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Song T, Deng J, Chen C, Wang X, Han T, Wang X, Fang T, Tian X, Fang F. Long-term effectiveness and tolerability of ketogenic diet therapy in patients with genetic developmental and epileptic encephalopathy onset within the first 6 months of life. Epilepsia Open 2024; 9:643-652. [PMID: 38235958 PMCID: PMC10984301 DOI: 10.1002/epi4.12899] [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: 07/17/2023] [Revised: 12/31/2023] [Accepted: 01/03/2024] [Indexed: 01/19/2024] Open
Abstract
OBJECTIVE To investigate the effectiveness and tolerability of ketogenic diet therapy (KDT) in patients with developmental and epileptic encephalopathy (DEE) associated with genetic etiology which onset within the first 6 months of life, and to explore the association between response to KDT and genotype/clinical parameters. METHODS We retrospectively reviewed data from patients with genetic DEE who started KDT at Beijing Children's Hospital between January 1, 2016, and December 31, 2021. RESULTS A total of 32 patients were included, involving 14 pathogenic or likely pathogenic single genes, and 16 (50.0%) patients had sodium/potassium channel gene variants. The median age at onset of epilepsy was 1.0 (IQR: 0.1, 3.0) months. The median age at initiation of KDT was 10.0 (IQR: 5.3, 13.8) months and the median duration of maintenance was 14.0 (IQR: 7.0, 26.5) months, with a mean blood β-hydroxybutyrate of 2.49 ± 0.62 mmol/L. During the maintenance period of KDT, 26 (81.3%) patients had a ≥50% reduction of seizure frequency, of which 12 (37.5%) patients achieved seizure freedom. Better responses were observed in patients with STXBP1 variants, with four out of five patients achieving seizure freedom. There were no statistically differences in the age of onset, duration of epilepsy before KDT, blood ketone values, or the presence of ion channel gene variants between the seizure-free patients and the others. The most common adverse effects were gastrointestinal side effects, which occurred in 21 patients (65.6%), but all were mild and easily corrected. Only one patient discontinued KDT due to nephrolithiasis. SIGNIFICANCE KDT is effective in treating early onset genetic DEE, and no statistically significant relationship has been found between genotype and effectiveness in this study. KDT is well tolerated in most young patients, with mild and reversible gastrointestinal side effects being the most common, but usually not the reason to discontinue KDT. PLAIN LANGUAGE SUMMARY This study evaluated the response and side effects of ketogenic diet therapy (KDT) in patients who had seizures within the first 6 months of life, and were diagnosed with genetic developmental and epileptic encephalopathy (DEE), a type of severe epilepsy with developmental delay caused by gene variants. Thirty-two patients involving 14 gene variants who started KDT at Beijing Children's Hospital between were included. KDT was effective in treating early onset genetic DEE in this cohort, and patients with STXBP1 variants responded better; however, no statistically significant relationship was found between gene variant and response. Most young patients tolerated KDT well, with mild and reversible gastrointestinal side effects being the most common.
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Affiliation(s)
- Tianyu Song
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Jie Deng
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Chunhong Chen
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Xiaohui Wang
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Tongli Han
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Xu Wang
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Tie Fang
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Xiaojuan Tian
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Fang Fang
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
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Cali E, Rocca C, Salpietro V, Houlden H. Epileptic Phenotypes Associated With SNAREs and Related Synaptic Vesicle Exocytosis Machinery. Front Neurol 2022; 12:806506. [PMID: 35095745 PMCID: PMC8792400 DOI: 10.3389/fneur.2021.806506] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 11/16/2021] [Indexed: 01/29/2023] Open
Abstract
SNAREs (soluble N-ethylmaleimide sensitive factor attachment protein receptor) are an heterogeneous family of proteins that, together with their key regulators, are implicated in synaptic vesicle exocytosis and synaptic transmission. SNAREs represent the core component of this protein complex. Although the specific mechanisms of the SNARE machinery is still not completely uncovered, studies in recent years have provided a clearer understanding of the interactions regulating the essential fusion machinery for neurotransmitter release. Mutations in genes encoding SNARE proteins or SNARE complex associated proteins have been associated with a variable spectrum of neurological conditions that have been recently defined as “SNAREopathies.” These include neurodevelopmental disorder, autism spectrum disorder (ASD), movement disorders, seizures and epileptiform abnormalities. The SNARE phenotypic spectrum associated with seizures ranges from simple febrile seizures and infantile spasms, to severe early-onset epileptic encephalopathies. Our study aims to review and delineate the epileptic phenotypes associated with dysregulation of synaptic vesicle exocytosis and transmission, focusing on the main proteins of the SNARE core complex (STX1B, VAMP2, SNAP25), tethering complex (STXBP1), and related downstream regulators.
