BL, Chung WY, Oh SH, Kim YM. Clinical use of whole exome sequencing in children with developmental delay/intellectual disability. Pediatr Neonatol 2024:S1875-9572(24)00004-4. [PMID: 38281861 DOI: 10.1016/j.pedneo.2023.05.015] [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: 10/18/2022] [Revised: 04/14/2023] [Accepted: 05/19/2023] [Indexed: 01/30/2024] Open
Abstract
BACKGROUND Identifying the underlying etiology of developmental delay/intellectual disability (DD/ID) is challenging but important. The genetic diagnosis of unexplained DD/ID helps in the treatment and prognosis of the disability in patients. In this study, we reported our experience of using whole exome sequencing (WES) of children with unexplained DD/ID. METHODS We conducted a retrospective analysis of WES results of children under 19 years of age with unexplained DD/ID between January 2020 and December 2021. The demographic data of all patients and variants identified through WES were evaluated. Furthermore, we evaluated the clinical characteristics that influenced the identification of genetic causes. RESULTS Forty-one patients with DD/ID were included, of whom 21 (51.2 %) were male. The average age at symptom onset was 1.6 ± 1.3 years, and the duration from symptom onset to diagnosis was 3.1 ± 3.7 years. Hypotonia was the most common symptom (17 patients, 41.5 %), and epilepsy was confirmed in 10 patients (24.4 %). Twenty-two pathogenic/likely pathogenic variants were identified in 20 patients, and three variants of uncertain significance were identified in three patients. Family-based trio Sanger sequencing for candidate variants of 12 families was conducted; 10 variants were de novo, one variant paternally inherited, and two variants compound heterozygous. The diagnostic yield of WES for DD/ID was 48.8 % and was significantly high in patients with an early onset of DD/ID and facial dysmorphism. In contrast, patients with autism spectrum disorder (ASD) were more likely to have negative WES results compared with others without ASD. CONCLUSION The diagnostic yield of WES was 48.8 %. We conclude that patients' characteristics, such as dysmorphic features and the age of symptom onset, can predict the likelihood that WES will identify a causal variant of a phenotype.
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Affiliation(s)
- Yoon Hee Jo
- Department of Pediatrics, Pusan National University Hospital, Biomedical Research Institute, School of Medicine, Pusan National University, Busan, Republic of Korea
| | - Soo Han Choi
- Department of Pediatrics, Pusan National University Hospital, Biomedical Research Institute, School of Medicine, Pusan National University, Busan, Republic of Korea
| | - Hye Won Yoo
- Department of Pediatrics, Pusan National University Hospital, Biomedical Research Institute, School of Medicine, Pusan National University, Busan, Republic of Korea
| | - Min Jung Kwak
- Department of Pediatrics, Pusan National University Hospital, Biomedical Research Institute, School of Medicine, Pusan National University, Busan, Republic of Korea
| | - Kyung Hee Park
- Department of Pediatrics, Pusan National University Hospital, Biomedical Research Institute, School of Medicine, Pusan National University, Busan, Republic of Korea
| | - Juhyun Kong
- Department of Pediatrics, Pusan National University Children's Hospital, Biomedical Research Institute, School of Medicine, Pusan National University, Yangsan, Republic of Korea
| | - Yun-Jin Lee
- Department of Pediatrics, Pusan National University Children's Hospital, Biomedical Research Institute, School of Medicine, Pusan National University, Yangsan, Republic of Korea
| | - Sang Ook Nam
- Department of Pediatrics, Pusan National University Children's Hospital, Biomedical Research Institute, School of Medicine, Pusan National University, Yangsan, Republic of Korea
| | - Bo Lyun Lee
- Department of Pediatrics, Busan Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea
| | - Woo Yeong Chung
- Department of Pediatrics, Busan Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea
| | - Seung Hwan Oh
- Department of Laboratory Medicine, Pusan National University Yangsan Hospital, Biomedical Research Institute, School of Medicine, Pusan National University, Yangsan, Republic of Korea
| | - Young Mi Kim
- Department of Pediatrics, Pusan National University Hospital, Biomedical Research Institute, School of Medicine, Pusan National University, Busan, Republic of Korea.
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Valaparambil KA, Fasaludeen A, Priya L, Menon RN, Menon R, Sundaram S. Clinical Utility of Proband Only Clinical Exome Sequencing in Neurodevelopmental Disorders. Indian J Pediatr 2023:10.1007/s12098-023-04916-y. [PMID: 37943464 DOI: 10.1007/s12098-023-04916-y] [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: 05/15/2023] [Accepted: 10/23/2023] [Indexed: 11/10/2023]
Abstract
Chromosomal microarray is recommended as the first line of investigation in neurodevelopmental disorders (NDDs). However, advances in next-generation sequencing have unraveled more than 900 genes associated with NDDs, thus improving the genetic diagnosis. Therefore, this study was conducted to explore the utility of clinical exome sequencing (CES) in NDDs from a tertiary care centre in India. A retrospective observational analysis of 78 children with NDDs for whom CES was performed between 2017 and 2021 was conducted. The American College of Medical Genetics and Genomics (ACMG) criteria were used to classify the variants. The mean age was 5.8 ± 3.6 y, and 42 (53%) were male. Pathogenic, likely pathogenic, and variants of uncertain significance (VUS) were observed in 22 (28.2%), 10 (12.8%), and 26 (33.3%) patients, respectively, which included five copy number variants. The diagnostic yield for pathogenic and likely pathogenic variants in NDDs by CES was 41%, which was reasonably high.
