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Barbour K, Tian N, Yozawitz EG, Wolf S, McGoldrick PE, Sands TT, Nelson A, Basma N, Grinspan ZM. Population-based study of rare epilepsy incidence in a US urban population. Epilepsia 2024; 65:2341-2353. [PMID: 38795333 PMCID: PMC11315636 DOI: 10.1111/epi.18029] [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: 12/15/2023] [Revised: 05/13/2024] [Accepted: 05/13/2024] [Indexed: 05/27/2024]
Abstract
OBJECTIVE This study was undertaken to estimate incidence of rare epilepsies and compare with literature. METHODS We used electronic health record text search to identify children with 28 rare epilepsies in New York City (2010-2014). We estimated cumulative incidence and compared with literature. RESULTS Eight of 28 rare epilepsies had five or more prior estimates, and our measurements were within the published range for all. The most common were infantile epileptic spasms syndrome (1 in 2920 live births), Lennox-Gastaut syndrome (1 in 9690), and seizures associated with tuberous sclerosis complex (1 in 14 300). Fifteen of 28 had fewer than five prior estimates, and of these, we provided additional estimates for early infantile developmental and epileptic encephalopathy (1 in 32 700), epilepsy with myoclonic-atonic seizures (1 in 34 100), Sturge-Weber syndrome plus seizures/epilepsy (1 in 40 900), epilepsy in infancy with migrating focal seizures (1 in 54 500), Aicardi syndrome plus seizures/epilepsy (1 in 71 600), hypothalamic hamartoma with seizures (1 in 225 000), and Rasmussen syndrome (1 in 450 000). Five of 28 rare epilepsies had no prior estimates, and of these, we provided a new estimate for developmental/epileptic encephalopathy with spike-and-wave activation in sleep and/or continuous spikes and waves during sleep (1 in 34 100). Data were limited for the remaining 12 rare epilepsies, which were all genetic epilepsies, including PCDH19, CDKL5, Alpers disease, SCN8A, KCNQ2, SCN2A, GLUT1 deficiency, Phelan-McDermid syndrome, myoclonic epilepsy with ragged-red fibers, dup15q syndrome, ring chromosome 14, and ring chromosome 20. SIGNIFICANCE We estimated the incidence of rare epilepsies using population-based electronic health record data and literature review. More research is needed to better estimate the incidence of genetic epilepsies with nonspecific clinical features. Electronic health records may be a valuable data source for studying rare epilepsies and other rare diseases, particularly as genetic testing becomes more widely adopted.
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Affiliation(s)
- Kristen Barbour
- University of California, San Diego, San Diego, California, USA
| | - Niu Tian
- Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Elissa G Yozawitz
- Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Steven Wolf
- Boston Children's Health Physicians, Hawthorne, New York, USA
- New York Medical College, Valhalla, New York, USA
| | - Patricia E McGoldrick
- Boston Children's Health Physicians, Hawthorne, New York, USA
- New York Medical College, Valhalla, New York, USA
| | - Tristan T Sands
- Columbia University Irving Medical Center, New York, New York, USA
| | - Aaron Nelson
- New York University Langone Medical Center, New York, New York, USA
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Hunter MB, Yoong M, Sumpter RE, Verity K, Shetty J, McLellan A, Chin RFM. Incidence of early-onset epilepsy: A prospective population-based study. Seizure 2019; 75:49-54. [PMID: 31874359 DOI: 10.1016/j.seizure.2019.12.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 06/05/2019] [Accepted: 12/17/2019] [Indexed: 11/25/2022] Open
Abstract
PURPOSE The first five years of life reflect a critical period of development prior to formal education yet few epidemiological studies focus on children with early-onset epilepsy (CWEOE; onset <60 months). This study aimed to determine early-onset epilepsy incidence using a comprehensive case identification strategy, and examined socioeconomic status (SES) and ethnicity as risk factors. METHODS Through a prospective, population-based study, newly diagnosed CWEOE from Fife and Lothian, Scotland, were identified using multiple-source, active surveillance capture-recapture between May 2013 and June 2015. Crude, ascertainment-adjusted, age-adjusted, age- and gender-specific, and epilepsy-type incidence rates were determined. Risk ratios (RR) were calculated to examine SES and ethnicity as risk factors. RESULTS 59 (36 Male) CWEOE were identified. Ascertainment was 98% (95% CI 94-103). Crude annual incidence of epilepsy in children 0-59 months was 60.2 (95% CI 44.8-75.5) per 100,000 per year; ascertainment-adjusted annual incidence was 61.7 (95% CI 46.2-77.3) per year. Cumulative incidence of West Syndrome/Infantile Spasms was 6.7 per 10,000 live births (95% CI 3.6-12.3). Aetiology was unknown in almost two-thirds of CWEOE. Compared to White-British Isles (BI) children, Asian children (RR 2.6 [95% CI 1.2-5.7], p = .02) and White-non-BI children (RR 2.5 [95% CI 1.2-5.2], p = .02) had increased risk. SES was not a risk factor. CONCLUSION The high incidence of early-onset epilepsy is similar to previous studies and demonstrates a substantial disease burden. Cause of epilepsy remains unknown in almost two thirds of CWEOE. Ethnicity but not SES affects early-onset epilepsy risk.
