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Coughlin CR, Tseng LA, Abdenur JE, Ashmore C, Boemer F, Bok LA, Boyer M, Buhas D, Clayton PT, Das A, Dekker H, Evangeliou A, Feillet F, Footitt EJ, Gospe SM, Hartmann H, Kara M, Kristensen E, Lee J, Lilje R, Longo N, Lunsing RJ, Mills P, Papadopoulou MT, Pearl PL, Piazzon F, Plecko B, Saini AG, Santra S, Sjarif DR, Stockler-Ipsiroglu S, Striano P, Van Hove JLK, Verhoeven-Duif NM, Wijburg FA, Zuberi SM, van Karnebeek CDM. Consensus guidelines for the diagnosis and management of pyridoxine-dependent epilepsy due to α-aminoadipic semialdehyde dehydrogenase deficiency. J Inherit Metab Dis 2021; 44:178-192. [PMID: 33200442 DOI: 10.1002/jimd.12332] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/21/2020] [Accepted: 11/13/2020] [Indexed: 12/19/2022]
Abstract
Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is an autosomal recessive condition due to a deficiency of α-aminoadipic semialdehyde dehydrogenase, which is a key enzyme in lysine oxidation. PDE-ALDH7A1 is a developmental and epileptic encephalopathy that was historically and empirically treated with pharmacologic doses of pyridoxine. Despite adequate seizure control, most patients with PDE-ALDH7A1 were reported to have developmental delay and intellectual disability. To improve outcome, a lysine-restricted diet and competitive inhibition of lysine transport through the use of pharmacologic doses of arginine have been recommended as an adjunct therapy. These lysine-reduction therapies have resulted in improved biochemical parameters and cognitive development in many but not all patients. The goal of these consensus guidelines is to re-evaluate and update the two previously published recommendations for diagnosis, treatment, and follow-up of patients with PDE-ALDH7A1. Members of the International PDE Consortium initiated evidence and consensus-based process to review previous recommendations, new research findings, and relevant clinical aspects of PDE-ALDH7A1. The guideline development group included pediatric neurologists, biochemical geneticists, clinical geneticists, laboratory scientists, and metabolic dieticians representing 29 institutions from 16 countries. Consensus guidelines for the diagnosis and management of patients with PDE-ALDH7A1 are provided.
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Affiliation(s)
- Curtis R Coughlin
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Laura A Tseng
- Department of Pediatrics Emma Children's Hospital, Amsterdam University Medical Centre, Amsterdam, The Netherlands
| | - Jose E Abdenur
- Division of Metabolic Disorders, CHOC Children's Hospital, Orange, California, USA
| | - Catherine Ashmore
- Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
| | - François Boemer
- Department of Human Genetics, Centre Hospitalier Universitaire Sart-Tilman, Liège, Belgium
| | - Levinus A Bok
- Department of Pediatrics and Neonatology, Máxima Medical Center, Veldhoven, The Netherlands
| | - Monica Boyer
- Division of Metabolic Disorders, CHOC Children's Hospital, Orange, California, USA
| | - Daniela Buhas
- Division of Medical Genetics, Department of Specialized Medicine, Montreal Children's Hospital, McGill University Health Centre, Québec, Canada
| | - Peter T Clayton
- Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Anibh Das
- Clinic for Paediatric Kidney, Liver, and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Hanka Dekker
- VKS: Dutch Patient Organization for Metabolic Diseases, Zwolle, The Netherlands
| | - Athanasios Evangeliou
- Division of Child Neurology and Inherited Metabolic Disorders, 4th Department of Pediatrics, Aristotle University of Thessaloniki, General Hospital Papageorgiou, Thessaloniki, Greece
| | - François Feillet
- Reference Center for Inborn Errors of Metabolism, Pediatric Unit, University Hospital of Nancy, Nancy, France
- INSERM UMR S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, Nancy, France
| | - Emma J Footitt
- Department of Metabolic Paediatrics, Great Ormond Street Hospital, London, UK
| | - Sidney M Gospe
- Division of Pediatric Neurology, Departments of Neurology and Pediatrics, University of Washington, Seattle, Washington, USA
- Department of Pediatrics, Duke University, Durham, North Carolina, USA
| | - Hans Hartmann
- Clinic for Paediatric Kidney, Liver, and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Majdi Kara
- Department of Pediatrics, University of Tripoli, Tripoli, Libya
| | - Erle Kristensen
