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Daniels C, Greene C, Smith L, Pestana-Knight E, Demarest S, Zhang B, Benke TA, Poduri A, Olson H. CDKL5 deficiency disorder and other infantile-onset genetic epilepsies. Dev Med Child Neurol 2024; 66:456-468. [PMID: 37771170 PMCID: PMC10922313 DOI: 10.1111/dmcn.15747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 07/25/2023] [Accepted: 08/02/2023] [Indexed: 09/30/2023]
Abstract
AIM To differentiate phenotypic features of individuals with CDKL5 deficiency disorder (CDD) from those of individuals with other infantile-onset epilepsies. METHOD We performed a retrospective cohort study and ascertained individuals with CDD and comparison individuals with infantile-onset epilepsy who had epilepsy gene panel testing. We reviewed records, updated variant classifications, and compared phenotypic features. Wilcoxon rank-sum tests and χ2 or Fisher's exact tests were performed for between-cohort comparisons. RESULTS We identified 137 individuals with CDD (110 females, 80.3%; median age at last follow-up 3 year 11 months) and 313 individuals with infantile-onset epilepsies (156 females, 49.8%; median age at last follow-up 5 years 2 months; 35% with genetic diagnosis). Features reported significantly more frequently in the CDD group than in the comparison cohort included developmental and epileptic encephalopathy (81% vs 66%), treatment-resistant epilepsy (95% vs 71%), sequential seizures (46% vs 6%), epileptic spasms (66% vs 42%, with hypsarrhythmia in 30% vs 48%), regression (52% vs 29%), evolution to Lennox-Gastaut syndrome (23% vs 5%), diffuse hypotonia (72% vs 36%), stereotypies (69% vs 11%), paroxysmal movement disorders (29% vs 17%), cerebral visual impairment (94% vs 28%), and failure to thrive (38% vs 22%). INTERPRETATION CDD, compared with other suspected or confirmed genetic epilepsies presenting in the first year of life, is more often characterized by a combination of treatment-resistant epilepsy, developmental and epileptic encephalopathy, sequential seizures, spasms without hypsarrhythmia, diffuse hypotonia, paroxysmal movement disorders, cerebral visual impairment, and failure to thrive. Defining core phenotypic characteristics will improve precision diagnosis and treatment.
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Affiliation(s)
- Carolyn Daniels
- Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
| | - Caitlin Greene
- Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
| | - Lacey Smith
- Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
| | - Elia Pestana-Knight
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Scott Demarest
- Children’s Hospital Colorado, Aurora, CO, USA
- Department of Pediatrics, University of Colorado, School of Medicine, Aurora, CO, USA
| | - Bo Zhang
- Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
| | - Timothy A Benke
- Children’s Hospital Colorado, Aurora, CO, USA
- Department of Pediatrics, University of Colorado, School of Medicine, Aurora, CO, USA
- Department of Pharmacology, University of Colorado, School of Medicine, Aurora, CO, USA
- Department of Neurology, University of Colorado, School of Medicine, Aurora, CO, USA
- Department of Otolaryngology, University of Colorado, School of Medicine, Aurora, CO, USA
| | - Annapurna Poduri
- Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
- Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Heather Olson
- Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
- Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Department of Neurology, Boston Children’s Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
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Abreo TJ, Thompson EC, Madabushi A, Soh H, Varghese N, Vanoye CG, Springer K, Park KL, Johnson J, Sims S, Ji Z, Chavez AG, Jankovic MJ, Habte B, Zuberi A, Lutz C, Wang Z, Krishnan V, Dudler L, Einsele-Scholz S, Noebels JL, George AL, Maheshwari A, Tzingounis AV, Cooper EC. Plural molecular and cellular mechanisms of pore domain KCNQ2 encephalopathy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.04.574177. [PMID: 38260608 PMCID: PMC10802467 DOI: 10.1101/2024.01.04.574177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
KCNQ2 variants in children with neurodevelopmental impairment are difficult to assess due to their heterogeneity and unclear pathogenic mechanisms. We describe a child with neonatal-onset epilepsy, developmental impairment of intermediate severity, and KCNQ2 G256W heterozygosity. Analyzing prior KCNQ2 channel cryoelectron microscopy models revealed G256 as keystone of an arch-shaped non-covalent bond network linking S5, the pore turret, and the ion path. Co-expression with G256W dominantly suppressed conduction by wild-type subunits in heterologous cells. Ezogabine partly reversed this suppression. G256W/+ mice have epilepsy leading to premature deaths. Hippocampal CA1 pyramidal cells from G256W/+ brain slices showed hyperexcitability. G256W/+ pyramidal cell KCNQ2 and KCNQ3 immunolabeling was significantly shifted from axon initial segments to neuronal somata. Despite normal mRNA levels, G256W/+ mouse KCNQ2 protein levels were reduced by about 50%. Our findings indicate that G256W pathogenicity results from multiplicative effects, including reductions in intrinsic conduction, subcellular targeting, and protein stability. These studies reveal pore "turret arch" bonding as a KCNQ structural novelty and introduce a valid animal model of KCNQ2 encephalopathy. Our results, spanning structure to behavior, may be broadly applicable because the majority of KCNQ2 encephalopathy patients share variants near the selectivity filter.
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Affiliation(s)
- Timothy J Abreo
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Emma C Thompson
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Anuraag Madabushi
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Heun Soh
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - Nissi Varghese
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - Carlos G Vanoye
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Kristen Springer
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - Kristen L Park
- Department of Pediatrics, Childrens Colorado, University of Colorado, Aurora, CO, USA
- Department of Neurology, Childrens Colorado, University of Colorado, Aurora, CO, USA
| | | | | | - Zhigang Ji
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Ana G Chavez
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | | | - Bereket Habte
- Department of Pediatrics, Childrens Colorado, University of Colorado, Aurora, CO, USA
- Department of Neurology, Childrens Colorado, University of Colorado, Aurora, CO, USA
| | - Aamir Zuberi
- The Rare Disease Translational Center, Jackson Laboratory, Bar Harbor, ME, USA
| | - Cathleen Lutz
- The Rare Disease Translational Center, Jackson Laboratory, Bar Harbor, ME, USA
| | - Zhao Wang
- Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, USA
- CryoEM Core, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Vaishnav Krishnan
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX, USA
| | - Lisa Dudler
- Center for Human Genetics Tübingen, Tübingen, Germany
| | | | - Jeffrey L Noebels
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Alfred L George
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Atul Maheshwari
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | | | - Edward C Cooper
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
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3
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Bayat A, Iavarone S, Miceli F, Jakobsen AV, Johannesen KM, Nikanorova M, Ploski R, Szymanska K, Flamini R, Cooper EC, Weckhuysen S, Taglialatela M, Møller RS. Phenotypic and functional assessment of two novel KCNQ2 gain-of-function variants Y141N and G239S and effects of amitriptyline treatment. Neurotherapeutics 2024; 21:e00296. [PMID: 38241158 PMCID: PMC10903081 DOI: 10.1016/j.neurot.2023.10.006] [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: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 01/21/2024] Open
Abstract
While loss-of-function (LoF) variants in KCNQ2 are associated with a spectrum of neonatal-onset epilepsies, gain-of-function (GoF) variants cause a more complex phenotype that precludes neonatal-onset epilepsy. In the present work, the clinical features of three patients carrying a de novo KCNQ2 Y141N (n = 1) or G239S variant (n = 2) respectively, are described. All three patients had a mild global developmental delay, with prominent language deficits, and strong activation of interictal epileptic activity during sleep. Epileptic seizures were not reported. The absence of neonatal seizures suggested a GoF effect and prompted functional testing of the variants. In vitro whole-cell patch-clamp electrophysiological experiments in Chinese Hamster Ovary cells transiently-transfected with the cDNAs encoding Kv7.2 subunits carrying the Y141N or G239S variants in homomeric or heteromeric configurations with Kv7.2 subunits, revealed that currents from channels incorporating mutant subunits displayed increased current densities and hyperpolarizing shifts of about 10 mV in activation gating; both these functional features are consistent with an in vitro GoF phenotype. The antidepressant drug amitriptyline induced a reversible and concentration-dependent inhibition of current carried by Kv7.2 Y141N and G239S mutant channels. Based on in vitro results, amitriptyline was prescribed in one patient (G239S), prompting a significant improvement in motor, verbal, social, sensory and adaptive behavior skillsduring the two-year-treatment period. Thus, our results suggest that KCNQ2 GoF variants Y141N and G239S cause a mild DD with prominent language deficits in the absence of neonatal seizures and that treatment with the Kv7 channel blocker amitriptyline might represent a potential targeted treatment for patients with KCNQ2 GoF variants.
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Affiliation(s)
- Allan Bayat
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Center, Filadelfia, Dianalund, Denmark; Department for Regional Health Research, University of Southern Denmark, Odense, Denmark; Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
| | - Stefano Iavarone
- Section of Pharmacology, Department of Neuroscience, University of Naples "Federico II", Naples, Italy
| | - Francesco Miceli
- Section of Pharmacology, Department of Neuroscience, University of Naples "Federico II", Naples, Italy
| | - Anne V Jakobsen
- Department of Pediatrics, Danish Epilepsy Center, Filadelfia, Dianalund, Denmark
| | - Katrine M Johannesen
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Center, Filadelfia, Dianalund, Denmark; Department of Genetics, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Marina Nikanorova
- Department of Pediatrics, Danish Epilepsy Center, Filadelfia, Dianalund, Denmark
| | - Rafal Ploski
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
| | - Krystyna Szymanska
- Department of Pediatric Neurology, Medical University of Warsaw, Warsaw, Poland
| | | | - Edward C Cooper
- Departments of Neurology, Neuroscience, and Molecular and Human Genetics, Baylor College of Medicine, Houston TX, USA
| | - Sarah Weckhuysen
- Applied and Translational Genomics Group, VIB-Center for Molecular Neurology, VIB, University of Antwerp, Antwerp, Belgium; Neurology Department, University Hospital Antwerp, Antwerp, Belgium; Translational Neurosciences, Faculty of Medicine and Health Science, University of Antwerp, Antwerp, Belgium; μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Maurizio Taglialatela
- Section of Pharmacology, Department of Neuroscience, University of Naples "Federico II", Naples, Italy
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Center, Filadelfia, Dianalund, Denmark; Department for Regional Health Research, University of Southern Denmark, Odense, Denmark
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Zahra A, Liu R, Wang J, Wu J. Identifying the mechanism of action of the Kv7 channel opener, retigabine in the treatment of epilepsy. Neurol Sci 2023; 44:3819-3825. [PMID: 37442907 DOI: 10.1007/s10072-023-06955-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 07/06/2023] [Indexed: 07/15/2023]
Abstract
Epilepsy is characterized by recurrent epileptic seizures caused by high levels of neuronal excitability in the brain. Voltage-sensitive K+ channels (Kv) of the Kv7 (KCNQ) family encoded by the KCNQ gene are involved in a wide range of cellular processes, i.e., KCNQ2 and KCNQ3 channels mediate M-currents to inhibit neuronal excitability and reduce transmitter release throughout the nervous system. Thus, as a positive allosteric modulator (or opener) of KCNQ channels, retigabine has been the only clinically approved anti-seizure medication that acts on the KCNQ channels. This review discusses the biochemical mechanisms about how retigabine acts on Kv7 channels, significance in neuronal pathophysiology, preclinical efficacy, and clinical stage of development. Additional efforts are being made to emphasize the possible benefits and drawbacks of retigabine compared to currently available medications for treatment-resistant epilepsy.
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Affiliation(s)
- Aqeela Zahra
- Hubei Key Laboratory of Nanomedicine for Neurodegenerative Diseases, School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, 122 Loushi Rd, Wuhan, 430070, China
- Department of Zoology, University of Sialkot, Sialkot, 51310, Pakistan
| | - Ru Liu
- Beijing Tiantan Hospital, Capital Medical University, Beijing, 100070, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, 100070, China
- National Clinical Research Center for Neurological Disease, Beijing, 100070, China
| | - Jingjing Wang
- Hubei Key Laboratory of Nanomedicine for Neurodegenerative Diseases, School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, 122 Loushi Rd, Wuhan, 430070, China
| | - Jianping Wu
- Hubei Key Laboratory of Nanomedicine for Neurodegenerative Diseases, School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, 122 Loushi Rd, Wuhan, 430070, China.
- Beijing Tiantan Hospital, Capital Medical University, Beijing, 100070, China.
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, 100070, China.
- National Clinical Research Center for Neurological Disease, Beijing, 100070, China.
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5
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Dogaru CB, Duță C, Muscurel C, Stoian I. "Alphabet" Selenoproteins: Implications in Pathology. Int J Mol Sci 2023; 24:15344. [PMID: 37895024 PMCID: PMC10607139 DOI: 10.3390/ijms242015344] [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: 09/15/2023] [Revised: 10/08/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
Selenoproteins are a group of proteins containing selenium in the form of selenocysteine (Sec, U) as the 21st amino acid coded in the genetic code. Their synthesis depends on dietary selenium uptake and a common set of cofactors. Selenoproteins accomplish diverse roles in the body and cell processes by acting, for example, as antioxidants, modulators of the immune function, and detoxification agents for heavy metals, other xenobiotics, and key compounds in thyroid hormone metabolism. Although the functions of all this protein family are still unknown, several disorders in their structure, activity, or expression have been described by researchers. They concluded that selenium or cofactors deficiency, on the one hand, or the polymorphism in selenoproteins genes and synthesis, on the other hand, are involved in a large variety of pathological conditions, including type 2 diabetes, cardiovascular, muscular, oncological, hepatic, endocrine, immuno-inflammatory, and neurodegenerative diseases. This review focuses on the specific roles of selenoproteins named after letters of the alphabet in medicine, which are less known than the rest, regarding their implications in the pathological processes of several prevalent diseases and disease prevention.
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Affiliation(s)
| | | | - Corina Muscurel
- Department of Biochemistry, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania (I.S.)
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6
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Zhao R, Zhang L, Lu H. Analysis of the Clinical Features and Imaging Findings of Pontocerebellar Hypoplasia Type 2D Caused by Mutations in SEPSECS Gene. CEREBELLUM (LONDON, ENGLAND) 2023; 22:938-946. [PMID: 36085396 DOI: 10.1007/s12311-022-01470-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/25/2022] [Indexed: 06/15/2023]
Abstract
Pontocerebellar hypoplasia type 2D (PCH2D) caused by SEPSECS gene mutations is very rare and only described in a few case reports. In this study, we analyzed the clinical features and imaging findings of these individuals, so as to provide references for the clinic. We reported a case of PCH2D caused by a new complex heterozygote mutation in SEPSECS gene, and reviewed the literatures to summarize the clinical features and imaging findings and compare the differences between early-onset patients (EOPs) and late-onset patients (LOPs). Of 23 PCH2D patients, 19 cases were early-onset and 4 cases were late-onset, with average ages of 4.1 ± 4.0 years and 21.8 ± 9.4 years, females were more prevalent (14/19). EOPs mainly distributed in Arab countries (10/14) and Finland (4/14), while LOPs in East Asia (3/3). EOPs develop severe initial symptoms at the average age of 4.1 ± 7.8 months or shortly after birth, while LOPs experienced mild developmental delay in infancy. Microcephaly (10/11), intellectual disability (10/11), decreased motor function (10/11), and spastic or dystonic quadriplegia (8/10) were the common clinical features of EOPs and LOPs. EOPs also presented with visual impairment (5/7), seizures (4/7), neonatal irritability/opisthotonus (3/7), tremors/myoclonus (3/7), dysmorphic features (3/7), and other symptoms. EOPs were characterized by cerebellar symptoms (4/4). Magnetic resonance imaging (MRI) revealed progressive cerebellar atrophy followed by less pronounced cerebral atrophy, and there was no pons atrophy in LOPs. Most patients of PCH2D were severe early-onset, and a few were late-onset with milder symptoms. EOPs and LOPs shared some common clinical features and MRI findings, but also had their own characteristics.