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Affiliation(s)
- Elisa Cali
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Clarissa Rocca
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Vincenzo Salpietro
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Henry Houlden
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
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Wang J, Zhang J, Yang Y, Gao K, Wu Y, Zhang Y, Jiang Y. Efficacy of Ketogenic Diet for Infantile Spasms in Chinese Patients With or Without Monogenic Etiology. Front Pediatr 2022; 10:842666. [PMID: 35372146 PMCID: PMC8969902 DOI: 10.3389/fped.2022.842666] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 02/11/2022] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE The aim of this study was to evaluate the efficacy of the ketogenic diet (KD) for infantile spasms (IS) in patients with and without different causative genetic mutations. METHODS We retrospectively evaluated the data of 119 infants with IS who underwent whole-exome sequencing (WES) before KD treatment. The KD efficacy was analyzed at the 16th week after initiation. Patients showing ≥ 50% seizure reduction from baseline and/or the disappeared hypsarrhythmia were considered as the responders. Chi-squared tests or two-sided Fisher's exact tests were performed for categorical data and Mann-Whitney U-tests for non-parametric and continuous data. RESULTS The responder rate to KD in 119 patients was 47.90%. Six different causative monogenic mutations were identified in 32 (26.89%) patients with IS, including CDKL5 (n = 8), ALG13 (n = 3), KCNT1 (n = 8), SLC35A2 (n = 5), PCDH19 (n = 4), and STXBP1 (n = 4). Patients with CDKL5 mutations showed a significantly better response to KD (87.50%) than patients without CDKL5 mutations (p = 0.03). Seven of eight patients with CDKL5 mutations were responders, including five mutations located in functional motifs, and two mutations in the catalytic domain. CONCLUSION KD therapy was effective in infants with IS. Patients with CDKL5 mutations might have a better response to KD treatment.
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Affiliation(s)
- Jun Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Department of Neurology, Children's Hospital Affiliated to Capital Institute of Pediatrics, Beijing, China
| | - Jie Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China.,Children Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Ying Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China
| | - Kai Gao
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China
| | - Ye Wu
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China.,Children Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Yuehua Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China
| | - Yuwu Jiang
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China.,Children Epilepsy Center, Peking University First Hospital, Beijing, China.,Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
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Liu L, Liu F, Wang Q, Xie H, Li Z, Lu Q, Wang Y, Zhang M, Zhang Y, Picker J, Cui X, Zou L, Chen X. Confirming the contribution and genetic spectrum of de novo mutation in infantile spasms: Evidence from a Chinese cohort. Mol Genet Genomic Med 2021; 9:e1689. [PMID: 33951346 PMCID: PMC8222834 DOI: 10.1002/mgg3.1689] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/24/2021] [Accepted: 03/30/2021] [Indexed: 01/21/2023] Open
Abstract
Objective We determined the yield, genetic spectrum, and actual origin of de novo mutations (DNMs) for infantile spasms (ISs) in a Chinese cohort. The efficacy of levetiracetam (LEV) for STXBP1‐related ISs was explored also. Methods Targeted sequencing of 153 epilepsy‐related candidate genes was applied to 289 Chinese patients with undiagnosed ISs. Trio‐based amplicon deep sequencing was used for all DNMs to distinguish somatic/mosaic mutations from germline ones. Results Total of 26 DNMs were identified from 289 recruited Chinese patients with undiagnosed ISs. Among them, 24 DNMs were interpreted as pathogenic mutations based on American College of Medical Genetics and Genomics guidelines, contributing to 8.3% (24/289) of diagnosis yield in the Chinese IS cohort. CDKL5 and STXBP1 are the top genes with recurrent DNMs, accounting for 3.1% (9/289) of yield. Further deep resequencing for the trio members showed that 22.7% (5/22) of DNMs are actually somatic in the proband or a parent. These somatic carriers presented milder seizure attacks than those with true germline DNMs. After treatment with LEV for half a year, three patients with DNM in STXBP1 showed improved clinical symptoms, including seizure‐free and normal electroencephalogram, except for a patient with a second DNM in DIAPH3. Significance Our study confirmed the contribution and genetic spectrum of DNMs in Chinese IS patients. Somatic mutation account for a quarter of DNMs in IS cases. Treatment with LEV improved the prognosis of STXBP1‐related ISs.
