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Julia-Palacios NA, Kuseyri Hübschmann O, Olivella M, Pons R, Horvath G, Lücke T, Fung CW, Wong SN, Cortès-Saladelafont E, Rovira-Remisa MM, Yıldız Y, Mercimek-Andrews S, Assmann B, Stevanović G, Manti F, Brennenstuhl H, Jung-Klawitter S, Jeltsch K, Sivri HS, Garbade SF, García-Cazorla À, Opladen T. The continuously evolving phenotype of succinic semialdehyde dehydrogenase deficiency. J Inherit Metab Dis 2024; 47:447-462. [PMID: 38499966 DOI: 10.1002/jimd.12723] [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: 12/04/2023] [Revised: 02/15/2024] [Accepted: 02/20/2024] [Indexed: 03/20/2024]
Abstract
The objective of the study is to evaluate the evolving phenotype and genetic spectrum of patients with succinic semialdehyde dehydrogenase deficiency (SSADHD) in long-term follow-up. Longitudinal clinical and biochemical data of 22 pediatric and 9 adult individuals with SSADHD from the patient registry of the International Working Group on Neurotransmitter related Disorders (iNTD) were studied with in silico analyses, pathogenicity scores and molecular modeling of ALDH5A1 variants. Leading initial symptoms, with onset in infancy, were developmental delay and hypotonia. Year of birth and specific initial symptoms influenced the diagnostic delay. Clinical phenotype of 26 individuals (median 12 years, range 1.8-33.4 years) showed a diversifying course in follow-up: 77% behavioral problems, 76% coordination problems, 73% speech disorders, 58% epileptic seizures and 40% movement disorders. After ataxia, dystonia (19%), chorea (11%) and hypokinesia (15%) were the most frequent movement disorders. Involvement of the dentate nucleus in brain imaging was observed together with movement disorders or coordination problems. Short attention span (78.6%) and distractibility (71.4%) were the most frequently behavior traits mentioned by parents while impulsiveness, problems communicating wishes or needs and compulsive behavior were addressed as strongly interfering with family life. Treatment was mainly aimed to control epileptic seizures and psychiatric symptoms. Four new pathogenic variants were identified. In silico scoring system, protein activity and pathogenicity score revealed a high correlation. A genotype/phenotype correlation was not observed, even in siblings. This study presents the diversifying characteristics of disease phenotype during the disease course, highlighting movement disorders, widens the knowledge on the genotypic spectrum of SSADHD and emphasizes a reliable application of in silico approaches.
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Affiliation(s)
- Natalia Alexandra Julia-Palacios
- Inborn Errors of Metabolism Unit, Department of Neurology, Institut de Recerca Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain
| | - Oya Kuseyri Hübschmann
- Center for Pediatric and Adolescent Medicine Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Medical Faculty Heidelberg, Heidelberg, Germany
| | - Mireia Olivella
- Bioinfomatics and Medical Statistics Group, University of Vic-Central University of Catalonia, Vic, Spain
| | - Roser Pons
- First Department of Pediatrics, Aghia Sofia Hospital, University of Athens, Athens, Greece
| | - Gabriella Horvath
- Division of Biochemical Genetics, Department of Pediatrics, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Thomas Lücke
- St. Josef-Hospital, University Children's Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Cheuk-Wing Fung
- Department of Pediatrics and Adolescent Medicine, The Hong Kong Children's Hospital, Hong Kong, Hong Kong
| | - Suet-Na Wong
- Department of Pediatrics and Adolescent Medicine, The Hong Kong Children's Hospital, Hong Kong, Hong Kong
| | - Elisenda Cortès-Saladelafont
- Inborn Errors of Metabolism Unit, Department of Neurology, Institut de Recerca Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain
- Unit of Inherited Metabolic Diseases and Child Neurology, Department of Pediatrics, Hospital Germans Trias i Pujol, Badalona and Faculty of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - M Mar Rovira-Remisa
- Unit of Inherited Metabolic Diseases and Child Neurology, Department of Pediatrics, Hospital Germans Trias i Pujol, Badalona and Faculty of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Yılmaz Yıldız
- Division of Pediatric Metabolism, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Saadet Mercimek-Andrews