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Affiliation(s)
- Karthika Ajit Valaparambil
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, 695011, Kerala, India
| | - Alfiya Fasaludeen
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, 695011, Kerala, India
| | - Lakshmi Priya
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, 695011, Kerala, India
| | - Ramshekhar N Menon
- Pediatric Neurology and Neurodevelopmental Disorders, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, 695011, Kerala, India
| | - Ramesh Menon
- Department of Bioinformatics, MedGenome Labs, Bangalore, India
| | - Soumya Sundaram
- Pediatric Neurology and Neurodevelopmental Disorders, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, 695011, Kerala, India.
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Kim J, Teng LY, Shaker B, Na D, Koh HY, Kwon SS, Lee JS, Kim HD, Kang HC, Kim SH. Genotypes and phenotypes of DNM1 encephalopathy. J Med Genet 2023; 60:1076-1083. [PMID: 37248033 DOI: 10.1136/jmg-2023-109233] [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: 02/23/2023] [Accepted: 04/30/2023] [Indexed: 05/31/2023]
Abstract
BACKGROUND Variants in the dynamin-1 (DNM1) gene typically cause synaptopathy, leading to developmental and epileptic encephalopathy (DEE). We aimed to determine the genotypic and phenotypic spectrum of DNM1 encephalopathy beyond DEE. METHODS Electroclinical phenotyping and genotyping of patients with a DNM1 variant were conducted for patients undergoing next-generation sequencing at our centre, followed by a systematic review. RESULTS Six patients with heterozygous DNM1 variants were identified in our cohort. Three had a typical DEE phenotype characterised by epileptic spasms, tonic seizures and severe-to-profound intellectual disability with pathogenic variants located in the GTPase or middle domain. The other three patients had atypical phenotypes of milder cognitive impairment and focal epilepsy. Genotypically, two patients with atypical phenotypes had variants located in the GTPase domain, while the third patient had a novel variant (p.M648R) in the linker region between pleckstrin homology and GTPase effector domains. The third patient with an atypical phenotype showed normal development until he developed febrile status epilepticus. Our systematic review on 55 reported cases revealed that those with GTPase or middle domain variants had more severe intellectual disability (p<0.001) and lower functional levels of ambulation (p=0.001) or speech and language (p<0.001) than the rest. CONCLUSION DNM1-related phenotypes encompass a wide spectrum of epilepsy and neurodevelopmental disorders, with specific variants underlying different phenotypes.
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Affiliation(s)
- Jeehyun Kim
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea
| | - Lip-Yuen Teng
- Paediatric Neurology, Hospital Tunku Azizah, Kuala Lumpur, Malaysia
| | - Bilal Shaker
- Department of Biomedical Engineering, Chung-Ang University, Seoul, Korea
| | - Dokyun Na
- Department of Biomedical Engineering, Chung-Ang University, Seoul, Korea
| | - Hyun Yong Koh
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Soon Sung Kwon
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seodaemun-gu, Korea
| | - Joon Soo Lee
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea
- Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Seoul, Korea
- Epilepsy Research Institute, Yonsei University College of Medicine, Epilepsy Research Institute, Seoul, Korea
| | - Heung Dong Kim
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea
- Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Seoul, Korea
- Epilepsy Research Institute, Yonsei University College of Medicine, Epilepsy Research Institute, Seoul, Korea
| | - Hoon-Chul Kang
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea
- Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Seoul, Korea
- Epilepsy Research Institute, Yonsei University College of Medicine, Epilepsy Research Institute, Seoul, Korea
| | - Se Hee Kim
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea
- Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Seoul, Korea
- Epilepsy Research Institute, Yonsei University College of Medicine, Epilepsy Research Institute, Seoul, Korea
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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 2023:10.1007/s12098-023-04820-5. [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] [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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Chung CCY, Hue SPY, Ng NYT, Doong PHL, Chu ATW, Chung BHY. Meta-analysis of the diagnostic and clinical utility of exome and genome sequencing in pediatric and adult patients with rare diseases across diverse populations. Genet Med 2023; 25:100896. [PMID: 37191093 DOI: 10.1016/j.gim.2023.100896] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 05/07/2023] [Accepted: 05/10/2023] [Indexed: 05/17/2023] Open
Abstract
PURPOSE This meta-analysis aims to compare the diagnostic and clinical utility of exome sequencing (ES) vs genome sequencing (GS) in pediatric and adult patients with rare diseases across diverse populations. METHODS A meta-analysis was conducted to identify studies from 2011 to 2021. RESULTS One hundred sixty-one studies across 31 countries/regions were eligible, featuring 50,417 probands of diverse populations. Diagnostic rates of ES (0.38, 95% CI 0.36-0.40) and GS (0.34, 95% CI 0.30-0.38) were similar (P = .1). Within-cohort comparison illustrated 1.2-times odds of diagnosis by GS over ES (95% CI 0.79-1.83, P = .38). GS studies discovered a higher range of novel genes than ES studies; yet, the rate of variant of unknown significance did not differ (P = .78). Among high-quality studies, clinical utility of GS (0.77, 95% CI 0.64-0.90) was higher than that of ES (0.44, 95% CI 0.30-0.58) (P < .01). CONCLUSION This meta-analysis provides an important update to demonstrate the similar diagnostic rates between ES and GS and the higher clinical utility of GS over ES. With the newly published recommendations for clinical interpretation of variants found in noncoding regions of the genome and the trend of decreasing variant of unknown significance and GS cost, it is expected that GS will be more widely used in clinical settings.