- National Management of Newborn Screening and Advanced Laboratory Diagnostics in Inborn Errors of Metabolism, Department of Children and Adolescent Medicine, Oslo University Hospital, Oslo, Norway
| | - Joy Lee
- Department of Metabolic Medicine, The Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Rina Lilje
- Department of Children and Adolescent Medicine, Oslo University Hospital, Oslo, Norway
| | - Nicola Longo
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Roelineke J Lunsing
- Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Philippa Mills
- Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Maria T Papadopoulou
- Division of Child Neurology and Inherited Metabolic Disorders, 4th Department of Pediatrics, Aristotle University of Thessaloniki, General Hospital Papageorgiou, Thessaloniki, Greece
| | - Phillip L Pearl
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Flavia Piazzon
- Neurometabolic Clinic, Children's Institute, University of Sao Paulo, Brazil
| | - Barbara Plecko
- Division of General Pediatrics, Department of Pediatrics and Adolescent Medicine, Medical University of Graz, Graz, Austria
| | - Arushi G Saini
- Pediatric Neurology Unit, Department of Pediatrics, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Saikat Santra
- Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
| | - Damayanti R Sjarif
- Department of Child Health, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Sylvia Stockler-Ipsiroglu
- Division of Biochemical Genetics, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, IRCCS "G. Gaslini" Institute, Genoa, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genoa, Italy
| | - Johan L K Van Hove
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | | | - Frits A Wijburg
- Department of Pediatrics Emma Children's Hospital, Amsterdam University Medical Centre, Amsterdam, The Netherlands
| | - Sameer M Zuberi
- Paediatric Neurosciences Research Group, Royal Hospital for Children & School of Medicine, University of Glasgow, Glasgow, UK
| | - Clara D M van Karnebeek
- Department of Pediatrics Emma Children's Hospital, Amsterdam University Medical Centre, Amsterdam, The Netherlands
- Department of Pediatrics, Amalia Children's Hospital, Radboud Centre for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
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2
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Abstract
West syndrome (WS) is an early life epileptic encephalopathy associated with infantile spasms, interictal electroencephalography (EEG) abnormalities including high amplitude, disorganized background with multifocal epileptic spikes (hypsarrhythmia), and often neurodevelopmental impairments. Approximately 64% of the patients have structural, metabolic, genetic, or infectious etiologies and, in the rest, the etiology is unknown. Here we review the contribution of etiologies due to various metabolic disorders in the pathology of WS. These may include metabolic errors in organic molecules involved in amino acid and glucose metabolism, fatty acid oxidation, metal metabolism, pyridoxine deficiency or dependency, or acidurias in organelles such as mitochondria and lysosomes. We discuss the biochemical, clinical, and EEG features of these disorders as well as the evidence of how they may be implicated in the pathogenesis and treatment of WS. The early recognition of these etiologies in some cases may permit early interventions that may improve the course of the disease.
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Affiliation(s)
- Seda Salar
- Laboratory of Developmental EpilepsySaul R. Korey Department of NeurologyMontefiore/Einstein Epilepsy CenterAlbert Einstein College of MedicineBronxNew YorkU.S.A.
| | - Solomon L. Moshé
- Laboratory of Developmental EpilepsySaul R. Korey Department of NeurologyMontefiore/Einstein Epilepsy CenterAlbert Einstein College of MedicineBronxNew YorkU.S.A.
- Dominick P. Purpura Department of NeuroscienceMontefiore/Einstein Epilepsy CenterAlbert Einstein College of MedicineBronxNew YorkU.S.A.
- Department of PediatricsMontefiore/Einstein Epilepsy CenterAlbert Einstein College of MedicineBronxNew YorkU.S.A.
| | - Aristea S. Galanopoulou
- Laboratory of Developmental EpilepsySaul R. Korey Department of NeurologyMontefiore/Einstein Epilepsy CenterAlbert Einstein College of MedicineBronxNew YorkU.S.A.
- Dominick P. Purpura Department of NeuroscienceMontefiore/Einstein Epilepsy CenterAlbert Einstein College of MedicineBronxNew YorkU.S.A.
