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Fang C, Yang L, Xiao F, Yan K, Zhou W. Genotype and phenotype features and prognostic factors of neonatal-onset pyridoxine-dependent epilepsy: A systematic review. Epilepsy Res 2024; 202:107363. [PMID: 38636407 DOI: 10.1016/j.eplepsyres.2024.107363] [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: 01/22/2024] [Revised: 03/29/2024] [Accepted: 04/15/2024] [Indexed: 04/20/2024]
Abstract
Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is a rare autosomal recessive disorder due to a deficiency of α-aminoadipic semialdehyde dehydrogenase. This study aimed to systematically explore genotypic and phenotypic features and prognostic factors of neonatal-onset PDE. A literature search covering PubMed, Elsevier, and Web of Science was conducted from January 2006 to August 2023. We identified 56 eligible studies involving 169 patients and 334 alleles. The c.1279 G>C variant was the most common variant of neonatal-onset PDE (25.7 %). All patients were treated with pyridoxine; forty patients received dietary intervention therapy. 63.9 % of the patients were completely seizure-free; however, 68.6 % of the patients had neurodevelopmental delays. Additionally, homozygous c.1279 G>C variants were significantly associated with ventriculomegaly, abnormal white matter signal, and cysts (P<0.05). In contrast, homozygous c.1364 T>C was associated with clonic seizure (P=0.031). Pyridoxine used immediately at seizure onset was an independent protective factor for developmental delay (P=0.035; odds ratio [OR]: 3.14). Besides, pyridoxine used early in the neonatal period was a protective factor for language delay (P=0.044; OR: 4.59). In contrast, neonatal respiratory distress (P=0.001; OR: 127.44) and abnormal brain magnetic resonance imaging (P=0.049; OR: 3.64) were risk factors. Prenatal movement abnormality (P=0.041; OR: 20.56) and abnormal white matter signal (P=0.012; OR: 24.30) were risk factors for motor delay. Myoclonic seizure (P=0.023; OR: 7.13) and status epilepticus (P=0.000; OR: 9.93) were risk factors for breakthrough seizures. In conclusion, our study indicated that pyridoxine should be started immediately when unexplained neonatal seizures occur and not later than the neonatal period to prevent poor neurodevelopmental outcomes.
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Affiliation(s)
- Chuchu Fang
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China
| | - Lin Yang
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China; Center for Molecular Medicine, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China
| | - Feifan Xiao
- Center for Molecular Medicine, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China
| | - Kai Yan
- Department of Neonatology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China.
| | - Wenhao Zhou
- Center for Molecular Medicine, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China; Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China.
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The role of copy number variants in the genetic architecture of common familial epilepsies. Epilepsia 2024; 65:792-804. [PMID: 38101940 PMCID: PMC10948303 DOI: 10.1111/epi.17860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 12/08/2023] [Accepted: 12/11/2023] [Indexed: 12/17/2023]
Abstract
OBJECTIVE Copy number variants (CNVs) contribute to genetic risk and genetic etiology of both rare and common epilepsies. Whereas many studies have explored the role of CNVs in sporadic or severe cases, fewer have been done in familial generalized and focal epilepsies. METHODS We analyzed exome sequence data from 267 multiplex families and 859 first-degree relative pairs with a diagnosis of genetic generalized epilepsies or nonacquired focal epilepsies to predict CNVs. Validation and segregation studies were performed using an orthogonal method when possible. RESULTS We identified CNVs likely to contribute to epilepsy risk or etiology in the probands of 43 of 1116 (3.9%) families, including known recurrent CNVs (16p13.11 deletion, 15q13.3 deletion, 15q11.2 deletion, 16p11.2 duplication, 1q21.1 duplication, and 5-Mb duplication of 15q11q13). We also identified CNVs affecting monogenic epilepsy genes, including four families with CNVs disrupting the DEPDC5 gene, and a de novo deletion of HNRNPU in one affected individual from a multiplex family. Several large CNVs (>500 kb) of uncertain clinical significance were identified, including a deletion in 18q, a large duplication encompassing the SCN1A gene, and a 15q13.3 duplication (BP4-BP5). SIGNIFICANCE The overall CNV landscape in common familial epilepsies is similar to that of sporadic epilepsies, with large recurrent deletions at 15q11, 15q13, and 16p13 contributing in 2.5%-3% of families. CNVs that interrupt known epilepsy genes and rare, large CNVs were also identified. Multiple etiologies were found in a subset of families, emphasizing the importance of genetic testing for multiple affected family members. Rare CNVs found in a single proband remain difficult to interpret and require larger cohorts to confirm their potential role in disease. Overall, our work indicates that CNVs contribute to the complex genetic architecture of familial generalized and focal epilepsies, supporting the role for clinical testing in affected individuals.