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Affiliation(s)
- Ran Zhao
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Limin Zhang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Hong Lu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.
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Cheng H, Miao P, Wang Y, Guo Y, Gao L, Lou Y, Yang F, Liang M, Feng J. A Heterozygous Variant of FGF13 Caused X-Linked Developmental and Epileptic Encephalopathy 90 in a Chinese Family. Cytogenet Genome Res 2023; 163:36-41. [PMID: 37536293 DOI: 10.1159/000531932] [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: 11/23/2022] [Accepted: 04/25/2023] [Indexed: 08/05/2023] Open
Abstract
Developmental and epileptic encephalopathy (DEE) refers to a group of severe epilepsy encephalopathy and development disorders, and its typical clinical features include seizures, drug resistance, and developmental delay or regression. To date, limited studies have reported DEEs driven by FGF13. Here, we reported a girl with developmental and epileptic encephalopathy 90 caused by variant of FGF13. Her electroencephalogram (EEG) showed discontinuous hypsarrhythmia, and a heterozygous nonsynonymous variant in FGF13 [NM_004114.4: c.5C>G, p.(Ala2Gly)] was identified from the proband. The variant was not reported in public databases such as gnomAD and Exome Aggregation Consortium (ExAC), and was predicted to be damaging to proteins and classified as likely pathogenic according to the ACMG guidelines. The seizure was finally controlled by a combination of ACTH + zonisamide (10 mg/kg.d) + levetiracetam (52 mg/kg.d) + clonazepam (0.7 mg/kg.d).
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Affiliation(s)
- Haiying Cheng
- Department of Paediatrics, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Pu Miao
- Department of Paediatrics, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Ye Wang
- Department of Paediatrics, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yufan Guo
- Department of Paediatrics, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Liuyan Gao
- Department of Paediatrics, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yuting Lou
- Department of Paediatrics, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | | | | | - Jianhua Feng
- Department of Paediatrics, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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Okamura Y, Yoshioka D. What voltage-sensing phosphatases can reveal about the mechanisms of ion channel regulation by phosphoinositides. Biochem Soc Trans 2023; 51:827-839. [PMID: 37052219 DOI: 10.1042/bst20221065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/20/2023] [Accepted: 03/30/2023] [Indexed: 04/14/2023]
Abstract
Many membrane proteins including ion channels and ion transporters are regulated by membrane phospholipids such as phosphoinositides in cell membranes and organelles. Voltage-sensing phosphatase, VSP, is a voltage-sensitive phosphoinositide phosphatase which dephosphorylates PI(4,5)P2 into PI(4)P. VSP rapidly reduces the level of PI(4,5)P2 upon membrane depolarization, thus serving as a useful tool to quantitatively study phosphoinositide-regulation of ion channels and ion transporters using a cellular electrophysiology system. In this review, we focus on the application of VSPs to Kv7 family potassium channels, which have been important research targets in biophysics, pharmacology and medicine.
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Affiliation(s)
- Yasushi Okamura
- Laboratory of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Yamada Oka 2-2, Suita, Osaka 565-0871, Japan
| | - Daisuke Yoshioka
- Laboratory of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University, Yamada Oka 2-2, Suita, Osaka 565-0871, Japan
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Boonsimma P, Ittiwut C, Kamolvisit W, Ittiwut R, Chetruengchai W, Phokaew C, Srichonthong C, Poonmaksatit S, Desudchit T, Suphapeetiporn K, Shotelersuk V. Exome sequencing as first-tier genetic testing in infantile-onset pharmacoresistant epilepsy: diagnostic yield and treatment impact. Eur J Hum Genet 2023; 31:179-187. [PMID: 36198807 PMCID: PMC9905506 DOI: 10.1038/s41431-022-01202-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 09/06/2022] [Accepted: 09/20/2022] [Indexed: 11/09/2022] Open
Abstract
Pharmacoresistant epilepsy presenting during infancy poses both diagnostic and therapeutic challenges. We aim to identify diagnostic yield and treatment implications of exome sequencing (ES) as first-tier genetic testing for infantile-onset pharmacoresistant epilepsy. From June 2016 to December 2020, we enrolled patients with infantile-onset (age ≤ 12 months) pharmacoresistant epilepsy. 103 unrelated patients underwent ES. Clinical characteristics and changes in management due to the molecular diagnosis were studied. 42% (43/103) had epilepsy onset within the first month of life. After ES as first-tier genetic testing, 62% (64/103) of the cases were solved. Two partially solved cases (2%; 2/103) with heterozygous variants identified in ALDH7A1 known to cause autosomal recessive pyridoxine dependent epilepsy underwent genome sequencing (GS). Two novel large deletions in ALDH7A1 were detected in both cases. ES identified 66 pathogenic and likely pathogenic single nucleotide variants (SNVs) in 27 genes. 19 variants have not been previously reported. GS identified two additional copy number variations (CNVs). The most common disease-causing genes are SCN1A (13%; 13/103) and KCNQ2 (8%; 8/103). Eight percent (8/103) of the patients had treatable disorders and specific treatments were provided resulting in seizure freedom. Pyridoxine dependent epilepsy was the most common treatable epilepsy (6%; 6/103). Furthermore, 35% (36/103) had genetic defects which guided gene-specific treatments. Altogether, the diagnostic yield is 64%. Molecular diagnoses change management in 43% of the cases. This study substantiates the use of next generation sequencing (NGS) as the first-tier genetic investigation in infantile-onset pharmacoresistant epilepsy.
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Affiliation(s)
- Ponghatai Boonsimma
- Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Chupong Ittiwut
- Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Wuttichart Kamolvisit
- Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Rungnapa Ittiwut
- Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Wanna Chetruengchai
- Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Chureerat Phokaew
- Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Chalurmpon Srichonthong
- Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Sathida Poonmaksatit
- Division of Neurology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Tayard Desudchit
- Division of Neurology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Kanya Suphapeetiporn
- Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand.
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, 10330, Thailand.
| | - Vorasuk Shotelersuk
- Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, 10330, Thailand
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10
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Haviland I, Daniels CI, Greene CA, Drew J, Love-Nichols JA, Swanson LC, Smith L, Nie DA, Benke T, Sheidley BR, Zhang B, Poduri A, Olson HE. Genetic Diagnosis Impacts Medical Management for Pediatric Epilepsies. Pediatr Neurol 2023; 138:71-80. [PMID: 36403551 PMCID: PMC10099530 DOI: 10.1016/j.pediatrneurol.2022.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 10/05/2022] [Accepted: 10/19/2022] [Indexed: 11/18/2022]
Abstract
BACKGROUND Evidence of the impact of genetic diagnosis on medical management in individuals with previously unexplained epilepsy is lacking in the literature. Our goal was to determine the impact of genetic diagnosis on medical management in a cohort of individuals with early-onset epilepsy. METHODS We performed detailed phenotyping of individuals with epilepsy who underwent clinical genetic testing with an epilepsy panel and/or exome sequencing at Boston Children's Hospital between 2012 and 2019. We assessed the impact of genetic diagnosis on medical management. RESULTS We identified a genetic etiology in 152 of 602 (25%) individuals with infantile- or childhood-onset epilepsy who underwent next-generation sequencing. Diagnosis impacted medical management in at least one category for 72% of patients (110 of 152) and in more than one category in 34%. Treatment was impacted in 45% of individuals, including 36% with impact on antiseizure medication choice, 7% on use of disease-specific vitamin or metabolic treatments, 3% on pathway-driven off-label use of medications, and 10% on discussion of gene-specific clinical trials. Care coordination was impacted in 48% of individuals. Counseling on a change in prognosis was reported in 28% of individuals, and 1% of individuals had a correction of diagnosis. Impact was documented in 13 of 13 individuals with neurotypical development and in 55% of those with epilepsy onset after age two years. CONCLUSION We demonstrated meaningful impact of genetic diagnosis on medical care and prognosis in over 70% of individuals, including those with neurotypical development and age of epilepsy onset after age two years.
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Affiliation(s)
- Isabel Haviland
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Carolyn I Daniels
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Caitlin A Greene
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Jacqueline Drew
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts; Boston University Clinical Investigation Master's Program, Boston, Massachusetts
| | - Jamie A Love-Nichols
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts; Department of Genetics, Seattle Children's Hospital, Seattle, Washington
| | - Lindsay C Swanson
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Lacey Smith
- Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Duyu A Nie
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts; Departments of Pediatrics, Neurology and Neurosurgery, Warren Alpert Medical School of Brown University, Providence, Rhode Island; Division of Pediatric Neurology and the Children's Neurodevelopment Center (CNDC), Hasbro Children's Hospital, Providence, Rhode Island
| | - Timothy Benke
- Departments of Pediatrics, Neurology, Pharmacology, and Otolaryngology, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, Colorado
| | - Beth R Sheidley
- Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Bo Zhang
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts; Biostatistics and Research Design Center, Institutional Centers for Clinical and Translational Research, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Annapurna Poduri
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts; Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Heather E Olson
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts; Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts.
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11
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Brun L, Viemari J, Villard L. Mouse models of Kcnq2 dysfunction. Epilepsia 2022; 63:2813-2826. [PMID: 36047730 PMCID: PMC9828481 DOI: 10.1111/epi.17405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 01/12/2023]
Abstract
Variants in the Kv7.2 channel subunit encoded by the KCNQ2 gene cause epileptic disorders ranging from a benign form with self-limited epileptic seizures and normal development to severe forms with intractable epileptic seizures and encephalopathy. The biological mechanisms involved in these neurological diseases are still unclear. The disease remains intractable in patients affected by the severe form. Over the past 20 years, KCNQ2 models have been developed to elucidate pathological mechanisms and to identify new therapeutic targets. The diversity of Kcnq2 mouse models has proven invaluable to access neuronal networks and evaluate the associated cognitive deficits. This review summarizes the available models and their contribution to our current understanding of KCNQ2 epileptic disorders.
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Affiliation(s)
- Lucile Brun
- Aix Marseille Univ, Inserm, MMGMarseilleFrance
| | | | - Laurent Villard
- Aix Marseille Univ, Inserm, MMGMarseilleFrance,Service de Génétique Médicale, AP‐HM, Hôpital de La TimoneMarseilleFrance
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12
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Syrbe S. Developmental and epileptic encephalopathies – therapeutic consequences of genetic testing. MED GENET-BERLIN 2022. [DOI: 10.1515/medgen-2022-2145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
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 , Heidelberg , Germany
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13
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The correlation between multiple congenital anomalies hypotonia seizures syndrome 2 and PIGA: a case of novel PIGA germline variant and literature review. Mol Biol Rep 2022; 49:10469-10477. [DOI: 10.1007/s11033-022-07614-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/14/2022] [Accepted: 05/17/2022] [Indexed: 11/29/2022]
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14
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Burns W, Chaudhari BP, Haffner DN. Neurogenetic and Metabolic Mimics of Common Neonatal Neurological Disorders. Semin Pediatr Neurol 2022; 42:100972. [PMID: 35868729 DOI: 10.1016/j.spen.2022.100972] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/05/2022] [Accepted: 04/05/2022] [Indexed: 10/18/2022]
Abstract
Neurogenetic and metabolic diseases often present in the neonatal period, masquerading as other disorders, most commonly as neonatal encephalopathy and seizures. Advancements in our understanding of inborn errors of metabolism are leading to an increasing number of therapeutic options. Many of these treatments can improve long-term neurodevelopment and seizure control. However, the treatments are frequently condition-specific. A high index of suspicion is required for prompt identification and treatment. When suspected, simultaneous metabolic and molecular testing are recommended along with concurrent treatment.
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Affiliation(s)
- William Burns
- Division of Genetics and Genomic Medicine, Nationwide Children's Hospital, Columbus, OH; Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH.
| | - Bimal P Chaudhari
- Division of Genetics and Genomic Medicine, Nationwide Children's Hospital, Columbus, OH; Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH; Division of Neonatology, Nationwide Children's Hospital, Columbus, OH; Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH
| | - Darrah N Haffner
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH; Division of Neurology, Nationwide Children's Hospital, Columbus, OH
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15
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Miceli F, Millevert C, Soldovieri MV, Mosca I, Ambrosino P, Carotenuto L, Schrader D, Lee HK, Riviello J, Hong W, Risen S, Emrick L, Amin H, Ville D, Edery P, de Bellescize J, Michaud V, Van-Gils J, Goizet C, Willemsen MH, Kleefstra T, Møller RS, Bayat A, Devinsky O, Sands T, Korenke GC, Kluger G, Mefford HC, Brilstra E, Lesca G, Milh M, Cooper EC, Taglialatela M, Weckhuysen S. KCNQ2 R144 variants cause neurodevelopmental disability with language impairment and autistic features without neonatal seizures through a gain-of-function mechanism. EBioMedicine 2022; 81:104130. [PMID: 35780567 PMCID: PMC9254340 DOI: 10.1016/j.ebiom.2022.104130] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 01/10/2023] Open
Abstract
Background Prior studies have revealed remarkable phenotypic heterogeneity in KCNQ2-related disorders, correlated with effects on biophysical features of heterologously expressed channels. Here, we assessed phenotypes and functional properties associated with KCNQ2 missense variants R144W, R144Q, and R144G. We also explored in vitro blockade of channels carrying R144Q mutant subunits by amitriptyline. Methods Patients were identified using the RIKEE database and through clinical collaborators. Phenotypes were collected by a standardized questionnaire. Functional and pharmacological properties of variant subunits were analyzed by whole-cell patch-clamp recordings. Findings Detailed clinical information on fifteen patients (14 novel and 1 previously published) was analyzed. All patients had developmental delay with prominent language impairment. R144Q patients were more severely affected than R144W patients. Infantile to childhood onset epilepsy occurred in 40%, while 67% of sleep-EEGs showed sleep-activated epileptiform activity. Ten patients (67%) showed autistic features. Activation gating of homomeric Kv7.2 R144W/Q/G channels was left-shifted, suggesting gain-of-function effects. Amitriptyline blocked channels containing Kv7.2 and Kv7.2 R144Q subunits. Interpretation Patients carrying KCNQ2 R144 gain-of-function variants have developmental delay with prominent language impairment, autistic features, often accompanied by infantile- to childhood-onset epilepsy and EEG sleep-activated epileptiform activity. The absence of neonatal seizures is a robust and important clinical differentiator between KCNQ2 gain-of-function and loss-of-function variants. The Kv7.2/7.3 channel blocker amitriptyline might represent a targeted treatment. Funding Supported by FWO, GSKE, KCNQ2-Cure, Jack Pribaz Foundation, European Joint Programme on Rare Disease 2020, the Italian Ministry for University and Research, the Italian Ministry of Health, the European Commission, the University of Antwerp, NINDS, and Chalk Family Foundation.
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16
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Leonard H, Downs J, Benke TA, Swanson L, Olson H, Demarest S. CDKL5 deficiency disorder: clinical features, diagnosis, and management. Lancet Neurol 2022; 21:563-576. [PMID: 35483386 PMCID: PMC9788833 DOI: 10.1016/s1474-4422(22)00035-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 12/19/2021] [Accepted: 01/18/2022] [Indexed: 12/25/2022]
Abstract
CDKL5 deficiency disorder (CDD) was first identified as a cause of human disease in 2004. Although initially considered a variant of Rett syndrome, CDD is now recognised as an independent disorder and classified as a developmental epileptic encephalopathy. It is characterised by early-onset (generally within the first 2 months of life) seizures that are usually refractory to polypharmacy. Development is severely impaired in patients with CDD, with only a quarter of girls and a smaller proportion of boys achieving independent walking; however, there is clinical variability, which is probably genetically determined. Gastrointestinal, sleep, and musculoskeletal problems are common in CDD, as in other developmental epileptic encephalopathies, but the prevalence of cerebral visual impairment appears higher in CDD. Clinicians diagnosing infants with CDD need to be familiar with the complexities of this disorder to provide appropriate counselling to the patients' families. Despite some benefit from ketogenic diets and vagal nerve stimulation, there has been little evidence that conventional antiseizure medications or their combinations are helpful in CDD, but further treatment trials are finally underway.