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3
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Pena IA, Roussel Y, Daniel K, Mongeon K, Johnstone D, Weinschutz Mendes H, Bosma M, Saxena V, Lepage N, Chakraborty P, Dyment DA, van Karnebeek CDM, Verhoeven-Duif N, Bui TV, Boycott KM, Ekker M, MacKenzie A. Pyridoxine-Dependent Epilepsy in Zebrafish Caused by Aldh7a1 Deficiency. Genetics 2017; 207:1501-1518. [PMID: 29061647 PMCID: PMC5714462 DOI: 10.1534/genetics.117.300137] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 10/04/2017] [Indexed: 11/25/2022] Open
Abstract
Pyridoxine-dependent epilepsy (PDE) is a rare disease characterized by mutations in the lysine degradation gene ALDH7A1 leading to recurrent neonatal seizures, which are uniquely alleviated by high doses of pyridoxine or pyridoxal 5'-phosphate (vitamin B6 vitamers). Despite treatment, neurodevelopmental disabilities are still observed in most PDE patients underlining the need for adjunct therapies. Over 60 years after the initial description of PDE, we report the first animal model for this disease: an aldh7a1-null zebrafish (Danio rerio) displaying deficient lysine metabolism and spontaneous and recurrent seizures in the larval stage (10 days postfertilization). Epileptiform electrographic activity was observed uniquely in mutants as a series of population bursts in tectal recordings. Remarkably, as is the case in human PDE, the seizures show an almost immediate sensitivity to pyridoxine and pyridoxal 5'-phosphate, with a resulting extension of the life span. Lysine supplementation aggravates the phenotype, inducing earlier seizure onset and death. By using mass spectrometry techniques, we further explored the metabolic effect of aldh7a1 knockout. Impaired lysine degradation with accumulation of PDE biomarkers, B6 deficiency, and low γ-aminobutyric acid levels were observed in the aldh7a1-/- larvae, which may play a significant role in the seizure phenotype and PDE pathogenesis. This novel model provides valuable insights into PDE pathophysiology; further research may offer new opportunities for drug discovery to control seizure activity and improve neurodevelopmental outcomes for PDE.
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Affiliation(s)
- Izabella A Pena
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario K1H 8L1, Canada
- Department of Pediatrics, Faculty of Medicine, University of Ottawa, Ontario K1H 8L1, Canada
- Department of Biology, University of Ottawa, Ontario K1N 6N5, Canada
| | - Yann Roussel
- Department of Biology, University of Ottawa, Ontario K1N 6N5, Canada
| | - Kate Daniel
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario K1H 8L1, Canada
| | - Kevin Mongeon
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario K1H 8L1, Canada
- Department of Pediatrics, Faculty of Medicine, University of Ottawa, Ontario K1H 8L1, Canada
| | - Devon Johnstone
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario K1H 8L1, Canada
- Department of Pediatrics, Faculty of Medicine, University of Ottawa, Ontario K1H 8L1, Canada
| | | | - Marjolein Bosma
- Departments of Pediatrics and Clinical Genetics, Academic Medical Centre, 1105 AZ Amsterdam, The Netherlands
| | - Vishal Saxena
- Department of Biology, University of Ottawa, Ontario K1N 6N5, Canada
| | - Nathalie Lepage
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario K1H 8L1, Canada
| | - Pranesh Chakraborty
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario K1H 8L1, Canada
| | - David A Dyment
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario K1H 8L1, Canada
- Department of Pediatrics, Faculty of Medicine, University of Ottawa, Ontario K1H 8L1, Canada
| | - Clara D M van Karnebeek
- Departments of Pediatrics and Clinical Genetics, Academic Medical Centre, 1105 AZ Amsterdam, The Netherlands
- Department of Pediatrics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver V5Z 4H4, British Columbia, Canada
| | - Nanda Verhoeven-Duif
- Department of Genetics, Center for Molecular Medicine, University Medical Center (UMC), 3584 EA Utrecht, The Netherlands
| | - Tuan Vu Bui
- Department of Biology, University of Ottawa, Ontario K1N 6N5, Canada
| | - Kym M Boycott
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario K1H 8L1, Canada
- Department of Pediatrics, Faculty of Medicine, University of Ottawa, Ontario K1H 8L1, Canada
| | - Marc Ekker
- Department of Biology, University of Ottawa, Ontario K1N 6N5, Canada
| | - Alex MacKenzie
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario K1H 8L1, Canada
- Department of Pediatrics, Faculty of Medicine, University of Ottawa, Ontario K1H 8L1, Canada
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4
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Pena IA, MacKenzie A, Van Karnebeek CDM. Current knowledge for pyridoxine-dependent epilepsy: a 2016 update. Expert Rev Endocrinol Metab 2017; 12:5-20. [PMID: 30058881 DOI: 10.1080/17446651.2017.1273107] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Pyridoxine-dependent epilepsy (PDE) is a rare genetic condition characterized by intractable and recurrent neonatal seizures that are uniquely alleviated by high doses of pyridoxine (vitamin B6). This recessive disease is caused by mutations in ALDH7A1, a gene encoding Antiquitin, an enzyme central to lysine degradation. This results in the pathogenic accumulation of the lysine intermediates Aminoadipate Semialdehyde (AASA) and its cyclic equilibrium form Piperideine-6-carboxylate (P6C) in body fluids; P6C reacts with pyridoxal-5'-phosphate (PLP, the active form of vitamin B6) causing its inactivation and leading to pyridoxine-dependent seizures. While PDE is responsive to pharmacological dosages of pyridoxine, despite lifelong supplementation, neurodevelopment delays are observed in >75% of PDE cases. Thus, adjunct treatment strategies are emerging to both improve seizure control and moderate the delays in cognition. These adjunctive therapies, lysine restriction and arginine supplementation, separately or in combination (with pyridoxine thus termed 'triple therapy'), have shown promising results and are recommended in all PDE patients. Other new therapeutic strategies currently in preclinical phase of study include antisense therapy and substrate reduction therapy. We present here a comprehensive review of current treatment options as well as PDE phenotype, differential diagnosis, current management and views upon the future of PDE research.