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Affiliation(s)
- Matthew B Hunter
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.
| | - Michael Yoong
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK
| | - Ruth E Sumpter
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK
| | - Kirsten Verity
- Department of Paediatric Neurosciences, Royal Hospital for Sick Children, Edinburgh, UK
| | - Jay Shetty
- Department of Paediatric Neurosciences, Royal Hospital for Sick Children, Edinburgh, UK
| | - Ailsa McLellan
- Department of Paediatric Neurosciences, Royal Hospital for Sick Children, Edinburgh, UK
| | - Richard F M Chin
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK; Department of Paediatric Neurosciences, Royal Hospital for Sick Children, Edinburgh, UK
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Jia JL, Chen S, Sivarajah V, Stephens D, Cortez MA. Latitudinal differences on the global epidemiology of infantile spasms: systematic review and meta-analysis. Orphanet J Rare Dis 2018; 13:216. [PMID: 30486850 PMCID: PMC6262963 DOI: 10.1186/s13023-018-0952-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/14/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Infantile spasms represent the catastrophic, age-specific seizure type associated with acute and long-term neurological morbidity. However, due to rarity and heterogenous determination, there is persistent uncertainty of its pathophysiological and epidemiological characteristics. The purpose of the current study was to address a historically suspected latitudinal basis of infantile spasms incidence, and to interrogate a geographical basis of epidemiology, including the roles of latitude and other environmental factors, using meta-analytic and -regression methods. METHODS A systematic search was performed in Ovid MEDLINE and Embase for primary reports on infantile spasms incidence and prevalence epidemiology. RESULTS One thousand fifteen studies were screened to yield 54 eligible publications, from which 39 incidence figures and 18 prevalence figures were extracted. The pooled incidence was 0.249 cases/1000 live births. The pooled prevalence was 0.015 cases/1000 population. Univariate meta-regression determined a continental effect, with Europe demonstrating the highest onset compared from Asia (OR = 0.51, p = 0.004) and from North America (OR = 0.50, p = 0.004). Latitude was also positively correlated with incidence globally (OR = 1.02, p < 0.001). Sub-analyses determined a particularly elevated Scandinavian incidence compared to the rest of world (OR = 1.88, p < 0.001), and lack of latitudinal effect with Scandinavian exclusion (p = 0.10). Metrics of healthcare quality did not predict incidence. Multiple meta-regression determined that latitude was the key predictor of incidence (OR = 1.02, p = 0.001). CONCLUSIONS This is the first systematic epidemiological study of infantile spasms. Limitations included lack of Southern hemispheric representation, insufficient study selection and size to support some sub-continental analyses, and lack of accessible ethnic and healthcare quality data. Meta-analyses determined a novel, true geographical difference in incidence which is consistent with a latitudinal and/or ethnic contribution to epileptogenesis. These findings justify the establishment of a global registry of infantile spasms epidemiology to promote future systematic studies, clarify risk factors, and expand understanding of the pathophysiology.
