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Nagarajan B, Gowda VK, Yoganathan S, Sharawat IK, Srivastava K, Vora N, Badheka R, Danda S, Kalane U, Kaur A, Madaan P, Mehta S, Negi S, Panda PK, Rajadhyaksha S, Saini AG, Saini L, Shah S, Srinivasan VM, Suthar R, Thomas M, Vyas S, Sankhyan N, Sahu JK. Landscape of genetic infantile epileptic spasms syndrome-A multicenter cohort of 124 children from India. Epilepsia Open 2023; 8:1383-1404. [PMID: 37583270 PMCID: PMC10690684 DOI: 10.1002/epi4.12811] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 08/10/2023] [Indexed: 08/17/2023] Open
Abstract
OBJECTIVE Literature on the genotypic spectrum of Infantile Epileptic Spasms Syndrome (IESS) in children is scarce in developing countries. This multicentre collaboration evaluated the genotypic and phenotypic landscape of genetic IESS in Indian children. METHODS Between January 2021 and June 2022, this cross-sectional study was conducted at six centers in India. Children with genetically confirmed IESS, without definite structural-genetic and structural-metabolic etiology, were recruited and underwent detailed in-person assessment for phenotypic characterization. The multicentric data on the genotypic and phenotypic characteristics of genetic IESS were collated and analyzed. RESULTS Of 124 probands (60% boys, history of consanguinity in 15%) with genetic IESS, 105 had single gene disorders (104 nuclear and one mitochondrial), including one with concurrent triple repeat disorder (fragile X syndrome), and 19 had chromosomal disorders. Of 105 single gene disorders, 51 individual genes (92 variants including 25 novel) were identified. Nearly 85% of children with monogenic nuclear disorders had autosomal inheritance (dominant-55.2%, recessive-14.2%), while the rest had X-linked inheritance. Underlying chromosomal disorders included trisomy 21 (n = 14), Xq28 duplication (n = 2), and others (n = 3). Trisomy 21 (n = 14), ALDH7A1 (n = 10), SCN2A (n = 7), CDKL5 (n = 6), ALG13 (n = 5), KCNQ2 (n = 4), STXBP1 (n = 4), SCN1A (n = 4), NTRK2 (n = 4), and WWOX (n = 4) were the dominant single gene causes of genetic IESS. The median age at the onset of epileptic spasms (ES) and establishment of genetic diagnosis was 5 and 12 months, respectively. Pre-existing developmental delay (94.3%), early age at onset of ES (<6 months; 86.2%), central hypotonia (81.4%), facial dysmorphism (70.1%), microcephaly (77.4%), movement disorders (45.9%) and autistic features (42.7%) were remarkable clinical findings. Seizures other than epileptic spasms were observed in 83 children (66.9%). Pre-existing epilepsy syndrome was identified in 21 (16.9%). Nearly 60% had an initial response to hormonal therapy. SIGNIFICANCE Our study highlights a heterogenous genetic landscape and phenotypic pleiotropy in children with genetic IESS.
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Affiliation(s)
- Balamurugan Nagarajan
- Pediatric Neurology Unit, Department of PediatricsPostgraduate Institute of Medical Education and ResearchChandigarhIndia
| | - Vykuntaraju K. Gowda
- Department of Pediatric NeurologyIndira Gandhi Institute of Child HealthBengaluruIndia
| | - Sangeetha Yoganathan
- Pediatric Neurology Unit, Department of Neurological SciencesChristian Medical CollegeVelloreIndia
| | - Indar Kumar Sharawat
- Pediatric Neurology Division, Department of PediatricsAll India Institute of Medical SciencesRishikeshIndia
| | - Kavita Srivastava
- Pediatric Neurology Unit, Department of PediatricsBharati Vidyapeeth Deemed University Medical CollegePuneIndia
| | - Nitish Vora
- Royal Institute of Child NeurosciencesAhmedabadIndia
| | - Rahul Badheka
- Royal Institute of Child NeurosciencesAhmedabadIndia
| | - Sumita Danda
- Department of Medical GeneticsChristian Medical CollegeVelloreIndia
| | - Umesh Kalane
- Pediatric Neurology Division, Department of PediatricsAll India Institute of Medical SciencesRishikeshIndia
| | - Anupriya Kaur
- Genetics and Metabolic Unit, Department of PediatricsPostgraduate Institute of Medical Education and ResearchChandigarhIndia
| | - Priyanka Madaan
- Pediatric Neurology Unit, Department of PediatricsPostgraduate Institute of Medical Education and ResearchChandigarhIndia
- Department of Pediatric NeurologyAmrita Institute of Medical SciencesFaridabadIndia
| | - Sanjiv Mehta
- Royal Institute of Child NeurosciencesAhmedabadIndia
| | - Sandeep Negi
- Pediatric Neurology Unit, Department of PediatricsPostgraduate Institute of Medical Education and ResearchChandigarhIndia
| | - Prateek Kumar Panda
- Pediatric Neurology Division, Department of PediatricsAll India Institute of Medical SciencesRishikeshIndia
| | - Surekha Rajadhyaksha
- Pediatric Neurology Unit, Department of PediatricsBharati Vidyapeeth Deemed University Medical CollegePuneIndia
| | - Arushi Gahlot Saini
- Pediatric Neurology Unit, Department of PediatricsPostgraduate Institute of Medical Education and ResearchChandigarhIndia
| | - Lokesh Saini
- Pediatric Neurology Unit, Department of PediatricsPostgraduate Institute of Medical Education and ResearchChandigarhIndia
- Department of PediatricsAll India Institute of Medical SciencesJodhpurIndia
| | | | | | - Renu Suthar
- Pediatric Neurology Unit, Department of PediatricsPostgraduate Institute of Medical Education and ResearchChandigarhIndia
| | - Maya Thomas
- Pediatric Neurology Unit, Department of Neurological SciencesChristian Medical CollegeVelloreIndia
| | - Sameer Vyas
- Division of Neuroimaging and Interventional Neuroradiology, Department of Radiodiagnosis and ImagingPostgraduate Institute of Medical Education and ResearchChandigarhIndia
| | - Naveen Sankhyan
- Pediatric Neurology Unit, Department of PediatricsPostgraduate Institute of Medical Education and ResearchChandigarhIndia
| | - Jitendra Kumar Sahu
- Pediatric Neurology Unit, Department of PediatricsPostgraduate Institute of Medical Education and ResearchChandigarhIndia