- The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Medical Genetics, Faculty of Medicine and Dentistry, Women and Children's Health Research Institute, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
| | - Birgit Assmann
- Center for Pediatric and Adolescent Medicine Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Medical Faculty Heidelberg, Heidelberg, Germany
| | - Galina Stevanović
- Clinic of Neurology and Psychiatry for Children and Youth, School of Medicine, University of Belgrade, Belgrade, Serbia
| | - Filippo Manti
- Unit of Child Neurology and Psychiatry, Department of Human Neuroscience, Università degli Studi di Roma La Sapienza, Rome, Italy
| | - Heiko Brennenstuhl
- Center for Pediatric and Adolescent Medicine Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Medical Faculty Heidelberg, Heidelberg, Germany
- Institute of Human Genetics, Heidelberg University, Medical Faculty Heidelberg, Heidelberg, Germany
| | - Sabine Jung-Klawitter
- Center for Pediatric and Adolescent Medicine Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Medical Faculty Heidelberg, Heidelberg, Germany
| | - Kathrin Jeltsch
- Center for Pediatric and Adolescent Medicine Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Medical Faculty Heidelberg, Heidelberg, Germany
| | - H Serap Sivri
- Division of Pediatric Metabolism, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Sven F Garbade
- Center for Pediatric and Adolescent Medicine Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Medical Faculty Heidelberg, Heidelberg, Germany
| | - Àngels García-Cazorla
- Inborn Errors of Metabolism Unit, Department of Neurology, Institut de Recerca Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain
| | - Thomas Opladen
- Center for Pediatric and Adolescent Medicine Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg University, Medical Faculty Heidelberg, Heidelberg, Germany
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Tokatly Latzer I, Bertoldi M, Blau N, DiBacco ML, Elsea SH, García-Cazorla À, Gibson KM, Gropman AL, Hanson E, Hoffman C, Jeltsch K, Juliá-Palacios N, Knerr I, Lee HHC, Malaspina P, McConnell A, Opladen T, Oppebøen M, Rotenberg A, Walterfang M, Wang-Tso L, Wevers RA, Roullet JB, Pearl PL. Consensus guidelines for the diagnosis and management of succinic semialdehyde dehydrogenase deficiency. Mol Genet Metab 2024; 142:108363. [PMID: 38452608 PMCID: PMC11073920 DOI: 10.1016/j.ymgme.2024.108363] [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: 11/17/2023] [Revised: 02/27/2024] [Accepted: 02/29/2024] [Indexed: 03/09/2024]
Abstract
Succinic semialdehyde dehydrogenase deficiency (SSADHD) (OMIM #271980) is a rare autosomal recessive metabolic disorder caused by pathogenic variants of ALDH5A1. Deficiency of SSADH results in accumulation of γ-aminobutyric acid (GABA) and other GABA-related metabolites. The clinical phenotype of SSADHD includes a broad spectrum of non-pathognomonic symptoms such as cognitive disabilities, communication and language deficits, movement disorders, epilepsy, sleep disturbances, attention problems, anxiety, and obsessive-compulsive traits. Current treatment options for SSADHD remain supportive, but there are ongoing attempts to develop targeted genetic therapies. This study aimed to create consensus guidelines for the diagnosis and management of SSADHD. Thirty relevant statements were initially addressed by a systematic literature review, resulting in different evidence levels of strength according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria. The highest level of evidence (level A), based on randomized controlled trials, was unavailable for any of the statements. Based on cohort studies, Level B evidence was available for 12 (40%) of the statements. Thereupon, through a process following the Delphi Method and directed by the Appraisal of Guidelines for Research and Evaluation (AGREE II) criteria, expert opinion was sought, and members of an SSADHD Consensus Group evaluated all the statements. The group consisted of neurologists, epileptologists, neuropsychologists, neurophysiologists, metabolic disease specialists, clinical and biochemical geneticists, and laboratory scientists affiliated with 19 institutions from 11 countries who have clinical experience with SSADHD patients and have studied the disorder. Representatives from parent groups were also included in the Consensus Group. An analysis of the survey's results yielded 25 (83%) strong and 5 (17%) weak agreement strengths. These first-of-their-kind consensus guidelines intend to consolidate and unify the optimal care that can be provided to individuals with SSADHD.