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Jamali A, Kristensen E, Tangeraas T, Arntsen V, Sikiric A, Kupliauskiene G, Myren-Svelstad S, Berland S, Sejersted Y, Gerstner T, Hassel B, Bindoff LA, Brodtkorb E. The spectrum of pyridoxine dependent epilepsy across the age span: A nationwide retrospective observational study. Epilepsy Res 2023; 190:107099. [PMID: 36731270 DOI: 10.1016/j.eplepsyres.2023.107099] [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: 11/30/2022] [Revised: 01/20/2023] [Accepted: 01/26/2023] [Indexed: 01/30/2023]
Abstract
BACKGROUND Pyridoxine-dependent epilepsy (PDE) is a rare seizure disorder usually presenting with neonatal seizures. Most cases are caused by biallelic pathogenic ALDH7A1variants. While anti-seizure medications are ineffective, pyridoxine provides seizure control, and dietary interventions may be of benefit. As the natural history beyond adolescence is insufficiently explored, our study aimed to assess the spectrum of PDE at various ages in Norway. METHODS Patients were ascertained by contacting all Norwegian paediatric, neurological, and neurohabilitation departments and relevant professional societies. Medical records were collected and reviewed. RESULTS We identified 15 patients treated for PDE; 13 had ALDH7A1 variants (PDE-ALDH7A1), one had PNPO deficiency, and in one, aetiology remained obscure. Of those with PDE-ALDH7A1, 12 were alive at time of study; five were > 18 years old and six were < 4 years. Median age was 10 years (range 2 months-53 years). Estimated minimum prevalence was 6.3/million among children and 1.2/million among adults. Ten had seizure onset on the first day of life. Perinatal complications and neuroradiological abnormalities suggested additional seizure aetiologies in several patients. Pyridoxine had immediate effect in six, while six had delayed (>1 h) or uncertain effect. Median delay from first seizure to continuous treatment was 11 days (range 0-42). Nine experienced breakthrough seizures with intercurrent disease or due to pyridoxine discontinuation. Cognitive outcomes ranged from normal to severe intellectual disability. The condition appeared to remain stable in adult life. SIGNIFICANCE We found a much higher prevalence of PDE-ALDH7A1 in children relative to adults, suggesting previous underdiagnosis and early mortality. Perinatal complications are common and can delay diagnosis and initiation of pyridoxine treatment. Lifelong and continuous treatment with pyridoxine is imperative. Due to better diagnostics and survival, the number of adult patients is expected to rise.
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Affiliation(s)
- Ahmed Jamali
- Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway; Department of Neurology and Clinical Neurophysiology, St. Olav University Hospital, Trondheim, Norway
| | - Erle Kristensen
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway; Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway
| | - Trine Tangeraas
- Norwegian National Unit for Newborn Screening, Division of Paediatric and Adolescent Medicine, Oslo University Hospital, Oslo, Norway
| | - Vibeke Arntsen
- Department of Neurology and Clinical Neurophysiology, St. Olav University Hospital, Trondheim, Norway
| | - Alma Sikiric
- Department of Neurohabilitation, Oslo University Hospital, Oslo, Norway
| | - Guste Kupliauskiene
- Department of Paediatric and Adolescent Medicine, Stavanger University Hospital, Stavanger, Norway
| | - Sverre Myren-Svelstad
- Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway; Department of Neurology and Clinical Neurophysiology, St. Olav University Hospital, Trondheim, Norway
| | - Siren Berland
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Yngve Sejersted
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Thorsten Gerstner
- Department of Child Neurology and Rehabilitation, Sørlandet Hospital, Arendal, Norway
| | - Bjørnar Hassel
- Department of Neurohabilitation, Oslo University Hospital, Oslo, Norway; Department of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Laurence A Bindoff
- Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway; Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Eylert Brodtkorb
- Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway; Department of Neurology and Clinical Neurophysiology, St. Olav University Hospital, Trondheim, Norway.
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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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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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Pyridoxine-Dependent Epilepsy and Antiquitin Deficiency Resulting in Neonatal-Onset Refractory Seizures. Brain Sci 2021; 12:brainsci12010065. [PMID: 35053812 PMCID: PMC8773593 DOI: 10.3390/brainsci12010065] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 12/25/2021] [Accepted: 12/29/2021] [Indexed: 12/29/2022] Open
Abstract
Pyridoxine-dependent epilepsy (PDE) is an autosomal recessive neurometabolic disorder due to a deficiency of α-aminoadipic semialdehyde dehydrogenase (mutation in ALDH7A1 gene), more commonly known as antiquitin (ATQ). ATQ is one of the enzymes involved in lysine oxidation; thus, its deficiency leads to the accumulation of toxic metabolites in body fluids. PDE is characterized by persistent, recurrent neonatal seizures that cannot be well controlled by antiepileptic drugs but are responsive clinically and electrographically to daily pyridoxine (vitamin B6) supplementation. Although the phenotypic spectrum distinguishes between typical and atypical, pyridoxine-dependent is true for each. Diagnosis may pose a challenge mainly due to the rarity of the disorder and the fact that seizures may not occur until childhood or even late adolescence. Moreover, patients may not demonstrate an obvious clinical or electroencephalography response to the initial dose of pyridoxine. Effective treatment requires lifelong pharmacologic supplements of pyridoxine, and dietary lysine restriction and arginine enrichment should improve prognosis and avoid developmental delay and intellectual disability. The purpose of this review is to summarize briefly the latest reports on the etiology, clinical symptoms, diagnosis, and management of patients suffering from pyridoxine-dependent epilepsy.
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Hu K, Liang P. Transcriptome Analysis Reveals Higher Levels of Mobile Element-Associated Abnormal Gene Transcripts in Temporal Lobe Epilepsy Patients. Front Genet 2021; 12:767341. [PMID: 34868252 PMCID: PMC8640520 DOI: 10.3389/fgene.2021.767341] [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: 08/30/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
Mesial temporal lobe epilepsy (MTLE) is the most common form of epilepsy, and temporal lobe epilepsy patients with hippocampal sclerosis (TLE-HS) show worse drug treatment effects and prognosis. TLE has been shown to have a genetic component, but its genetic research has been mostly limited to coding sequences of genes with known association to epilepsy. Representing a major component of the genome, mobile elements (MEs) are believed to contribute to the genetic etiology of epilepsy despite limited research. We analyzed publicly available human RNA-seq-based transcriptome data to determine the role of mobile elements in epilepsy by performing de novo transcriptome assembly, followed by identification of spliced gene transcripts containing mobile element (ME) sequences (ME-transcripts), to compare their frequency across different sample groups. Significantly higher levels of ME-transcripts in hippocampal tissues of epileptic patients, particularly in TLE-HS, were observed. Among ME classes, short interspersed nuclear elements (SINEs) were shown to be the most frequent contributor to ME-transcripts, followed by long interspersed nuclear elements (LINEs) and DNA transposons. These ME sequences almost in all cases represent older MEs normally located in the intron sequences. For protein coding genes, ME sequences were mostly found in the 3'-UTR regions, with a significant portion also in the coding sequences (CDSs), leading to reading frame disruption. Genes associated with ME-transcripts showed enrichment for the mRNA splicing process and an apparent bias in epileptic transcriptomes toward neural- and epilepsy-associated genes. The findings of this study suggest that abnormal splicing involving MEs, leading to loss of functions in critical genes, plays a role in epilepsy, particularly in TLE-HS, thus providing a novel insight into the molecular mechanisms underlying epileptogenesis.