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Affiliation(s)
- Jason L. Jia
- Department of Medicine, University of Toronto, 190 Elizabeth Street R. Fraser Elliott Wing, Toronto, M5G 2C4 Canada
| | - Shiyi Chen
- Child Health Evaluative Sciences Research Program, SickKids Research Institute, The Hospital for Sick Children, Toronto, Canada
| | - Vishalini Sivarajah
- Department of Medicine, University of Toronto, 190 Elizabeth Street R. Fraser Elliott Wing, Toronto, M5G 2C4 Canada
| | - Derek Stephens
- Child Health Evaluative Sciences Research Program, SickKids Research Institute, The Hospital for Sick Children, Toronto, Canada
| | - Miguel A. Cortez
- Department of Pediatrics, Division of Neurology, University of Toronto, Toronto, Canada
- Neurosciences & Mental Health Program, Peter Gilgan Centre for Research and Learning, SickKids Research Institute, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8 Canada
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Gururaj S, Palmer EE, Sheehan GD, Kandula T, Macintosh R, Ying K, Morris P, Tao J, Dias KR, Zhu Y, Dinger ME, Cowley MJ, Kirk EP, Roscioli T, Sachdev R, Duffey ME, Bye A, Bhattacharjee A. A De Novo Mutation in the Sodium-Activated Potassium Channel KCNT2 Alters Ion Selectivity and Causes Epileptic Encephalopathy. Cell Rep 2018; 21:926-933. [PMID: 29069600 DOI: 10.1016/j.celrep.2017.09.088] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 06/12/2017] [Accepted: 09/26/2017] [Indexed: 12/31/2022] Open
Abstract
Early infantile epileptic encephalopathies (EOEE) are a debilitating spectrum of disorders associated with cognitive impairments. We present a clinical report of a KCNT2 mutation in an EOEE patient. The de novo heterozygous variant Phe240Leu SLICK was identified by exome sequencing and confirmed by Sanger sequencing. Phe240Leu rSlick and hSLICK channels were electrophysiologically, heterologously characterized to reveal three significant alterations to channel function. First, [Cl-]i sensitivity was reversed in Phe240Leu channels. Second, predominantly K+-selective WT channels were made to favor Na+ over K+ by Phe240Leu. Third, and consequent to altered ion selectivity, Phe240Leu channels had larger inward conductance. Further, rSlick channels induced membrane hyperexcitability when expressed in primary neurons, resembling the cellular seizure phenotype. Taken together, our results confirm that Phe240Leu is a "change-of-function" KCNT2 mutation, demonstrating unusual altered selectivity in KNa channels. These findings establish pathogenicity of the Phe240Leu KCNT2 mutation in the reported EOEE patient.
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Affiliation(s)
- Sushmitha Gururaj
- Pharmacology and Toxicology, University at Buffalo - The State University of New York, Buffalo, NY 14214, USA
| | - Elizabeth Emma Palmer
- Sydney Children's Hospital, Randwick, NSW 2031, Australia; University of New South Wales, Sydney, NSW 2031, Australia; Genetics of Learning Disability Service, Waratah, NSW 2298, Australia
| | - Garrett D Sheehan
- Pharmacology and Toxicology, University at Buffalo - The State University of New York, Buffalo, NY 14214, USA
| | - Tejaswi Kandula
- Sydney Children's Hospital, Randwick, NSW 2031, Australia; University of New South Wales, Sydney, NSW 2031, Australia
| | | | - Kevin Ying
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW 2298, Australia
| | - Paula Morris
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW 2298, Australia
| | - Jiang Tao
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW 2298, Australia
| | - Kerith-Rae Dias
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW 2298, Australia
| | - Ying Zhu
- Genetics of Learning Disability Service, Waratah, NSW 2298, Australia; SEALS Pathology, Randwick, NSW 2031, Australia
| | - Marcel E Dinger
- University of New South Wales, Sydney, NSW 2031, Australia; Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW 2298, Australia
| | - Mark J Cowley
- University of New South Wales, Sydney, NSW 2031, Australia; Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW 2298, Australia
| | - Edwin P Kirk
- Sydney Children's Hospital, Randwick, NSW 2031, Australia; University of New South Wales, Sydney, NSW 2031, Australia; SEALS Pathology, Randwick, NSW 2031, Australia
| | - Tony Roscioli
- Sydney Children's Hospital, Randwick, NSW 2031, Australia; University of New South Wales, Sydney, NSW 2031, Australia; SEALS Pathology, Randwick, NSW 2031, Australia
| | - Rani Sachdev
- Sydney Children's Hospital, Randwick, NSW 2031, Australia; University of New South Wales, Sydney, NSW 2031, Australia
| | - Michael E Duffey
- Physiology and Biophysics, University at Buffalo - The State University of New York, Buffalo, NY 14214, USA
| | - Ann Bye
- Sydney Children's Hospital, Randwick, NSW 2031, Australia; University of New South Wales, Sydney, NSW 2031, Australia
| | - Arin Bhattacharjee
- Pharmacology and Toxicology, University at Buffalo - The State University of New York, Buffalo, NY 14214, USA; Program for Neuroscience, University at Buffalo - The State University of New York, Buffalo, NY 14214, USA.