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Chen H, Chen Y, Wu H, Qiu X, Yu X, Wang R, Zhong J, Peng J. De novo variants in PHF21A cause intellectual developmental disorder with behavioral abnormalities and craniofacial dysmorphism with or without seizures: A case report and literature review. Seizure 2023; 111:138-146. [PMID: 37633153 DOI: 10.1016/j.seizure.2023.08.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 08/07/2023] [Accepted: 08/17/2023] [Indexed: 08/28/2023] Open
Abstract
PURPOSE PHF21A has been associated with intellectual developmental disorder with behavioral abnormalities and craniofacial dysmorphism with or without seizures (IDDBCS). Here, we report a new patient with IDDBCS and review previously reported patients. METHODS We reviewed the phenotypic and genetic spectrum of the newly diagnosed patient and previously reported patients with IDDBCS. RESULTS Among 12 patients (11 whose cases were previously reported and the patient whose case we report here), all patients (100%) had intellectual disability (ID) and motor development delay. Three of 8 patients (37.5%) for whom information on cognition was available had severe ID; ID was moderate in two patients (25%) and mild in three patients (37.5%). Seven of the 12 patients (58.33%) had an epileptic phenotype, and the majority (5/7, 71.42%) of affected individuals developed developmental and epileptic encephalopathy (DEE). Of the 5 patients with DEE, three developed infantile epileptic spasm syndrome (IESS). The seizures of 2 patients (2/5, 40%) were controlled by antiseizure medications. Overgrowth, ADHD, hypotonia, ASD, and sleep disorders were observed in 100%, 77.78%, 70%, 50%, and 33.33% of patients, respectively. All of the variants (100%) were de novo heterozygous variants. Three of the 12 patients (25%) had the same variant (p.Arg580*). The most common types of variants were frameshift variants (7/12, 58.33%), followed by nonsense variants (4/12, 33.33%) and missense variants (1/12, 8.33%). Genotype-phenotype relationships for IDDBCS were uncertain, as phenotypic variability was observed among patients with the same variant (p.Arg580*). The patient whose case we report here had a novel PHF21A gene variant (p.Gln97fs*20), which caused neurodevelopmental delay, macrocephaly, and IESS. CONCLUSION The core phenotypes of IDDBCS include neurodevelopmental delay (intellectual disability and impaired motor skills), craniofacial abnormalities, and overgrowth. ADHD, hypotonia, epilepsy, ASD, and sleep disorders are common symptoms of IDDBCS. Notably, DEE is the dominant phenotype of epilepsy, especially IESS. PHF21A may be a candidate gene for DEE. De novo variants are the main mode of inheritance. The most common types of variants are frameshift variants, and the variant p.Arg580* in PHF21A is located at a mutation hot spot.
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Affiliation(s)
- Hui Chen
- Department of Neurology, Children's Hospital of Jiangxi Province, Nanchang, China
| | - Yong Chen
- Department of Neurology, Children's Hospital of Jiangxi Province, Nanchang, China
| | - Huaping Wu
- Department of Neurology, Children's Hospital of Jiangxi Province, Nanchang, China
| | - Xiaolu Qiu
- Child healthcare department, Children's Hospital of Jiangxi Province, Nanchang, China
| | - Xiongying Yu
- Department of Neurology, Children's Hospital of Jiangxi Province, Nanchang, China
| | - Ruiyan Wang
- Department of Neurology, Children's Hospital of Jiangxi Province, Nanchang, China.
| | - Jianmin Zhong
- Department of Neurology, Children's Hospital of Jiangxi Province, Nanchang, China.
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.
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Duc NM, Thu NTM, Bui CB, Hoa G, Le Trung Hieu N. Genotype and phenotype characteristics of West syndrome in 20 Vietnamese children: Two novel variants detected by next-generation sequencing. Epilepsy Res 2023; 190:107094. [PMID: 36689859 DOI: 10.1016/j.eplepsyres.2023.107094] [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: 11/17/2022] [Revised: 01/16/2023] [Accepted: 01/19/2023] [Indexed: 01/21/2023]
Abstract
BACKGROUND In children with West syndrome (WS), whose treatment is challenging due to drug resistance and poor prognosis, investigation of genetic etiology and genotype-phenotype characteristics might assist in treatment optimization and genetic counseling. OBJECTIVE In this study, we aimed to present the results of genetic analysis and the corresponding phenotypes in a cohort of twenty children with WS in Vietnam. METHODS Our study was designed as a single-institution retrospective case series, in which consecutive sampling was used to select WS children having undergone genetic testing. Identified variants were investigated individually or as a variant combination by bioinformatics platforms. Clinical data were used to establish the genotype-phenotype correlation and compare clinical characteristics between groups of genetic causes and unknown causes. RESULTS Genetic testing identified at least one variant in 17/20 children. According to ACMG 2015, of all variants, one variant (3.9%) was classified as a benign variant, 16 variants (61.5%) were variants of uncertain significance, 4 (15.4%) were likely pathogenic variants, and 5 (19.2%) were pathogenic variants. These 26 variants belonged to 21 genes, of which eight candidate genes were CREBBP, MED25, HDAC8, SCN3A, ABCD1, TSC2, COL4A1, and NDUFA10. Two novel variants of SCN3A and TSC2 were found. Predicted pathogenic variant combinations were identified in two cases. Compared to three children of unknown etiology, five children with genetic causes had a higher rate of abnormal brain structures, developmental delay, and treatment resistance. CONCLUSIONS WS has a genetically heterogeneous etiology, and some cases might be polygenically susceptible. Our findings expand the disease's genotype-phenotype spectrum and support previous literature results that genetic etiology poses an unfavorable outcome in WS.