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Affiliation(s)
| | - Shirley P Y Hue
- Hong Kong Genome Institute, Hong Kong Special Administrative Region
| | - Nicole Y T Ng
- Department of Paediatrics and Adolescent Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Phoenix H L Doong
- Department of Paediatrics and Adolescent Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Annie T W Chu
- Hong Kong Genome Institute, Hong Kong Special Administrative Region.
| | - Brian H Y Chung
- Hong Kong Genome Institute, Hong Kong Special Administrative Region; Department of Paediatrics and Adolescent Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region.
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Kwon SS, Cho YK, Hahn S, Oh J, Won D, Shin S, Kang JM, Ahn JG, Lee ST, Choi JR. Genetic diagnosis of inborn errors of immunity using clinical exome sequencing. Front Immunol 2023; 14:1178582. [PMID: 37325673 PMCID: PMC10264570 DOI: 10.3389/fimmu.2023.1178582] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 05/15/2023] [Indexed: 06/17/2023] Open
Abstract
Inborn errors of immunity (IEI) include a variety of heterogeneous genetic disorders in which defects in the immune system lead to an increased susceptibility to infections and other complications. Accurate, prompt diagnosis of IEI is crucial for treatment plan and prognostication. In this study, clinical utility of clinical exome sequencing (CES) for diagnosis of IEI was evaluated. For 37 Korean patients with suspected symptoms, signs, or laboratory abnormalities associated with IEI, CES that covers 4,894 genes including genes related to IEI was performed. Their clinical diagnosis, clinical characteristics, family history of infection, and laboratory results, as well as detected variants, were reviewed. With CES, genetic diagnosis of IEI was made in 15 out of 37 patients (40.5%). Seventeen pathogenic variants were detected from IEI-related genes, BTK, UNC13D, STAT3, IL2RG, IL10RA, NRAS, SH2D1A, GATA2, TET2, PRF1, and UBA1, of which four variants were previously unreported. Among them, somatic causative variants were identified from GATA2, TET2, and UBA1. In addition, we identified two patients incidentally diagnosed IEI by CES, which was performed to diagnose other diseases of patients with unrecognized IEI. Taken together, these results demonstrate the utility of CES for the diagnosis of IEI, which contributes to accurate diagnosis and proper treatments.
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Affiliation(s)
- Soon Sung Kwon
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Youn Keong Cho
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Seungmin Hahn
- Department of Pediatric Hemato-oncology, Yonsei Cancer Center, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jiyoung Oh
- Division of Clinical Genetics, Department of Pediatrics, Severance Children’s Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Dongju Won
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Saeam Shin
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Ji-Man Kang
- Department of Pediatrics, Severance Children’s Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
- Institute for Immunology and Immunological Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jong Gyun Ahn
- Department of Pediatrics, Severance Children’s Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
- Institute for Immunology and Immunological Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
- Dxome, Seoul, Republic of Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
- Dxome, Seoul, Republic of Korea
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Kim SH, Kwon SS, Park MR, Lee HA, Kim JH, Cha J, Kim S, Baek ST, Kim SH, Lee JS, Kim HD, Choi JR, Lee ST, Kang HC. Detecting low-variant allele frequency mosaic pathogenic variants of NF1, TSC2, and AKT3 genes from blood in patients with neurodevelopmental disorders. J Mol Diagn 2023:S1525-1578(23)00080-6. [PMID: 37088138 DOI: 10.1016/j.jmoldx.2023.04.003] [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: 01/15/2023] [Revised: 04/05/2023] [Accepted: 04/10/2023] [Indexed: 04/25/2023] Open
Abstract
Growing evidence indicates that early, and late postzygotic mosaicism can cause neurodevelopmental disorders (NDD), but detection of low variant allele frequency (VAF) mosaic variants from blood remains a challenge. We reviewed data of 2,162 patients with NDDs who underwent conventional genetic tests and performed a deep sequencing using specifically designed mosaic NGS panel in the patients with negative genetic test results. Forty-four patents with neurocutaneous syndrome, malformation of cortical development or nonlesional epileptic encephalopathies were included. In total, mosaic variants were detected from blood in 1.2% (25/2,162) of the patients. Using conventional NGS panels, 22 mosaic variants (VAF 8.8-29.8%) were identified in 18 different genes including TSC2, DCX, SLC2A1, PCDH19, DNM1, STXBP1, SCN2A, SCN1A, PURA, POGZ, PAFAH1B1, NF1, KIF21A, KCNQ2, GABRA1, EEF1A2, CDKL5, and ARID1B. Using a specifically designed mosaicism NGS panel, three mosaic variants of the NF1, TSC2, and AKT3 genes were identified (VAF 2.0-11.2%). Mosaic variants were found frequently in the patients who had neurocutaneous syndrome (2/7, 28.6%) whereas only one or no mosaic variant was detected for patients who had malformations of cortical development (1/20, 5%) or nonlesional epileptic encephalopathies (0%, 0/17). In summary, mosaic variants contribute to spectrum of NDDs can be detected from blood via the conventional NGS and specifically designed mosaicism NGS panels, and detection of mosaic variants using blood will increase diagnostic yield.