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5
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Palmer EE, Schofield D, Shrestha R, Kandula T, Macintosh R, Lawson JA, Andrews I, Sampaio H, Johnson AM, Farrar MA, Cardamone M, Mowat D, Elakis G, Lo W, Zhu Y, Ying K, Morris P, Tao J, Dias KR, Buckley M, Dinger ME, Cowley MJ, Roscioli T, Kirk EP, Bye A, Sachdev RK. Integrating exome sequencing into a diagnostic pathway for epileptic encephalopathy: Evidence of clinical utility and cost effectiveness. Mol Genet Genomic Med 2018; 6:186-199. [PMID: 29314763 PMCID: PMC5902395 DOI: 10.1002/mgg3.355] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/26/2017] [Accepted: 10/30/2017] [Indexed: 12/16/2022] Open
Abstract
Background Epileptic encephalopathies are a devastating group of neurological conditions in which etiological diagnosis can alter management and clinical outcome. Exome sequencing and gene panel testing can improve diagnostic yield but there is no cost‐effectiveness analysis of their use or consensus on how to best integrate these tests into clinical diagnostic pathways. Methods We conducted a retrospective cost‐effectiveness study comparing trio exome sequencing with a standard diagnostic approach, for a well‐phenotyped cohort of 32 patients with epileptic encephalopathy, who remained undiagnosed after “first‐tier” testing. Sensitivity analysis was included with a range of commercial exome and multigene panels. Results The diagnostic yield was higher for the exome sequencing (16/32; 50%) than the standard arm (2/32; 6.2%). The trio exome sequencing pathway was cost‐effective compared to the standard diagnostic pathway with a cost saving of AU$5,236 (95% confidence intervals $2,482; $9,784) per additional diagnosis; the standard pathway cost approximately 10 times more per diagnosis. Sensitivity analysis demonstrated that the majority of commercial exome sequencing and multigene panels studied were also cost‐effective. The clinical utility of all diagnoses was reported. Conclusion Our study supports the integration of exome sequencing and gene panel testing into the diagnostic pathway for epileptic encephalopathy, both in terms of cost effectiveness and clinical utility. We propose a diagnostic pathway that integrates initial rapid screening for treatable causes and comprehensive genomic screening. This study has important implications for health policy and public funding for epileptic encephalopathy and other neurological conditions.