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Affiliation(s)
- Kai Hu
- Department of Biological Sciences, Brock University, St. Catharines, ON, Canada.,Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Ping Liang
- Department of Biological Sciences, Brock University, St. Catharines, ON, Canada
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La Mendola FMC, Timpanaro T, Caruso D, Garozzo MT, Presti S, Romano C, Praticò ER, Lombardo G, Zanghì A, Falsaperla R. ALDH7A1 Gene and Its Related Pyridoxine-Dependent Epilepsy. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1728686] [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
AbstractDespite being classically reported as caused by mutations in solute carriers genes (SLC2A1), it has been recently shown that also mutations in ALDH7A1 can cause pyridoxine-dependent epilepsy (PDE). ALDH7A1 is a gene encoding for the antiquitin, an enzyme that catalyzes the nicotinamide adenine dinucleotide-dependent dehydrogenation of L-α-aminoadipic semialdehyde/L-Δ1-piperideine 6-carboxylate. It is a highly treatable disorder, but nevertheless it is still not certain when to consider this diagnosis and how to test for it. It is possible to identify a classical form and an atypical one of PDE associated with more than 70 mutations of ALDH7A1 gene. The typical form is characterized by the onset of seizures within the first month of life and can be treated with pyridoxine in monotherapy, as they are not responsive to traditional anticonvulsant therapy. The atypical forms are equally pyridoxine-dependent, but are characterized by a later onset of seizures, sometimes up to the age of 3 years. Several brain abnormalities have been associated with ALDH7A1 mutations. Seizure control is achieved by the administration of high-dose pyridoxine, which must be started in the patient as soon as possible. However, it has been observed that pyridoxine therapy does not prevent developmental delay in most cases; in these cases, it can be recommended and useful to supplement arginine with pyridoxine therapy associated with a dietary restriction of lysine.
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Affiliation(s)
| | - Tiziana Timpanaro
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Daniela Caruso
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Maria Teresa Garozzo
- Unit of Pediatric and Pediatric Emergency, Hospital “Cannizzaro,” Catania, Italy
| | - Santiago Presti
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Catia Romano
- Italian Blind Union, Catania section, Catania, Italy
| | | | - Giulia Lombardo
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Antonio Zanghì
- Department of Medical and Surgical Sciences and Advanced Technology “G.F. Ingrassia,” 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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9
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Jiao X, Gong P, Wu Y, Zhang Y, Yang Z. Analysis of the Phenotypic Variability as Well as Impact of Early Diagnosis and Treatment in Six Affected Families With ALDH7A1 Deficiency. Front Genet 2021; 12:644447. [PMID: 33868381 PMCID: PMC8047191 DOI: 10.3389/fgene.2021.644447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 03/15/2021] [Indexed: 11/13/2022] Open
Abstract
Objective To describe the clinical characteristics of 12 patients from six families with pyridoxine-dependent epilepsy (PDE) carrying ALDH7A1 mutations, and analyze the impact of early diagnosis and treatment, as well as possible genotype–phenotype relationship. Methods Clinical and genetics data of 12 patients were collected. Results Family 1–3 presented with symptoms in the neonatal period, while family 4-6 presented during early infancy. In the same family, the age of onset was similar. The focal motor seizure appeared in all patients. The affected identical twins from family 4 were diagnosed with infantile spasms. Mutation analysis identified nine different ALDH7A1 mutations among six families. The neurodevelopment of siblings in family 1 was mild delay and normal separately due to the minor difference of delayed diagnosis time. Siblings in family 2 showed severely delayed and normal development respectively due to the significant difference of a delayed diagnosis for 4 years. In family 5, although the difference of the delayed diagnosis time is up to 7 years, the nearly normal psychomotor development in both patients might be due to infrequent seizures before the delayed diagnosis. A severe phenotype exhibited in family 3, 4, and 6. The survived affected patients presented with severe developmental delay or refractory seizures and their twins or older sisters presented a similar clinical history and died in the early days of life. Mutation analysis showed D511N and IVS11 + 1G > A in family 3, V188A and exon1 deletion in family 4, and Y354C and exon 8–13 deletion in family 6. Conclusion Patients from the same family often have the same phenotype, including onset age and seizure type. Early treatment with pyridoxine and infrequent seizures showed positive relationship with prognosis. The deletion of exon 1 and exon 8–13 might be associated with the severe phenotype.
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Affiliation(s)
- Xianru Jiao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Pan Gong
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Ye Wu
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yuehua Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Zhixian Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
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10
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Ge X, Jiang S, Wang Z, Hu N, Jiang R, Cai Z, Wu B, Zhang Y, Gong P. Prognostic Biomarker ZNF311 and Its Correlation With Tumor Progression and Immune Infiltrates in Glioma. World Neurosurg 2021; 151:e37-e46. [PMID: 33746099 DOI: 10.1016/j.wneu.2021.03.064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/12/2021] [Accepted: 03/12/2021] [Indexed: 02/06/2023]
Abstract
BACKGROUND Gliomas, particularly high-grade gliomas, are the most common primary brain tumors. From the Chinese Glioma Genome Atlas (CGGA) database, the relationships between the altered molecular pathways and gliomas could be easily observed. A close connection in the occurrence of the pathogenesis exists between the microenvironment, the glioma, and the associated genes. METHODS Validation of the role of ZNF311 oncogene was confirmed by data from the CGGA dataset on glioblastoma and low-grade glioma. Furthermore, we used CIBERSORT to analyze the correlation between ZNF311 and cancer immune infiltrates. RESULTS According to our analysis, ZNF311 was expressed higher in patients with grade-depended glioma with poor prognosis. In addition, we obtained valuable prognostic results between isocitrate dehydrogenase 1 (IDH1) and ZNF311 through the analysis of integrated correlations. Similarly, we simultaneously revealed the prognostic results between 1p/19q and ZNF311. In addition, we found that ZNF311 is correlated with a large number of tumor-infiltrating immune cells. CONCLUSIONS Based on the study findings, we conclude that ZNF311 is potentially a novel biomarker for assessing prognosis and immune infiltration in glioblastoma and diffuse glioma cases.