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Affiliation(s)
- Helen Leonard
- Telethon Kids Institute, The University of Western Australia, Perth, WA, Australia.
| | - Jenny Downs
- Telethon Kids Institute, The University of Western Australia, Perth, WA, Australia; Curtin School of Allied Health, Curtin University, Perth, WA, Australia
| | - Tim A Benke
- Department of Neurology, Children's Hospital Colorado, Aurora, CO, USA; Department of Pediatrics, University of Colorado at Denver, Aurora, CO, USA; Department of Pharmacology, University of Colorado at Denver, Aurora, CO, USA; Department of Neurology, University of Colorado at Denver, Aurora, CO, USA; Department of Otolaryngology, University of Colorado at Denver, Aurora, CO, USA
| | - Lindsay Swanson
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Heather Olson
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Scott Demarest
- Department of Neurology, Children's Hospital Colorado, Aurora, CO, USA; Department of Pediatrics, University of Colorado at Denver, Aurora, CO, USA; Department of Neurology, University of Colorado at Denver, Aurora, CO, USA
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17
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Zuberi SM, Wirrell E, Yozawitz E, Wilmshurst JM, Specchio N, Riney K, Pressler R, Auvin S, Samia P, Hirsch E, Galicchio S, Triki C, Snead OC, Wiebe S, Cross JH, Tinuper P, Scheffer IE, Perucca E, Moshé SL, Nabbout R. ILAE classification and definition of epilepsy syndromes with onset in neonates and infants: Position statement by the ILAE Task Force on Nosology and Definitions. Epilepsia 2022; 63:1349-1397. [PMID: 35503712 DOI: 10.1111/epi.17239] [Citation(s) in RCA: 197] [Impact Index Per Article: 98.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 03/20/2022] [Accepted: 03/21/2022] [Indexed: 12/20/2022]
Abstract
The International League Against Epilepsy (ILAE) Task Force on Nosology and Definitions proposes a classification and definition of epilepsy syndromes in the neonate and infant with seizure onset up to 2 years of age. The incidence of epilepsy is high in this age group and epilepsy is frequently associated with significant comorbidities and mortality. The licensing of syndrome specific antiseizure medications following randomized controlled trials and the development of precision, gene-related therapies are two of the drivers defining the electroclinical phenotypes of syndromes with onset in infancy. The principal aim of this proposal, consistent with the 2017 ILAE Classification of the Epilepsies, is to support epilepsy diagnosis and emphasize the importance of classifying epilepsy in an individual both by syndrome and etiology. For each syndrome, we report epidemiology, clinical course, seizure types, electroencephalography (EEG), neuroimaging, genetics, and differential diagnosis. Syndromes are separated into self-limited syndromes, where there is likely to be spontaneous remission and developmental and epileptic encephalopathies, diseases where there is developmental impairment related to both the underlying etiology independent of epileptiform activity and the epileptic encephalopathy. The emerging class of etiology-specific epilepsy syndromes, where there is a specific etiology for the epilepsy that is associated with a clearly defined, relatively uniform, and distinct clinical phenotype in most affected individuals as well as consistent EEG, neuroimaging, and/or genetic correlates, is presented. The number of etiology-defined syndromes will continue to increase, and these newly described syndromes will in time be incorporated into this classification. The tables summarize mandatory features, cautionary alerts, and exclusionary features for the common syndromes. Guidance is given on the criteria for syndrome diagnosis in resource-limited regions where laboratory confirmation, including EEG, MRI, and genetic testing, might not be available.
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Affiliation(s)
- Sameer M Zuberi
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Institute of Health & Wellbeing, Collaborating Centre of European Reference Network EpiCARE, University of Glasgow, Glasgow, UK
| | - Elaine Wirrell
- Divisions of Child and Adolescent Neurology and Epilepsy, Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | - Elissa Yozawitz
- Isabelle Rapin Division of Child Neurology, Saul R. Korey Department of Neurology, Montefiore Medical Center, Bronx, New York, USA
| | - Jo M Wilmshurst
- Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Nicola Specchio
- Rare and Complex Epilepsy Unit, Department of Neuroscience, Bambino Gesu' Children's Hospital, IRCCS, Member of European Reference Network EpiCARE, Rome, Italy
| | - Kate Riney
- Neurosciences Unit, Queensland Children's Hospital, South Brisbane, Queensland, Australia.,Faculty of Medicine, University of Queensland, St Lucia, Queensland, Australia
| | - Ronit Pressler
- Clinical Neuroscience, UCL- Great Ormond Street Institute of Child Health, London, UK.,Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children NHS Foundation Trust, Member of European Reference Network EpiCARE, London, UK
| | - Stephane Auvin
- AP-HP, Hôpital Robert-Debré, INSERM NeuroDiderot, DMU Innov-RDB, Neurologie Pédiatrique, Member of European Reference Network EpiCARE, Université de Paris, Paris, France
| | - Pauline Samia
- Department of Paediatrics and Child Health, Aga Khan University, Nairobi, Kenya
| | - Edouard Hirsch
- Neurology Epilepsy Unit "Francis Rohmer", INSERM 1258, FMTS, Strasbourg University, Strasbourg, France
| | - Santiago Galicchio
- Child Neurology Department, Victor J Vilela Child Hospital of Rosario, Santa Fe, Argentina
| | - Chahnez Triki
- Child Neurology Department, LR19ES15 Neuropédiatrie, Sfax Medical School, University of Sfax, Sfax, Tunisia
| | - O Carter Snead
- Pediatric Neurology, Hospital for Sick Children, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Samuel Wiebe
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - J Helen Cross
- Programme of Developmental Neurosciences, UCL NIHR BRC Great Ormond Street Institute of Child Health, Great Ormond Street Hospital for Children, Member of European Reference Network EpiCARE, London, UK.,Young Epilepsy, Lingfield, UK
| | - Paolo Tinuper
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche, Bologna, Italy
| | - Ingrid E Scheffer
- Austin Health and Royal Children's Hospital, Florey Institute, Murdoch Children's Research Institute, University of Melbourne, Melbourne, Victoria, Australia
| | - Emilio Perucca
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia.,Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Solomon L Moshé
- Isabelle Rapin Division of Child Neurology, Saul R. Korey Department of Neurology, Bronx, New York, USA.,Departments of Neuroscience and Pediatrics, Albert Einstein College of Medicine, Bronx, New York, USA.,Montefiore Medical Center, Bronx, New York, USA
| | - Rima Nabbout
- Reference Centre for Rare Epilepsies, Department of Pediatric Neurology, Necker-Enfants Malades University Hospital, APHP, Member of European Reference Network EpiCARE, Institut Imagine, INSERM, UMR 1163, Université Paris cité, Paris, France
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18
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Gain of function due to increased opening probability by two KCNQ5 pore variants causing developmental and epileptic encephalopathy. Proc Natl Acad Sci U S A 2022; 119:e2116887119. [PMID: 35377796 PMCID: PMC9169635 DOI: 10.1073/pnas.2116887119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Variants in genes encoding neuronally expressed potassium channel subunits are frequent causes of developmental and epileptic encephalopathies (DEEs). Characterization of their functional consequences is critical to confirm diagnosis, assess prognosis, and implement personalized treatments. In the present work, we describe two patients carrying variants in KCNQ5, a gene very recently and rarely found involved in DEEs, and reveal that they both cause remarkable gain-of-function consequences on channel activity. A PIP2-independent increase in open probability, without effects on membrane abundance or single-channel conductance, was responsible for the observed mutation-induced functional changes, thus revealing a pathomolecular disease mechanism for DEEs. Developmental and epileptic encephalopathies (DEEs) are neurodevelopmental diseases characterized by refractory epilepsy, distinct electroencephalographic and neuroradiological features, and various degrees of developmental delay. Mutations in KCNQ2, KCNQ3, and, more rarely, KCNQ5 genes encoding voltage-gated potassium channel subunits variably contributing to excitability control of specific neuronal populations at distinct developmental stages have been associated to DEEs. In the present work, the clinical features of two DEE patients carrying de novo KCNQ5 variants affecting the same residue in the pore region of the Kv7.5 subunit (G347S/A) are described. The in vitro functional properties of channels incorporating these variants were investigated with electrophysiological and biochemical techniques to highlight pathophysiological disease mechanisms. Currents carried by Kv7.5 G347 S/A channels displayed: 1) large (>10 times) increases in maximal current density, 2) the occurrence of a voltage-independent component, 3) slower deactivation kinetics, and 4) hyperpolarization shift in activation. All these functional features are consistent with a gain-of-function (GoF) pathogenetic mechanism. Similar functional changes were also observed when the same variants were introduced at the corresponding position in Kv7.2 subunits. Nonstationary noise analysis revealed that GoF effects observed for both Kv7.2 and Kv7.5 variants were mainly attributable to an increase in single-channel open probability, without changes in membrane abundance or single-channel conductance. The mutation-induced increase in channel opening probability was insensitive to manipulation of membrane levels of the critical Kv7 channel regulator PIP2. These results reveal a pathophysiological mechanism for KCNQ5-related DEEs, which might be exploited to implement personalized treatments.
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19
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Jiao X, Gong P, Niu Y, Zhang Y, Yang Z. A Rare Presentation Characterized by Epileptic Spasms in ALDH7A1, Pyridox(am)ine-5′-Phosphate Oxidase, and PLPBP Deficiency. Front Genet 2022; 13:804461. [PMID: 35495162 PMCID: PMC9039010 DOI: 10.3389/fgene.2022.804461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 03/07/2022] [Indexed: 11/25/2022] Open
Abstract
Objective: To analyze the clinical feature, treatment, and prognosis of epileptic spasms (ES) in vitamin B6–dependent epilepsy, including patients with pyridoxine-dependent epilepsy (PDE) caused by ALDH7A1 mutation, pyridox(am)ine-5′-phosphate oxidase (PNPO) deficiency, and PLPBP deficiency. Methods: We analyzed data from a cohort of 54 cases with PDE, 13 cases with PNPO deficiency, and 2 cases with PLPBP deficiency and looked for the presentation of ES among them. Results: A total of 11 patients with the seizure presentation of ES have been collected. Among them, four patients carried mutations in ALDH7A1, six carried mutations in PNPO, and the remaining one carried mutation in PLPBP. The analysis of this cohort identified nine cases presenting as infantile spasms distributed in the three diseases and two cases presenting as Ohtahara syndrome diagnosed with PDE and PNPO deficiency, respectively. In the PDE and PLPBP deficiency groups, seizures were controlled by pyridoxine monotherapy, and the remaining one had refractory seizures due to secondary brain atrophy. In the groups with PNPO deficiency, one patient showed seizure-free when treated by PLP combined with valproic acid, three still had infrequent seizures treated by PLP monotherapy or pyridoxine or PLP combined with other antiseizure medications, and two died. In two cases presenting as Ohtahara syndrome, after regular treatment, one showed seizure-free, the others showed a marked decrease in seizure frequency, and they both showed an improvement in EEG. Significance: ES might be a common form of seizures in PNPO deficiency, and EEG presented as hypsarrhythmia or a burst suppression pattern. It is difficult for pyridoxine to control frequent seizures caused by secondary brain injury. In our PNPO deficiency cohort, patients with infantile spasms did not respond better to PLP than pyridoxine. Timely and correct treatment could prevent the transformation of the child’s disease from Ohtahara syndrome and infantile spasms to subsequent epileptic encephalopathy or refractory epilepsy.
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20
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Cali E, Rocca C, Salpietro V, Houlden H. Epileptic Phenotypes Associated With SNAREs and Related Synaptic Vesicle Exocytosis Machinery. Front Neurol 2022; 12:806506. [PMID: 35095745 PMCID: PMC8792400 DOI: 10.3389/fneur.2021.806506] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 11/16/2021] [Indexed: 01/29/2023] Open
Abstract
SNAREs (soluble N-ethylmaleimide sensitive factor attachment protein receptor) are an heterogeneous family of proteins that, together with their key regulators, are implicated in synaptic vesicle exocytosis and synaptic transmission. SNAREs represent the core component of this protein complex. Although the specific mechanisms of the SNARE machinery is still not completely uncovered, studies in recent years have provided a clearer understanding of the interactions regulating the essential fusion machinery for neurotransmitter release. Mutations in genes encoding SNARE proteins or SNARE complex associated proteins have been associated with a variable spectrum of neurological conditions that have been recently defined as “SNAREopathies.” These include neurodevelopmental disorder, autism spectrum disorder (ASD), movement disorders, seizures and epileptiform abnormalities. The SNARE phenotypic spectrum associated with seizures ranges from simple febrile seizures and infantile spasms, to severe early-onset epileptic encephalopathies. Our study aims to review and delineate the epileptic phenotypes associated with dysregulation of synaptic vesicle exocytosis and transmission, focusing on the main proteins of the SNARE core complex (STX1B, VAMP2, SNAP25), tethering complex (STXBP1), and related downstream regulators.
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Affiliation(s)
- Elisa Cali
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Clarissa Rocca
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Vincenzo Salpietro
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Henry Houlden
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
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21
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Peng P, Kessi M, Mao L, He F, Zhang C, Chen C, Pang N, Yin F, Pan Z, Peng J. Etiologic Classification of 541 Infantile Spasms Cases: A Cohort Study. Front Pediatr 2022; 10:774828. [PMID: 35330882 PMCID: PMC8940518 DOI: 10.3389/fped.2022.774828] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 01/31/2022] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE To explore the etiology of infantile spasms (IS) in a large Chinese cohort based on the United States National Infantile Spasms Consortium (NISC) classification. METHODS In the present study, we recruited IS patients diagnosed at a single center (Xiangya Hospital, Central South University) between Jan 2010 and Aug 2019. Thereafter, we collected their clinical and genetic information retrospectively. Their underlying etiologies were classified according to the NISC classification and then compared in different scenarios to understand their distribution. RESULTS A total of 541 patients with IS from 18 provinces were included in this study. The underlying etiology was identified in 53.2% of the cases: structural-acquired, 25.3%; genetic, 12.9%; genetic-structural, 7.2%; structural-congenital, 5.0%; metabolic, 2.4%; infections, 0.4% and immune, 0%. Whole-exome sequencing (WES) provided the highest diagnostic yield (26.9%). In structural-acquired IS, the proportion of hypoglycemic brain injuries was significant, second only to hypoxic-ischemic encephalopathy. There was no patient discovered to have Down syndrome. STXBP1, CDKL5, TSC2, KCNQ2, IRF2BPL, and TSC1 were the most frequently implicated genes. Genetic causes were found to be the most common cause of IS in the early onset group, while structural-acquired etiologies were common in males and preterm babies. Patients with pre-spasm seizures were associated with a higher proportion of identified causes than those without. Non-acquired structural etiologies were more common in patients without hypsarrhythmia than in those with hypsarrhythmia. SIGNIFICANCE The most prevalent cause of IS was structural acquired followed by genetic causes. When brain MRI fails to detect the etiology, we propose WES as the next step. Structural-acquired IS and cases with genetic disorders are characteristic of the Chinese cohort, however, the etiology differs with the patient's age of onset, gestation age at birth, sex, and the presence/absence of both pre-spasm seizures, and hypsarrhythmia.