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Affiliation(s)
- Nguyen Minh Duc
- Neurology Department, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City 70000, Vietnam.
| | - Nguyen Thuy Minh Thu
- Neurology Department, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City 70000, Vietnam; Neurology Department, Children Hospital 2, Ho Chi Minh City 70000, Vietnam.
| | - Chi-Bao Bui
- School of Medicine, Vietnam National University, Ho Chi Minh City 70701, Vietnam.
| | - Giang Hoa
- Medical Genetics Institute, Ho Chi Minh City 70000, Vietnam.
| | - Nguyen Le Trung Hieu
- Neurology Department, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City 70000, Vietnam; Neurology Department, Children Hospital 2, Ho Chi Minh City 70000, Vietnam.
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Syrbe S. Developmental and epileptic encephalopathies - therapeutic consequences of genetic testing. MED GENET-BERLIN 2022; 34:215-224. [PMID: 38835873 PMCID: PMC11006352 DOI: 10.1515/medgen-2022-2145] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
Developmental and epileptic encephalopathies comprise a heterogeneous group of monogenic neurodevelopmental disorders characterized by early-onset seizures, marked epileptic activity and abnormal neurocognitive development. The identification of an increasing number of underlying genetic alterations and their pathophysiological roles in cellular signaling drives the way toward novel precision therapies. The implementation of novel treatments that target the underlying mechanisms gives hope for disease modification that will improve not only the seizure burden but also the neurodevelopmental outcome of affected children. So far, beneficial effects are mostly reported in individual trials and small numbers of patients. There is a need for international collaborative studies to define the natural history and relevant outcome measures and to test novel pharmacological approaches.
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Affiliation(s)
- Steffen Syrbe
- Division of Paediatric Epileptology, Centre for Paediatrics and Adolescent Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
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Krey I, Johannesen KM, Kohnen O, Lemke JR. Genetic testing in adults with developmental and epileptic encephalopathy - what do we know? MED GENET-BERLIN 2022; 34:207-213. [PMID: 38835877 PMCID: PMC11006368 DOI: 10.1515/medgen-2022-2144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
Knowledge of underlying genetic causes of developmental and epileptic encephalopathies (DEE) in adults is still limited when compared to the routine diagnostic approach in similarly affected children. A well-documented longitudinal study of adults with DEE is of utmost importance to understand the natural history of the respective entity. This information is of great value especially for genetic counselling of newly diagnosed children with identical genetic diagnoses and may impact treatment and management of affected individuals. In our meta-analysis we provide an overview of the most recurrent genetic findings across an adult DEE cohort (n = 1 , 020 ). The gene mostly associated with a pathogenic or likely pathogenic variant in adult DEE is SCN1A, followed by MECP2 and CHD2. Studies employing exome sequencing and calling of both single nucleotide variants and copy number variants are associated with diagnostic yields of almost 50 %. Finally, we highlight three remarkable cases, each representing the oldest individual ever published with their genetic diagnosis, i. e., Angelman syndrome, Miller-Dieker syndrome, and CAMK2A-related disorder, and describe lessons learned from each of these adults.
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Affiliation(s)
- Ilona Krey
- Institute of Human Genetics, University of Leipzig Medical Center, Philipp-Rosenthal-Straße 55, 04103 Leipzig, Germany
| | - Kathrine M Johannesen
- Department of Epilepsy Genetics and Personalized Medicine, The Danish Epilepsy Centre, Dianalund, Denmark
- Department of Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Oona Kohnen
- Swiss Epilepsy Center, Klinik Lengg, Zurich, Switzerland
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Philipp-Rosenthal-Straße 55, 04103 Leipzig, Germany
- Center for Rare Diseases, University of Leipzig Medical Center, Leipzig, Germany
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6
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Ding J, Li X, Tian H, Wang L, Guo B, Wang Y, Li W, Wang F, Sun T. SCN1A Mutation-Beyond Dravet Syndrome: A Systematic Review and Narrative Synthesis. Front Neurol 2022; 12:743726. [PMID: 35002916 PMCID: PMC8739186 DOI: 10.3389/fneur.2021.743726] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 11/29/2021] [Indexed: 12/28/2022] Open
Abstract
Background:SCN1A is one of the most common epilepsy genes. About 80% of SCN1A gene mutations cause Dravet syndrome (DS), which is a severe and catastrophic epileptic encephalopathy. More than 1,800 mutations have been identified in SCN1A. Although it is known that SCN1A is the main cause of DS and genetic epilepsy with febrile seizures plus (GEFS+), there is a dearth of information on the other related diseases caused by mutations of SCN1A. Objective: The aim of this study is to systematically review the literature associated with SCN1A and other non-DS-related disorders. Methods: We searched PubMed and SCOPUS for all the published cases related to gene mutations of SCN1A until October 20, 2021. The results reported by each study were summarized narratively. Results: The PubMed and SCOPUS search yielded 2,889 items. A total of 453 studies published between 2005 and 2020 met the final inclusion criteria. Overall, 303 studies on DS, 93 on GEFS+, three on Doose syndrome, nine on the epilepsy of infancy with migrating focal seizures (EIMFS), six on the West syndrome, two on the Lennox–Gastaut syndrome (LGS), one on the Rett syndrome, seven on the nonsyndromic epileptic encephalopathy (NEE), 19 on hemiplegia migraine, six on autism spectrum disorder (ASD), two on nonepileptic SCN1A-related sudden deaths, and two on the arthrogryposis multiplex congenital were included. Conclusion: Aside from DS, SCN1A also causes other epileptic encephalopathies, such as GEFS+, Doose syndrome, EIMFS, West syndrome, LGS, Rett syndrome, and NEE. In addition to epilepsy, hemiplegic migraine, ASD, sudden death, and arthrogryposis multiplex congenital can also be caused by mutations of SCN1A.