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Affiliation(s)
- Itay Tokatly Latzer
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; School of Medicine, Faculty of Medicine and Health Sciences, Tel-Aviv University, Tel Aviv, Israel.
| | - Mariarita Bertoldi
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Italy.
| | - Nenad Blau
- Division of Metabolism, University Children's Hospital, Zürich, Switzerland; Children's Research Center, University Children's Hospital Zurich, Switzerland.
| | - Melissa L DiBacco
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Sarah H Elsea
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Àngels García-Cazorla
- Neurometabolic Unit, Neurology Department, Institut de Recerca, Hospital Sant Joan de Déu, Barcelona, Spain.
| | - K Michael Gibson
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, USA.
| | - Andrea L Gropman
- Division of Neurogenetics and Neurodevelopmental Disabilities, Children's National Hospital, Washington, D.C, USA.
| | - Ellen Hanson
- Human Neurobehavioral Core, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, MA 02115, USA.
| | | | - Kathrin Jeltsch
- Heidelberg University, Medical Faculty Heidelberg, Center for Pediatric and Adolescent Medicine, Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg, Germany.
| | - Natalia Juliá-Palacios
- Neurometabolic Unit, Neurology Department, Institut de Recerca, Hospital Sant Joan de Déu, Barcelona, Spain.
| | - Ina Knerr
- National Centre for Inherited Metabolic Disorders, Children's Health Ireland, Temple Street, Dublin, Ireland.
| | - Henry H C Lee
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA.
| | - Patrizia Malaspina
- Department of Biology, Tor Vergata University, Via della Ricerca Scientifica s.n.c., Rome 00133, Italy.
| | | | - Thomas Opladen
- Heidelberg University, Medical Faculty Heidelberg, Center for Pediatric and Adolescent Medicine, Department I, Division of Pediatric Neurology and Metabolic Medicine, Heidelberg, Germany.
| | | | - Alexander Rotenberg
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA.
| | - Mark Walterfang
- Neuropsychiatry, Royal Melbourne Hospital, Melbourne, Australia; Department of Psychiatry, University of Melbourne, Melbourne, Australia; Florey Institute of Neuroscience and Mental Health, Melbourne, Australia; Department of Health and Medical Sciences, Edith Cowan University, Perth, Australia.
| | - Lee Wang-Tso
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan
| | - Ron A Wevers
- Translational Metabolic Laboratory, Department Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands.
| | - Jean-Baptiste Roullet
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, USA.
| | - Phillip L Pearl
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
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Ortigoza-Escobar JD. Catching the Culprit: How Chorea May Signal an Inborn Error of Metabolism. Tremor Other Hyperkinet Mov (N Y) 2023; 13:36. [PMID: 37810989 PMCID: PMC10558026 DOI: 10.5334/tohm.801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Accepted: 09/27/2023] [Indexed: 10/10/2023] Open
Abstract
Background Movement disorders, particularly chorea, are uncommon in inborn errors of metabolism, but their identification is essential for improved clinical outcomes. In this context, comprehensive descriptions of movement disorders are limited and primarily derived from single cases or small patient series, highlighting the need for increased awareness and additional research in this field. Methods A systematic review was conducted using the MEDLINE database and GeneReviews. The search included studies on inborn errors of metabolism associated with chorea, athetosis, or ballismus. The review adhered to PRISMA guidelines. Results The systematic review analyzed 76 studies out of 2350 records, encompassing the period from 1964 to 2022. Chorea was observed in 90.1% of the 173 patients, followed by athetosis in 5.7%. Various inborn errors of metabolism showed an association with chorea, with trace elements and metals being the most frequent. Cognitive and developmental abnormalities were common in the cohort. Frequent neurological features included seizures, dysarthria, and optic atrophy, whereas non-neurological features included, among others, facial dysmorphia and failure to thrive. Neuroimaging and biochemical testing played crucial roles in aiding diagnosis, revealing abnormal findings in 34.1% and 47.9% of patients, respectively. However, symptomatic treatment efficacy for movement disorders was limited. Discussion This study emphasizes the complexities of chorea in inborn errors of metabolism. A systematic approach with red flags, biochemical testing, and neuroimaging is required for diagnosis. Collaboration between neurologists, geneticists, and metabolic specialists is crucial for improving early detection and individualized treatment. Utilizing genetic testing technologies and potential therapeutic avenues can aid in the improvement of patient outcomes.