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Affiliation(s)
- Elizabeth E Palmer
- Sydney Children's Hospital, Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia.,Genetics of Learning Disability Service, Waratah, NSW, Australia.,The Garvan Institute for Medical Research, Darlinghurst, Sydney, NSW, Australia
| | - Deborah Schofield
- The Garvan Institute for Medical Research, Darlinghurst, Sydney, NSW, Australia.,Faculty of Pharmacy, The University of Sydney, Sydney, NSW, Australia.,The Murdoch Children's Research Institute, Melbourne, Vic., Australia
| | - Rupendra Shrestha
- Faculty of Pharmacy, The University of Sydney, Sydney, NSW, Australia
| | - Tejaswi Kandula
- Sydney Children's Hospital, Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia
| | | | - John A Lawson
- Sydney Children's Hospital, Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia
| | - Ian Andrews
- Sydney Children's Hospital, Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia
| | - Hugo Sampaio
- Sydney Children's Hospital, Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia
| | - Alexandra M Johnson
- Sydney Children's Hospital, Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia
| | - Michelle A Farrar
- Sydney Children's Hospital, Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia
| | - Michael Cardamone
- Sydney Children's Hospital, Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia
| | - David Mowat
- Sydney Children's Hospital, Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia
| | | | - William Lo
- SEALS pathology, Randwick, NSW, Australia
| | - Ying Zhu
- Genetics of Learning Disability Service, Waratah, NSW, Australia.,SEALS pathology, Randwick, NSW, Australia
| | - Kevin Ying
- The Garvan Institute for Medical Research, Darlinghurst, Sydney, NSW, Australia
| | - Paula Morris
- The Garvan Institute for Medical Research, Darlinghurst, Sydney, NSW, Australia
| | - Jiang Tao
- The Garvan Institute for Medical Research, Darlinghurst, Sydney, NSW, Australia.,St Vincent's Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Kerith-Rae Dias
- The Garvan Institute for Medical Research, Darlinghurst, Sydney, NSW, Australia
| | | | - Marcel E Dinger
- The Garvan Institute for Medical Research, Darlinghurst, Sydney, NSW, Australia.,St Vincent's Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Mark J Cowley
- The Garvan Institute for Medical Research, Darlinghurst, Sydney, NSW, Australia.,St Vincent's Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Tony Roscioli
- Sydney Children's Hospital, Randwick, NSW, Australia.,SEALS pathology, Randwick, NSW, Australia
| | - Edwin P Kirk
- Sydney Children's Hospital, Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia.,SEALS pathology, Randwick, NSW, Australia
| | - Ann Bye
- Sydney Children's Hospital, Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia
| | - Rani K Sachdev
- Sydney Children's Hospital, Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia
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Martin HC, Kim GE, Pagnamenta AT, Murakami Y, Carvill GL, Meyer E, Copley RR, Rimmer A, Barcia G, Fleming MR, Kronengold J, Brown MR, Hudspith KA, Broxholme J, Kanapin A, Cazier JB, Kinoshita T, Nabbout R, Bentley D, McVean G, Heavin S, Zaiwalla Z, McShane T, Mefford HC, Shears D, Stewart H, Kurian MA, Scheffer IE, Blair E, Donnelly P, Kaczmarek LK, Taylor JC. Clinical whole-genome sequencing in severe early-onset epilepsy reveals new genes and improves molecular diagnosis. Hum Mol Genet 2014; 23:3200-11. [PMID: 24463883 PMCID: PMC4030775 DOI: 10.1093/hmg/ddu030] [Citation(s) in RCA: 188] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 01/20/2014] [Indexed: 11/13/2022] Open
Abstract
In severe early-onset epilepsy, precise clinical and molecular genetic diagnosis is complex, as many metabolic and electro-physiological processes have been implicated in disease causation. The clinical phenotypes share many features such as complex seizure types and developmental delay. Molecular diagnosis has historically been confined to sequential testing of candidate genes known to be associated with specific sub-phenotypes, but the diagnostic yield of this approach can be low. We conducted whole-genome sequencing (WGS) on six patients with severe early-onset epilepsy who had previously been refractory to molecular diagnosis, and their parents. Four of these patients had a clinical diagnosis of Ohtahara Syndrome (OS) and two patients had severe non-syndromic early-onset epilepsy (NSEOE). In two OS cases, we found de novo non-synonymous mutations in the genes KCNQ2 and SCN2A. In a third OS case, WGS revealed paternal isodisomy for chromosome 9, leading to identification of the causal homozygous missense variant in KCNT1, which produced a substantial increase in potassium channel current. The fourth OS patient had a recessive mutation in PIGQ that led to exon skipping and defective glycophosphatidyl inositol biosynthesis. The two patients with NSEOE had likely pathogenic de novo mutations in CBL and CSNK1G1, respectively. Mutations in these genes were not found among 500 additional individuals with epilepsy. This work reveals two novel genes for OS, KCNT1 and PIGQ. It also uncovers unexpected genetic mechanisms and emphasizes the power of WGS as a clinical tool for making molecular diagnoses, particularly for highly heterogeneous disorders.