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Affiliation(s)
- Jiangwei Ding
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China.,Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Xinxiao Li
- Department of Neurosurgery, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Haiyan Tian
- Department of Neurology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Lei Wang
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China.,Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
| | - Baorui Guo
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China.,Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Yangyang Wang
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China.,Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
| | - Wenchao Li
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China.,Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
| | - Feng Wang
- Department of Neurosurgery, The First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Tao Sun
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China.,Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
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Sheidley BR, Malinowski J, Bergner AL, Bier L, Gloss DS, Mu W, Mulhern MM, Partack EJ, Poduri A. Genetic testing for the epilepsies: A systematic review. Epilepsia 2021; 63:375-387. [PMID: 34893972 DOI: 10.1111/epi.17141] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Numerous genetic testing options for individuals with epilepsy have emerged over the past decade without clear guidelines regarding optimal testing strategies. We performed a systematic evidence review (SER) and conducted meta-analyses of the diagnostic yield of genetic tests commonly utilized for patients with epilepsy. We also assessed nonyield outcomes (NYOs) such as changes in treatment and/or management, prognostic information, recurrence risk determination, and genetic counseling. METHODS We performed an SER, in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), using PubMed, Embase, CINAHL, and Cochrane Central through December of 2020. We included studies that utilized genome sequencing (GS), exome sequencing (ES), multigene panel (MGP), and/or genome-wide comparative genomic hybridization/chromosomal microarray (CGH/CMA) in cohorts (n ≥ 10) ascertained for epilepsy. Quality assessment was undertaken using ROBINS-I (Risk of Bias in Non-Randomized Studies of Interventions). We estimated diagnostic yields and 95% confidence intervals with random effects meta-analyses and narratively synthesized NYOs. RESULTS From 5985 nonduplicated articles published through 2020, 154 met inclusion criteria and were included in meta-analyses of diagnostic yield; 43 of those were included in the NYO synthesis. The overall diagnostic yield across all test modalities was 17%, with the highest yield for GS (48%), followed by ES (24%), MGP (19%), and CGH/CMA (9%). The only phenotypic factors that were significantly associated with increased yield were (1) the presence of developmental and epileptic encephalopathy and/or (2) the presence of neurodevelopmental comorbidities. Studies reporting NYOs addressed clinical and personal utility of testing. SIGNIFICANCE This comprehensive SER, focused specifically on the literature regarding patients with epilepsy, provides a comparative assessment of the yield of clinically available tests, which will help shape clinician decision-making and policy regarding insurance coverage for genetic testing. We highlight the need for prospective assessment of the clinical and personal utility of genetic testing for patients with epilepsy and for standardization in reporting patient characteristics.
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Affiliation(s)
- Beth R Sheidley
- Epilepsy Genetics Program, Division of Epilepsy and Neurophysiology, Department of Neurology, Boston Children's Hospital, Boston, Massachusetts, USA
| | | | - Amanda L Bergner
- Department of Genetics and Development, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Louise Bier
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, New York, USA
| | - David S Gloss
- Department of Neurology, Charleston Area Medical Center, Charleston, West Virginia, USA
| | - Weiyi Mu
- Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Maureen M Mulhern
- Department of Pathology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA.,Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Emily J Partack
- Genomics Services, Quest Diagnostics, Marlborough, Massachusetts, USA
| | - Annapurna Poduri
- Epilepsy Genetics Program, Division of Epilepsy and Neurophysiology, Department of Neurology, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Neurology, Harvard Medical School, Boston, Massachusetts, USA
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8
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Saffari A, Schröter J, Garbade SF, Alecu JE, Ebrahimi-Fakhari D, Hoffmann GF, Kölker S, Ries M, Syrbe S. Quantitative retrospective natural history modeling of WDR45-related developmental and epileptic encephalopathy - a systematic cross-sectional analysis of 160 published cases. Autophagy 2021; 18:1715-1727. [PMID: 34818117 DOI: 10.1080/15548627.2021.1990671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
WDR45-related neurodevelopmental disorder (NDD) is a clinically-heterogenous congenital disorder of macroautophagy/autophagy. The natural history of this ultra-orphan disease remains incompletely understood, leading to delays in diagnosis and lack of quantifiable outcome measures. In this cross-sectional study, we model quantitative natural history data for WDR45-related NDD using a standardized analysis of 160 published cases, representing the largest cohort to date. The primary outcome of this study was survival. Age at disease onset, diagnostic delay and geographic distribution were quantified as secondary endpoints. Our tertiary aim was to explore and quantify the spectrum of WDR45-related phenotypes. Survival estimations showed low mortality until 39 years of age. Median age at onset was 10 months, with a median diagnostic delay of 6.2 years. Geographic distribution appeared worldwide with clusters in North America, East Asia, Western Europe and the Middle East. The clinical spectrum was highly variable with a bi-phasic evolution characterized by early-onset developmental and epileptic encephalopathy during childhood followed by a progressive dystonia-parkinsonism syndrome along with cognitive decline during early adulthood. Female individuals showed milder disease severity. The majority of pathogenic WDR45 variants were predicted to result in a loss of WDR45 expression, without clear genotype-phenotype associations. Our results provide clinical and epidemiological data that may facilitate an earlier diagnosis, enable anticipatory guidance and counseling of affected families and provide the foundation for endpoints for future interventional trials.Abbreviations: BPAN: beta-propeller protein-associated neurodegeneration; CNS: central nervous system; DEE: developmental and epileptic encephalopathy; MRI: magnetic resonance imaging; NBIA: neurodegeneration with brain iron accumulation; NDD: neurodevelopmental disorder; NGS: next-generation sequencing; WDR45/WIPI4: WD repeat domain 45.