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Affiliation(s)
- Se Hee Kim
- Pediatric Neurology, Department of Pediatrics, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, Republic of Korea
| | - Soon Sung Kwon
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Mi Ri Park
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hyeon Ah Lee
- Department of Laboratory Medicine, Graduate School of Medical Science, Brain Korea 21 PLUS Project, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Ji Hun Kim
- Pediatric Neurology, Department of Pediatrics, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, Republic of Korea
| | - JiHoon Cha
- Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Sangwoo Kim
- Department of Biomedical Systems Informatics, Yonsei University College of Medicine, Seoul, Republic of Korea; Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Seung Tae Baek
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Se Hoon Kim
- Department of Pathology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Joon Soo Lee
- Pediatric Neurology, Department of Pediatrics, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, Republic of Korea
| | - Heung Dong Kim
- Pediatric Neurology, Department of Pediatrics, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, Republic of Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; Dxome, Seoul, Republic of Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; Dxome, Seoul, Republic of Korea.
| | - Hoon-Chul Kang
- Pediatric Neurology, Department of Pediatrics, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, Republic of Korea.
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Hatch HAM, Secombe J. Molecular and cellular events linking variants in the histone demethylase KDM5C to the intellectual disability disorder Claes-Jensen syndrome. FEBS J 2022; 289:7776-7787. [PMID: 34536985 PMCID: PMC8930784 DOI: 10.1111/febs.16204] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/02/2021] [Accepted: 09/16/2021] [Indexed: 01/14/2023]
Abstract
The widespread availability of genetic testing for those with neurodevelopmental disorders has highlighted the importance of many genes necessary for the proper development and function of the nervous system. One gene found to be genetically altered in the X-linked intellectual disability disorder Claes-Jensen syndrome is KDM5C, which encodes a histone demethylase that regulates transcription by altering chromatin. While the genetic link between KDM5C and cognitive (dys)function is clear, how KDM5C functions to control transcriptional programs within neurons to impact their growth and activity remains the subject of ongoing research. Here, we review our current knowledge of Claes-Jensen syndrome and discuss important new data using model organisms that have revealed the importance of KDM5C in regulating aspects of neuronal development and function. Continued research into the molecular and cellular activities regulated by KDM5C is expected to provide critical etiological insights into Claes-Jensen syndrome and highlight potential targets for developing therapies to improve the quality of life of those affected.
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Affiliation(s)
- Hayden A M Hatch
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Julie Secombe
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, USA
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10
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Diagnostic performance of automated, streamlined, daily updated exome analysis in patients with neurodevelopmental delay. Mol Med 2022; 28:38. [PMID: 35346031 PMCID: PMC8962085 DOI: 10.1186/s10020-022-00464-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 03/15/2022] [Indexed: 11/29/2022] Open
Abstract
Background The diagnostic yield of whole-exome sequencing (WES) varies from 30%–50% among patients with mild to severe neurodevelopmental delay (NDD)/intellectual disability (ID). Routine retrospective reanalysis of undiagnosed patients has increased the total diagnostic yield by 10–15%. Here, we performed proband-only WES of 1065 patients with NDD/ID and applied a prospective, daily reanalysis automated pipeline to patients without clinically significant variants to facilitate diagnoses. Methods The study included 1065 consecutive patients from 1056 nonconsanguineous unrelated families from 10 multimedical centers in South Korea between April 2018 and August 2021. WES data were analyzed daily using automatically updated databases with variant classification and symptom similarity scoring systems. Results At the initial analysis, 402 patients from 1056 unrelated families (38.0%, 402/1,056 families) had a positive genetic diagnosis. Daily prospective, automated reanalysis resulted in the identification of 34 additional diagnostic variants in 31 patients (3%), which increased our molecular diagnostic yield to 41% (433/1056 families). Among these 31 patients, 26 were diagnosed with 23 different diseases that were newly discovered after 2019. The time interval between the first analysis and the molecular diagnosis by reanalysis was 1.2 ± 0.9 years, which was shorter in the patients enrolled during the latter part of the study period. Conclusion Daily updated databases and reanalysis systems enhance the diagnostic performance in patients with NDD/ID, contributing to the rapid diagnosis of undiagnosed patients by applying the latest molecular genetic information. Supplementary Information The online version contains supplementary material available at 10.1186/s10020-022-00464-x.