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Affiliation(s)
- Izabella Agostinho Pena
- a Children's Hospital of Eastern Ontario (CHEO) Research Institute , Ottawa , ON , Canada
- b Department of Cellular and Molecular Medicine , University of Ottawa , Ottawa , ON , Canada
| | - Alex MacKenzie
- a Children's Hospital of Eastern Ontario (CHEO) Research Institute , Ottawa , ON , Canada
- b Department of Cellular and Molecular Medicine , University of Ottawa , Ottawa , ON , Canada
| | - Clara D M Van Karnebeek
- c Department of Pediatrics, BC Children's Hospital Research Institute, Centre for Molecular Medicine and Therapeutics , University of British Columbia , Vancouver BC , Canada
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5
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Abstract
Two observations stimulated the interest in vitamin B-6 and alkaline phosphatase in brain: the marked increase in plasma pyridoxal phosphate and the occurrence of pyridoxine responsive seizures in hypophosphatasia. The increase in plasma pyridoxal phosphate indicates the importance of tissue non-specific alkaline phosphatase (TNAP) in transferring vitamin B-6 into the tissues. Vitamin B-6 is involved in the biosynthesis of most of the neurotransmitters. Decreased gamma-aminobutyrate (GABA) appears to be most directly related to the development of seizures in vitamin B-6 deficiency. Cytosolic pyridoxal phosphatase/chronophin may interact with vitamin B-6 metabolism and neuronal development and function. Ethanolaminephosphate phospholyase interacts with phosphoethanolamine metabolism. Extracellular pyridoxal phosphate may interact with purinoceptors and calcium channels. In conclusion, TNAP clearly influences extracellular and intracellular metabolism of vitamin B-6 in brain, particularly during developmental stages. While effects on GABA metabolism appear to be the major contributor to seizures, multiple other intra- and extra-cellular metabolic systems may be affected directly and/or indirectly by altered vitamin B-6 hydrolysis and uptake resulting from variations in alkaline phosphatase activity.
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6
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Jansen LA, Hevner RF, Roden WH, Hahn SH, Jung S, Gospe SM. Glial localization of antiquitin: implications for pyridoxine-dependent epilepsy. Ann Neurol 2014; 75:22-32. [PMID: 24122892 DOI: 10.1002/ana.24027] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 08/26/2013] [Accepted: 09/10/2013] [Indexed: 11/10/2022]
Abstract
OBJECTIVE A high incidence of structural brain abnormalities has been reported in individuals with pyridoxine-dependent epilepsy (PDE). PDE is caused by mutations in ALDH7A1, also known as antiquitin. How antiquitin dysfunction leads to cerebral dysgenesis is unknown. In this study, we analyzed tissue from a child with PDE as well as control human and murine brain to determine the normal distribution of antiquitin, its distribution in PDE, and associated brain malformations. METHODS Formalin-fixed human brain sections were subjected to histopathology and fluorescence immunohistochemistry studies. Frozen brain tissue was utilized for measurement of PDE-associated metabolites and Western blot analysis. Comparative studies of antiquitin distribution were performed in developing mouse brain sections. RESULTS Histologic analysis of PDE cortex revealed areas of abnormal radial neuronal organization consistent with type Ia focal cortical dysplasia. Heterotopic neurons were identified in subcortical white matter, as was cortical astrogliosis, hippocampal sclerosis, and status marmoratus of the basal ganglia. Highly elevated levels of lysine metabolites were present in postmortem PDE cortex. In control human and developing mouse brain, antiquitin immunofluorescence was identified in radial glia, mature astrocytes, ependyma, and choroid plexus epithelium, but not in neurons. In PDE cortex, antiquitin immunofluorescence was greatly attenuated with evidence of perinuclear accumulation in astrocytes. INTERPRETATION Antiquitin is expressed within glial cells in the brain, and its dysfunction in PDE is associated with neuronal migration abnormalities and other structural brain defects. These malformations persist despite postnatal pyridoxine supplementation and likely contribute to neurodevelopmental impairments.
