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Fasaludeen A, McTague A, Jose M, Banerjee M, Sundaram S, Madhusoodanan UK, Radhakrishnan A, Menon RN. Genetic variant interpretation for the neurologist - A pragmatic approach in the next-generation sequencing era in childhood epilepsy. Epilepsy Res 2024; 201:107341. [PMID: 38447235 DOI: 10.1016/j.eplepsyres.2024.107341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 02/14/2024] [Accepted: 02/29/2024] [Indexed: 03/08/2024]
Abstract
Genetic advances over the past decade have enhanced our understanding of the genetic landscape of childhood epilepsy. However a major challenge for clinicians ha been understanding the rationale and systematic approach towards interpretation of the clinical significance of variant(s) detected in their patients. As the clinical paradigm evolves from gene panels to whole exome or whole genome testing including rapid genome sequencing, the number of patients tested and variants identified per patient will only increase. Each step in the process of variant interpretation has limitations and there is no single criterion which enables the clinician to draw reliable conclusions on a causal relationship between the variant and disease without robust clinical phenotyping. Although many automated online analysis software tools are available, these carry a risk of misinterpretation. This guideline provides a pragmatic, real-world approach to variant interpretation for the child neurologist. The focus will be on ascertaining aspects such as variant frequency, subtype, inheritance pattern, structural and functional consequence with regard to genotype-phenotype correlations, while refraining from mere interpretation of the classification provided in a genetic test report. It will not replace the expert advice of colleagues in clinical genetics, however as genomic investigations become a first-line test for epilepsy, it is vital that neurologists and epileptologists are equipped to navigate this landscape.
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Affiliation(s)
- Alfiya Fasaludeen
- Dept of Neurology, Sree Chitra Tirunal Institute for Medical Sciences & Technology (SCTIMST), Thiruvananthapuram, Kerala, India
| | - Amy McTague
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London, United Kingdom; Department of Neurology, Great Ormond Street Hospital, London, United Kingdom
| | - Manna Jose
- Dept of Neurology, Sree Chitra Tirunal Institute for Medical Sciences & Technology (SCTIMST), Thiruvananthapuram, Kerala, India
| | - Moinak Banerjee
- Human Molecular Genetics Laboratory, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
| | - Soumya Sundaram
- Dept of Neurology, Sree Chitra Tirunal Institute for Medical Sciences & Technology (SCTIMST), Thiruvananthapuram, Kerala, India
| | - U K Madhusoodanan
- Department of Biochemistry, Sree Chitra Tirunal Institute for Medical Sciences & Technology (SCTIMST), Thiruvananthapuram, Kerala, India
| | - Ashalatha Radhakrishnan
- Dept of Neurology, Sree Chitra Tirunal Institute for Medical Sciences & Technology (SCTIMST), Thiruvananthapuram, Kerala, India
| | - Ramshekhar N Menon
- Dept of Neurology, Sree Chitra Tirunal Institute for Medical Sciences & Technology (SCTIMST), Thiruvananthapuram, Kerala, India.
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Zhang X, Li Z, Liu Y, Gai Z. Great Expectations: Induced pluripotent stem cell technologies in neurodevelopmental impairments. Int J Med Sci 2021; 18:459-473. [PMID: 33390815 PMCID: PMC7757149 DOI: 10.7150/ijms.51842] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 11/09/2020] [Indexed: 12/15/2022] Open
Abstract
Somatic cells such as skin fibroblasts, umbilical cord blood, peripheral blood, urinary epithelial cells, etc., are transformed into induced pluripotent stem cells (iPSCs) by reprogramming technology, a milestone in the stem-cell research field. IPSCs are similar to embryonic stem cells (ESCs), exhibiting the potential to differentiate into various somatic cells. Still, the former avoid problems of immune rejection and medical ethics in the study of ESCs and clinical trials. Neurodevelopmental disorders are chronic developmental brain dysfunctions that affect cognition, exercise, social adaptability, behavior, etc. Due to various inherited or acquired causes, they seriously affect the physical and psychological health of infants and children. These include generalized stunting / mental disability (GDD/ID), Epilepsy, autism spectrum disease (ASD), and attention deficit hyperactivity disorder (ADHD). Most neurodevelopmental disorders are challenging to cure. Establishing a neurodevelopmental disorder system model is essential for researching and treating neurodevelopmental disorders. At this stage, the scarcity of samples is a bigger problem for studying neurological diseases based on the donor, ethics, etc. Some iPSCs are reprogrammed from somatic cells that carry disease-causing mutations. They differentiate into nerve cells by induction, which has the original characteristics of diseases. Disease-specific iPSCs are used to study the mechanism and pathogenesis of neurodevelopmental disorders. The process provided samples and the impetus for developing drugs and developing treatment plans for neurodevelopmental disorders. Here, this article mainly introduced the development of iPSCs, the currently established iPSCs disease models, and artificial organoids related to neurodevelopmental impairments. This technology will promote our understanding of neurodevelopmental impairments and bring great expectations to children with neurological disorders.