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11
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Park HS, Lee YH, Hong N, Won D, Rhee Y. Germline Mutations Related to Primary Hyperparathyroidism Identified by Next-Generation Sequencing. Front Endocrinol (Lausanne) 2022; 13:853171. [PMID: 35586626 PMCID: PMC9109676 DOI: 10.3389/fendo.2022.853171] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 03/29/2022] [Indexed: 12/03/2022] Open
Abstract
Primary hyperparathyroidism (PHPT) is characterized by overproduction of parathyroid hormone and subsequent hypercalcemia. Approximately 10% of PHPT cases are hereditary, and several genes, such as MEN1, RET, CASR, and CDC73, are responsible for the familial forms of PHPT. However, other genetic mutations involved in the etiology of PHPT are largely unknown. In this study, we identified genetic variants that might be responsible for PHPT, including familial PHPT, benign sporadic PHPT, and sporadic parathyroid cancer, using next-generation sequencing (NGS). A total of 107 patients with PHPT who underwent NGS from 2017 to 2021 at Severance Hospital were enrolled. We reviewed the pathogenic variants, likely pathogenic variants, and variants of uncertain significance (VUS) according to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology criteria. Of the 107 patients (mean age: 47.6 ± 16.1 years, women 73.8%), 12 patients were diagnosed with familial PHPT, 13 with parathyroid cancer, and 82 with benign sporadic PHPT. Using NGS, we identified three pathogenic variants in two genes (CDC73 and MEN1), 10 likely pathogenic variants in six genes (CASR, CDC73, LRP5, MEN1, SDHA, and VHL), and 39 non-synonymous VUS variants that could be related to parathyroid disease. Interestingly, we identified one GCM2 variant (c.1162A>G [p.Lys388Glu]) and five APC variants that were previously reported in familial isolated hyperparathyroidism, benign sporadic PHPT, and parathyroid cancer. We also analyzed the characteristics of subjects with positive genetic test results (pathogenic or likely pathogenic variants), and 76.9% of them had at least one of the following features: 1) age < 40 years, 2) family history of PHPT, 3) multiglandular PHPT, or 4) recurrent PHPT. In this study, we analyzed the NGS data of patients with PHPT and observed variants that could possibly be related to PHPT pathogenesis. NGS screening for selected patients with PHPT might help in the diagnosis and management of the disease.
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Affiliation(s)
- Hye-Sun Park
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Yeon Hee Lee
- Department of Internal Medicine, Seoul Eco Internal Medicine Clinic, Seoul, South Korea
| | - Namki Hong
- Department of Internal Medicine, Endocrine Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - Dongju Won
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Yumie Rhee
- Department of Internal Medicine, Endocrine Research Institute, Yonsei University College of Medicine, Seoul, South Korea
- *Correspondence: Yumie Rhee,
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12
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Kim SH, Kwon SS, Lee JS, Kim HD, Lee ST, Choi JR, Shin S, Kang HC. Analysis of trio test in neurodevelopmental disorders. Front Pediatr 2022; 10:1073083. [PMID: 36619507 PMCID: PMC9816327 DOI: 10.3389/fped.2022.1073083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 11/21/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Trio test has been widely used for diagnosis of various hereditary disorders. We aimed to investigate the contribution of trio test in genetically diagnosing neurodevelopmental disorders (NDD). METHODS We retrospectively reviewed 2,059 NDD cases with genetic test results. The trio test was conducted in 563 cases. Clinical usefulness, optimal timing, and methods for the trio test were reviewed. RESULTS Pathogenic or likely pathogenic variants were detected in 112 of 563 (19.9%) patients who underwent the trio test. With trio test results, the overall diagnostic yield increased by 5.4% (112/2,059). Of 165 de novo variants detected, 149 were pathogenic and we detected 85 novel pathogenic variants. Pathogenic, de novo variants were frequently detected in CDKL5, ATP1A3, and STXBP1. CONCLUSION The trio test is an efficient method for genetically diagnosing NDD. We identified specific situations where a certain trio test is more appropriate, thereby providing a guide for clinicians when confronted with variants of unknown significance of specific genes.
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Affiliation(s)
- Se Hee Kim
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
| | - Soon Sung Kwon
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Joon Soo Lee
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
| | - Heung Dong Kim
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Saeam Shin
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Hoon-Chul Kang
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
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13
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Singh R, Cohen ASA, Poulton C, Hjortshøj TD, Akahira-Azuma M, Mendiratta G, Khan WA, Azmanov DN, Woodward KJ, Kirchhoff M, Shi L, Edelmann L, Baynam G, Scott SA, Jabs EW. Deletion of ERF and CIC causes abnormal skull morphology and global developmental delay. Cold Spring Harb Mol Case Stud 2021; 7:mcs.a005991. [PMID: 34117072 PMCID: PMC8208047 DOI: 10.1101/mcs.a005991] [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: 11/06/2020] [Accepted: 04/26/2021] [Indexed: 11/24/2022] Open
Abstract
The ETS2 repressor factor (ERF) is a transcription factor in the RAS-MEK-ERK signal transduction cascade that regulates cell proliferation and differentiation, and pathogenic sequence variants in the ERF gene cause variable craniosynostosis inherited in an autosomal dominant pattern. The reported ERF variants are largely loss-of-function, implying haploinsufficiency as a primary disease mechanism; however, ERF gene deletions have not been reported previously. Here we describe three probands with macrocephaly, craniofacial dysmorphology, and global developmental delay. Clinical genetic testing for fragile X and other relevant sequencing panels were negative; however, chromosomal microarray identified heterozygous deletions (63.7–583.2 kb) on Chromosome 19q13.2 in each proband that together included five genes associated with Mendelian diseases (ATP1A3, ERF, CIC, MEGF8, and LIPE). Parental testing indicated that the aberrations were apparently de novo in two of the probands and were inherited in the one proband with the smallest deletion. Deletion of ERF is consistent with the reported loss-of-function ERF variants, prompting clinical copy-number-variant classifications of likely pathogenic. Moreover, the recent characterization of heterozygous loss-of-function CIC sequence variants as a cause of intellectual disability and neurodevelopmental disorders inherited in an autosomal dominant pattern is also consistent with the developmental delays and intellectual disabilities identified among the two probands with CIC deletions. Taken together, this case series adds to the previously reported patients with ERF and/or CIC sequence variants and supports haploinsufficiency of both genes as a mechanism for a variable syndromic cranial phenotype with developmental delays and intellectual disability inherited in an autosomal dominant pattern.