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Affiliation(s)
- Laura A Jansen
- Department of Neurology, University of Washington, Seattle, WA; Seattle Children's Research Institute, Seattle, WA
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7
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Stockler S, Plecko B, Gospe SM, Coulter-Mackie M, Connolly M, van Karnebeek C, Mercimek-Mahmutoglu S, Hartmann H, Scharer G, Struijs E, Tein I, Jakobs C, Clayton P, Van Hove JLK. Pyridoxine dependent epilepsy and antiquitin deficiency: clinical and molecular characteristics and recommendations for diagnosis, treatment and follow-up. Mol Genet Metab 2011; 104:48-60. [PMID: 21704546 DOI: 10.1016/j.ymgme.2011.05.014] [Citation(s) in RCA: 185] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2011] [Revised: 05/18/2011] [Accepted: 05/19/2011] [Indexed: 11/18/2022]
Abstract
Antiquitin (ATQ) deficiency is the main cause of pyridoxine dependent epilepsy characterized by early onset epileptic encephalopathy responsive to large dosages of pyridoxine. Despite seizure control most patients have intellectual disability. Folinic acid responsive seizures (FARS) are genetically identical to ATQ deficiency. ATQ functions as an aldehyde dehydrogenase (ALDH7A1) in the lysine degradation pathway. Its deficiency results in accumulation of α-aminoadipic semialdehyde (AASA), piperideine-6-carboxylate (P6C) and pipecolic acid, which serve as diagnostic markers in urine, plasma, and CSF. To interrupt seizures a dose of 100 mg of pyridoxine-HCl is given intravenously, or orally/enterally with 30 mg/kg/day. First administration may result in respiratory arrest in responders, and thus treatment should be performed with support of respiratory management. To make sure that late and masked response is not missed, treatment with oral/enteral pyridoxine should be continued until ATQ deficiency is excluded by negative biochemical or genetic testing. Long-term treatment dosages vary between 15 and 30 mg/kg/day in infants or up to 200 mg/day in neonates, and 500 mg/day in adults. Oral or enteral pyridoxal phosphate (PLP), up to 30 mg/kg/day can be given alternatively. Prenatal treatment with maternal pyridoxine supplementation possibly improves outcome. PDE is an organic aciduria caused by a deficiency in the catabolic breakdown of lysine. A lysine restricted diet might address the potential toxicity of accumulating αAASA, P6C and pipecolic acid. A multicenter study on long term outcomes is needed to document potential benefits of this additional treatment. The differential diagnosis of pyridoxine or PLP responsive seizure disorders includes PLP-responsive epileptic encephalopathy due to PNPO deficiency, neonatal/infantile hypophosphatasia (TNSALP deficiency), familial hyperphosphatasia (PIGV deficiency), as well as yet unidentified conditions and nutritional vitamin B6 deficiency. Commencing treatment with PLP will not delay treatment in patients with pyridox(am)ine phosphate oxidase (PNPO) deficiency who are responsive to PLP only.
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Affiliation(s)
- Sylvia Stockler
- Division of Biochemical Diseases, British Columbia Children's Hospital, University of British Columbia, 4480 Oak Street, Vancouver BC, Canada V6H 3V4.
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8
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Mills PB, Footitt EJ, Mills KA, Tuschl K, Aylett S, Varadkar S, Hemingway C, Marlow N, Rennie J, Baxter P, Dulac O, Nabbout R, Craigen WJ, Schmitt B, Feillet F, Christensen E, De Lonlay P, Pike MG, Hughes MI, Struys EA, Jakobs C, Zuberi SM, Clayton PT. Genotypic and phenotypic spectrum of pyridoxine-dependent epilepsy (ALDH7A1 deficiency). ACTA ACUST UNITED AC 2010; 133:2148-59. [PMID: 20554659 PMCID: PMC2892945 DOI: 10.1093/brain/awq143] [Citation(s) in RCA: 184] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Pyridoxine-dependent epilepsy was recently shown to be due to mutations in the ALDH7A1 gene, which encodes antiquitin, an enzyme that catalyses the nicotinamide adenine dinucleotide-dependent dehydrogenation of l-α-aminoadipic semialdehyde/l-Δ1-piperideine 6-carboxylate. However, whilst this is a highly treatable disorder, there is general uncertainty about when to consider this diagnosis and how to test for it. This study aimed to evaluate the use of measurement of urine l-α-aminoadipic semialdehyde/creatinine ratio and mutation analysis of ALDH7A1 (antiquitin) in investigation of patients with suspected or clinically proven pyridoxine-dependent epilepsy and to characterize further the phenotypic spectrum of antiquitin deficiency. Urinary l-α-aminoadipic semialdehyde concentration was determined by liquid chromatography tandem mass spectrometry. When this was above the normal range, DNA sequencing of the ALDH7A1 gene was performed. Clinicians were asked to complete questionnaires on clinical, biochemical, magnetic resonance imaging and electroencephalography features of patients. The clinical spectrum of antiquitin deficiency extended from ventriculomegaly detected on foetal ultrasound, through abnormal foetal movements and a multisystem neonatal disorder, to the onset of seizures and autistic features after the first year of life. Our relatively large series suggested that clinical diagnosis of pyridoxine dependent epilepsy can be challenging because: (i) there may be some response to antiepileptic drugs; (ii) in infants with multisystem pathology, the response to pyridoxine may not be instant and obvious; and (iii) structural brain abnormalities may co-exist and be considered sufficient cause of epilepsy, whereas the fits may be a consequence of antiquitin deficiency and are then responsive to pyridoxine. These findings support the use of biochemical and DNA tests for antiquitin deficiency and a clinical trial of pyridoxine in infants and children with epilepsy across a broad range of clinical scenarios.