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Affiliation(s)
- Pan Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Leilei Mao
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Fang He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Ciliu Zhang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Chen Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Nan Pang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Zou Pan
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
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Zou D, Wang L, Liao J, Xiao H, Duan J, Zhang T, Li J, Yin Z, Zhou J, Yan H, Huang Y, Zhan N, Yang Y, Ye J, Chen F, Zhu S, Wen F, Guo J. Genome sequencing of 320 Chinese children with epilepsy: a clinical and molecular study. Brain 2021; 144:3623-3634. [PMID: 34145886 PMCID: PMC8719847 DOI: 10.1093/brain/awab233] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 05/25/2021] [Accepted: 06/05/2021] [Indexed: 02/05/2023] Open
Abstract
The aim of this study is to evaluate the diagnostic value of genome sequencing in children with epilepsy, and to provide genome sequencing-based insights into the molecular genetic mechanisms of epilepsy to help establish accurate diagnoses, design appropriate treatments and assist in genetic counselling. We performed genome sequencing on 320 Chinese children with epilepsy, and interpreted single-nucleotide variants and copy number variants of all samples. The complete pedigree and clinical data of the probands were established and followed up. The clinical phenotypes, treatments, prognoses and genotypes of the patients were analysed. Age at seizure onset ranged from 1 day to 17 years, with a median of 4.3 years. Pathogenic/likely pathogenic variants were found in 117 of the 320 children (36.6%), of whom 93 (29.1%) had single-nucleotide variants, 22 (6.9%) had copy number variants and two had both single-nucleotide variants and copy number variants. Single-nucleotide variants were most frequently found in SCN1A (10/95, 10.5%), which is associated with Dravet syndrome, followed by PRRT2 (8/95, 8.4%), which is associated with benign familial infantile epilepsy, and TSC2 (7/95, 7.4%), which is associated with tuberous sclerosis. Among the copy number variants, there were three with a length <25 kilobases. The most common recurrent copy number variants were 17p13.3 deletions (5/24, 20.8%), 16p11.2 deletions (4/24, 16.7%), and 7q11.23 duplications (2/24, 8.3%), which are associated with epilepsy, developmental retardation and congenital abnormalities. Four particular 16p11.2 deletions and two 15q11.2 deletions were considered to be susceptibility factors contributing to neurodevelopmental disorders associated with epilepsy. The diagnostic yield was 75.0% in patients with seizure onset during the first postnatal month, and gradually decreased in patients with seizure onset at a later age. Forty-two patients (13.1%) were found to be specifically treatable for the underlying genetic cause identified by genome sequencing. Three of them received corresponding targeted therapies and demonstrated favourable prognoses. Genome sequencing provides complete genetic diagnosis, thus enabling individualized treatment and genetic counselling for the parents of the patients. Genome sequencing is expected to become the first choice of methods for genetic testing of patients with epilepsy.
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Affiliation(s)
- Dongfang Zou
- Department of Neurology, Shenzhen Children’s Hospital, Shenzhen, China
| | - Lin Wang
- BGI-Shenzhen, Shenzhen 518083, China
| | - Jianxiang Liao
- Department of Neurology, Shenzhen Children’s Hospital, Shenzhen, China
| | | | - Jing Duan
- Department of Neurology, Shenzhen Children’s Hospital, Shenzhen, China
| | | | | | | | - Jing Zhou
- BGI-Shenzhen, Shenzhen 518083, China
| | | | | | | | - Ying Yang
- BGI-Shenzhen, Shenzhen 518083, China
| | - Jingyu Ye
- BGI-Shenzhen, Shenzhen 518083, China
| | - Fang Chen
- BGI-Shenzhen, Shenzhen 518083, China
| | - Shida Zhu
- BGI-Shenzhen, Shenzhen 518083, China
| | - Feiqiu Wen
- Department of Hematology and Oncology, Shenzhen Children’s Hospital, Shenzhen, China
- Correspondence may also be addressed to: Feiqiu Wen Shenzhen Children’s Hospital No. 7019 Yitian Road, Shenzhen 518038 Guangdong, China E-mail:
| | - Jian Guo
- BGI-Shenzhen, Shenzhen 518083, China
- Correspondence to: Jian Guo BGI-Shenzhen, Beishan Industry Zone Shenzhen 518083, Guangdong, China E-mail:
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Schoenmakers E, Chatterjee K. Human Genetic Disorders Resulting in Systemic Selenoprotein Deficiency. Int J Mol Sci 2021; 22:12927. [PMID: 34884733 PMCID: PMC8658020 DOI: 10.3390/ijms222312927] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 11/26/2021] [Accepted: 11/27/2021] [Indexed: 01/01/2023] Open
Abstract
Selenium, a trace element fundamental to human health, is incorporated as the amino acid selenocysteine (Sec) into more than 25 proteins, referred to as selenoproteins. Human mutations in SECISBP2, SEPSECS and TRU-TCA1-1, three genes essential in the selenocysteine incorporation pathway, affect the expression of most if not all selenoproteins. Systemic selenoprotein deficiency results in a complex, multifactorial disorder, reflecting loss of selenoprotein function in specific tissues and/or long-term impaired selenoenzyme-mediated defence against oxidative and endoplasmic reticulum stress. SEPSECS mutations are associated with a predominantly neurological phenotype with progressive cerebello-cerebral atrophy. Selenoprotein deficiency due to SECISBP2 and TRU-TCA1-1 defects are characterized by abnormal circulating thyroid hormones due to lack of Sec-containing deiodinases, low serum selenium levels (low SELENOP, GPX3), with additional features (myopathy due to low SELENON; photosensitivity, hearing loss, increased adipose mass and function due to reduced antioxidant and endoplasmic reticulum stress defence) in SECISBP2 cases. Antioxidant therapy ameliorates oxidative damage in cells and tissues of patients, but its longer term benefits remain undefined. Ongoing surveillance of patients enables ascertainment of additional phenotypes which may provide further insights into the role of selenoproteins in human biological processes.
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Affiliation(s)
| | - Krishna Chatterjee
- Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke’s Hospital, University of Cambridge, Cambridge CB2 0QQ, UK;
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Yang SM, Cao CD, Ding Y, Wang MJ, Yue SJ. D-bifunctional protein deficiency caused by HSD17B4 gene mutation in a neonate. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2021; 23:1058-1063. [PMID: 34719423 DOI: 10.7499/j.issn.1008-8830.2107158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A 15-day-old boy was admitted to the hospital due to repeated convulsions for 14 days. The main clinical manifestations were uncontrolled seizures, hypoergia, feeding difficulties, limb hypotonia, and bilateral hearing impairment. Clinical neurophysiology showed reduced brainstem auditory evoked potential on both sides and burst-suppression pattern on electroencephalogram. Measurement of very-long-chain fatty acids in serum showed that C26:0 was significantly increased. Genetic testing showed a pathogenic compound heterozygous mutation, c.101C>T(p.Ala34Val) and c.1448_1460del(p.Ala483Aspfs*37), in the HSD17B4 gene. This article reports a case of D-bifunctional protein deficiency caused by HSD17B4 gene mutation and summarizes the epidemiological and clinical features, diagnosis, and treatment of this disease, with a focus on the differential diagnosis of this disease from Ohtahara syndrome.
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Affiliation(s)
- Shu-Mei Yang
- Department of Neonatology, Xiangya Hospital, Central South University, Changsha 410008, China (Yue S-J, )
| | - Chuan-Ding Cao
- Department of Neonatology, Xiangya Hospital, Central South University, Changsha 410008, China (Yue S-J, )
| | - Ying Ding
- Department of Neonatology, Xiangya Hospital, Central South University, Changsha 410008, China (Yue S-J, )
| | - Ming-Jie Wang
- Department of Neonatology, Xiangya Hospital, Central South University, Changsha 410008, China (Yue S-J, )
| | - Shao-Jie Yue
- Department of Neonatology, Xiangya Hospital, Central South University, Changsha 410008, China (Yue S-J, )
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Spoto G, Saia MC, Amore G, Gitto E, Loddo G, Mainieri G, Nicotera AG, Di Rosa G. Neonatal Seizures: An Overview of Genetic Causes and Treatment Options. Brain Sci 2021; 11:brainsci11101295. [PMID: 34679360 PMCID: PMC8534058 DOI: 10.3390/brainsci11101295] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/16/2021] [Accepted: 09/26/2021] [Indexed: 01/04/2023] Open
Abstract
Seizures are the most frequent neurological clinical symptoms of the central nervous system (CNS) during the neonatal period. Neonatal seizures may be ascribed to an acute event or symptomatic conditions determined by genetic, metabolic or structural causes, outlining the so-called 'Neonatal Epilepsies'. To date, three main groups of neonatal epilepsies are recognised during the neonatal period: benign familial neonatal epilepsy (BFNE), early myoclonic encephalopathy (EME) and 'Ohtahara syndrome' (OS). Recent advances showed the role of several genes in the pathogenesis of these conditions, such as KCNQ2, KCNQ3, ARX, STXBP1, SLC25A22, CDKL5, KCNT1, SCN2A and SCN8A. Herein, we reviewed the current knowledge regarding the pathogenic variants most frequently associated with neonatal seizures, which should be considered when approaching newborns affected by these disorders. In addition, we considered the new possible therapeutic strategies reported in these conditions.
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Affiliation(s)
- Giulia Spoto
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi”, University of Messina, 98125 Messina, Italy; (G.S.); (M.C.S.); (G.A.); (G.D.R.)
| | - Maria Concetta Saia
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi”, University of Messina, 98125 Messina, Italy; (G.S.); (M.C.S.); (G.A.); (G.D.R.)
| | - Greta Amore
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi”, University of Messina, 98125 Messina, Italy; (G.S.); (M.C.S.); (G.A.); (G.D.R.)
| | - Eloisa Gitto
- Unit of Neonatal Intensive Care, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi”, University of Messina, 98125 Messina, Italy;
| | | | - Greta Mainieri
- Department of Biomedical and NeuroMotor Sciences, University of Bologna, 40138 Bologna, Italy;
| | - Antonio Gennaro Nicotera
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi”, University of Messina, 98125 Messina, Italy; (G.S.); (M.C.S.); (G.A.); (G.D.R.)
- Correspondence: ; Tel.: +39-090-221-2911
| | - Gabriella Di Rosa
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi”, University of Messina, 98125 Messina, Italy; (G.S.); (M.C.S.); (G.A.); (G.D.R.)
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Genetic-cellular epilepsy: Clues to diagnosing newborns with neonatal seizures. Seizure 2021; 92:68-75. [PMID: 34474328 DOI: 10.1016/j.seizure.2021.08.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 08/18/2021] [Accepted: 08/20/2021] [Indexed: 11/21/2022] Open
Abstract
OBJECTIVE The aim of this study was to analyse clinical characteristics of newborns with genetic-cellular epilepsy (GCE) to compare them to those of newborns with seizures with other aetiologies and elucidate clues to the diagnosis of GCE. METHODS This retrospective single-centre study analysed data from an 8-year cohort of newborns with seizures from 2010-2017. Clinical, neurophysiological, laboratory, and imaging data and outcomes of children with GCE were compared to those of newborns with seizures with other aetiologies. RESULTS A total of 112 newborns (N = 68; 61% boys) were included. Hypoxic-ischaemic encephalopathy (N = 42; 29%) was the most common seizure aetiology; GCE (with pathogenic variants KCNQ2, KCNQ3, SCN2A, TBC1D24, CHD2, and STXBP) was diagnosed in 9 (6%). The group of newborns with GCE significantly differed from the group with seizures with other aetiologies in terms of family history of epilepsy (p = 0.000), neonatal epileptic status (NES) (p = 0.007), normal imaging studies (p = 0.000), and outcomes (p = 0.034), but did not differ regarding the type and age of seizure onset, number of antiepileptic drugs administered, and EEG results. Positive family history of epilepsy (p = 0.027), presence of NES (p = 0.041), and normal imaging studies (p = 0.002) were most indicative of the diagnosis of GCE. Probability of GCE with this combination was 0.92. CONCLUSION In a heterogenous group of newborns with seizures, a positive family history of epilepsy, presence of NES, and normal imaging studies were most indicative of the diagnosis of GCE.
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Turkdogan D, Turkyilmaz A, Sager G, Ozturk G, Unver O, Say M. Chromosomal microarray and exome sequencing in unexplained early infantile epileptic encephalopathies in a highly consanguineous population. Int J Neurosci 2021:1-18. [PMID: 34380004 DOI: 10.1080/00207454.2021.1967349] [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: 10/20/2022]
Abstract
AIM To identify genetic causes for early infantile epileptic encephalopathies (EIEE) in Turkish children with mostly consanguineous parents. METHODS In a selected EIEE group (N = 59) based on results of nongenetic and initial genetic testing with unexplained etiology, 49 patients underwent array-based comparative genomic hybridization (aCGH) and 49 patients underwent whole exome sequencing (WES) including 39 with negative aCGH results and 10 with WES-only. RESULTS Diagnostic yield of aCGH and WES for pathogenic or likely pathogenic variants was 14.3% and 38.8%, respectively. Including de novo variants of uncertain significance linked to compatible phenotypes, increased the diagnostic yield of WES to 61.2%. Out of 38 positive variants, 18 (47.4%) were novel and 16 (42.1%) were de novo. Twenty-one (56.8%) patients had recessive variants inherited from mostly consanguineous healthy parents (85.7%). Fourteen (37.8%) of patients with diagnostic results had positive variants in established EIEE genes. Seizures started during neonatal period in 32.4% patients. Posture or movement disorders were comorbid with EIEE in 40.5% of diagnosed patients. We identified treatable metabolic disorders in 8.1% of patients and pathogenic variants in genes which support using targeted medicine in 19% of patients. CONCLUSIONS Detailed electro-clinical phenotyping led to expansion of some of the known phenotypes with non-neurological and neurological findings in addition to seizures, as well as suggestion of candidate genes (SEC24B, SLC16A2 and PRICKLE2) and a copy number variant (microduplication of Xp21.1p11.4). The high ratio of recessive inheritance could be important for family counseling.
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Affiliation(s)
- Dilsad Turkdogan
- Medical Faculty, Department of Pediatric Neurology, Marmara University, Pendik, Istanbul, Turkey
| | - Ayberk Turkyilmaz
- Medical Faculty, Department of Medical Genetics, Marmara University, Pendik, Istanbul, Turkey
| | - Gunes Sager
- Medical Faculty, Department of Pediatric Neurology, Marmara University, Pendik, Istanbul, Turkey
| | - Gulten Ozturk
- Medical Faculty, Department of Pediatric Neurology, Marmara University, Pendik, Istanbul, Turkey
| | - Olcay Unver
- Medical Faculty, Department of Pediatric Neurology, Marmara University, Pendik, Istanbul, Turkey
| | - Merve Say
- Bioinformatics, Private Practice, Kadıkoy, Istanbul, Turkey
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The relationship between the characteristics of burst suppression pattern and different etiologies in epilepsy. Sci Rep 2021; 11:15903. [PMID: 34354098 PMCID: PMC8342459 DOI: 10.1038/s41598-021-95040-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 07/14/2021] [Indexed: 11/08/2022] Open
Abstract
To analyze the relationship between the characteristics of burst suppression (BS) pattern and different etiologies in epilepsy. Patients with a BS pattern who were younger than 6 months old were screened from our electroencephalogram (EEG) database. The synchronized and symmetric BS patterns under different etiologies in epilepsy were analyzed. A total of 32 patients had a BS pattern on EEG. The etiologies included genetic disorders (37.5%), cortical malformations (28.1%), inborn errors of metabolism (12.5%), and unknown (21.9%). Twenty-five patients were diagnosed with Ohtahara syndrome, one as early myoclonic encephalopathy, and one as epilepsy of infancy with migrating focal seizure. Five cases could not be classified into any epileptic syndrome. Asynchronous BS pattern was identified in 18 cases, of which 13 (72%) patients had genetic and/or metabolic etiologies. Synchronous BS pattern was identified in 14 cases, of which 8 (57%) patients had structural etiologies. Twenty-three patients had symmetric BS patterns, of which 15 (65%) patients had genetic etiologies. Nine patients had asymmetric BS patterns, of which 8 (89%) patients had structural etiologies. Patients with genetic epilepsies tended to have asynchronous and symmetric BS patterns, whereas those with structural epilepsies were more likely to have synchronous and asymmetric BS patterns.