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Affiliation(s)
- Ram Singh
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Sema4, Stamford, Connecticut 06902, USA
| | - Ana S A Cohen
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Sema4, Stamford, Connecticut 06902, USA
| | - Cathryn Poulton
- Genetic Service of Western Australia, King Edward Memorial Hospital, Perth, Western Australia 6008, Australia
| | - Tina Duelund Hjortshøj
- Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark
| | - Moe Akahira-Azuma
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Geetu Mendiratta
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Sema4, Stamford, Connecticut 06902, USA
| | - Wahab A Khan
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Sema4, Stamford, Connecticut 06902, USA
| | - Dimitar N Azmanov
- Department of Diagnostic Genomics, PathWest Laboratory Medicine, QEII Medical Centre, Nedlands, Western Australia 6009, Australia.,Pathology and Laboratory Medicine, Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Karen J Woodward
- Department of Diagnostic Genomics, PathWest Laboratory Medicine, QEII Medical Centre, Nedlands, Western Australia 6009, Australia.,Pathology and Laboratory Medicine, Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Maria Kirchhoff
- Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark
| | - Lisong Shi
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Sema4, Stamford, Connecticut 06902, USA
| | - Lisa Edelmann
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Sema4, Stamford, Connecticut 06902, USA
| | - Gareth Baynam
- Western Australian Register of Developmental Anomalies and Genetic Services of Western Australia, King Edward Memorial Hospital, Perth, Western Australia 6008, Australia.,Faculty of Health and Medical Sciences, Division of Paediatrics and Telethon Kids Institute, University of Western Australia, Perth, Western Australia 6008, Australia.,Faculty of Medicine, University of Notre Dame, Australia, Perth, Western Australia 6160, Australia
| | - Stuart A Scott
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Sema4, Stamford, Connecticut 06902, USA
| | - Ethylin Wang Jabs
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
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14
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Varesio C, Gana S, Asaro A, Ballante E, Cabini RF, Tartara E, Bagnaschi M, Pasca L, Valente M, Orcesi S, Cereda C, Veggiotti P, Borgatti R, Valente EM, De Giorgis V. Diagnostic Yield and Cost-Effectiveness of "Dynamic" Exome Analysis in Epilepsy with Neurodevelopmental Disorders: A Tertiary-Center Experience in Northern Italy. Diagnostics (Basel) 2021; 11:diagnostics11060948. [PMID: 34070668 PMCID: PMC8228291 DOI: 10.3390/diagnostics11060948] [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: 04/09/2021] [Revised: 05/18/2021] [Accepted: 05/24/2021] [Indexed: 02/02/2023] Open
Abstract
Background: The advent of next-generation sequencing (NGS) techniques in clinical practice led to a significant advance in gene discovery. We aimed to describe diagnostic yields of a “dynamic” exome-based approach in a cohort of patients with epilepsy associated with neurodevelopmental disorders. Methods: We conducted a retrospective, observational study on 72 probands. All patients underwent a first diagnostic level of a 135 gene panel, a second of 297 genes for inconclusive cases, and finally, a whole-exome sequencing for negative cases. Diagnostic yields at each step and cost-effectiveness were the objects of statistical analysis. Results: Overall diagnostic yield in our cohort was 37.5%: 29% of diagnoses derived from the first step analysis, 5.5% from the second step, and 3% from the third. A significant difference emerged between the three diagnostic steps (p < 0.01), between the first and second (p = 0.001), and the first and third (p << 0.001). The cost-effectiveness plane indicated that our exome-based “dynamic” approach was better in terms of cost savings and higher diagnostic rate. Conclusions: Our findings suggested that “dynamic” NGS techniques applied to well-phenotyped individuals can save both time and resources. In patients with unexplained epilepsy comorbid with NDDs, our approach might maximize the number of diagnoses achieved.
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Affiliation(s)
- Costanza Varesio
- Department of Child Neurology and Psychiatry, IRCCS Mondino Foundation, 27100 Pavia, Italy; (L.P.); (S.O.); (R.B.); (V.D.G.)