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Affiliation(s)
- Xinqi Ge
- Medical School of Nantong University, Nantong, China; Department of Clinical Biobank, Nantong University Affiliated Hospital, Nantong, China
| | - Shichen Jiang
- Department of Neurosurgery, Nantong University Affiliated Hospital, Nantong, China
| | - Ziheng Wang
- Department of Clinical Biobank, Nantong University Affiliated Hospital, Nantong, China; Department of Neurosurgery, Nantong University Affiliated Hospital, Nantong, China
| | - Nan Hu
- Medical School of Nantong University, Nantong, China; Department of Clinical Biobank, Nantong University Affiliated Hospital, Nantong, China
| | - Rui Jiang
- Department of Neurosurgery, Nantong University Affiliated Hospital, Nantong, China
| | - Zishu Cai
- Department of Neurosurgery, Nantong University Affiliated Hospital, Nantong, China
| | - Bin Wu
- Department of Neurosurgery, Nantong University Affiliated Hospital, Nantong, China
| | - Yu Zhang
- Department of Neurosurgery, Nantong University Affiliated Hospital, Nantong, China
| | - Peipei Gong
- Department of Neurosurgery, Nantong University Affiliated Hospital, Nantong, China.
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11
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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: 40] [Impact Index Per Article: 13.3] [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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12
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Gibaud M, Barth M, Lefranc J, Mention K, Villeneuve N, Schiff M, Maurey H, Barthez MA, Caubel I, Chouchane M, Doummar D, Kossorotoff M, Lamblin MD, Roubertie A, Nabbout R, Van Bogaert P. West Syndrome Is an Exceptional Presentation of Pyridoxine- and Pyridoxal Phosphate-Dependent Epilepsy: Data From a French Cohort and Review of the Literature. Front Pediatr 2021; 9:621200. [PMID: 33748042 PMCID: PMC7973036 DOI: 10.3389/fped.2021.621200] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 01/04/2021] [Indexed: 12/04/2022] Open
Abstract
Objective: To characterize the electro-clinical presentation of patients with pyridoxine-dependent epilepsy (PDE) and pyridoxal phosphate (PLP)-dependent epilepsy in order to determine whether some of them could be diagnosed as de novo West syndrome, i. e., West syndrome that starts after the age of 2 months without other types of seizures (focal seizures for instance) before the onset of epileptic spasms. Methods: We analyzed data from an unpublished cohort of 28 genetically confirmed cases of PDE with antiquitine (ATQ) deficiency and performed a review of the literature looking for description of West syndrome in patients with either PDE with ATQ deficiency or PLP-dependent epilepsy with Pyridox(am)ine phosphate oxidase (PNPO) deficiency. Results: Of the 28 cases from the ATQ deficiency French cohort, 5 had spasms. In four cases, spasms were associated with other types of seizures (myoclonus, focal seizures). In the last case, seizures started on the day of birth. None of these cases corresponded to de novo West syndrome. The review of the literature found only one case of PNPO deficiency presenting as de novo West syndrome and no case of ATQ deficiency. Significance: The presentation of PDE- and PLP-dependent epilepsy as de novo West syndrome is so exceptional that it probably does not justify a systematic trial of pyridoxine or PLP. We propose considering a therapeutic trial with these vitamins in West syndrome if spasms are associated with other seizure types or start before the age of 2 months.
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Affiliation(s)
- Marc Gibaud
- Service de neuropédiatrie, CHU d'Angers, Angers, France
| | - Magalie Barth
- Service de génétique médicale, CHU d'Angers, Angers, France
| | | | - Karine Mention
- Centre de référence des Maladies Héréditaires du métabolisme, Hôpital Jeanne de Flandre CHRU Lille, Lille, France
| | - Nathalie Villeneuve
- Service de neuropédiatrie, Hôpital de la Timone, APHM Marseille, Marseille, France
| | - Manuel Schiff
- Centre de référence maladies héréditaires du métabolisme Hôpital Robert Debré, APHP Paris, Paris, France
| | - Hélène Maurey
- Service de neuropédiatrie Hôpital Kremlin-Bicêtre APHP Paris, Paris, France
| | | | | | | | - Diane Doummar
- Service de neuropédiatrie, Hôpital d'Enfants Armand-Trousseau APHP Paris, Paris, France
| | - Manoëlle Kossorotoff
- Service de neuropédiatrie et maladies métaboliques, Hôpital Necker-Enfants Malades APHP Paris, Paris, France
| | - Marie-Dominique Lamblin
- Service de physiologie et explorations fonctionnelles, Hôpital Jeanne de Flandre CHRU Lille, Lille, France
| | - Agathe Roubertie
- Service de neuropédiatrie, CHU de Montpellier, Montpellier, France
| | - Rima Nabbout
- Service de neuropédiatrie et maladies métaboliques, Hôpital Necker-Enfants Malades APHP Paris, Paris, France
| | - Patrick Van Bogaert
- Service de neuropédiatrie, CHU d'Angers, Angers, France.,Laboratoire Angevin de Recherche en Ingénierie des Systèmes (LARIS), Université d'Angers, Angers, France
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13
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Kava MP, Bryant L, Rowe P, Lewis B, Greed L, Balasubramaniam S. Beneficial outcome of early dietary lysine restriction as an adjunct to pyridoxine therapy in a child with pyridoxine dependant epilepsy due to Antiquitin deficiency. JIMD Rep 2020; 54:9-15. [PMID: 32685344 PMCID: PMC7358673 DOI: 10.1002/jmd2.12121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 03/23/2020] [Accepted: 03/30/2020] [Indexed: 11/10/2022] Open