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Affiliation(s)
- Philippa B Mills
- Institute of Child Health, University College London with Great Ormond Street Hospital for Children, National Health Service Trust, London, UK
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9
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Bennett CL, Huynh HM, Chance PF, Glass IA, Gospe SM. Genetic heterogeneity for autosomal recessive pyridoxine-dependent seizures. Neurogenetics 2005; 6:143-9. [PMID: 16075246 DOI: 10.1007/s10048-005-0221-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2005] [Accepted: 05/16/2005] [Indexed: 10/25/2022]
Abstract
Pyridoxine-dependent seizure (PDS) is a rare autosomal recessive intractable seizure disorder only controlled by a daily supplementation of pharmacological doses of pyridoxine (Vitamin B6). Although glutamate decarboxylase utilizes pyridoxal phosphate as a cofactor during conversion of the excitatory amino acid, glutamate, to the inhibitory neurotransmitter, gamma-amino butyric acid (GABA), several studies have failed to demonstrate a linkage to either of the glutamate-decarboxylase-encoding genes (GAD1 and GAD2) and PDS excluding involvement of this functional candidate. However, in 2000, a locus for PDS was mapped to a 5 cM interval at chromosome 5q31 in four consanguineous and one multisib pedigree (Z(max)=8.43 at theta=0 for marker D5S2017) [Cormier-Daire et al. in Am J Hum Genet 67(4):991-993 2000]. We undertook molecular genetic studies of six nonconsanguineous North American families, using up to ten microsatellite markers to perform haplotype segregation analysis of the 5q31 locus. Assignment to the chromosome 5q PDS locus was excluded in one of the six North American PDS pedigrees, as chromosome 5q31 haplotypes were incompatible with linkage to this locus. The remaining five PDS pedigrees showed haplotype segregation consistent with linkage to 5q31, generating a maximum combined lod score of 1.87 (theta=0) at marker D5S2011. In this study, we establish genetic heterogeneity for PDS, catalog 21 genes within the originally defined PDS interval, and identify additional recombinations that indicate a higher priority interval, containing just 11 genes.
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Affiliation(s)
- C L Bennett
- Division of Genetics and Developmental Medicine, Department of Pediatrics, University of Washington and Children's Hospital and Regional Medical Center, Seattle, USA.
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10
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Yoshii A, Takeoka M, Kelly PJ, Krishnamoorthy KS. Focal status epilepticus as atypical presentation of pyridoxine-dependent epilepsy. J Child Neurol 2005; 20:696-8. [PMID: 16225819 DOI: 10.1177/08830738050200081301] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Pyridoxine-dependent epilepsy usually presents in the neonatal period or even in utero, is refractory to antiepileptic medications, and is treatable with lifelong administration of pyridoxine. The seizures are typically generalized tonic-clonic, although myoclonic seizures or infantile spasms have been described. We report an infant who presented at 5 months of age with a right-sided clonic seizure with fever. Subsequently, she had recurrent right focal or generalized seizures despite sequential treatment with various antiepileptic medications. At 7 months, she was hospitalized with status epilepticus, which was finally controlled with pyridoxine. After she became seizure free, she continued to have a strong left arm preference with mild weakness of the right arm and delayed language skill. Eventually, she outgrew these symptoms. This case illustrates that pyridoxine-dependent epilepsy, although rare, must be included in the differential diagnosis of focal seizures, especially when the seizures are refractory to traditional antiepileptic drugs.