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Affiliation(s)
- Hilary C Martin
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Grace E Kim
- Departments of Cellular and Molecular Physiology and Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Alistair T Pagnamenta
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK, NIHR Biomedical Research Centre, Oxford, UK
| | - Yoshiko Murakami
- Department of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Gemma L Carvill
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA, USA
| | - Esther Meyer
- Neurosciences Unit, UCL-Institute of Child Health, London, UK, Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Richard R Copley
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK, NIHR Biomedical Research Centre, Oxford, UK
| | - Andrew Rimmer
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Giulia Barcia
- Department of Paediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Paris, France
| | - Matthew R Fleming
- Departments of Cellular and Molecular Physiology and Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Jack Kronengold
- Departments of Cellular and Molecular Physiology and Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Maile R Brown
- Departments of Cellular and Molecular Physiology and Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Karl A Hudspith
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK, NIHR Biomedical Research Centre, Oxford, UK
| | - John Broxholme
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Alexander Kanapin
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | | | - Taroh Kinoshita
- Department of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Rima Nabbout
- Department of Paediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Paris, France
| | | | - Gil McVean
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Sinéad Heavin
- Departments of Medicine and Paediatrics, Florey Institute, The University of Melbourne, Austin Health and Royal Children's Hospital, Melbourne, VIC, Australia
| | - Zenobia Zaiwalla
- Department of Clinical Neurophysiology, John Radcliffe Hospital, Oxford, UK
| | - Tony McShane
- Department of Paediatrics, Children's Hospital Oxford, John Radcliffe Hospital, Oxford, UK
| | - Heather C Mefford
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA, USA
| | - Deborah Shears
- Department of Clinical Genetics, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Helen Stewart
- Department of Clinical Genetics, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Manju A Kurian
- Neurosciences Unit, UCL-Institute of Child Health, London, UK
| | - Ingrid E Scheffer
- Departments of Medicine and Paediatrics, Florey Institute, The University of Melbourne, Austin Health and Royal Children's Hospital, Melbourne, VIC, Australia
| | - Edward Blair
- Department of Clinical Genetics, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Peter Donnelly
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Leonard K Kaczmarek
- Departments of Cellular and Molecular Physiology and Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Jenny C Taylor
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK, NIHR Biomedical Research Centre, Oxford, UK,
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Chiyonobu T, Inoue N, Morimoto M, Kinoshita T, Murakami Y. Glycosylphosphatidylinositol (GPI) anchor deficiency caused by mutations in PIGW is associated with West syndrome and hyperphosphatasia with mental retardation syndrome. J Med Genet 2013; 51:203-7. [PMID: 24367057 DOI: 10.1136/jmedgenet-2013-102156] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Glycosylphosphatidylinositol (GPI) is a glycolipid that anchors 150 or more kinds of proteins to the human cell surface. There are at least 26 genes involved in the biosynthesis and remodelling of GPI anchored proteins (GPI-APs). Recently, inherited GPI deficiencies (IGDs) were reported which cause intellectual disability often accompanied by epilepsy, coarse facial features and multiple anomalies that vary in severity depending upon the degree of defect and/or step in the pathway of affected gene. METHODS AND RESULTS A patient born to non-consanguineous parents developed intractable seizures with typical hypsarrhythmic pattern in electroencephalography, and was diagnosed as having West syndrome. Because the patient showed severe developmental delay with dysmorphic facial features and hyperphosphatasia, characteristics often seen in IGDs, the patient was tested for GPI deficiency. The patient had decreased surface expression of GPI-APs on blood granulocytes and was identified to be compound heterozygous for NM_178517:c.211A>C and c.499A>G mutations in PIGW by targeted sequencing. CONCLUSION Here we describe the first patient with deficiency of PIGW, which is involved in the addition of the acyl-chain to inositol in an early step of GPI biosynthesis. Therefore, IGD should be considered in West syndrome and flow cytometric analysis of blood cells is effective in screening IGD.
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Affiliation(s)
- Tomohiro Chiyonobu
- Department of Pediatrics, Kyoto Prefectural University of Medicine, Kamigyo, Kyoto, Japan
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