Abstract
Pyridoxine-dependent epilepsy (PDE) is a potentially treatable vitamin-responsive epileptic encephalopathy. The most prevalent form of PDE is due to an underlying genetic defect in ALDH7A1 encoding Antiquitin (ATQ), an enzyme with α-aminoadipic semialdehyde dehydrogenase (AASADH) activity which facilitates cerebral lysine degradation. Devastating outcomes including intellectual disability and significant developmental delays are still observed in 75% to 80% of pyridoxine responsive individuals with good seizure control, potentially attributable to the accumulation of toxic intermediates α-aminoadipic semialdehyde (AASA) and its cyclic form Δ1-piperideine-6-carboxylate (P6C) in plasma, urine and CSF. Thus, adjunct treatment strategies incorporating lysine restriction and arginine supplementation, separately or in combination with pyridoxine have been attempted to enhance seizure control and improve cognitive function. We describe a 4 year old girl with classical PDE who demonstrated significant improvements in clinical, neurological and developmental outcomes including absence of clinical seizures and cessation of antiepileptic medications since age 3 months, normalisation of EEG, significant improvement in the white matter signal throughout the cerebrum on neuroimaging and significant reduction in urine P6C and pipecolic acid levels post- combined therapy with lysine restricted diet in conjunction with pyridoxine and folinic acid. Lysine restriction was well tolerated with impressive compliance and plasma lysine levels remained within the lower reference ranges; mean level 70 μmol/L (ref range 52-196 μmol/L). This case further emphasizes the benefit of early dietary intervention as an effective adjunct in the management of PDE.
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Affiliation(s)
- Maina P. Kava
- Department of NeurologyPerth Children's HospitalPerthWestern AustraliaAustralia
- Department of Metabolic Medicine and RheumatologyPerth Children's HospitalPerthWestern AustraliaAustralia
- School of Paediatrics and Child HealthUniversity of Western AustraliaPerthWestern AustraliaAustralia
| | - Leah Bryant
- Department of Nutrition and DieteticsPerth Children's HospitalPerthWestern AustraliaAustralia
| | - Peter Rowe
- Department of NeurologyPerth Children's HospitalPerthWestern AustraliaAustralia
- West Perth Child Development ServiceCommunity HealthWest PerthWestern AustraliaAustralia
| | - Barry Lewis
- Department of Clinical BiochemistryPathWestNedlandsWestern AustraliaAustralia
| | - Lawrence Greed
- Department of Clinical BiochemistryPathWestNedlandsWestern AustraliaAustralia
| | - Shanti Balasubramaniam
- Department of Metabolic Medicine and RheumatologyPerth Children's HospitalPerthWestern AustraliaAustralia
- Western Sydney Genetics ProgramThe Children's Hospital at WestmeadSydneyNew South WalesAustralia
- Discipline of Genetic Medicine, Sydney Medical SchoolUniversity of SydneySydneyNew South WalesAustralia
- Discipline of Child & Adolescent Health, Sydney Medical SchoolUniversity of SydneySydneyNew South WalesAustralia
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14
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Precise detection of low-level somatic mutation in resected epilepsy brain tissue. Acta Neuropathol 2019; 138:901-912. [PMID: 31377847 DOI: 10.1007/s00401-019-02052-6] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/11/2019] [Accepted: 07/29/2019] [Indexed: 01/16/2023]
Abstract
Low-level somatic mutations have been shown to be the major genetic etiology of intractable epilepsy. The extents thereof, however, have yet to be systematically and accurately explored in a large cohort of resected epilepsy brain tissues. Moreover, clinically useful and precise analysis tools for detecting low-level somatic mutations from unmatched formalin-fixed paraffin-embedded (FFPE) brain samples, the most clinically relevant samples, are still lacking. In total, 446 tissues samples from 232 intractable epilepsy patients with various brain pathologies were analyzed using deep sequencing (average read depth, 1112x) of known epilepsy-related genes (up to 28 genes) followed by confirmatory site-specific amplicon sequencing. Pathogenic mutations were discovered in 31.9% (74 of 232) of the resected epilepsy brain tissues and were recurrently found in only eight major focal epilepsy genes, including AKT3, DEPDC5, MTOR, PIK3CA, TSC1, TSC2, SCL35A2, and BRAF. Somatic mutations, two-hit mutations, and germline mutations accounted for 22.0% (51), 0.9% (2), and 9.1% (21) of the patients with intractable epilepsy, respectively. The majority of pathogenic somatic mutations (62.3%, 33 of 53) had a low variant allelic frequency of less than 5%. The use of deep sequencing replicates in the eight major focal epilepsy genes robustly increased PPVs to 50-100% and sensitivities to 71-100%. In an independent FCDII cohort of only unmatched FFPE brain tissues, deep sequencing replicates in the eight major focal epilepsy genes identified pathogenic somatic mutations in 33.3% (5 of 15) of FCDII individuals (similar to the genetic detecting rate in the entire FCDII cohort) without any false-positive calls. Deep sequencing replicates of major focal epilepsy genes in unmatched FFPE brain tissues can be used to accurately and efficiently detect low-level somatic mutations, thereby improving overall patient care by enriching genetic counseling and informing treatment decisions.