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy;
- Correspondence: ; Tel.: +39-0382-380289
| | - Simone Gana
- Medical Genetics Unit, IRCCS Mondino Foundation, 27100 Pavia, Italy; (S.G.); (A.A.); (M.V.); (E.M.V.)
| | - Alessia Asaro
- Medical Genetics Unit, IRCCS Mondino Foundation, 27100 Pavia, Italy; (S.G.); (A.A.); (M.V.); (E.M.V.)
| | - Elena Ballante
- BioData Science Center, IRCCS Mondino Foundation, 27100 Pavia, Italy;
- Department of Mathematics, University of Pavia, 27100 Pavia, Italy;
| | - Raffaella Fiamma Cabini
- Department of Mathematics, University of Pavia, 27100 Pavia, Italy;
- Istituto Nazionale di Fisica Nucleare Section of Pavia, 27100 Pavia, Italy
| | - Elena Tartara
- Epilepsy Center, IRCCS Mondino Foundation, 27100 Pavia, Italy;
| | - Michela Bagnaschi
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy;
| | - Ludovica Pasca
- Department of Child Neurology and Psychiatry, IRCCS Mondino Foundation, 27100 Pavia, Italy; (L.P.); (S.O.); (R.B.); (V.D.G.)
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy;
| | - Marialuisa Valente
- Medical Genetics Unit, IRCCS Mondino Foundation, 27100 Pavia, Italy; (S.G.); (A.A.); (M.V.); (E.M.V.)
- Laboratory of Clinical Pathology Microbiology and Genetics, SS. Annunziata, 74100 Taranto, Italy
| | - Simona Orcesi
- Department of Child Neurology and Psychiatry, IRCCS Mondino Foundation, 27100 Pavia, Italy; (L.P.); (S.O.); (R.B.); (V.D.G.)
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy;
| | - Cristina Cereda
- Molecular Genetics and Cytogenetics Section, IRCCS Mondino Foundation, 27100 Pavia, Italy;
- Genomic and Post-Genomic Unit, IRCCS Mondino Foundation, 27100 Pavia, Italy
| | - Pierangelo Veggiotti
- Pediatric Neurology Unit, Vittore Buzzi Hospital, 20100 Milano, Italy;
- Biomedical and Clinical Sciences Department, Luigi Sacco Hospital, University of Milan, 20100 Milano, Italy
| | - Renato Borgatti
- Department of Child Neurology and Psychiatry, IRCCS Mondino Foundation, 27100 Pavia, Italy; (L.P.); (S.O.); (R.B.); (V.D.G.)
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy;
| | - Enza Maria Valente
- Medical Genetics Unit, IRCCS Mondino Foundation, 27100 Pavia, Italy; (S.G.); (A.A.); (M.V.); (E.M.V.)
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
| | - Valentina De Giorgis
- Department of Child Neurology and Psychiatry, IRCCS Mondino Foundation, 27100 Pavia, Italy; (L.P.); (S.O.); (R.B.); (V.D.G.)
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15
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Lee YR, Kim SH, Ben-Mahmoud A, Kim OH, Choi TI, Lee KH, Ku B, Eum J, Kee Y, Lee S, Cha J, Won D, Lee ST, Choi JR, Lee JS, Kim HD, Kim HG, Bonkowsky JL, Kang HC, Kim CH. Eif2b3 mutants recapitulate phenotypes of vanishing white matter disease and validate novel disease alleles in zebrafish. Hum Mol Genet 2021; 30:331-342. [PMID: 33517449 DOI: 10.1093/hmg/ddab033] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/02/2020] [Accepted: 01/20/2021] [Indexed: 02/06/2023] Open
Abstract
Leukodystrophy with vanishing white matter (VWM), also called Childhood Ataxia with Central Nervous System Hypomyelination, is caused by mutations in the subunits of the eukaryotic translation initiation factor, EIF2B1, EIF2B2, EIF2B3, EIF2B4 or EIF2B5. However, little is known regarding the underlying pathogenetic mechanisms, and there is no curative treatment for VWM. In this study, we established the first EIF2B3 animal model for VWM disease in vertebrates by CRISPR mutagenesis of the highly conserved zebrafish ortholog eif2b3. Using CRISPR, we generated two mutant alleles in zebrafish eif2b3, 10- and 16-bp deletions, respectively. The eif2b3 mutants showed defects in myelin development and glial cell differentiation, and increased expression of genes in the induced stress response pathway. Interestingly, we also found ectopic angiogenesis and increased VEGF expression. Ectopic angiogenesis in the eif2b3 mutants was reduced by the administration of VEGF receptor inhibitor SU5416. Using the eif2b3 mutant zebrafish model together with in silico protein modeling analysis, we demonstrated the pathogenicity of 18 reported mutations in EIF2B3, as well as of a novel variant identified in a 19-month-old female patient: c.503 T > C (p.Leu168Pro). In summary, our zebrafish mutant model of eif2b3 provides novel insights into VWM pathogenesis and offers rapid functional analysis of human EIF2B3 gene variants.