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New avenues in molecular genetics for the diagnosis and application of therapeutics to the epilepsies. Epilepsy Behav 2021; 121:106428. [PMID: 31400936 DOI: 10.1016/j.yebeh.2019.07.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 06/14/2019] [Accepted: 07/06/2019] [Indexed: 11/22/2022]
Abstract
Genetic epidemiology studies have shown that most epilepsies involve some genetic cause. In addition, twin studies have helped strengthen the hypothesis that in most patients with epilepsy, a complex inheritance is involved. More recently, with the development of high-density single-nucleotide polymorphism (SNP) microarrays and next-generation sequencing (NGS) technologies, the discovery of genes related to the epilepsies has accelerated tremendously. Especially, the use of whole exome sequencing (WES) has had a considerable impact on the identification of rare genetic variants with large effect sizes, including inherited or de novo mutations in severe forms of childhood epilepsies. The identification of pathogenic variants in patients with these childhood epilepsies provides many benefits for patients and families, such as the confirmation of the genetic nature of the diseases. This process will allow for better genetic counseling, more accurate therapy decisions, and a significant positive emotional impact. However, to study the genetic component of the more common forms of epilepsy, the use of high-density SNP arrays in genome-wide association studies (GWAS) seems to be the strategy of choice. As such, researchers can identify loci containing genetic variants associated with the common forms of epilepsy. The knowledge generated over the past two decades about the effects of the mutations that cause the monogenic epilepsy is tremendous; however, the scientific community is just starting to apply this information in order to generate better target treatments.
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Epilepsy Syndromes in the First Year of Life and Usefulness of Genetic Testing for Precision Therapy. Genes (Basel) 2021; 12:genes12071051. [PMID: 34356067 PMCID: PMC8307222 DOI: 10.3390/genes12071051] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/23/2021] [Accepted: 07/05/2021] [Indexed: 12/18/2022] Open
Abstract
The high pace of gene discovery has resulted in thrilling advances in the field of epilepsy genetics. Clinical testing with comprehensive gene panels, exomes, or genomes are now increasingly available and have led to a significant higher diagnostic yield in early-onset epilepsies and enabled precision medicine approaches. These have been instrumental in providing insights into the pathophysiology of both early-onset benign and self-limited syndromes and devastating developmental and epileptic encephalopathies (DEEs). Genetic heterogeneity is seen in many epilepsy syndromes such as West syndrome and epilepsy of infancy with migrating focal seizures (EIMFS), indicating that two or more genetic loci produce the same or similar phenotypes. At the same time, some genes such as SCN2A can be associated with a wide range of epilepsy syndromes ranging from self-limited familial neonatal epilepsy at the mild end to Ohtahara syndrome, EIFMS, West syndrome, Lennox–Gastaut syndrome, or unclassifiable DEEs at the severe end of the spectrum. The aim of this study was to review the clinical and genetic heterogeneity associated with epilepsy syndromes starting in the first year of life including: Self-limited familial neonatal, neonatal-infantile or infantile epilepsies, genetic epilepsy with febrile seizures plus spectrum, myoclonic epilepsy in infancy, Ohtahara syndrome, early myoclonic encephalopathy, West syndrome, Dravet syndrome, EIMFS, and unclassifiable DEEs. We also elaborate on the advantages and pitfalls of genetic testing in such conditions. Finally, we describe how a genetic diagnosis can potentially enable precision therapy in monogenic epilepsies and emphasize that early genetic testing is a cornerstone for such therapeutic strategies.
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Phitsanuwong C. Genetic and Metabolic Neonatal Epilepsies. Pediatr Ann 2021; 50:e245-e253. [PMID: 34115564 DOI: 10.3928/19382359-20210518-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Seizures are a common neonatal neurological disorder with an incidence of 1 to 5 in 1,000 live births. Genetic and metabolic epilepsies account for 10% to 12% of all neonatal seizures. Correct identification and diagnosis are important factors, as they carry treatment and management implications. Clinical history, neurological examination, seizure types, epilepsy syndromes, and electroencephalogram findings can be used to guide the diagnosis of epilepsy. Genetic and metabolic epilepsies in neonates can be categorized practically into two groups: amenably treatable disorders, and the most common genetic epilepsies. The treatable disorders primarily consist of inborn errors of metabolism that have a specific therapy. The most common genetic epilepsies include monogenic disorders, which usually result from channelopathies, synaptic vesicle docking/release defect, or dysfunction of cell signaling. A step-wise diagnostic approach to genetic and metabolic epilepsies is proposed in this article to aid clinicians in providing care for newborns with seizures. [Pediatr Ann. 2020;50(6):e245-e253.].
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Portale A, Comella M, Salomone G, Di Nora A, Marino L, Leonardi R, Praticò AD, Falsaperla R. The Spectrum of KCNQ2- and KCNQ3-Related Epilepsy. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1727099] [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
Abstract
KCNQ genes encode for a family of six transmembrane domains, single pore-loop, and K+ channel α-subunits that have a wide range of physiological correlates. In the brain, KCNQ2 and KCNQ3 heteromultimers are thought to underlie the M-current which is essential in raising the threshold for firing an action potential; mutations in these genes may cause several types of infantile epilepsies. KCNQ2-related disorders represent a continuum of overlapping neonatal epileptic phenotypes that range from KCNQ2 benign familial neonatal epilepsy (BFNE), a seizure disorder that occur in children who typically have a normal psychomotor development and are inherited as an autosomal dominant trait, to KCNQ2 early-onset epileptic encephalopathy (EOEE) as the result of a de novo pathogenic variant. KCNQ3-related disorders are rarer and include BFNE, benign familial infantile epilepsy and KCNQ3-related epileptic encephalopathy with intellectual disability with or without seizures and/or cortical visual impairment. For both KCNQ2- and KCNQ3-related disorders, it is possible to use several drugs for different classes of mutations (i.e., gain of function vs. loss of function), and usually their effects vary in relation to the clinical presentation and the phenotype of the patient. However, KCNQ2-EOEE patients have a worse response to treatment than KCNQ2-BFNE patients and usually become drug resistant with multiple daily seizures.
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Affiliation(s)
- Anna Portale
- Unit of Pediatrics, Avola Hospital, Siracusa, Italy
| | - Mattia Comella
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Giulia Salomone
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Alessandra Di Nora
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Lidia Marino
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Roberta Leonardi
- 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
| | - 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
| | - Raffaele Falsaperla
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
- Unit of Neonatal Intensive Care and Neonatology, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
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Boets S, Johannesen KM, Destree A, Manti F, Ramantani G, Lesca G, Vercueil L, Koenig MK, Striano P, Møller RS, Cooper E, Weckhuysen S. Adult phenotype of KCNQ2 encephalopathy. J Med Genet 2021; 59:528-535. [PMID: 33811133 DOI: 10.1136/jmedgenet-2020-107449] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 03/02/2021] [Accepted: 03/10/2021] [Indexed: 11/03/2022]
Abstract
BACKGROUND Pathogenic KCNQ2 variants are a frequent cause of developmental and epileptic encephalopathy. METHODS We recruited 13 adults (between 18 years and 45 years of age) with KCNQ2 encephalopathy and reviewed their clinical, EEG, neuroimaging and treatment history. RESULTS While most patients had daily seizures at seizure onset, seizure frequency declined or remitted during childhood and adulthood. The most common seizure type was tonic seizures (early) infancy, and tonic-clonic and focal impaired awareness seizures later in life. Ten individuals (77%) were seizure-free at last follow-up. In 38% of the individuals, earlier periods of seizure freedom lasting a minimum of 2 years followed by seizure recurrence had occurred. Of the 10 seizure-free patients, 4 were receiving a single antiseizure medication (ASM, carbamazepine, lamotrigine or levetiracetam), and 2 had stopped taking ASM. Intellectual disability (ID) ranged from mild to profound, with the majority (54%) of individuals in the severe category. At last contact, six individuals (46%) remained unable to walk independently, six (46%) had limb spasticity and four (31%) tetraparesis/tetraplegia. Six (46%) remained non-verbal, 10 (77%) had autistic features/autism, 4 (31%) exhibited aggressive behaviour and 4 (31%) destructive behaviour with self-injury. Four patients had visual problems, thought to be related to prematurity in one. Sleep problems were seen in six (46%) individuals. CONCLUSION Seizure frequency declines over the years and most patients are seizure-free in adulthood. Longer seizure-free periods followed by seizure recurrence are common during childhood and adolescence. Most adult patients have severe ID. Motor, language and behavioural problems are an issue of continuous concern.
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Affiliation(s)
- Stephanie Boets
- Neurology Department, University Hospital Antwerp, Antwerp, Belgium
| | - Katrine M Johannesen
- Department of Epilepsy Genetics and Personalized Treatment, The Danish Epilepsy Centre Filadelfia, Dianalund, Denmark.,Institute for Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Anne Destree
- Department of Human Genetics, Institute of Pathology and Genetics, Gosselies, Belgium
| | - Filippo Manti
- Department of Human Neuroscience, University of Rome La Sapienza, Roma, Lazio, Italy
| | - Georgia Ramantani
- Department of Neuropediatrics, University Children's Hospital, Zurich, Switzerland
| | - Gaetan Lesca
- Department of Genetics, University Hospitals of Lyon, Lyon, France.,Neuroscience Research Center, Claude Bernard Lyon I University, Lyon, France
| | - Laurent Vercueil
- Grenoble Institute of Neurosciences (GIN), University Grenoble Alpes, La Tronche, France
| | - Mary Kay Koenig
- Department of Pediatrics, University of Texas McGovern Medical School, Houston, Texas, USA
| | - Pasquale Striano
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, "G Gaslini" Institute, Genova, Italy.,Pediatric Neurology and Muscular Diseases Unit, IRCCS' G Gaslini" Institute, Genova, Italy
| | - Rikke Steensbjerre Møller
- Department of Epilepsy Genetics and Personalized Treatment, The Danish Epilepsy Centre Filadelfia, Dianalund, Denmark.,Institute for Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Edward Cooper
- Department of Neurology, Baylor College of Medicine, Houston, Texas, USA
| | - Sarah Weckhuysen
- Neurology Department, University Hospital Antwerp, Antwerp, Belgium .,Applied & Translational Neurogenomics Group, VIB-Center for Molecular Neurology, VIB, Antwerp, Belgium.,Translational Neuroscience Group, University of Antwerp, Antwerp, Belgium
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Abstract
Seizures are the most common neurological emergency in the neonates, and this age group has the highest incidence of seizures compared with any other period of life. The author provides a narrative review of recent advances in the genetics of neonatal epilepsies, new neonatal seizure classification system, diagnostics, and treatment of neonatal seizures based on a comprehensive literature review (MEDLINE using PubMED and OvidSP vendors with appropriate keywords to incorporate recent evidence), personal practice, and experience. Knowledge regarding various systemic and postzygotic genetic mutations responsible for neonatal epilepsy has been exploded in recent times, as well as better delineation of clinical phenotypes associated with rare neonatal epilepsies. An International League Against Epilepsy task force on neonatal seizure has proposed a new neonatal seizure classification system and also evaluated the specificity of semiological features related to particular etiology. Although continuous video electroencephalogram (EEG) is the gold standard for monitoring neonatal seizures, amplitude-integrated EEGs have gained significant popularity in resource-limited settings. There is tremendous progress in the automated seizure detection algorithm, including the availability of a fully convolutional neural network using artificial machine learning (deep learning). There is a substantial need for ongoing research and clinical trials to understand optimal medication selection (first line, second line, and third line) for neonatal seizures, treatment duration of antiepileptic drugs after cessation of seizures, and strategies to improve neuromorbidities such as cerebral palsy, epilepsy, and developmental impairments. Although in recent times, levetiracetam use has been significantly increased for neonatal seizures, a multicenter, randomized, blinded, controlled phase IIb trial confirmed the superiority of phenobarbital over levetiracetam in the acute suppression of neonatal seizures. While there is no single best choice available for the management of neonatal seizures, institutional guidelines should be formed based on a consensus of local experts to mitigate wide variability in the treatment and to facilitate early diagnosis and treatment.
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Affiliation(s)
- Debopam Samanta
- Child Neurology Section, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States
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35
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Mary L, Nourisson E, Feger C, Laugel V, Chaigne D, Keren B, Afenjar A, Billette T, Trost D, Cieuta-Walti C, Gerard B, Piton A, Schaefer E. Pathogenic variants in KCNQ2 cause intellectual deficiency without epilepsy: Broadening the phenotypic spectrum of a potassium channelopathy. Am J Med Genet A 2021; 185:1803-1815. [PMID: 33754465 DOI: 10.1002/ajmg.a.62181] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 01/19/2021] [Accepted: 03/11/2021] [Indexed: 12/22/2022]
Abstract
High-throughput sequencing (HTS) improved the molecular diagnosis in individuals with intellectual deficiency (ID) and helped to broaden the phenotype of previously known disease-causing genes. We report herein four unrelated patients with isolated ID, carriers of a likely pathogenic variant in KCNQ2, a gene usually implicated in benign familial neonatal seizures (BFNS) or early onset epileptic encephalopathy (EOEE). Patients were diagnosed by targeted HTS or exome sequencing. Pathogenicity of the variants was assessed by multiple in silico tools. Patients' ID ranged from mild to severe with predominance of speech disturbance and autistic features. Three of the four variants disrupted the same amino acid. Compiling all the pathogenic variants previously reported, we observed a strong overlap between variants causing EOEE, isolated ID, and BFNS and an important intra-familial phenotypic variability, although missense variants in the voltage-sensing domain and the pore are significantly associated to EOEE (p < 0.01, Fisher test). Thus, pathogenic variants in KCNQ2 can be associated with isolated ID. We did not highlight strong related genotype-phenotype correlations in KCNQ2-related disorders. A second genetic hit, a burden of rare variants, or other extrinsic factors may explain such a phenotypic variability. However, it is of interest to study encephalopathy genes in non-epileptic ID patients.
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Affiliation(s)
- Laura Mary
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Elsa Nourisson
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Claire Feger
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Vincent Laugel
- Service de Neuropédiatrie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Denys Chaigne
- Service de Neuropédiatrie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Boris Keren
- Département de Génétique, Centre de Référence des Déficiences Intellectuelles de Causes Rares, Groupe de Recherche Clinique "Déficiences Intellectuelles et Autisme," Université Pierre et Marie Curie, Hôpital de la Pitié-Salpêtrière, Paris, France.,Institut du Cerveau et de la Moelle Épinière, Sorbonne Universités, Université Pierre et Marie Curie (Université Paris 06), UMRS 1127, INSERM U 1127, CNRS UMR 7225, Paris, France
| | - Alexandra Afenjar
- Centre de Référence Déficiences Intellectuelles de Causes Rares, Département de Génétique et Embryologie Médicale, Hôpital Trousseau, Sorbonne Universités, Paris, France
| | - Thierry Billette
- Assistance Publique-Hôpitaux de Paris, Service de Neuropédiatrie, Hôpital Armand Trousseau, Paris, France
| | | | | | - Bénédicte Gerard
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Amélie Piton
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.,Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR-7104, Inserm U964, Université de Strasbourg, Strasbourg, France
| | - Elise Schaefer
- Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, Institut de Génétique Médicale d'Alsace, Strasbourg, France
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36
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Millichap JJ, Harden CL, Dlugos DJ, French JA, Butterfield NN, Grayson C, Aycardi E, Pimstone SN. Capturing seizures in clinical trials of antiseizure medications for KCNQ2-DEE. Epilepsia Open 2021; 6:38-44. [PMID: 33681646 PMCID: PMC7918316 DOI: 10.1002/epi4.12466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 12/29/2020] [Accepted: 12/31/2020] [Indexed: 11/16/2022] Open
Abstract
Literature review of patients with KCNQ2 developmental and epileptic encephalopathy (KCNQ2-DEE) reveals, based on 16 reports including 139 patients, a clinical phenotype that includes age- and disease-specific stereotyped seizures. The typical seizure type of KCNQ2-DEE, focal tonic, starts within 0-5 days of life and is readily captured by video-electroencephalography VEEG for clinical and genetic diagnosis. After initial identification, KCNQ2-DEE seizures are clinically apparent and can be clearly identified without the use of EEG or VEEG. Therefore, we propose that the 2019 recommendations from the International League against Epilepsy (ILAE), the Pediatric Epilepsy Research Consortium (PERC), for capturing and recording seizures for clinical trials (Epilepsia Open, 4, 2019, 537) are suitable for use in KCNQ2-DEE‒associated antiseizure medicine (ASM) treatment trials. The ILAE/PERC consensus guidance states that a caregiver-maintained seizure diary, completed by caregivers who are trained to recognize seizures using within-patient historical recordings, accurately captures seizures prospectively in a clinical trial. An alternative approach historically endorsed by the Food and Drug Administration (FDA) compares seizure counts captured on VEEG before and after treatment. A major advantage of the ILAE/PERC strategy is that it expands the numbers of eligible patients who meet inclusion criteria of clinical trials while maintaining accurate seizure counts (Epilepsia Open, 4, 2019, 537). Three recent phase 3 pivotal pediatric trials investigating ASMs to treat syndromic seizures in patients as young as 2 years of age (N Engl J Med, 17, 2017, 699; Lancet, 21, 2020, 2243; Lancet, 17, 2018, 1085); and ongoing phase 2 open-label pediatric clinical trial that includes pediatric epileptic syndromes as young as 1 month of age (Am J Med Genet A, 176, 2018, 773), have already used caregiver-maintained seizure diaries successfully. For determining the outcome of a KCNQ2-DEE ASM treatment trial, the use of a seizure diary to count seizures by trained observers is feasible because the seizures of KCNQ2-DEE are clinically apparent. This strategy is supported by successful precedent in clinical trials in similar age groups and has the endorsement of the international pediatric epilepsy community.