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Affiliation(s)
- Afshin Saffari
- Division of Pediatric Epileptology, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany.,Division of Neuropediatrics and Inherited Metabolic Diseases, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Julian Schröter
- Division of Pediatric Epileptology, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany.,Division of Neuropediatrics and Inherited Metabolic Diseases, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Sven F Garbade
- Division of Neuropediatrics and Inherited Metabolic Diseases, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Julian E Alecu
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Darius Ebrahimi-Fakhari
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Georg F Hoffmann
- Division of Neuropediatrics and Inherited Metabolic Diseases, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Stefan Kölker
- Division of Neuropediatrics and Inherited Metabolic Diseases, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Markus Ries
- Division of Neuropediatrics and Inherited Metabolic Diseases, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Steffen Syrbe
- Division of Pediatric Epileptology, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
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9
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Helman G, Mendes MI, Nicita F, Darbelli L, Sherbini O, Moore T, Derksen A, Amy Pizzino, Carrozzo R, Torraco A, Catteruccia M, Aiello C, Goffrini P, Figuccia S, Smith DEC, Hadzsiev K, Hahn A, Biskup S, Brösse I, Kotzaeridou U, Gauck D, Grebe TA, Elmslie F, Stals K, Gupta R, Bertini E, Thiffault I, Taft RJ, Schiffmann R, Brandl U, Haack TB, Salomons GS, Simons C, Bernard G, van der Knaap MS, Vanderver A, Husain RA. Expanded phenotype of AARS1-related white matter disease. Genet Med 2021; 23:2352-2359. [PMID: 34446925 DOI: 10.1038/s41436-021-01286-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 07/08/2021] [Accepted: 07/09/2021] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Recent reports of individuals with cytoplasmic transfer RNA (tRNA) synthetase-related disorders have identified cases with phenotypic variability from the index presentations. We sought to assess phenotypic variability in individuals with AARS1-related disease. METHODS A cross-sectional survey was performed on individuals with biallelic variants in AARS1. Clinical data, neuroimaging, and genetic testing results were reviewed. Alanyl tRNA synthetase (AlaRS) activity was measured in available fibroblasts. RESULTS We identified 11 affected individuals. Two phenotypic presentations emerged, one with early infantile-onset disease resembling the index cases of AARS1-related epileptic encephalopathy with deficient myelination (n = 7). The second (n = 4) was a later-onset disorder, where disease onset occurred after the first year of life and was characterized on neuroimaging by a progressive posterior predominant leukoencephalopathy evolving to include the frontal white matter. AlaRS activity was significantly reduced in five affected individuals with both early infantile-onset and late-onset phenotypes. CONCLUSION We suggest that variants in AARS1 result in a broader clinical spectrum than previously appreciated. The predominant form results in early infantile-onset disease with epileptic encephalopathy and deficient myelination. However, a subgroup of affected individuals manifests with late-onset disease and similarly rapid progressive clinical decline. Longitudinal imaging and clinical follow-up will be valuable in understanding factors affecting disease progression and outcome.
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Affiliation(s)
- Guy Helman
- Murdoch Children's Research Institute, The Royal Children's Hospital, Parkville, VIC, Australia.,Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Marisa I Mendes
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Francesco Nicita
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Lama Darbelli
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.,Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Department of Pediatrics, McGill University, Montreal, QC, Canada.,Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Omar Sherbini
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Travis Moore
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.,Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Alexa Derksen
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.,Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Amy Pizzino
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Rosalba Carrozzo
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Alessandra Torraco
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Michela Catteruccia
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Chiara Aiello
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Paola Goffrini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Sonia Figuccia
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Desiree E C Smith
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Kinga Hadzsiev
- Department of Medical Genetics, University of Pécs, Pécs, Hungary
| | - Andreas Hahn
- Department of Child Neurology, Justus-Liebig-University, Giessen, Germany
| | - Saskia Biskup
- Praxis fuer Humangenetik and CeGaT GmbH, Tuebingen, Germany
| | - Ines Brösse
- Division of Child Neurology and Inherited Metabolic Diseases, Centre for Paediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Urania Kotzaeridou
- Division of Child Neurology and Inherited Metabolic Diseases, Centre for Paediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Darja Gauck
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Theresa A Grebe
- Division of Genetics and Metabolism, Department of Child Health, Phoenix Children's Hospital, University of Arizona College of Medicine, Phoenix, AZ, USA
| | - Frances Elmslie
- South West Thames Regional Genetics Service, St George's University Hospital, London, UK
| | - Karen Stals
- Molecular Genetics Department, Royal Devon and Exeter NHS Foundation Trust, Exeter, UK
| | - Rajat Gupta
- Department of Neurology, Birmingham Children's Hospital, Birmingham, UK
| | - Enrico Bertini
- Department of Neurosciences, Unit of Muscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Isabelle Thiffault
- Children's Mercy Kansas City, Center for Pediatric Genomic Medicine, Kansas City, MO, USA.,Department of Pathology and Laboratory Medicine, Children's Mercy Hospitals, Kansas City, MO, USA.,School of Medicine, University of Missouri-Kansas City, Kansas City, MO, USA
| | | | | | - Ulrich Brandl
- Department of Neuropediatrics, Jena University Hospital, Jena, Germany
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Gajja S Salomons
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Cas Simons
- Murdoch Children's Research Institute, The Royal Children's Hospital, Parkville, VIC, Australia.,Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Geneviève Bernard
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.,Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Department of Pediatrics, McGill University, Montreal, QC, Canada.,Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Marjo S van der Knaap
- Department of Child Neurology, Emma Children's Hospital, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam and Amsterdam Neuroscience, Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, The Netherlands
| | - Adeline Vanderver
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA. .,Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA.
| | - Ralf A Husain
- Department of Neuropediatrics, Jena University Hospital, Jena, Germany.