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Affiliation(s)
- Akira Yoshii
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
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11
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Baxter P. Pyridoxine-dependent seizures: a clinical and biochemical conundrum. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1647:36-41. [PMID: 12686105 DOI: 10.1016/s1570-9639(03)00045-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Pyridoxine-dependent seizures have been recognised for 40 years, but the clinical and biochemical features are still not understood. It is a rare recessively inherited condition where classically a baby starts convulsing in utero and continues to do so after birth, until given pyridoxine. Many of these early onset cases also have an acute encephalopathy and other clinical features. Late onset cases are now recognised with a less severe form of the condition. Seizures can break through with intercurrent illness but otherwise remain controlled on pharmacologic doses of pyridoxine. The long-term outcome is affected by several factors including whether onset is early or late and how soon pyridoxine is given. Biochemical studies have been sparse, on very small numbers. There does not appear to be any defect in the uptake or metabolism of pyridoxine or pyridoxal phosphate (PLP). For a long time glutamic acid decarboxylase (GAD), a pyridoxal-dependent enzyme, has been suspected to be the abnormal gene product, but glutamate and gamma-aminobutyric acid (GABA) studies on the cerebrospinal fluid (CSF) have been contradictory and recent genetic studies have not found any linkage to the two brain isoforms. A recent report describes raised pipecolic acid levels in patients but how this ties in is unexplained.
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Affiliation(s)
- Peter Baxter
- Ryegate Centre Paediatric Neurology, Sheffield Childrens Hospital, Tapton Crescent Road, Sheffield S10 5DD, UK.
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Kelly A, Stanley CA. Disorders of glutamate metabolism. MENTAL RETARDATION AND DEVELOPMENTAL DISABILITIES RESEARCH REVIEWS 2002; 7:287-95. [PMID: 11754524 DOI: 10.1002/mrdd.1040] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The significant role the amino acid glutamate assumes in a number of fundamental metabolic pathways is becoming better understood. As a central junction for interchange of amino nitrogen, glutamate facilitates both amino acid synthesis and degradation. In the liver, glutamate is the terminus for release of ammonia from amino acids, and the intrahepatic concentration of glutamate modulates the rate of ammonia detoxification into urea. In pancreatic beta-cells, oxidation of glutamate mediates amino acid-stimulated insulin secretion. In the central nervous system, glutamate serves as an excitatory neurotransmittor. Glutamate is also the precursor of the inhibitory neurotransmittor GABA, as well as glutamine, a potential mediator of hyperammonemic neurotoxicity. The recent identification of a novel form of congenital hyperinsulinism associated with asymptomatic hyperammonemia assigns glutamate oxidation by glutamate dehydrogenase a more important role than previously recognized in beta-cell insulin secretion and hepatic and CNS ammonia detoxification. Disruptions of glutamate metabolism have been implicated in other clinical disorders, such as pyridoxine-dependent seizures, confirming the importance of intact glutamate metabolism. This article will review glutamate metabolism and clinical disorders associated with disrupted glutamate metabolism.
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Affiliation(s)
- A Kelly
- Division of Endocrinology, Department of Pediatrics, The Children's Hospital of Philadelphia, University of Pennsylvania Medical School, 19104, USA
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Abstract
Pyridoxine-dependent seizures, although a rare clinical entity, have been recognized as an etiology of intractable seizures in neonates and infants for more than 45 years. Recent research has focused on the molecular and neurochemical aspects of this disorder, as well as the optimal treatment of the condition. This review discusses the clinical features and management of patients with pyridoxine-dependent seizures together with a new hypothesis suggesting that an abnormality of pyridoxine transport may underlie the pathophysiology of this autosomal-recessive disorder.
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Affiliation(s)
- Sidney M Gospe
- Division of Pediatric Neurology, Department of Neurology, University of Washington, and Children's Hospital and Regional Medical Center, Seattle, WA 98105, USA
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Goto T, Matsuo N, Takahashi T. CSF glutamate/GABA concentrations in pyridoxine-dependent seizures: etiology of pyridoxine-dependent seizures and the mechanisms of pyridoxine action in seizure control. Brain Dev 2001; 23:24-9. [PMID: 11226725 DOI: 10.1016/s0387-7604(00)00193-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Several lines of evidence suggest that the binding affinity of glutamate decarboxylase (GAD) to the active form of pyridoxine is low in cases of pyridoxine-dependent seizures (PDS) and that a quantitative imbalance between excitatory (i.e. glutamate) and inhibitory (i.e. gamma-aminobutyric acid, GABA) neurotransmitters could cause refractory seizures. However, inconsistent findings with GAD insufficiency have been reported in PDS. We report a case of PDS that is not accompanied by an elevated cerebrospinal fluid (CSF) glutamate concentration. Intravenous pyridoxine phosphate terminated generalized seizures which were otherwise refractory to conventional anti-epileptic medicines. No seizure occurred once oral pyridoxine (13.5 mg/kg per day) was started in combination with phenobarbital sodium (PB, 3.7 mg/kg per day). The electroencephalogram (EEG) normalized approximately 8 months after pyridoxine was started. The patient is gradually acquiring developmental milestones during the 15 months follow-up period. The CSF glutamate and GABA concentrations were determined on three separate occasions: (1) during status epilepticus; (2) during a seizure-free period with administration of pyridoxine and PB; and (3) 6 days after suspension of pyridoxine and PB and immediately before a convulsion. The CSF glutamate level was below the sensitivity of detection (<1.0 microM) on each of the three occasions; the CSF GABA level was within the normal range or moderately elevated. The CSF and serum concentrations of vitamin B6-related substances, before pyridoxine supplementation, were within the normal range. We suggest that (1) PDS is not a discrete disease of single etiology in that insufficient activation of GAD may not account for seizure susceptibility in all cases and (2) mechanism(s) of anti-convulsive effect of pyridoxine, at least in some cases, may be independent of GAD activation.