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Affiliation(s)
- John J. Millichap
- Epilepsy Center and Division of NeurologyAnn & Robert H. Lurie Children’s Hospital of ChicagoChicagoILUSA
- Departments of Pediatrics and NeurologyNorthwestern University Feinberg School of MedicineChicagoILUSA
| | | | - Dennis J. Dlugos
- Children's Hospital of PhiladelphiaPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPAUSA
| | | | | | - Celene Grayson
- Xenon Pharmaceuticals, Inc.BurnabyBritish ColumbiaCanada
| | | | - Simon N. Pimstone
- Xenon Pharmaceuticals, Inc.BurnabyBritish ColumbiaCanada
- Division of General Internal MedicineUniversity of British ColumbiaBurnabyBritish ColumbiaCanada
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37
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Simkin D, Marshall KA, Vanoye CG, Desai RR, Bustos BI, Piyevsky BN, Ortega JA, Forrest M, Robertson GL, Penzes P, Laux LC, Lubbe SJ, Millichap JJ, George AL, Kiskinis E. Dyshomeostatic modulation of Ca 2+-activated K + channels in a human neuronal model of KCNQ2 encephalopathy. eLife 2021; 10:64434. [PMID: 33544076 PMCID: PMC7864629 DOI: 10.7554/elife.64434] [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] [Received: 10/28/2020] [Accepted: 01/20/2021] [Indexed: 12/22/2022] Open
Abstract
Mutations in KCNQ2, which encodes a pore-forming K+ channel subunit responsible for neuronal M-current, cause neonatal epileptic encephalopathy, a complex disorder presenting with severe early-onset seizures and impaired neurodevelopment. The condition is exceptionally difficult to treat, partially because the effects of KCNQ2 mutations on the development and function of human neurons are unknown. Here, we used induced pluripotent stem cells (iPSCs) and gene editing to establish a disease model and measured the functional properties of differentiated excitatory neurons. We find that patient iPSC-derived neurons exhibit faster action potential repolarization, larger post-burst afterhyperpolarization and a functional enhancement of Ca2+-activated K+ channels. These properties, which can be recapitulated by chronic inhibition of M-current in control neurons, facilitate a burst-suppression firing pattern that is reminiscent of the interictal electroencephalography pattern in patients. Our findings suggest that dyshomeostatic mechanisms compound KCNQ2 loss-of-function leading to alterations in the neurodevelopmental trajectory of patient iPSC-derived neurons.
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Affiliation(s)
- Dina Simkin
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States.,Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Kelly A Marshall
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Carlos G Vanoye
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Reshma R Desai
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Bernabe I Bustos
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Brandon N Piyevsky
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Juan A Ortega
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Marc Forrest
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, United States.,Center for Autism and Neurodevelopment, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Gabriella L Robertson
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Peter Penzes
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, United States.,Center for Autism and Neurodevelopment, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Linda C Laux
- Epilepsy Center and Division of Neurology, Departments of Pediatrics and Neurology, Ann & Robert H. Lurie Children's Hospital of Chicago, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Steven J Lubbe
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - John J Millichap
- Epilepsy Center and Division of Neurology, Departments of Pediatrics and Neurology, Ann & Robert H. Lurie Children's Hospital of Chicago, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Alfred L George
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Evangelos Kiskinis
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States.,Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, United States
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38
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Pressler RM, Cilio MR, Mizrahi EM, Moshé SL, Nunes ML, Plouin P, Vanhatalo S, Yozawitz E, de Vries LS, Puthenveettil Vinayan K, Triki CC, Wilmshurst JM, Yamamoto H, Zuberi SM. The ILAE classification of seizures and the epilepsies: Modification for seizures in the neonate. Position paper by the ILAE Task Force on Neonatal Seizures. Epilepsia 2021; 62:615-628. [PMID: 33522601 DOI: 10.1111/epi.16815] [Citation(s) in RCA: 131] [Impact Index Per Article: 43.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 12/23/2020] [Accepted: 12/23/2020] [Indexed: 12/23/2022]
Abstract
Seizures are the most common neurological emergency in the neonatal period and in contrast to those in infancy and childhood, are often provoked seizures with an acute cause and may be electrographic-only. Hence, neonatal seizures may not fit easily into classification schemes for seizures and epilepsies primarily developed for older children and adults. A Neonatal Seizures Task Force was established by the International League Against Epilepsy (ILAE) to develop a modification of the 2017 ILAE Classification of Seizures and Epilepsies, relevant to neonates. The neonatal classification framework emphasizes the role of electroencephalography (EEG) in the diagnosis of seizures in the neonate and includes a classification of seizure types relevant to this age group. The seizure type is determined by the predominant clinical feature. Many neonatal seizures are electrographic-only with no evident clinical features; therefore, these are included in the proposed classification. Clinical events without an EEG correlate are not included. Because seizures in the neonatal period have been shown to have a focal onset, a division into focal and generalized is unnecessary. Seizures can have a motor (automatisms, clonic, epileptic spasms, myoclonic, tonic), non-motor (autonomic, behavior arrest), or sequential presentation. The classification allows the user to choose the level of detail when classifying seizures in this age group.
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Affiliation(s)
- Ronit M Pressler
- Clinical Neuroscience, UCL- Great Ormond Street Institute of Child Health, London, UK.,Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
| | - Maria Roberta Cilio
- Division of Pediatric Neurology, Institute for Experimental and Clinical Research, Saint-Luc University Hospital, Université Catholique de Louvain, Brussels, Belgium
| | - Eli M Mizrahi
- Departments of Neurology and Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Solomon L Moshé
- Isabelle Rapin Division of Child Neurology, Saul R. Korey Department of Neurology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA.,Department of Pediatrics, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA
| | - Magda L Nunes
- Pontificia Universidade Catolica do Rio Grande do Sul - PUCRS School of Medicine and the Brain Institute, Porto Alegre, RS, Brazil
| | - Perrine Plouin
- Department of Clinical Neurophysiology, Hospital Necker Enfant Malades, Paris, France
| | - Sampsa Vanhatalo
- Department of Clinical Neurophysiology and BABA center Children's Hospital, HUS Imaging, Neuroscience Center, Helsinki Institute of Life Science, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland
| | - Elissa Yozawitz
- Isabelle Rapin Division of Child Neurology, Saul R. Korey Department of Neurology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA.,Department of Pediatrics, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA
| | - Linda S de Vries
- Department of Neonatology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | | | - Chahnez C Triki
- Department of Child Neurology, Hedi Chaker Hospital, LR19ES15 Sfax University, Sfax, Tunisia
| | - Jo M Wilmshurst
- Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Hitoshi Yamamoto
- Department of Pediatrics, St. Marianna University School of Medicine, Kawasaki, Japan
| | - Sameer M Zuberi
- Paediatric Neurosciences Research Group, Royal Hospital for Children & Institute of Health & Wellbeing, University of Glasgow, Glasgow, UK
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39
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Howell KB, Freeman JL, Mackay MT, Fahey MC, Archer J, Berkovic SF, Chan E, Dabscheck G, Eggers S, Hayman M, Holberton J, Hunt RW, Jacobs SE, Kornberg AJ, Leventer RJ, Mandelstam S, McMahon JM, Mefford HC, Panetta J, Riseley J, Rodriguez-Casero V, Ryan MM, Schneider AL, Smith LJ, Stark Z, Wong F, Yiu EM, Scheffer IE, Harvey AS. The severe epilepsy syndromes of infancy: A population-based study. Epilepsia 2021; 62:358-370. [PMID: 33475165 DOI: 10.1111/epi.16810] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/07/2020] [Accepted: 12/22/2020] [Indexed: 01/07/2023]
Abstract
OBJECTIVE To study the epilepsy syndromes among the severe epilepsies of infancy and assess their incidence, etiologies, and outcomes. METHODS A population-based cohort study was undertaken of severe epilepsies with onset before age 18 months in Victoria, Australia. Two epileptologists reviewed clinical features, seizure videos, and electroencephalograms to diagnose International League Against Epilepsy epilepsy syndromes. Incidence, etiologies, and outcomes at age 2 years were determined. RESULTS Seventy-three of 114 (64%) infants fulfilled diagnostic criteria for epilepsy syndromes at presentation, and 16 (14%) had "variants" of epilepsy syndromes in which there was one missing or different feature, or where all classical features had not yet emerged. West syndrome (WS) and "WS-like" epilepsy (infantile spasms without hypsarrhythmia or modified hypsarrhythmia) were the most common syndromes, with a combined incidence of 32.7/100 000 live births/year. The incidence of epilepsy of infancy with migrating focal seizures (EIMFS) was 4.5/100 000 and of early infantile epileptic encephalopathy (EIEE) was 3.6/100 000. Structural etiologies were common in "WS-like" epilepsy (100%), unifocal epilepsy (83%), and WS (39%), whereas single gene disorders predominated in EIMFS, EIEE, and Dravet syndrome. Eighteen (16%) infants died before age 2 years. Development was delayed or borderline in 85 of 96 (89%) survivors, being severe-profound in 40 of 96 (42%). All infants with EIEE or EIMFS had severe-profound delay or were deceased, but only 19 of 64 (30%) infants with WS, "WS-like," or "unifocal epilepsy" had severe-profound delay, and only two of 64 (3%) were deceased. SIGNIFICANCE Three quarters of severe epilepsies of infancy could be assigned an epilepsy syndrome or "variant syndrome" at presentation. In this era of genomic testing and advanced brain imaging, diagnosing epilepsy syndromes at presentation remains clinically useful for guiding etiologic investigation, initial treatment, and prognostication.
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Affiliation(s)
- Katherine B Howell
- Department of Neurology, Royal Children's Hospital, Melbourne, Vic, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia
| | - Jeremy L Freeman
- Department of Neurology, Royal Children's Hospital, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia
| | - Mark T Mackay
- Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia
| | - Michael C Fahey
- Department of Neurology, Monash Children's Hospital, Melbourne, Vic, Australia.,Department of Paediatrics, Monash University, Melbourne, Vic, Australia
| | - John Archer
- Department of Medicine, Epilepsy Research Centre, Austin Health, University of Melbourne, Melbourne, Vic, Australia
| | - Samuel F Berkovic
- Department of Medicine, Epilepsy Research Centre, Austin Health, University of Melbourne, Melbourne, Vic, Australia.,Florey Institute of Neuroscience and Mental Health, Melbourne, Vic, Australia
| | - Eunice Chan
- Department of Neurology, Royal Children's Hospital, Melbourne, Vic, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia
| | - Gabriel Dabscheck
- Department of Neurology, Royal Children's Hospital, Melbourne, Vic, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia
| | - Stefanie Eggers
- Victorian Clinical Genetics Service, Melbourne, Vic, Australia
| | - Michael Hayman
- Department of Neurology, Royal Children's Hospital, Melbourne, Vic, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia.,Department of Neurology, Monash Children's Hospital, Melbourne, Vic, Australia
| | - James Holberton
- Department of Neonatology, Mercy Hospital for Women, Melbourne, Vic, Australia
| | - Rodney W Hunt
- Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia.,Department of Neonatology, Royal Children's Hospital, Melbourne, Vic, Australia
| | - Susan E Jacobs
- Neonatal Services, Royal Women's Hospital, Melbourne, Vic, Australia
| | - Andrew J Kornberg
- Department of Neurology, Royal Children's Hospital, Melbourne, Vic, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia
| | - Richard J Leventer
- Department of Neurology, Royal Children's Hospital, Melbourne, Vic, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia
| | - Simone Mandelstam
- Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia.,Florey Institute of Neuroscience and Mental Health, Melbourne, Vic, Australia.,Department of Radiology, Royal Children's Hospital, Melbourne, Vic, Australia
| | - Jacinta M McMahon
- Department of Medicine, Epilepsy Research Centre, Austin Health, University of Melbourne, Melbourne, Vic, Australia
| | - Heather C Mefford
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA
| | | | - Jessica Riseley
- Victorian Clinical Genetics Service, Melbourne, Vic, Australia
| | - Victoria Rodriguez-Casero
- Department of Neurology, Royal Children's Hospital, Melbourne, Vic, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia
| | - Monique M Ryan
- Department of Neurology, Royal Children's Hospital, Melbourne, Vic, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia
| | - Amy L Schneider
- Department of Medicine, Epilepsy Research Centre, Austin Health, University of Melbourne, Melbourne, Vic, Australia
| | - Lindsay J Smith
- Department of Neurology, Monash Children's Hospital, Melbourne, Vic, Australia
| | - Zornitza Stark
- Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia
| | - Flora Wong
- Department of Paediatrics, Monash University, Melbourne, Vic, Australia.,Monash Newborn, Monash Children's Hospital, Melbourne, Vic, Australia
| | - Eppie M Yiu
- Department of Neurology, Royal Children's Hospital, Melbourne, Vic, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia
| | - Ingrid E Scheffer
- Department of Neurology, Royal Children's Hospital, Melbourne, Vic, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia.,Department of Medicine, Epilepsy Research Centre, Austin Health, University of Melbourne, Melbourne, Vic, Australia.,Florey Institute of Neuroscience and Mental Health, Melbourne, Vic, Australia
| | - A Simon Harvey
- Department of Neurology, Royal Children's Hospital, Melbourne, Vic, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Vic, Australia.,Murdoch Children's Research Institute, Melbourne, Vic, Australia
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40
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Paprocka J, Jezela-Stanek A, Tylki-Szymańska A, Grunewald S. Congenital Disorders of Glycosylation from a Neurological Perspective. Brain Sci 2021; 11:brainsci11010088. [PMID: 33440761 PMCID: PMC7827962 DOI: 10.3390/brainsci11010088] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 01/01/2021] [Accepted: 01/04/2021] [Indexed: 12/11/2022] Open
Abstract
Most plasma proteins, cell membrane proteins and other proteins are glycoproteins with sugar chains attached to the polypeptide-glycans. Glycosylation is the main element of the post-translational transformation of most human proteins. Since glycosylation processes are necessary for many different biological processes, patients present a diverse spectrum of phenotypes and severity of symptoms. The most frequently observed neurological symptoms in congenital disorders of glycosylation (CDG) are: epilepsy, intellectual disability, myopathies, neuropathies and stroke-like episodes. Epilepsy is seen in many CDG subtypes and particularly present in the case of mutations in the following genes: ALG13, DOLK, DPAGT1, SLC35A2, ST3GAL3, PIGA, PIGW, ST3GAL5. On brain neuroimaging, atrophic changes of the cerebellum and cerebrum are frequently seen. Brain malformations particularly in the group of dystroglycanopathies are reported. Despite the growing number of CDG patients in the world and often neurological symptoms dominating in the clinical picture, the number of performed screening tests eg transferrin isoforms is systematically decreasing as broadened genetic testing is recently more favored. The aim of the review is the summary of selected neurological symptoms in CDG described in the literature in one paper. It is especially important for pediatric neurologists not experienced in the field of metabolic medicine. It may help to facilitate the diagnosis of this expanding group of disorders. Biochemically, this paper focuses on protein glycosylation abnormalities.