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Affiliation(s)
- Juan Darío Ortigoza-Escobar
- Department of Paediatric Neurology, Hospital Sant Joan de Déu, Barcelona, Spain
- European Reference Network for Rare Neurological Diseases (ERN-RND), Barcelona, Spain
- U-703 Centre for Biomedical Research on Rare Diseases (CIBER-ER), Instituto de Salud Carlos III, Barcelona, Spain
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Ataxia in Neurometabolic Disorders. Metabolites 2022; 13:metabo13010047. [PMID: 36676973 PMCID: PMC9866741 DOI: 10.3390/metabo13010047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/19/2022] [Accepted: 12/19/2022] [Indexed: 12/29/2022] Open
Abstract
Ataxia is a movement disorder that manifests during the execution of purposeful movements. It results from damage to the structures of the cerebellum and its connections or the posterior cords of the spinal cord. It should be noted that, in addition to occurring as part of many diseases, pediatric ataxia is a common symptom in neurometabolic diseases. To date, there are more than 150 inherited metabolic disorders that can manifest as ataxia in children. Neuroimaging studies (magnetic resonance imaging of the head and spinal cord) are essential in the diagnosis of ataxia, and genetic studies are performed when metabolic diseases are suspected. It is important to remember that most of these disorders are progressive if left untreated. Therefore, it is crucial to include neurometabolic disorders in the differential diagnosis of ataxia, so that an early diagnosis can be made. Initiating prompt treatment influences positive neurodevelopmental outcomes.
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Pearl PL, DiBacco ML, Papadelis C, Opladen T, Hanson E, Roullet JB, Gibson KM. Succinic Semialdehyde Dehydrogenase Deficiency: Review of the Natural History Study. J Child Neurol 2021; 36:1153-1161. [PMID: 33393837 PMCID: PMC8254814 DOI: 10.1177/0883073820981262] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The SSADHD Natural History Study was initiated in 2019 to define the natural course and identify biomarkers correlating with severity. METHODS The study is conducted by 4 institutions: BCH (US clinical), WSU (bioanalytical core), USF (biostatistical core), and Heidelberg (iNTD), with support from the family advocacy group (SSADH Association). Recruitment goals were to study 20 patients on-site at BCH, 10 with iNTD, and 25 as a standard-of care cohort. RESULTS At this half-way point of this longitudinal study, 28 subjects have been recruited (57% female, mean 9 years, range 18 months-40 years). Epilepsy is present in half and increases in incidence and severity, as do psychiatric symptoms, in adolescence and adulthood. The average Full Scale IQ (FSIQ) was 53 (Verbal score of 56, Non Verbal score of 49), and half scored as having ASD. Although there was no correlation between gene variant and phenotypic severity, there were extreme cases of lowest functioning in one individual and highest in another that may have genotype-phenotype correlation. The most common EEG finding was mild background slowing with rare epileptiform activity, whereas high-density EEG and magnetoencephalography showed reduction in the gamma frequency band consistent with GABAergic dysfunction. MR spectroscopy showed elevations in the GABA/NAA ratio in all regions studied with no crossover between subjects and controls. CONCLUSIONS The SSADH Natural History Study is providing a unique opportunity to study the complex pathophysiology longitudinally and derive electrophysiologic, neuroimaging, and laboratory data for correlation and to serve as biomarkers for clinical trials and prognostic assessments in this ultra-rare inherited disorder of GABA metabolism.