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10
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Sub-genic intolerance, ClinVar, and the epilepsies: A whole-exome sequencing study of 29,165 individuals. Am J Hum Genet 2021; 108:965-982. [PMID: 33932343 DOI: 10.1016/j.ajhg.2021.04.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 04/08/2021] [Indexed: 12/23/2022] Open
Abstract
Both mild and severe epilepsies are influenced by variants in the same genes, yet an explanation for the resulting phenotypic variation is unknown. As part of the ongoing Epi25 Collaboration, we performed a whole-exome sequencing analysis of 13,487 epilepsy-affected individuals and 15,678 control individuals. While prior Epi25 studies focused on gene-based collapsing analyses, we asked how the pattern of variation within genes differs by epilepsy type. Specifically, we compared the genetic architectures of severe developmental and epileptic encephalopathies (DEEs) and two generally less severe epilepsies, genetic generalized epilepsy and non-acquired focal epilepsy (NAFE). Our gene-based rare variant collapsing analysis used geographic ancestry-based clustering that included broader ancestries than previously possible and revealed novel associations. Using the missense intolerance ratio (MTR), we found that variants in DEE-affected individuals are in significantly more intolerant genic sub-regions than those in NAFE-affected individuals. Only previously reported pathogenic variants absent in available genomic datasets showed a significant burden in epilepsy-affected individuals compared with control individuals, and the ultra-rare pathogenic variants associated with DEE were located in more intolerant genic sub-regions than variants associated with non-DEE epilepsies. MTR filtering improved the yield of ultra-rare pathogenic variants in affected individuals compared with control individuals. Finally, analysis of variants in genes without a disease association revealed a significant burden of loss-of-function variants in the genes most intolerant to such variation, indicating additional epilepsy-risk genes yet to be discovered. Taken together, our study suggests that genic and sub-genic intolerance are critical characteristics for interpreting the effects of variation in genes that influence epilepsy.
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11
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Choi HS, Ko A, Kim SH, Lee ST, Choi JR, Lee JS, Kim HD, Kang HC. Disparate treatment outcomes according to presence of pathogenic mutations in West syndrome. Epilepsia 2021; 62:1656-1664. [PMID: 34008866 DOI: 10.1111/epi.16924] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 04/26/2021] [Accepted: 04/26/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE It has been known that West syndrome (WS) patients with an unknown etiology have better clinical outcomes than patients with an identified etiology of any kind. However, after the exponential discovery of genes with mutations responsible for developmental and epileptic encephalopathy (DEE), a significant proportion of patients with a previously unknown etiology have been reclassified as having a genetic etiology, requiring reinvestigation of this concept. Therefore, this study investigated clinical outcomes of WS patients with genetic and unknown etiologies. METHODS Patients diagnosed with WS without structural or metabolic abnormalities were included in this study. The DEE gene panel, comprising 172 genes, was performed for all patients. All patients were treated using the same treatment protocol for vigabatrin and high-dose prednisolone add-on therapy. Favorable responders were defined as patients who were seizure-free and whose electroencephalogram showed Burden of Amplitudes and Epileptiform Discharges scores of 2 or less. RESULTS Of the 58 patients included in the study, 17 (29.3%) patients had an identified genetic etiology. There was no significant difference in rates of favorable response at 1 and 3 months after treatment, but significantly higher proportions of patients exhibited favorable responses among those with an unknown etiology at long-term follow-up (41.2% vs. 78.0%, p = .006 at 6 months; 29.4% vs. 65.9%, p = .011 at 1 year; 23.5 vs. 65.9%, p = .003 at 2 years). Moreover, the mental, psychomotor, and social age quotients of the patients with an identified genetic etiology were reduced to a significantly greater degree since diagnosis compared with those of the patients with an unknown etiology. SIGNIFICANCE WS patients with genetic and unknown etiologies did not initially exhibit significantly different response rates to the vigabatrin and high-dose prednisolone add-on treatment. However, patients with a genetic etiology exhibited significantly higher relapse rates and significantly poorer long-term responses.
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Affiliation(s)
- Han Som Choi
- Department of Pediatrics, Ewha Womans University Seoul Hospital, Ewha Womans University School of Medicine, Seoul, South Korea.,Division of Pediatric Neurology, Department of Pediatrics, Epilepsy Research Institute, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Ara Ko
- Department of Pediatrics, Pusan National University Children's Hospital, Pusan National University School of Medicine, Yangsan, South Korea.,Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Se Hee Kim
- Division of Pediatric Neurology, Department of Pediatrics, Epilepsy Research Institute, Severance Children's Hospital, Yonsei University College of Medicine, 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
| | - Joon Soo Lee
- Division of Pediatric Neurology, Department of Pediatrics, Epilepsy Research Institute, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Heung Dong Kim
- Division of Pediatric Neurology, Department of Pediatrics, Epilepsy Research Institute, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Hoon-Chul Kang
- Division of Pediatric Neurology, Department of Pediatrics, Epilepsy Research Institute, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, South Korea
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12
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The genetic landscape of intellectual disability and epilepsy in adults and the elderly: a systematic genetic work-up of 150 individuals. Genet Med 2021; 23:1492-1497. [PMID: 33911214 PMCID: PMC8354852 DOI: 10.1038/s41436-021-01153-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 03/07/2021] [Accepted: 03/08/2021] [Indexed: 12/31/2022] Open
Abstract
Purpose Genetic diagnostics of neurodevelopmental disorders with epilepsy (NDDE) are predominantly applied in children, thus limited information is available regarding adults or elderly. Methods We investigated 150 adult/elderly individuals with NDDE by conventional karyotyping, FMR1 testing, chromosomal microarray, panel sequencing, and for unresolved cases, also by exome sequencing (nsingle = 71, ntrios = 24). Results We identified (likely) pathogenic variants in 71 cases (47.3%) comprising fragile X syndrome (n = 1), disease-causing copy number (n = 23), and single-nucleotide variants (n = 49). Seven individuals displayed multiple independent genetic diagnoses. The diagnostic yield correlated with the severity of intellectual disability. Individuals with anecdotal evidence of exogenic early-life events (e.g., nuchal cord, complications at delivery) with alleged/unproven association to the disorder had a particularly high yield of 58.3%. Screening for disease-specific comorbidities was indicated in 45.1% and direct treatment consequences arose in 11.8% of diagnosed individuals. Conclusion Panel/exome sequencing displayed the highest yield and should be considered as first-tier diagnostics in NDDE. This high yield and the numerous indications for additional screening or treatment modifications arising from genetic diagnoses indicate a current medical undersupply of genetically undiagnosed adult/elderly individuals with NDDE. Moreover, knowledge of the course of elderly individuals will ultimately help in counseling newly diagnosed individuals with NDDE.