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Affiliation(s)
- Justyna Paprocka
- Department of Pediatric Neurology, Faculty of Medical Science in Katowice, Medical University of Silesia, 40-752 Katowice, Poland
- Correspondence: ; Tel.: +48-606-415-888
| | - Aleksandra Jezela-Stanek
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, 01-138 Warsaw, Poland;
| | - Anna Tylki-Szymańska
- Department of Pediatrics, Nutrition and Metabolic Diseases, The Children’s Memorial Health Institute, W 04-730 Warsaw, Poland;
| | - Stephanie Grunewald
- NIHR Biomedical Research Center (BRC), Metabolic Unit, Great Ormond Street Hospital and Institute of Child Health, University College London, London SE1 9RT, UK;
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41
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Rong T, Yao R, Deng Y, Lin Q, Wang G, Wang J, Jiang F, Jiang Y. Case Report: A Relatively Mild Phenotype Produced by Novel Mutations in the SEPSECS Gene. Front Pediatr 2021; 9:805575. [PMID: 35155316 PMCID: PMC8826681 DOI: 10.3389/fped.2021.805575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 12/20/2021] [Indexed: 12/05/2022] Open
Abstract
Mutations in the human O-phosphoseryl-tRNA:selenocysteinyl-tRNA synthase gene (SEPSECS) are associated with progressive cerebello-cerebral atrophy (PCCA), also known as pontocerebellar hypoplasia type 2D (PCH2D). Early-onset profound developmental delay, progressive microcephaly, and hypotonia that develops toward severe spasticity have been previously reported with SEPSECS mutations. Herein we report a case with severe global developmental delay, myogenic changes in the lower limbs, and insomnia, but without progressive microcephaly and brain atrophy during infancy and toddlerhood in a child harboring the SEPSECS missense variant c.194A>G (p. Asn65Ser) and a novel splicing mutation c.701+1G>A. With these findings we communicate the first Chinese SEPSECS mutant case, and our report indicates that SEPSECS mutations can give rise to a milder phenotype.
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Affiliation(s)
- Tingyu Rong
- Department of Developmental and Behavioral Pediatrics, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Center for Brain Science and Brain-Inspired Technology, Shanghai, China
| | - Ruen Yao
- Department of Medical Genetics and Molecular Diagnostic Laboratory, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yujiao Deng
- Department of Developmental and Behavioral Pediatrics, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Center for Brain Science and Brain-Inspired Technology, Shanghai, China
| | - Qingmin Lin
- Department of Developmental and Behavioral Pediatrics, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Center for Brain Science and Brain-Inspired Technology, Shanghai, China
| | - Guanghai Wang
- Department of Developmental and Behavioral Pediatrics, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Center for Brain Science and Brain-Inspired Technology, Shanghai, China
| | - Jian Wang
- Department of Medical Genetics and Molecular Diagnostic Laboratory, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Fan Jiang
- Department of Developmental and Behavioral Pediatrics, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Center for Brain Science and Brain-Inspired Technology, Shanghai, China
| | - Yanrui Jiang
- Department of Developmental and Behavioral Pediatrics, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Center for Brain Science and Brain-Inspired Technology, Shanghai, China
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42
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Bayat A, Kløvgaard M, Johannesen KM, Barakat TS, Kievit A, Montomoli M, Parrini E, Pietrafusa N, Schelhaas J, van Slegtenhorst M, Miya K, Guerrini R, Tranebjærg L, Tümer Z, Rubboli G, Møller RS. Deciphering the premature mortality in PIGA-CDG - An untold story. Epilepsy Res 2020; 170:106530. [PMID: 33508693 DOI: 10.1016/j.eplepsyres.2020.106530] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 11/27/2020] [Accepted: 12/04/2020] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Congenital disorder of glycosylation (CDG) due to a defective phosphatidylinositol glycan anchor biosynthesis class A protein (PIGA) is a severe X-linked developmental and epileptic encephalopathy. Seizures are often treatment refractory, and patients have intellectual disability and global developmental delay. Previous reports have suggested that patients with PIGA-CDG have a high risk of premature mortality. This study aimed to evaluate the observed high mortality and the causes of death in PIGA-CDG patients. METHODS We reviewed the literature and collected additional unpublished patients through an international network. RESULTS In total, we reviewed the data of 88 patients of whom 30 patients born alive were deceased, and the overall mortality before the age of 20 years was 30 % (26/88). Age at death ranged from 15 days to 48 years of life. The median age at death was two years and more than half of the patients deceased in early childhood. The PIGA-specific mortality rate/1000 person-years was 44.9/1000 person-years (95 %, CI 31.4-64.3). There were no cases of definite or probable sudden unexpected death in epilepsy (SUDEP) and half of the patients died due to respiratory failure (15/30, 50 %) or possible SUDEP (3/30, 10 %). Three patients (10 %) died from severe cardiomyopathy, liver failure and gastrointestinal bleeding, respectively. The cause of death was unclassified in nine patients (30 %). Autopsies were rarely performed and the true cause of death remains unknown for the majority of patients. SIGNIFICANCE Our data indicate an increased risk of premature death in patients with PIGA-CDG when compared to most monogenic developmental and epileptic encephalopathies.
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Affiliation(s)
- Allan Bayat
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark; Department for Regional Health Services, University of Southern Denmark, Odense, Denmark.
| | - Marius Kløvgaard
- The Epilepsy Clinic, Department of Neurology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Katrine M Johannesen
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark; Department for Regional Health Services, University of Southern Denmark, Odense, Denmark
| | - Tahsin Stefan Barakat
- Department of Clinical Genetics, Erasmus MC - University Medical Center, Rotterdam, the Netherlands
| | - Anneke Kievit
- Department of Clinical Genetics, Erasmus MC - University Medical Center, Rotterdam, the Netherlands
| | - Martino Montomoli
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Meyer Children's Hospital, University of Florence, Florence, Italy
| | - Elena Parrini
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Meyer Children's Hospital, University of Florence, Florence, Italy
| | - Nicola Pietrafusa
- Department of Neuroscience and Neurorehabilitation, Bambino Gesù Pediatric Hospital, Rome, Italy
| | - Jurgen Schelhaas
- Stichting Epilepsie Instellingen Nederland (SEIN), the Netherlands
| | - Marjon van Slegtenhorst
- Department of Clinical Genetics, Erasmus MC - University Medical Center, Rotterdam, the Netherlands
| | - Kazushi Miya
- Department of Educational Sciences (Human Development and Welfare Course), University of Toyama, Faculty of Human Development, Toyama, Japan
| | - Renzo Guerrini
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Meyer Children's Hospital, University of Florence, Florence, Italy
| | - Lisbeth Tranebjærg
- Kennedy Center, Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Zeynep Tümer
- Kennedy Center, Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Guido Rubboli
- Department for Regional Health Services, University of Southern Denmark, Odense, Denmark; Department of Clinical Medicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark; Department for Regional Health Services, University of Southern Denmark, Odense, Denmark
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43
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von Hardenberg S, Richter MF, Hethey S, Yaspo ML, Auber B, Schlegelberger B, Illig T, Guthmann F, Christen HJ, Ripperger T, Bergmann AK. Rational therapy with vigabatrin and a ketogenic diet in a patient with GAD1 deficiency. Brain 2020; 143:e91. [PMID: 33146701 DOI: 10.1093/brain/awaa289] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Affiliation(s)
| | - Manuela F Richter
- Department of Neonatology, Children's and Youth Hospital Auf der Bult, Hannover, Germany
| | - Sven Hethey
- Department of Neuropediatric, Children's and Youth Hospital Auf der Bult, Hannover, Germany
| | - Marie-Laure Yaspo
- Otto Warburg Laboratory Gene Regulation and Systems Biology of Cancer, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Bernd Auber
- Department of Human Genetics, Hannover Medical School, Hannover, Germany
| | | | - Thomas Illig
- Department of Human Genetics, Hannover Medical School, Hannover, Germany
| | - Florian Guthmann
- Department of Neonatology, Children's and Youth Hospital Auf der Bult, Hannover, Germany
| | - Hans-Jürgen Christen
- Department of Neuropediatric, Children's and Youth Hospital Auf der Bult, Hannover, Germany
| | - Tim Ripperger
- Department of Human Genetics, Hannover Medical School, Hannover, Germany
| | - Anke K Bergmann
- Department of Human Genetics, Hannover Medical School, Hannover, Germany
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44
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Lobo FA, Vacas S, Rossetti AO, Robba C, Taccone FS. Does electroencephalographic burst suppression still play a role in the perioperative setting? Best Pract Res Clin Anaesthesiol 2020; 35:159-169. [PMID: 34030801 DOI: 10.1016/j.bpa.2020.10.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 10/21/2020] [Accepted: 10/27/2020] [Indexed: 12/18/2022]
Abstract
With the widespread use of electroencephalogram [EEG] monitoring during surgery or in the Intensive Care Unit [ICU], clinicians can sometimes face the pattern of burst suppression [BS]. The BS pattern corresponds to the continuous quasi-periodic alternation between high-voltage slow waves [the bursts] and periods of low voltage or even isoelectricity of the EEG signal [the suppression] and is extremely rare outside ICU and the operative room. BS can be secondary to increased anesthetic depth or a marker of cerebral damage, as a therapeutic endpoint [i.e., refractory status epilepticus or refractory intracranial hypertension]. In this review, we report the neurophysiological features of BS to better define its role during intraoperative and critical care settings.
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Affiliation(s)
- Francisco Almeida Lobo
- Anesthesiology Department, Centro Hospitalar de Trás-os-Montes e Alto Douro, Avenida da Noruega, Lordelo, 5000-508, Vila Real, Portugal.
| | - Susana Vacas
- Department of Anesthesiology and Perioperative Medicine, University of California Los Angeles, Reagan UCLA Medical Center, 757 Westwood Plaza #3325, Los Angeles, CA, 90095, USA.
| | - Andrea O Rossetti
- Department of Neurology, Lausanne University Hospital and University of Lausanne, CH-1011, Lausanne, Switzerland.
| | - Chiara Robba
- Azienda Ospedaliera Universitaria San Martino di Genova, Largo Rosanna Benzi,15, 16100, Genova, Italy.
| | - Fabio Silvio Taccone
- Hopital Érasme, Université Libre de Bruxelles, Department of Intensive Care Medicine, Route de Lennik, 808 1070, Brussels, Belgium.
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45
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Matricardi S, De Liso P, Freri E, Costa P, Castellotti B, Magri S, Gellera C, Granata T, Musante L, Lesca G, Oertel J, Craiu D, Hammer TB, Møller RS, Barisic N, Abou Jamra R, Polster T, Vigevano F, Marini C. Neonatal developmental and epileptic encephalopathy due to autosomal recessive variants in
SLC13A5
gene. Epilepsia 2020; 61:2474-2485. [DOI: 10.1111/epi.16699] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 08/18/2020] [Accepted: 08/31/2020] [Indexed: 02/06/2023]
Affiliation(s)
- Sara Matricardi
- Department of Child Neuropsychiatry Children’s Hospital Ancona Italy
| | - Paola De Liso
- Department of Neuroscience Istituto di Ricovero e Cura a Carattere Scientifico Bambino Gesù Children's Hospital Rome Italy
| | - Elena Freri
- Department of Pediatric Neuroscience Istituto di Ricovero e Cura a Carattere Scientifico Foundation Carlo Besta Neurological Institute Milan Italy
| | - Paola Costa
- Department of Neuropsychiatry Institute for Maternal and Child Health Istituto di Ricovero e Cura a Carattere Scientifico Burlo Garofolo Trieste Italy
| | - Barbara Castellotti
- Unit of Medical Genetics and Neurogenetics Istituto di Ricovero e Cura a Carattere Scientifico Foundation Carlo Besta Neurological Institute Milan Italy
| | - Stefania Magri
- Unit of Medical Genetics and Neurogenetics Istituto di Ricovero e Cura a Carattere Scientifico Foundation Carlo Besta Neurological Institute Milan Italy
| | - Cinzia Gellera
- Unit of Medical Genetics and Neurogenetics Istituto di Ricovero e Cura a Carattere Scientifico Foundation Carlo Besta Neurological Institute Milan Italy
| | - Tiziana Granata
- Department of Pediatric Neuroscience Istituto di Ricovero e Cura a Carattere Scientifico Foundation Carlo Besta Neurological Institute Milan Italy
| | - Luciana Musante
- Department of Medical Genetics Institute for Maternal and Child Health Istituto di Ricovero e Cura a Carattere Scientifico Burlo Garofolo Trieste Italy
| | - Gaetan Lesca
- Department of Medical Genetics Lyon Civil Hospices Lyon France
| | - Julie Oertel
- Department of Medical Genetics Archet Hospital 2, Nice University Hospital Center Nice France
| | - Dana Craiu
- Department of Clinical Neurosciences Carol Davila University of Medicine and Pharmacy Bucharest Bucharest Romania
- Pediatric Neurology Clinic Alexandru Obregia Hospital Bucharest Romania
| | | | - Rikke S. Møller
- Danish Epilepsy Center Filadelfia Dianalund Denmark
- Institute for Regional Health Services University of Southern Denmark Odense Denmark
| | - Nina Barisic
- Division of Child Neurology Department of Pediatrics Clinical Medical Center Zagreb University of Zagreb Medical School Zagreb Croatia
| | - Rami Abou Jamra
- Institute of Human Genetics University Medical Center Leipzig Leipzig Germany
| | - Tilman Polster
- Pediatric Epileptology Mara HospitalBethel Epilepsy Center Bielefeld Germany
| | - Federico Vigevano
- Department of Neuroscience Istituto di Ricovero e Cura a Carattere Scientifico Bambino Gesù Children's Hospital Rome Italy
| | - Carla Marini
- Department of Child Neuropsychiatry Children’s Hospital Ancona Italy
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46
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Tran B, Ji ZG, Xu M, Tsuchida TN, Cooper EC. Two KCNQ2 Encephalopathy Variants in the Calmodulin-Binding Helix A Exhibit Dominant-Negative Effects and Altered PIP 2 Interaction. Front Physiol 2020; 11:1144. [PMID: 33041849 PMCID: PMC7518097 DOI: 10.3389/fphys.2020.571813] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 08/18/2020] [Indexed: 11/13/2022] Open
Abstract
Heterozygous missense variants in KCNQ2, which encodes the potassium channel subunit Kv7.2, are among the most common genetic causes of severe neonatal-onset epileptic encephalopathy. Because about 20% of known severe Kv7.2 missense changes lie within the intracellular C-terminal region, improving understanding of the underlying pathogenic mechanisms is important. We analyzed the basis for the severe phenotypes of Kv7.2 A337T and A337G, variants in the C-terminal’s calmodulin (CaM)-binding Helix A. When expressed heterologously in mammalian cells, alone or in combination with wild type Kv7.2 or with wild type Kv7.2 and Kv7.3, both variants strongly suppressed channel currents. A337T channels expressed alone exhibited significantly reduced protein half-life and surface trafficking and co-immunoprecipitated less CaM. For both variants, increasing cellular phosphatidylinositol 4,5-bisphosphate (PIP2) by overexpression of PI(4)P5-kinase restored current densities. For both variants, the fraction of current suppressed by activation of M1 muscarinic receptors with 10 μM oxotremorine methiodide, which depletes PIP2, was less than for controls. During voltage-sensitive phosphatase-induced transient PIP2 depletion and resynthesize, potassium current inhibition and recovery kinetics were both markedly slowed. These results suggest that these variants may reduce currents by a mechanism not previously described: slowing of PIP2 migration between the bulk membrane and binding sites mediating channel electromechanical coupling. A novel Kv7.2/3-selective opener, SF0034, rescued current amplitudes. Our findings show that these two Helix A variants suppress channel current density strongly, consistent with their severe heterozygous phenotypes, implicate impairment of CaM and PIP2 regulation in KCNQ2 encephalopathy pathogenesis, and highlight the potential usefulness of selective Kv7 openers for this distinctive pathogenic mechanism and patient subgroup.