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Affiliation(s)
- Xue Zhang
- Pediatric Research Institute, Qilu Children's Hospital, Cheeloo College of Medicine, Shandong University, Ji'nan 250022, China.,Jinan Pediatric Research Institute, Jinan Children's Hospital, Ji'nan 250022, China.,Neonatal Intensive Care Unit, Children's Medical Center, The Second Hospital of Shandong University, Ji'nan 250033, China
| | - Zilong Li
- Pediatric Research Institute, Qilu Children's Hospital, Cheeloo College of Medicine, Shandong University, Ji'nan 250022, China.,Jinan Pediatric Research Institute, Jinan Children's Hospital, Ji'nan 250022, China
| | - Yi Liu
- Pediatric Research Institute, Qilu Children's Hospital, Cheeloo College of Medicine, Shandong University, Ji'nan 250022, China.,Jinan Pediatric Research Institute, Jinan Children's Hospital, Ji'nan 250022, China
| | - Zhongtao Gai
- Pediatric Research Institute, Qilu Children's Hospital, Cheeloo College of Medicine, Shandong University, Ji'nan 250022, China.,Jinan Pediatric Research Institute, Jinan Children's Hospital, Ji'nan 250022, China
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Suga M, Kondo T, Inoue H. Modeling Neurological Disorders with Human Pluripotent Stem Cell-Derived Astrocytes. Int J Mol Sci 2019; 20:E3862. [PMID: 31398826 PMCID: PMC6720891 DOI: 10.3390/ijms20163862] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/30/2019] [Accepted: 07/31/2019] [Indexed: 12/20/2022] Open
Abstract
Astrocytes play vital roles in neurological disorders. The use of human induced pluripotent stem cell (iPSC)-derived astrocytes provides a chance to explore the contributions of astrocytes in human diseases. Here we review human iPSC-based models for neurological disorders associated with human astrocytes and discuss the points of each model.
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Affiliation(s)
- Mika Suga
- iPSC-based Drug Discovery and Development Team, RIKEN BioResource Research Center (BRC), Kyoto 619-0237, Japan
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto 606-8507, Japan
| | - Takayuki Kondo
- iPSC-based Drug Discovery and Development Team, RIKEN BioResource Research Center (BRC), Kyoto 619-0237, Japan
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto 606-8507, Japan
- Medical-risk Avoidance based on iPS Cells Team, RIKEN Center for Advanced Intelligence Project (AIP), Kyoto 606-8507, Japan
| | - Haruhisa Inoue
- iPSC-based Drug Discovery and Development Team, RIKEN BioResource Research Center (BRC), Kyoto 619-0237, Japan.
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto 606-8507, Japan.
- Medical-risk Avoidance based on iPS Cells Team, RIKEN Center for Advanced Intelligence Project (AIP), Kyoto 606-8507, Japan.
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Page S, Patel R, Raut S, Al-Ahmad A. Neurological diseases at the blood-brain barrier: Stemming new scientific paradigms using patient-derived induced pluripotent cells. Biochim Biophys Acta Mol Basis Dis 2018; 1866:165358. [PMID: 30593893 DOI: 10.1016/j.bbadis.2018.12.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 11/15/2018] [Accepted: 12/05/2018] [Indexed: 02/08/2023]
Abstract
The blood-brain barrier (BBB) is a component of the neurovascular unit formed by specialized brain microvascular endothelial cells (BMECs) surrounded by a specific basement membrane interacting with astrocytes, neurons, and pericytes. The BBB plays an essential function in the maintenance of brain homeostasis, by providing a physical and chemical barrier against pathogens and xenobiotics. Although the disruption of the BBB occurs with several neurological disorders, the scarcity of patient material source and lack of reliability of current in vitro models hindered our ability to model the BBB during such neurological conditions. The development of novel in vitro models based on patient-derived stem cells opened new venues in modeling the human BBB in vitro, by being more accurate than existing in vitro models, but also bringing such models closer to the in vivo setting. In addition, patient-derived models of the BBB opens the avenue to address the contribution of genetic factors commonly associated with certain neurological diseases on the BBB pathophysiology. This review provides a comprehensive understanding of the BBB, the current development of stem cell-based models in the field, the current challenges and limitations of such models.
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Affiliation(s)
- Shyanne Page
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, School of Pharmacy, Amarillo, TX, United States of America
| | - Ronak Patel
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, School of Pharmacy, Amarillo, TX, United States of America
| | - Snehal Raut
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, School of Pharmacy, Amarillo, TX, United States of America
| | - Abraham Al-Ahmad
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, School of Pharmacy, Amarillo, TX, United States of America.
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