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13
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Scalia B, Venti V, Ciccia LM, Criscione R, Lo Bianco M, Sciuto L, Falsaperla R, Zanghì A, Praticò AD. Aristaless-Related Homeobox (ARX): Epilepsy Phenotypes beyond Lissencephaly and Brain Malformations. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1727140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractThe Aristaless-related homeobox (ARX) transcription factor is involved in the development of GABAergic and cholinergic neurons in the forebrain. ARX mutations have been associated with a wide spectrum of neurodevelopmental disorders in humans and are responsible for both malformation (in particular lissencephaly) and nonmalformation complex phenotypes. The epilepsy phenotypes related to ARX mutations are West syndrome and X-linked infantile spasms, X-linked myoclonic epilepsy with spasticity and intellectual development and Ohtahara and early infantile epileptic encephalopathy syndrome, which are related in most of the cases to intellectual disability and are often drug resistant. In this article, we shortly reviewed current knowledge of the function of ARX with a particular attention on its consequences in the development of epilepsy during early childhood.
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Affiliation(s)
- Bruna Scalia
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Valeria Venti
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Lina M. Ciccia
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Roberta Criscione
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Manuela Lo Bianco
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Laura Sciuto
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Raffaele Falsaperla
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
- Neonatal Intensive Care unit and Neonatology, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
| | - Antonio Zanghì
- Department of Medical and Surgical Sciences and Advanced Technology “G.F. Ingrassia,” University of Catania, Catania, Italy
| | - Andrea D. Praticò
- Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
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14
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Cong Y, So V, Tijssen MAJ, Verbeek DS, Reggiori F, Mauthe M. WDR45, one gene associated with multiple neurodevelopmental disorders. Autophagy 2021; 17:3908-3923. [PMID: 33843443 PMCID: PMC8726670 DOI: 10.1080/15548627.2021.1899669] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The WDR45 gene is localized on the X-chromosome and variants in this gene are linked to six different neurodegenerative disorders, i.e., ß-propeller protein associated neurodegeneration, Rett-like syndrome, intellectual disability, and epileptic encephalopathies including developmental and epileptic encephalopathy, early-onset epileptic encephalopathy and West syndrome and potentially also specific malignancies. WDR45/WIPI4 is a WD-repeat β-propeller protein that belongs to the WIPI (WD repeat domain, phosphoinositide interacting) family. The precise cellular function of WDR45 is still largely unknown, but deletions or conventional variants in WDR45 can lead to macroautophagy/autophagy defects, malfunctioning mitochondria, endoplasmic reticulum stress and unbalanced iron homeostasis, suggesting that this protein functions in one or more pathways regulating directly or indirectly those processes. As a result, the underlying cause of the WDR45-associated disorders remains unknown. In this review, we summarize the current knowledge about the cellular and physiological functions of WDR45 and highlight how genetic variants in its encoding gene may contribute to the pathophysiology of the associated diseases. In particular, we connect clinical manifestations of the disorders with their potential cellular origin of malfunctioning and critically discuss whether it is possible that one of the most prominent shared features, i.e., brain iron accumulation, is the primary cause for those disorders. Abbreviations: ATG/Atg: autophagy related; BPAN: ß-propeller protein associated neurodegeneration; CNS: central nervous system; DEE: developmental and epileptic encephalopathy; EEG: electroencephalograph; ENO2/neuron-specific enolase, enolase 2; EOEE: early-onset epileptic encephalopathy; ER: endoplasmic reticulum; ID: intellectual disability; IDR: intrinsically disordered region; MRI: magnetic resonance imaging; NBIA: neurodegeneration with brain iron accumulation; NCOA4: nuclear receptor coactivator 4; PtdIns3P: phosphatidylinositol-3-phosphate; RLS: Rett-like syndrome; WDR45: WD repeat domain 45; WIPI: WD repeat domain, phosphoinositide interacting
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Affiliation(s)
- Yingying Cong
- Department of Biomedical Sciences of Cells & Systems, Molecular Cell Biology Section, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Vincent So
- Department of Biomedical Sciences of Cells & Systems, Molecular Cell Biology Section, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Marina A J Tijssen
- Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Expertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Dineke S Verbeek
- Expertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Fulvio Reggiori
- Department of Biomedical Sciences of Cells & Systems, Molecular Cell Biology Section, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Expertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Mario Mauthe
- Department of Biomedical Sciences of Cells & Systems, Molecular Cell Biology Section, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Expertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, The Netherlands
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15
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Syrbe S. Präzisionsmedizin für genetische Epilepsien – am Anfang des Weges? ZEITSCHRIFT FÜR EPILEPTOLOGIE 2021. [DOI: 10.1007/s10309-021-00409-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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16
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Abstract
One in three epilepsy cases is drug resistant, and seizures often begin in infancy, when they are life-threatening and when therapeutic options are highly limited. An important tool for prioritizing and validating genes associated with epileptic conditions, which is suitable for large-scale screening, is disease modeling in Drosophila. Approximately two-thirds of disease genes are conserved in Drosophila, and gene-specific fly models exhibit behavioral changes that are related to symptoms of epilepsy. Models are based on behavior readouts, seizure-like attacks and paralysis following stimulation, and neuronal, cell-biological readouts that are in the majority based on changes in nerve cell activity or morphology. In this review, we focus on behavioral phenotypes. Importantly, Drosophila modeling is independent of, and complementary to, other approaches that are computational and based on systems analysis. The large number of known epilepsy-associated gene variants indicates a need for efficient research strategies. We will discuss the status quo of epilepsy disease modelling in Drosophila and describe promising steps towards the development of new drugs to reduce seizure rates and alleviate other epileptic symptoms.