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15
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Laciak AR, Korasick DA, Wyatt JW, Gates KS, Tanner JJ. Structural and biochemical consequences of pyridoxine-dependent epilepsy mutations that target the aldehyde binding site of aldehyde dehydrogenase ALDH7A1. FEBS J 2019; 287:173-189. [PMID: 31302938 DOI: 10.1111/febs.14997] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 06/21/2019] [Accepted: 07/10/2019] [Indexed: 01/17/2023]
Abstract
In humans, certain mutations in the gene encoding aldehyde dehydrogenase 7A1 are associated with pyridoxine-dependent epilepsy (PDE). Understanding the impact of PDE-causing mutations on the structure and activity of ALDH7A1 could allow for the prediction of symptom-severity and aid the development of patient-specific medical treatments. Herein, we investigate the biochemical and structural consequences of PDE missense mutations targeting residues in the aldehyde substrate binding site: N167S, P169S, A171V, G174V, and W175G. All but G174V could be purified for biochemical and X-ray crystallographic analysis. W175G has a relatively mild kinetic defect, exhibiting a fivefold decrease in kcat with no change in Km . P169S and N167S have moderate defects, characterized by catalytic efficiencies of 20- and 100-times lower than wild-type, respectively. A171V has a profound functional defect, with catalytic efficiency 2000-times lower than wild-type. The crystal structures of the variants are the first for any PDE-associated mutant of ALDH7A1. The structures show that missense mutations that decrease the steric bulk of the side chain tend to create a cavity in the active site. The protein responds by relaxing into the vacant space, and this structural perturbation appears to cause misalignment of the aldehyde substrate in W175G and N167S. The P169S structure is nearly identical to that of the wild-type enzyme; however, analysis of B-factors suggests the catalytic defect may result from altered protein dynamics. The A171V structure suggests that the potential for steric clash with Val171 prevents Glu121 from ion pairing with the amino group of the aldehyde substrate. ENZYMES: Aldehyde dehydrogenase 7A1 (EC1.2.1.31). DATABASES: Coordinates have been deposited in the Protein Data Bank under the following accession codes: 6O4B, 6O4C, 6O4D, 6O4E, 6O4F, 6O4G, 6O4H.
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Affiliation(s)
- Adrian R Laciak
- Department of Chemistry, University of Missouri, Columbia, MO, USA
| | - David A Korasick
- Department of Biochemistry, University of Missouri, Columbia, MO, USA
| | - Jesse W Wyatt
- Department of Chemistry, University of Missouri, Columbia, MO, USA
| | - Kent S Gates
- Department of Chemistry, University of Missouri, Columbia, MO, USA.,Department of Biochemistry, University of Missouri, Columbia, MO, USA
| | - John J Tanner
- Department of Chemistry, University of Missouri, Columbia, MO, USA.,Department of Biochemistry, University of Missouri, Columbia, MO, USA
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16
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Coughlin CR, Swanson MA, Spector E, Meeks NJ, Kronquist KE, Aslamy M, Wempe MF, van Karnebeek CD, Gospe SM, Aziz VG, Tsai BP, Gao H, Nagy PL, Hyland K, van Dooren SJ, Salomons GS, Van Hove JL. The genotypic spectrum of ALDH7A1 mutations resulting in pyridoxine dependent epilepsy: A common epileptic encephalopathy. J Inherit Metab Dis 2019; 42:353-361. [PMID: 30043187 PMCID: PMC6345606 DOI: 10.1002/jimd.12045] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Pyridoxine dependent epilepsy (PDE) is a treatable epileptic encephalopathy characterized by a positive response to pharmacologic doses of pyridoxine. Despite seizure control, at least 75% of individuals have intellectual disability and developmental delay. Current treatment paradigms have resulted in improved cognitive outcomes emphasizing the importance of an early diagnosis. As genetic testing is increasingly accepted as first tier testing for epileptic encephalopathies, we aimed to provide a comprehensive overview of ALDH7A1 mutations that cause PDE. The genotypes, ethnic origin and reported gender was collected from 185 subjects with a diagnosis of PDE. The population frequency for the variants in this report and the existing literature were reviewed in the Genome Aggregation Database (gnomAD). Novel variants identified in population databases were also evaluated through in silico prediction software and select variants were over-expressed in an E.coli-based expression system to measure α-aminoadipic semialdehyde dehydrogenase activity and production of α-aminoadipic acid. This study adds 47 novel variants to the literature resulting in a total of 165 reported pathogenic variants. Based on this report, in silico predictions, and general population data, we estimate an incidence of approximately 1:64,352 live births. This report provides a comprehensive overview of known ALDH7A1 mutations that cause PDE, and suggests that PDE may be more common than initially estimated. Due to the relative high frequency of the disease, the likelihood of under-diagnosis given the wide clinical spectrum and limited awareness among clinicians as well as the cognitive improvement noted with early treatment, newborn screening for PDE may be warranted.