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Affiliation(s)
- Phillip L Pearl
- Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA
| | - Melissa L DiBacco
- Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA
| | - Christos Papadelis
- Jane and John Justin Neuroscience Center, Cook Children’s Health Care System, 1500 Cooper Street, Fort Worth, TX 76104, USA; Department of Pediatrics, TCU and UNTHSC School of Medicine, Fort Worth, TX, USA; Laboratory of Children’s Brain Dynamics, Division of Newborn Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Thomas Opladen
- Department of Child Neurology and Metabolic Disorders, University Children’s Hospital, Heidelberg, Germany
| | - Ellen Hanson
- Neurodevelopmental Core, Boston Children’s Hospital, Harvard Medical School, Boston, MA
| | - Jean-Baptiste Roullet
- College of Pharmacy, Department of Pharmacotherapy, Washington State University, Spokane, WA
| | - K. Michael Gibson
- College of Pharmacy, Department of Pharmacotherapy, Washington State University, Spokane, WA
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Gavrilovici C, Rho JM. Metabolic epilepsies amenable to ketogenic therapies: Indications, contraindications, and underlying mechanisms. J Inherit Metab Dis 2021; 44:42-53. [PMID: 32654164 DOI: 10.1002/jimd.12283] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 07/04/2020] [Accepted: 07/07/2020] [Indexed: 12/20/2022]
Abstract
Metabolic epilepsies arise in the context of rare inborn errors of metabolism (IEM), notably glucose transporter type 1 deficiency syndrome, succinic semialdehyde dehydrogenase deficiency, pyruvate dehydrogenase complex deficiency, nonketotic hyperglycinemia, and mitochondrial cytopathies. A common feature of these disorders is impaired bioenergetics, which through incompletely defined mechanisms result in a wide spectrum of neurological symptoms, such as epileptic seizures, developmental delay, and movement disorders. The ketogenic diet (KD) has been successfully utilized to treat such conditions to varying degrees. While the mechanisms underlying the clinical efficacy of the KD in IEM remain unclear, it is likely that the proposed heterogeneous targets influenced by the KD work in concert to rectify or ameliorate the downstream negative consequences of genetic mutations affecting key metabolic enzymes and substrates-such as oxidative stress and cell death. These beneficial effects can be broadly grouped into restoration of impaired bioenergetics and synaptic dysfunction, improved redox homeostasis, anti-inflammatory, and epigenetic activity. Hence, it is conceivable that the KD might prove useful in other metabolic disorders that present with epileptic seizures. At the same time, however, there are notable contraindications to KD use, such as fatty acid oxidation disorders. Clearly, more research is needed to better characterize those metabolic epilepsies that would be amenable to ketogenic therapies, both experimentally and clinically. In the end, the expanded knowledge base will be critical to designing metabolism-based treatments that can afford greater clinical efficacy and tolerability compared to current KD approaches, and improved long-term outcomes for patients.
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Affiliation(s)
- Cezar Gavrilovici
- Departments of Neurosciences and Pediatrics, University of California San Diego, Rady Children's Hospital, San Diego, California, USA
| | - Jong M Rho
- Departments of Neurosciences and Pediatrics, University of California San Diego, Rady Children's Hospital, San Diego, California, USA
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7
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Koenig MK, Hodgeman R, Riviello JJ, Chung W, Bain J, Chiriboga CA, Ichikawa K, Osaka H, Tsuji M, Gibson KM, Bonnen PE, Pearl PL. Phenotype of GABA-transaminase deficiency. Neurology 2017; 88:1919-1924. [PMID: 28411234 DOI: 10.1212/wnl.0000000000003936] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 02/27/2017] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE We report a case series of 10 patients with γ-aminobutyric acid (GABA)-transaminase deficiency including a novel therapeutic trial and an expanded phenotype. METHODS Case ascertainment, literature review, comprehensive evaluations, and long-term treatment with flumazenil. RESULTS All patients presented with neonatal or early infantile-onset encephalopathy; other features were hypotonia, hypersomnolence, epilepsy, choreoathetosis, and accelerated linear growth. EEGs showed burst-suppression, modified hypsarrhythmia, multifocal spikes, and generalized spike-wave. Five of the 10 patients are currently alive with age at last follow-up between 18 months and 9.5 years. Treatment with continuous flumazenil was implemented in 2 patients. One patient, with a milder phenotype, began treatment at age 21 months and has continued for 20 months with improved alertness and less excessive adventitious movements. The second patient had a more severe phenotype and was 7 years of age at initiation of flumazenil, which was not continued. CONCLUSIONS GABA-transaminase deficiency presents with neonatal or infantile-onset encephalopathy including hypersomnolence and choreoathetosis. A widened phenotypic spectrum is reported as opposed to lethality by 2 years of age. The GABA-A benzodiazepine receptor antagonist flumazenil may represent a therapeutic strategy.