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Affiliation(s)
- Baouyen Tran
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Zhi-Gang Ji
- Department of Neurology, Baylor College of Medicine, Houston, TX, United States
| | - Mingxuan Xu
- Department of Neurology, Baylor College of Medicine, Houston, TX, United States
| | - Tammy N Tsuchida
- Departments of Pediatrics and Neurology, Children's National Medical Center, Washington, DC, United States
| | - Edward C Cooper
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States.,Department of Neurology, Baylor College of Medicine, Houston, TX, United States.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
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47
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Alghamdi M, Bashiri FA, Abdelhakim M, Adly N, Jamjoom DZ, Sumaily KM, Alghanem B, Arold ST. Phenotypic and molecular spectrum of pyridoxamine-5'-phosphate oxidase deficiency: A scoping review of 87 cases of pyridoxamine-5'-phosphate oxidase deficiency. Clin Genet 2020; 99:99-110. [PMID: 32888189 PMCID: PMC7820968 DOI: 10.1111/cge.13843] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/30/2020] [Accepted: 08/31/2020] [Indexed: 12/29/2022]
Abstract
Pyridoxamine-5'-phosphate oxidase (PNPO) deficiency is an autosomal recessive pyridoxal 5'-phosphate (PLP)-vitamin-responsive epileptic encephalopathy. The emerging feature of PNPO deficiency is the occurrence of refractory seizures in the first year of life. Pre-maturity and fetal distress, combined with neonatal seizures, are other associated key characteristics. The phenotype results from a dependency of PLP which regulates several enzymes in the body. We present the phenotypic and genotypic spectrum of (PNPO) deficiency based on a literature review (2002-2020) of reports (n = 33) of patients with confirmed PNPO deficiency (n = 87). All patients who received PLP (n = 36) showed a clinical response, with a complete dramatic PLP response with seizure cessation observed in 61% of patients. In spite of effective seizure control with PLP, approximately 56% of patients affected with PLP-dependent epilepsy suffer developmental delay/intellectual disability. There is no diagnostic biomarker, and molecular testing required for diagnosis. However, we noted that cerebrospinal fluid (CSF) PLP was low in 81%, CSF glycine was high in 80% and urinary vanillactic acid was high in 91% of the cases. We observed only a weak correlation between the severity of PNPO protein disruption and disease outcomes, indicating the importance of other factors, including seizure onset and time of therapy initiation. We found that pre-maturity, the delay in initiation of PLP therapy and early onset of seizures correlate with a poor neurocognitive outcome. Given the amenability of PNPO to PLP therapy for seizure control, early diagnosis is essential.
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Affiliation(s)
- Malak Alghamdi
- Medical Genetics Division, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia.,Department of Pediatrics, King Saud University Medical City, Riyadh, Saudi Arabia
| | - Fahad A Bashiri
- Department of Pediatrics, King Saud University Medical City, Riyadh, Saudi Arabia.,Neurology division, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Marwa Abdelhakim
- Computer, Electrical and Mathematical Science and Engineering Division (CEMSE), Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Nouran Adly
- College of Medicine Research Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Dima Z Jamjoom
- Department of Radiology and Medical Imaging, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Khalid M Sumaily
- Clinical Biochemistry Unit, Department of Laboratory Medicine, King Saud University Medical City, King Saud University, Riyadh, Saudi Arabia
| | - Bandar Alghanem
- Medical Research Core Facility and Platforms (MRCFP), King Abdullah International Medical, Research Center/King Saud bin Abdulaziz University for Health Sciences (KSAU-HS), King, Abdulaziz Medical City (KAMC), NGHA, Riyadh, Saudi Arabia
| | - Stefan T Arold
- Computational Bioscience, Research Center (CBRC); Division of Biological and Environmental Sciences and Engineering, (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.,Centre de Biochimie Structurale, CNRS, INSERM, Université de Montpellier, Montpellier, France
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48
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Cabasson S, Van-Gils J, Villéga F, Abi-Warde MT, Barcia G, Lazaro L, Cancés C, Chelly J, Karsenty C, Rivera S, de Saint-Martin A, Trimouille A, Villard L, Pédespan JM. Early-onset epileptic encephalopathy related to germline PIGA mutations: A series of 5 cases. Eur J Paediatr Neurol 2020; 28:214-220. [PMID: 32694024 DOI: 10.1016/j.ejpn.2020.06.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 05/25/2020] [Accepted: 06/07/2020] [Indexed: 11/26/2022]
Abstract
The molecular diagnosis of early-onset epileptic encephalopathy (EOEE), an expanding field in child neurology, is becoming increasingly possible thanks to the widespread availability of next-generation sequencing and whole-exome sequencing. In the past 15 years, mutations in STXBP1, KCNQ2, SCN2A, SCN8A and numerous other genes have been reported, giving a more accurate insight for these rare diseases. Among these genes, germline mutations in Phosphatidyl Inositol Glycan A (PIGA) gene were first reported in 2012. Located on Xp22.2, PIGA is involved in the synthesis of GPI (glycosylphosphatidylinositol) which acts as a membrane anchor for different proteins: enzymes, adhesion molecules, regulation of the complement way, and co-receptor in transduction signal. Children suffering from this condition exhibit developmental delay with early-onset epilepsy, severe dysmorphic signs, multi-visceral anomalies and early death in the most severe forms. Here, we report five cases of germline PIGA mutations, with two missense mutations that have not been reported to date. We provide a new insight into the electroclinical phenotype. At the onset, epileptic spasms and focal-onset seizures with upper limbs and ocular involvements were present. Epilepsy proved pharmacoresistant in 4 out of 5 cases. Interictal EEG may be normal at the onset of epilepsy, but abnormalities in electroencephalographic studies were eventually present in all cases. Different types of seizures may be present simultaneously, and epileptic phenotypes evolve with aging.
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Affiliation(s)
- Sébastien Cabasson
- Unité de neurologie de l'enfant et de l'adolescent. Centre Hospitalo-Universitaire de Bordeaux, Hôpital Pellegrin Enfants, Place Amélie-Raba-Léon, 33 076, Bordeaux cedex, France.
| | - Julien Van-Gils
- Service de génétique médicale. Centre Hospitalo-Universitaire de Bordeaux, Hôpital Pellegrin Enfants, Place Amélie-Raba-Léon, 33 076, Bordeaux cedex, France
| | - Frédéric Villéga
- Unité de neurologie de l'enfant et de l'adolescent. Centre Hospitalo-Universitaire de Bordeaux, Hôpital Pellegrin Enfants, Place Amélie-Raba-Léon, 33 076, Bordeaux cedex, France
| | - Marie-Thérèse Abi-Warde
- Département de neurologie pédiatrique, CHRU de Strasbourg, 1 avenue Molière, 67 000, Strasbourg, France
| | - Giulia Barcia
- Service de génétique médicale. Unité de génétique moléculaire, unité d'embryologie moléculaire. Hôpital Necker-Enfants Malades, Tour Lavoisier (3(ème) étage), 149 rue de Sèvres, 75743, Paris cedex 15, France
| | - Leila Lazaro
- Service de pédiatrie. Centre hospitalier de la côte basque, 13 avenue de l'interne Jacques-Loëb, 64 109, Bayonne, France
| | - Claude Cancés
- Service de Neuropédiatrie, Hôpital Purpan, 330 avenue de Grande-Bretagne, 31300, Toulouse, France
| | - Jamel Chelly
- Unité de génétique moléculaire, Nouvel Hôpital Civil, 1 place de l'Hôpital, BP 426, 67 091, Strasbourg cedex, France
| | - Caroline Karsenty
- Service de Neuropédiatrie, Hôpital Purpan, 330 avenue de Grande-Bretagne, 31300, Toulouse, France
| | - Serge Rivera
- Service de pédiatrie. Centre hospitalier de la côte basque, 13 avenue de l'interne Jacques-Loëb, 64 109, Bayonne, France
| | - Anne de Saint-Martin
- Département de neurologie pédiatrique, CHRU de Strasbourg, 1 avenue Molière, 67 000, Strasbourg, France
| | - Aurélien Trimouille
- Service de génétique médicale. Centre Hospitalo-Universitaire de Bordeaux, Hôpital Pellegrin Enfants, Place Amélie-Raba-Léon, 33 076, Bordeaux cedex, France
| | - Laurent Villard
- Département de génétique médicale, Laboratoire de génétique moléculaire, Assistance publique-Hôpitaux de Marseille, 264 rue Saint-Pierre, 13 385, Marseille cedex 5, France
| | - Jean-Michel Pédespan
- Unité de neurologie de l'enfant et de l'adolescent. Centre Hospitalo-Universitaire de Bordeaux, Hôpital Pellegrin Enfants, Place Amélie-Raba-Léon, 33 076, Bordeaux cedex, France
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Schoenmakers E, Chatterjee K. Human Disorders Affecting the Selenocysteine Incorporation Pathway Cause Systemic Selenoprotein Deficiency. Antioxid Redox Signal 2020; 33:481-497. [PMID: 32295391 PMCID: PMC7409586 DOI: 10.1089/ars.2020.8097] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Significance: Generalized selenoprotein deficiency has been associated with mutations in SECISBP2, SEPSECS, and TRU-TCA1-1, 3 factors that are crucial for incorporation of the amino acid selenocysteine (Sec) into at least 25 human selenoproteins. SECISBP2 and TRU-TCA1-1 defects are characterized by a multisystem phenotype due to deficiencies of antioxidant and tissue-specific selenoproteins, together with abnormal thyroid hormone levels reflecting impaired hormone metabolism by deiodinase selenoenzymes. SEPSECS mutations are associated with a predominantly neurological phenotype with progressive cerebello-cerebral atrophy. Recent Advances: The recent identification of individuals with defects in genes encoding components of the selenocysteine insertion pathway has delineated complex and multisystem disorders, reflecting a lack of selenoproteins in specific tissues, oxidative damage due to lack of oxidoreductase-active selenoproteins and other pathways whose nature is unclear. Critical Issues: Abnormal thyroid hormone metabolism in patients can be corrected by triiodothyronine (T3) treatment. No specific therapies for other phenotypes (muscular dystrophy, male infertility, hearing loss, neurodegeneration) exist as yet, but their severity often requires supportive medical intervention. Future Directions: These disorders provide unique insights into the role of selenoproteins in humans. The long-term consequences of reduced cellular antioxidant capacity remain unknown, and future surveillance of patients may reveal time-dependent phenotypes (e.g., neoplasia, aging) or consequences of deficiency of selenoproteins whose function remains to be elucidated. The role of antioxidant therapies requires evaluation. Antioxid. Redox Signal. 33, 481-497.
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Affiliation(s)
- Erik Schoenmakers
- Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, United Kingdom
| | - Krishna Chatterjee
- Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, United Kingdom
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Rochtus AM, Goldstein RD, Holm IA, Brownstein CA, Pérez‐Palma E, Haynes R, Lal D, Poduri AH. The role of sodium channels in sudden unexpected death in pediatrics. Mol Genet Genomic Med 2020; 8:e1309. [PMID: 32449611 PMCID: PMC7434613 DOI: 10.1002/mgg3.1309] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/21/2020] [Accepted: 04/27/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Sudden Unexpected Death in Pediatrics (SUDP) is a tragic event, likely caused by the complex interaction of multiple factors. The presence of hippocampal abnormalities in many children with SUDP suggests that epilepsy-related mechanisms may contribute to death, similar to Sudden Unexplained Death in Epilepsy. Because of known associations between the genes SCN1A and SCN5A and sudden death, and shared mechanisms and patterns of expression in genes encoding many voltage-gated sodium channels (VGSCs), we hypothesized that individuals dying from SUDP have pathogenic variants across the entire family of cardiac arrhythmia- and epilepsy-associated VGSC genes. METHODS To address this hypothesis, we evaluated whole-exome sequencing data from infants and children with SUDP for variants in VGSC genes, reviewed the literature for all SUDP-associated variants in VGSCs, applied a novel paralog analysis to all variants, and evaluated all variants according to American College of Medical Genetics and Genomics (ACMG) guidelines. RESULTS In our cohort of 73 cases of SUDP, we assessed 11 variants as pathogenic in SCN1A, SCN1B, and SCN10A, genes with long-standing disease associations, and in SCN3A, SCN4A, and SCN9A, VGSC gene paralogs with more recent disease associations. From the literature, we identified 82 VGSC variants in SUDP cases. Pathogenic variants clustered at conserved amino acid sites intolerant to variation across the VGSC genes, which is unlikely to occur in the general population (p < .0001). For 54% of variants previously reported in literature, we identified conflicting evidence regarding pathogenicity when applying ACMG criteria and modern population data. CONCLUSION We report variants in several VGSC genes in cases with SUDP, involving both arrhythmia- and epilepsy-associated genes. Accurate variant assessment as well as future studies are essential for an improved understanding of the contribution of sodium channel-related variants to SUDP.
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Affiliation(s)
- Anne M. Rochtus
- Department of NeurologyBoston Children's Hospital and Harvard Medical SchoolBostonMAUSA
- Robert’s Program on Sudden Death in PediatricsBoston Children’s HospitalBostonMAUSA
- Department of PediatricsUniversity of LeuvenLeuvenBelgium
| | - Richard D. Goldstein
- Robert’s Program on Sudden Death in PediatricsBoston Children’s HospitalBostonMAUSA
- Department of PediatricsBoston Children’s Hospital and Harvard Medical SchoolBostonMAUSA
| | - Ingrid A. Holm
- Robert’s Program on Sudden Death in PediatricsBoston Children’s HospitalBostonMAUSA
- Department of PediatricsBoston Children’s Hospital and Harvard Medical SchoolBostonMAUSA
- Department of MedicineDivision of Genetics and Genomics and the Manton Center for Orphan Disease ResearchBoston Children's HospitalBostonMAUSA
| | - Catherine A. Brownstein
- Robert’s Program on Sudden Death in PediatricsBoston Children’s HospitalBostonMAUSA
- Department of PediatricsBoston Children’s Hospital and Harvard Medical SchoolBostonMAUSA
- Department of MedicineDivision of Genetics and Genomics and the Manton Center for Orphan Disease ResearchBoston Children's HospitalBostonMAUSA
| | - Eduardo Pérez‐Palma
- Genomic Medicine InstituteLerner Research InstituteCleveland ClinicClevelandOHUSA
- Cologne Center for GenomicsUniversity of CologneCologneGermany
| | - Robin Haynes
- Robert’s Program on Sudden Death in PediatricsBoston Children’s HospitalBostonMAUSA
- Department of PathologyBoston Children’s Hospital and Harvard Medical SchoolBostonMAUSA
| | - Dennis Lal
- Genomic Medicine InstituteLerner Research InstituteCleveland ClinicClevelandOHUSA
- Cologne Center for GenomicsUniversity of CologneCologneGermany
- Stanley Center for Psychiatric ResearchBroad Institute of Harvard and MITCambridgeMAUSA
| | - Annapurna H. Poduri
- Department of NeurologyBoston Children's Hospital and Harvard Medical SchoolBostonMAUSA
- Robert’s Program on Sudden Death in PediatricsBoston Children’s HospitalBostonMAUSA
- Stanley Center for Psychiatric ResearchBroad Institute of Harvard and MITCambridgeMAUSA
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