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Affiliation(s)
- T Goto
- Department of Pediatrics, Keio University School of Medicine, Shinanomachi 35, Shinjuku-ku, 160-8582, Tokyo, Japan
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Plecko B, St�ckler-Ipsiroglu S, Paschke E, Erwa W, Struys EA, Jakobs C. Pipecolic acid elevation in plasma and cerebrospinal fluid of two patients with pyridoxine-dependent epilepsy. Ann Neurol 2001. [DOI: 10.1002/1531-8249(200007)48:1<121::aid-ana20>3.0.co;2-v] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Nabbout R, Soufflet C, Plouin P, Dulac O. Pyridoxine dependent epilepsy: a suggestive electroclinical pattern. Arch Dis Child Fetal Neonatal Ed 1999; 81:F125-9. [PMID: 10448181 PMCID: PMC1720985 DOI: 10.1136/fn.81.2.f125] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS To determine if there is an electroencephalographic pattern suggestive of pyridoxine dependent epilepsy that could be used to improve the chances of early diagnosis. METHODS A retrospective study was made of all the clinical records and electroencephalograms of neonates identified with pyridoxine dependent seizures between 1983 and 1994, at this hospital. Neonates whose seizures began after more than 28 days of life were excluded; in all, five patients from four families were studied. Follow up ranged from 2 to 10 years. RESULTS A history of miscarriage and neonatal death during an epileptic seizure had occurred in the siblings of two families. One mother reported rhythmic movements of her child during the last month of pregnancy. At birth, all babies were hypotonic; four had decreased visual alertness. All babies were agitated, irritable, jittery, hyperalert, and exhibited sleeplessness and a startle reaction to touch and sound. Age of onset of seizures varied from 30 minutes to 3 days. Seizures of various types were recorded in all cases on EEG tracings, including spasms, myoclonic seizures, partial clonic, and secondary generalised seizures. Burst-suppression patterns occurred in three cases, and a combination of continuous and discontinuous patterns in two others. Bilateral high voltage delta slow wave activity was observed in four patients. Psychomotor delay was severe in three patients, moderate in one, and mild in one. CONCLUSIONS There is an identifiable EEG pattern that is highly suggestive of pyridoxine dependent epilepsy. Pyridoxine dependent epilepsy is probably underdiagnosed.
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Affiliation(s)
- R Nabbout
- Department of Neuropaediatrics, INSERM U 29 Université René Descartes, Hospital Saint Vincent de Paul, Paris, France
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Affiliation(s)
- S M Gospe
- Department of Neurology, University of California, Davis, USA
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Bass NE, Wyllie E, Cohen B, Joseph SA. Pyridoxine-dependent epilepsy: the need for repeated pyridoxine trials and the risk of severe electrocerebral suppression with intravenous pyridoxine infusion. J Child Neurol 1996; 11:422-4. [PMID: 8877616 DOI: 10.1177/088307389601100519] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- N E Bass
- Department of Neurology, Cleveland Clinic Foundation, Ohio, USA
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Abstract
An abnormality in the pyridoxal-5'-phosphate (PLP) dependent enzyme, glutamic acid decarboxylase (GAD), which synthesizes gamma-aminobutyric acid (GABA), may underlie the epileptic syndrome of pyridoxine-dependent seizures. GABA synthesis by skin fibroblasts from an infant with pyridoxine-dependent seizures, and from five controls, was measured. PLP independent GAD activity was similar in control and patient fibroblasts, whereas the patient's PLP dependent GAD activity was reduced compared with controls. These findings support the hypothesis for the expression of this familial disease.
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Affiliation(s)
- S M Gospe
- Department of Neurology, University of California, Davis, Sacramento 95817
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