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Affiliation(s)
- Mary Kay Koenig
- From Child and Adolescent Neurology (M.K.K.), University of Texas Medical School, Houston; Neurology (R.H., P.L.P.), Boston Children's Hospital, Harvard Medical School, MA; Child Neurology (J.J.R., W.C., J.B., C.A.C.), Columbia University School of Medicine, New York, NY; Neurology (K.I., M.T.), Kanagawa Children's Medical Center, Yokohama; Pediatrics (H.O.), Jichi Medical School, Tochigi, Japan; Experimental and Systems Pharmacology (K.M.G.), Washington State University, Spokane; and Molecular and Human Genetics (P.E.B.), Baylor College of Medicine, Houston, TX
| | - Ryan Hodgeman
- From Child and Adolescent Neurology (M.K.K.), University of Texas Medical School, Houston; Neurology (R.H., P.L.P.), Boston Children's Hospital, Harvard Medical School, MA; Child Neurology (J.J.R., W.C., J.B., C.A.C.), Columbia University School of Medicine, New York, NY; Neurology (K.I., M.T.), Kanagawa Children's Medical Center, Yokohama; Pediatrics (H.O.), Jichi Medical School, Tochigi, Japan; Experimental and Systems Pharmacology (K.M.G.), Washington State University, Spokane; and Molecular and Human Genetics (P.E.B.), Baylor College of Medicine, Houston, TX
| | - James J Riviello
- From Child and Adolescent Neurology (M.K.K.), University of Texas Medical School, Houston; Neurology (R.H., P.L.P.), Boston Children's Hospital, Harvard Medical School, MA; Child Neurology (J.J.R., W.C., J.B., C.A.C.), Columbia University School of Medicine, New York, NY; Neurology (K.I., M.T.), Kanagawa Children's Medical Center, Yokohama; Pediatrics (H.O.), Jichi Medical School, Tochigi, Japan; Experimental and Systems Pharmacology (K.M.G.), Washington State University, Spokane; and Molecular and Human Genetics (P.E.B.), Baylor College of Medicine, Houston, TX
| | - Wendy Chung
- From Child and Adolescent Neurology (M.K.K.), University of Texas Medical School, Houston; Neurology (R.H., P.L.P.), Boston Children's Hospital, Harvard Medical School, MA; Child Neurology (J.J.R., W.C., J.B., C.A.C.), Columbia University School of Medicine, New York, NY; Neurology (K.I., M.T.), Kanagawa Children's Medical Center, Yokohama; Pediatrics (H.O.), Jichi Medical School, Tochigi, Japan; Experimental and Systems Pharmacology (K.M.G.), Washington State University, Spokane; and Molecular and Human Genetics (P.E.B.), Baylor College of Medicine, Houston, TX
| | - Jennifer Bain
- From Child and Adolescent Neurology (M.K.K.), University of Texas Medical School, Houston; Neurology (R.H., P.L.P.), Boston Children's Hospital, Harvard Medical School, MA; Child Neurology (J.J.R., W.C., J.B., C.A.C.), Columbia University School of Medicine, New York, NY; Neurology (K.I., M.T.), Kanagawa Children's Medical Center, Yokohama; Pediatrics (H.O.), Jichi Medical School, Tochigi, Japan; Experimental and Systems Pharmacology (K.M.G.), Washington State University, Spokane; and Molecular and Human Genetics (P.E.B.), Baylor College of Medicine, Houston, TX
| | - Claudia A Chiriboga
- From Child and Adolescent Neurology (M.K.K.), University of Texas Medical School, Houston; Neurology (R.H., P.L.P.), Boston Children's Hospital, Harvard Medical School, MA; Child Neurology (J.J.R., W.C., J.B., C.A.C.), Columbia University School of Medicine, New York, NY; Neurology (K.I., M.T.), Kanagawa Children's Medical Center, Yokohama; Pediatrics (H.O.), Jichi Medical School, Tochigi, Japan; Experimental and Systems Pharmacology (K.M.G.), Washington State University, Spokane; and Molecular and Human Genetics (P.E.B.), Baylor College of Medicine, Houston, TX