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Affiliation(s)
- Curtis R. Coughlin
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
- These authors contributed equally to the manuscript
- Correspondence: Curtis Coughlin II,
| | - Michael A. Swanson
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
- These authors contributed equally to the manuscript
| | - Elaine Spector
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
- Molecular Genetics Laboratory, Department of Pathology and Laboratory Medicine, Children’s Hospital Colorado, Aurora, CO 80045, USA
| | - Naomi J.L. Meeks
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
- Molecular Genetics Laboratory, Department of Pathology and Laboratory Medicine, Children’s Hospital Colorado, Aurora, CO 80045, USA
| | - Kathryn E. Kronquist
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
- Molecular Genetics Laboratory, Department of Pathology and Laboratory Medicine, Children’s Hospital Colorado, Aurora, CO 80045, USA
| | - Mezhgan Aslamy
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Michael F. Wempe
- School of Pharmacy, Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Clara D.M. van Karnebeek
- Department 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 BC V5Z4H4, Canada
| | - Sidney M. Gospe
- Division of Pediatric Neurology, Departments of Neurology and Pediatrics, University of Washington, Seattle, WA, USA
- Seattle Children’s Research Institute, Seattle, WA, USA
| | | | | | - Hanlin Gao
- Fulgent Genetics, Temple City, CA, 91780, USA
| | - Peter L. Nagy
- Medical Neurogenetics Laboratories, LLC, Atlanta, GA, USA
| | - Keith Hyland
- Medical Neurogenetics Laboratories, LLC, Atlanta, GA, USA
| | - Silvy J.M. van Dooren
- Department of Clinical Chemistry, Metabolic Unit, VU University Medical Center & Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Gajja S. Salomons
- Department of Clinical Chemistry, Metabolic Unit, VU University Medical Center & Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Johan L.K. Van Hove
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
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17
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Krestel H, Meier JC. RNA Editing and Retrotransposons in Neurology. Front Mol Neurosci 2018; 11:163. [PMID: 29875629 PMCID: PMC5974252 DOI: 10.3389/fnmol.2018.00163] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 04/30/2018] [Indexed: 12/28/2022] Open
Abstract
Compared to sites in protein-coding sequences many more targets undergoing adenosine to inosine (A-to-I) RNA editing were discovered in non-coding regions of human cerebral transcripts, particularly in genetic transposable elements called retrotransposons. We review here the interaction mechanisms of RNA editing and retrotransposons and their impact on normal function and human neurological diseases. Exemplarily, A-to-I editing of retrotransposons embedded in protein-coding mRNAs can contribute to protein abundance and function via circular RNA formation, alternative splicing, and exonization or silencing of retrotransposons. Interactions leading to disease are not very well understood. We describe human diseases with involvement of the central nervous system including inborn errors of metabolism, neurodevelopmental disorders, neuroinflammatory and neurodegenerative and paroxysmal diseases, in which retrotransposons (Alu and/or L1 elements) appear to be causally involved in genetic rearrangements. Sole binding of single-stranded retrotransposon transcripts by RNA editing enzymes rather than enzymatic deamination may have a homeostatic effect on retrotransposon turnover. We also review evidence in support of the emerging pathophysiological function of A-to-I editing of retrotransposons in inflammation and its implication for different neurological diseases including amyotrophic lateral sclerosis, frontotemporal dementia, Alzheimer's and Parkinson's disease, and epilepsy.
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Affiliation(s)
- Heinz Krestel
- Department of Neurology, Bern University Hospital and University of Bern, Bern, Switzerland.,Department for BioMedical Research, Bern University Hospital and University of Bern, Bern, Switzerland
| | - Jochen C Meier
- Division Cell Physiology, Zoological Institute, Technical University Braunschweig, Braunschweig, Germany
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18
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Larsen PA, Hunnicutt KE, Larsen RJ, Yoder AD, Saunders AM. Warning SINEs: Alu elements, evolution of the human brain, and the spectrum of neurological disease. Chromosome Res 2018; 26:93-111. [PMID: 29460123 PMCID: PMC5857278 DOI: 10.1007/s10577-018-9573-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 01/14/2018] [Accepted: 01/15/2018] [Indexed: 12/28/2022]
Abstract
Alu elements are a highly successful family of primate-specific retrotransposons that have fundamentally shaped primate evolution, including the evolution of our own species. Alus play critical roles in the formation of neurological networks and the epigenetic regulation of biochemical processes throughout the central nervous system (CNS), and thus are hypothesized to have contributed to the origin of human cognition. Despite the benefits that Alus provide, deleterious Alu activity is associated with a number of neurological and neurodegenerative disorders. In particular, neurological networks are potentially vulnerable to the epigenetic dysregulation of Alu elements operating across the suite of nuclear-encoded mitochondrial genes that are critical for both mitochondrial and CNS function. Here, we highlight the beneficial neurological aspects of Alu elements as well as their potential to cause disease by disrupting key cellular processes across the CNS. We identify at least 37 neurological and neurodegenerative disorders wherein deleterious Alu activity has been implicated as a contributing factor for the manifestation of disease, and for many of these disorders, this activity is operating on genes that are essential for proper mitochondrial function. We conclude that the epigenetic dysregulation of Alu elements can ultimately disrupt mitochondrial homeostasis within the CNS. This mechanism is a plausible source for the incipient neuronal stress that is consistently observed across a spectrum of sporadic neurological and neurodegenerative disorders.
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Affiliation(s)
- Peter A Larsen
- Department of Biology, Duke University, Durham, NC, 27708, USA.
- Duke Lemur Center, Duke University, Durham, NC, 27708, USA.
- Department of Biology, Duke University, 130 Science Drive, Box 90338, Durham, NC, 27708, USA.
| | | | - Roxanne J Larsen
- Duke University School of Medicine, Duke University, Durham, NC, 27710, USA
| | - Anne D Yoder
- Department of Biology, Duke University, Durham, NC, 27708, USA
- Duke Lemur Center, Duke University, Durham, NC, 27708, USA
| | - Ann M Saunders
- Zinfandel Pharmaceuticals Inc, Chapel Hill, NC, 27709, USA
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Steward CA, Parker APJ, Minassian BA, Sisodiya SM, Frankish A, Harrow J. Genome annotation for clinical genomic diagnostics: strengths and weaknesses. Genome Med 2017; 9:49. [PMID: 28558813 PMCID: PMC5448149 DOI: 10.1186/s13073-017-0441-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The Human Genome Project and advances in DNA sequencing technologies have revolutionized the identification of genetic disorders through the use of clinical exome sequencing. However, in a considerable number of patients, the genetic basis remains unclear. As clinicians begin to consider whole-genome sequencing, an understanding of the processes and tools involved and the factors to consider in the annotation of the structure and function of genomic elements that might influence variant identification is crucial. Here, we discuss and illustrate the strengths and weaknesses of approaches for the annotation and classification of important elements of protein-coding genes, other genomic elements such as pseudogenes and the non-coding genome, comparative-genomic approaches for inferring gene function, and new technologies for aiding genome annotation, as a practical guide for clinicians when considering pathogenic sequence variation. Complete and accurate annotation of structure and function of genome features has the potential to reduce both false-negative (from missing annotation) and false-positive (from incorrect annotation) errors in causal variant identification in exome and genome sequences. Re-analysis of unsolved cases will be necessary as newer technology improves genome annotation, potentially improving the rate of diagnosis.