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Affiliation(s)
- Yu-Ri Lee
- Department of Biology, Chungnam National University, Daejeon, Korea
| | - Se Hee Kim
- Department of Pediatrics, Division of Pediatric Neurology, Pediatric Epilepsy Clinic, Epilepsy Research Institute, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, Korea
| | - Afif Ben-Mahmoud
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Doha, Qatar
| | - Oc-Hee Kim
- Department of Biology, Chungnam National University, Daejeon, Korea
| | - Tae-Ik Choi
- Department of Biology, Chungnam National University, Daejeon, Korea
| | - Kang-Han Lee
- Department of Biology, Chungnam National University, Daejeon, Korea
| | - Bonsu Ku
- Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
| | - Juneyong Eum
- Division of Biomedical Convergence, Kangwon National University, Chuncheon, Korea
| | - Yun Kee
- Division of Biomedical Convergence, Kangwon National University, Chuncheon, Korea
| | - Sangkyu Lee
- College of Pharmacy, Kyungpook National University, Daegu, Korea
| | - Jihoon Cha
- Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - DongJu Won
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Joon Soo Lee
- Department of Pediatrics, Division of Pediatric Neurology, Pediatric Epilepsy Clinic, Epilepsy Research Institute, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, Korea
| | - Heung Dong Kim
- Department of Pediatrics, Division of Pediatric Neurology, Pediatric Epilepsy Clinic, Epilepsy Research Institute, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, Korea
| | - Hyung-Goo Kim
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Doha, Qatar
| | - Joshua L Bonkowsky
- Department of Pediatrics, University of Utah School of Medicine and Brain and Spine Center, Primary Children's Hospital, Salt Lake City, UT, USA
| | - Hoon-Chul Kang
- Department of Pediatrics, Division of Pediatric Neurology, Pediatric Epilepsy Clinic, Epilepsy Research Institute, Yonsei University College of Medicine, Severance Children's Hospital, Seoul, Korea
| | - Cheol-Hee Kim
- Department of Biology, Chungnam National University, Daejeon, Korea
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16
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Keller N, Paketci C, Edem P, Thiele H, Yis U, Wirth B, Karakaya M. De novo DNM1L variant presenting with severe muscular atrophy, dystonia and sensory neuropathy. Eur J Med Genet 2020; 64:104134. [PMID: 33387674 DOI: 10.1016/j.ejmg.2020.104134] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/01/2020] [Accepted: 12/27/2020] [Indexed: 11/27/2022]
Abstract
DNM1L encodes dynamin-related protein 1 (DRP1), a multi-domain GTPase essential for mitochondrial and peroxisomal division. Autosomal dominant and recessive variants in DNM1L cause encephalopathy due to defective mitochondrial and peroxisomal fission 1 (EMPF1), which presents as a complex and clinically heterogeneous neurological disorder of variable severity, often accompanied by seizures. Clinical features are diverse, and no clear phenotype-genotype correlations were drawn to date. DNM1L-related sensory neuropathy has recently been reported as a predominant feature in one case with a de novo variant in the GTPase domain. Herein we present a second case with DNM1L-related sensory neuropathy as the predominant underlying feature without motor neuron involvement, which resulted in severe muscular atrophy and generalized dystonia.
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Affiliation(s)
- Natalie Keller
- Institute of Human Genetics, Center for Molecular Medicine Cologne (CMMC), Institute of Genetics, and Center for Rare Diseases Cologne, University of Cologne, Cologne, Germany
| | - Cem Paketci
- Dokuz Eylül University, Department of Pediatric Neurology, Izmir, Turkey
| | - Pinar Edem
- Dokuz Eylül University, Department of Pediatric Neurology, Izmir, Turkey
| | - Holger Thiele
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Uluc Yis
- Dokuz Eylül University, Department of Pediatric Neurology, Izmir, Turkey
| | - Brunhilde Wirth
- Institute of Human Genetics, Center for Molecular Medicine Cologne (CMMC), Institute of Genetics, and Center for Rare Diseases Cologne, University of Cologne, Cologne, Germany
| | - Mert Karakaya
- Institute of Human Genetics, Center for Molecular Medicine Cologne (CMMC), Institute of Genetics, and Center for Rare Diseases Cologne, University of Cologne, Cologne, Germany.
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17
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Won D, Kim SH, Kim B, Lee ST, Kang HC, Choi JR. Reanalysis of Genomic Sequencing Results in a Clinical Laboratory: Advantages and Limitations. Front Neurol 2020; 11:612. [PMID: 32695065 PMCID: PMC7338758 DOI: 10.3389/fneur.2020.00612] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 05/25/2020] [Indexed: 11/13/2022] Open
Abstract
Genetic diagnosis of patients with neurodevelopmental disorders is imperative and a standard clinical practice. Considering the continuous accumulation of data on disease-causing variants, reanalysis of previously established sequencing data is important. Periodic reanalysis of variants with uncertain significance has become mandatory in clinical laboratories. Therefore, to confirm the utility of the reanalysis of targeted gene panel data in clinical laboratories, we re-evaluated the data of two groups of patients who had undergone targeted gene panel testing for neurodevelopmental disorders (n = 116) and epileptic encephalopathy (n = 384). This reanalysis was based on a reannotation process reflecting updated databases. Six (5.2%) and seven (1.8%) new pathogenic or likely pathogenic variants were identified in these two groups, respectively, attributable to the updated guidelines and de novo reports from unrelated patients. Although relatively low, considerable increase in the diagnostic yield was confirmed. We suggest that reanalysis of genetic variants, mainly using changes in databases and updated interpretations, should be implemented as a routine practice in clinical laboratories.
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Affiliation(s)
- Dongju Won
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Se Hee Kim
- Division of Pediatric Neurology, Department of Pediatrics, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - Borahm Kim
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Hoon-Chul Kang
- Division of Pediatric Neurology, Department of Pediatrics, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
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