| | - Kazushi Ichikawa
- From Child and Adolescent Neurology (M.K.K.), University of Texas Medical School, Houston; Neurology (R.H., P.L.P.), Boston Children's Hospital, Harvard Medical School, MA; Child Neurology (J.J.R., W.C., J.B., C.A.C.), Columbia University School of Medicine, New York, NY; Neurology (K.I., M.T.), Kanagawa Children's Medical Center, Yokohama; Pediatrics (H.O.), Jichi Medical School, Tochigi, Japan; Experimental and Systems Pharmacology (K.M.G.), Washington State University, Spokane; and Molecular and Human Genetics (P.E.B.), Baylor College of Medicine, Houston, TX
| | - Hitoshi Osaka
- From Child and Adolescent Neurology (M.K.K.), University of Texas Medical School, Houston; Neurology (R.H., P.L.P.), Boston Children's Hospital, Harvard Medical School, MA; Child Neurology (J.J.R., W.C., J.B., C.A.C.), Columbia University School of Medicine, New York, NY; Neurology (K.I., M.T.), Kanagawa Children's Medical Center, Yokohama; Pediatrics (H.O.), Jichi Medical School, Tochigi, Japan; Experimental and Systems Pharmacology (K.M.G.), Washington State University, Spokane; and Molecular and Human Genetics (P.E.B.), Baylor College of Medicine, Houston, TX
| | - Megumi Tsuji
- From Child and Adolescent Neurology (M.K.K.), University of Texas Medical School, Houston; Neurology (R.H., P.L.P.), Boston Children's Hospital, Harvard Medical School, MA; Child Neurology (J.J.R., W.C., J.B., C.A.C.), Columbia University School of Medicine, New York, NY; Neurology (K.I., M.T.), Kanagawa Children's Medical Center, Yokohama; Pediatrics (H.O.), Jichi Medical School, Tochigi, Japan; Experimental and Systems Pharmacology (K.M.G.), Washington State University, Spokane; and Molecular and Human Genetics (P.E.B.), Baylor College of Medicine, Houston, TX
| | - K Michael Gibson
- From Child and Adolescent Neurology (M.K.K.), University of Texas Medical School, Houston; Neurology (R.H., P.L.P.), Boston Children's Hospital, Harvard Medical School, MA; Child Neurology (J.J.R., W.C., J.B., C.A.C.), Columbia University School of Medicine, New York, NY; Neurology (K.I., M.T.), Kanagawa Children's Medical Center, Yokohama; Pediatrics (H.O.), Jichi Medical School, Tochigi, Japan; Experimental and Systems Pharmacology (K.M.G.), Washington State University, Spokane; and Molecular and Human Genetics (P.E.B.), Baylor College of Medicine, Houston, TX
| | - Penelope E Bonnen
- From Child and Adolescent Neurology (M.K.K.), University of Texas Medical School, Houston; Neurology (R.H., P.L.P.), Boston Children's Hospital, Harvard Medical School, MA; Child Neurology (J.J.R., W.C., J.B., C.A.C.), Columbia University School of Medicine, New York, NY; Neurology (K.I., M.T.), Kanagawa Children's Medical Center, Yokohama; Pediatrics (H.O.), Jichi Medical School, Tochigi, Japan; Experimental and Systems Pharmacology (K.M.G.), Washington State University, Spokane; and Molecular and Human Genetics (P.E.B.), Baylor College of Medicine, Houston, TX
| | - Phillip L Pearl
- From Child and Adolescent Neurology (M.K.K.), University of Texas Medical School, Houston; Neurology (R.H., P.L.P.), Boston Children's Hospital, Harvard Medical School, MA; Child Neurology (J.J.R., W.C., J.B., C.A.C.), Columbia University School of Medicine, New York, NY; Neurology (K.I., M.T.), Kanagawa Children's Medical Center, Yokohama; Pediatrics (H.O.), Jichi Medical School, Tochigi, Japan; Experimental and Systems Pharmacology (K.M.G.), Washington State University, Spokane; and Molecular and Human Genetics (P.E.B.), Baylor College of Medicine, Houston, TX.
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