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Affiliation(s)
- Charles A Steward
- Congenica Ltd, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1DR, UK. .,The Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK.
| | | | - Berge A Minassian
- Department of Pediatrics (Neurology), University of Texas Southwestern, Dallas, TX, USA.,Program in Genetics and Genome Biology and Department of Paediatrics (Neurology), The Hospital for Sick Children and University of Toronto, Toronto, Canada
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, WC1N 3BG, UK.,Chalfont Centre for Epilepsy, Chesham Lane, Chalfont St Peter, Buckinghamshire, SL9 0RJ, UK
| | - Adam Frankish
- The Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK.,European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Jennifer Harrow
- The Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK.,Illumina Inc, Great Chesterford, Essex, CB10 1XL, UK
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Abstract
PURPOSE OF REVIEW This article summarizes the emerging landscape of pediatric epilepsy, highlighting genetic contributions, and reviews approaches to genetic evaluation for pediatric epilepsy in this context. RECENT FINDINGS Advances in understanding the genetic basis for epilepsy over the last several years have been due in large part to the identification of de novo genetic variation underlying sporadic severe epilepsy in children; the genetic underpinnings of the more common epilepsies remain largely unknown. Next-generation sequencing approaches have been added to the repertoire of clinical tests for the evaluation of pediatric epilepsy, improving our ability to make positive diagnoses. Yields of over 50% are now being reported in selected groups of patients. Genetic variation contributing to the risk for pediatric epilepsy spans continua of scale and influence. The highest yield of genetic testing is currently in children with sporadic severe epilepsy caused by de novo variation. The approach to genetic evaluation and interpretation of results requires an understanding of (1) the epilepsy phenotype and (2) the particular advantages and limitations of the different genetic tests available. Our understanding of genetic variation will continue to improve over time and "negative" results are best conceptualized as "unresolved" or "negative for now."
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Affiliation(s)
- Tristan T Sands
- Division of Child Neurology, Columbia University Medical Center, 180 Fort Washington Avenue, New York, NY, 10032, USA.
| | - Hyunmi Choi
- Division of Child Neurology, Columbia University Medical Center, 180 Fort Washington Avenue, New York, NY, 10032, USA
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21
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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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Pyridoxine-Dependent Epilepsy: An Expanding Clinical Spectrum. Pediatr Neurol 2016; 59:6-12. [PMID: 26995068 DOI: 10.1016/j.pediatrneurol.2015.12.013] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 12/16/2015] [Accepted: 12/18/2015] [Indexed: 11/20/2022]
Abstract
BACKGROUND Pyridoxine-dependent epilepsy is a rare autosomal recessive epileptic encephalopathy caused by antiquitin (ALDH7A1) deficiency. In spite of adequate seizure control, 75% of patients suffer intellectual developmental disability. Antiquitin deficiency affects lysine catabolism resulting in accumulation of α-aminoadipic semialdehyde/pyrroline 6' carboxylate and pipecolic acid. Beside neonatal refractory epileptic encephalopathy, numerous neurological manifestations and metabolic/biochemical findings have been reported. METHODS AND RESULTS We present a phenotypic spectrum of antiquitin deficiency based on a literature review (2006 to 2015) of reports (n = 49) describing the clinical presentation of confirmed patients (n > 200) and a further six patient vignettes. Possible presentations include perinatal asphyxia; neonatal withdrawal syndrome; sepsis; enterocolitis; hypoglycemia; neuroimaging abnormalities (corpus callosum and cerebellar abnormalities, hemorrhage, white matter lesions); biochemical abnormalities (lactic acidosis, electrolyte disturbances, neurotransmitter abnormalities); and seizure response to pyridoxine, pyridoxal-phosphate, and folinic acid dietary interventions. DISCUSSION The phenotypic spectrum of pyridoxine-dependent epilepsy is wide, including a myriad of neurological and systemic symptoms. Its hallmark feature is refractory seizures during the first year of life. Given its amenability to treatment with lysine-lowering strategies in addition to pyridoxine supplementation for optimal seizure control and developmental outcomes, early diagnosis of pyridoxine-dependent epilepsy is essential. All infants presenting with unexplained seizures should be screened for antiquitin deficiency by determination of α-aminoadipic semialdehyde/pyrroline 6' carboxylate (in urine, plasma or cerebrospinal fluid) and ALDH7A1 molecular analysis.
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Abstract
Vitamin-dependent epilepsies and multiple metabolic epilepsies are amenable to treatment that markedly improves the disease course. Knowledge of these amenably treatable severe pediatric epilepsies allows for early identification, testing, and treatment. These disorders present with various phenotypes, including early onset epileptic encephalopathy (refractory neonatal seizures, early myoclonic encephalopathy, and early infantile epileptic encephalopathy), infantile spasms, or mixed generalized seizure types in infancy, childhood, or even adolescence and adulthood. The disorders are presented as vitamin responsive epilepsies such as pyridoxine, pyridoxal-5-phosphate, folinic acid, and biotin; transportopathies like GLUT-1, cerebral folate deficiency, and biotin thiamine responsive disorder; amino and organic acidopathies including serine synthesis defects, creatine synthesis disorders, molybdenum cofactor deficiency, and cobalamin deficiencies; mitochondrial disorders; urea cycle disorders; neurotransmitter defects; and disorders of glucose homeostasis. In each case, targeted intervention directed toward the underlying metabolic pathophysiology affords for the opportunity to significantly effect the outcome and prognosis of an otherwise severe pediatric epilepsy.
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Affiliation(s)
- Phillip L Pearl
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA.
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