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Affiliation(s)
- Paul Lasko
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, Netherlands
- Department of Biology, McGill University, Montréal, Québec, Canada
| | - Kevin Lüthy
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, Netherlands
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17
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Kessi M, Chen B, Peng J, Tang Y, Olatoutou E, He F, Yang L, Yin F. Intellectual Disability and Potassium Channelopathies: A Systematic Review. Front Genet 2020; 11:614. [PMID: 32655623 PMCID: PMC7324798 DOI: 10.3389/fgene.2020.00614] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/20/2020] [Indexed: 01/15/2023] Open
Abstract
Intellectual disability (ID) manifests prior to adulthood as severe limitations to intellectual function and adaptive behavior. The role of potassium channelopathies in ID is poorly understood. Therefore, we aimed to evaluate the relationship between ID and potassium channelopathies. We hypothesized that potassium channelopathies are strongly associated with ID initiation, and that both gain- and loss-of-function mutations lead to ID. This systematic review explores the burden of potassium channelopathies, possible mechanisms, advancements using animal models, therapies, and existing gaps. The literature search encompassed both PubMed and Embase up to October 2019. A total of 75 articles describing 338 cases were included in this review. Nineteen channelopathies were identified, affecting the following genes: KCNMA1, KCNN3, KCNT1, KCNT2, KCNJ10, KCNJ6, KCNJ11, KCNA2, KCNA4, KCND3, KCNH1, KCNQ2, KCNAB1, KCNQ3, KCNQ5, KCNC1, KCNB1, KCNC3, and KCTD3. Twelve of these genes presented both gain- and loss-of-function properties, three displayed gain-of-function only, three exhibited loss-of-function only, and one had unknown function. How gain- and loss-of-function mutations can both lead to ID remains largely unknown. We identified only a few animal studies that focused on the mechanisms of ID in relation to potassium channelopathies and some of the few available therapeutic options (channel openers or blockers) appear to offer limited efficacy. In conclusion, potassium channelopathies contribute to the initiation of ID in several instances and this review provides a comprehensive overview of which molecular players are involved in some of the most prominent disease phenotypes.
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Affiliation(s)
- Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China.,Kilimanjaro Christian Medical University College, Moshi, Tanzania.,Mawenzi Regional Referral Hospital, Moshi, Tanzania
| | - Baiyu Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Yulin Tang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Eleonore Olatoutou
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fang He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Lifen Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
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18
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Wu TH, Peng J, Zhang CL, Wu LW, Yang LF, Peng P, Pang N, Yin F, He F. [Mutations in aminoacyl-tRNA synthetase genes: an analysis of 10 cases]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2020; 22:595-601. [PMID: 32571458 PMCID: PMC7390216 DOI: 10.7499/j.issn.1008-8830.1912040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 04/26/2020] [Indexed: 06/11/2023]
Abstract
OBJECTIVE To study the clinical features of the diseases associated with aminoacyl-tRNA synthetases (ARS) deficiency. METHODS A retrospective analysis was performed of the clinical and gene mutation data of 10 children who were diagnosed with ARS gene mutations, based on next-generation sequencing from January 2016 to October 2019. RESULTS The age of onset ranged from 0 to 9 years among the 10 children. Convulsion was the most common initial symptom (7 children). Clinical manifestations included ataxia and normal or mildly retarded intellectual development (with or without epilepsy; n=4) and onset of epilepsy in childhood with developmental regression later (n=2). Some children experienced disease onset in the neonatal period and had severe epileptic encephalopathy, with myoclonus, generalized tonic-clonic seizure, and convulsive seizure (n=4); 3 had severe delayed development, 2 had feeding difficulty, and 1 had hearing impairment. Mutations were found in five genes: 3 had novel mutations in the AARS2 gene (c.331G>C, c.2682+5G>A, c.2164C>T, and c.761G>A), 2 had known mutations in the DARS2 gene (c.228-16C>A and c.536G>A), 1 had novel mutations in the CARS2 gene (c.1036C>T and c.323T>G), 1 had novel mutations in the RARS2 gene (c.1210A>G and c.622C>T), and 3 had novel mutations in the AARS gene (c.1901T>A, c.229C>T, c.244C>T, c.961G>C, c.2248C>T, and Chr16:70298860-70316687del). CONCLUSIONS A high heterogeneity is observed in the clinical phenotypes of the diseases associated with the ARS deficiency. A total of 14 novel mutations in 5 genes are reported in this study, which enriches the clinical phenotypes and genotypes of the diseases associated with ARS deficiency.
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Affiliation(s)
- Teng-Hui Wu
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha 410008, China.
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