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Affiliation(s)
- Liying Liu
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China
| | - Fang Liu
- Graduate School of Peking, Union Medical College, Beijing, China.,Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Qiuhong Wang
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China
| | - Hua Xie
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Zhengchang Li
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Qian Lu
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China.,Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
| | - Yangyang Wang
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China
| | - Mengna Zhang
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China
| | - Yu Zhang
- Department of Lab Center, Capital Institute of Pediatrics, Beijing, China
| | - Jonathan Picker
- Division of Genetics & Genomics (Department of Medicine) and Department of Child & Adolescent Psychiatry, Boston Children's Hospital, Boston, MA, USA
| | - Xiaodai Cui
- Department of Lab Center, Capital Institute of Pediatrics, Beijing, China
| | - Liping Zou
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China.,Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
| | - Xiaoli Chen
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China.,Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, China
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Suri M, Evers JMG, Laskowski RA, O'Brien S, Baker K, Clayton-Smith J, Dabir T, Josifova D, Joss S, Kerr B, Kraus A, McEntagart M, Morton J, Smith A, Splitt M, Thornton JM, Wright CF. Protein structure and phenotypic analysis of pathogenic and population missense variants in STXBP1. Mol Genet Genomic Med 2017; 5:495-507. [PMID: 28944233 PMCID: PMC5606886 DOI: 10.1002/mgg3.304] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/17/2017] [Accepted: 05/20/2017] [Indexed: 01/07/2023] Open
Abstract
Background Syntaxin‐binding protein 1, encoded by STXBP1, is highly expressed in the brain and involved in fusing synaptic vesicles with the plasma membrane. Studies have shown that pathogenic loss‐of‐function variants in this gene result in various types of epilepsies, mostly beginning early in life. We were interested to model pathogenic missense variants on the protein structure to investigate the mechanism of pathogenicity and genotype–phenotype correlations. Methods We report 11 patients with pathogenic de novo mutations in STXBP1 identified in the first 4293 trios of the Deciphering Developmental Disorder (DDD) study, including six missense variants. We analyzed the structural locations of the pathogenic missense variants from this study and the literature, as well as population missense variants extracted from Exome Aggregation Consortium (ExAC). Results Pathogenic variants are significantly more likely to occur at highly conserved locations than population variants, and be buried inside the protein domain. Pathogenic mutations are also more likely to destabilize the domain structure compared with population variants, increasing the proportion of (partially) unfolded domains that are prone to aggregation or degradation. We were unable to detect any genotype–phenotype correlation, but unlike previously reported cases, most of the DDD patients with STXBP1 pathogenic variants did not present with very early‐onset or severe epilepsy and encephalopathy, though all have developmental delay with intellectual disability and most display behavioral problems and suffered seizures in later childhood. Conclusion Variants across STXBP1 that cause loss of function can result in severe intellectual disability with or without seizures, consistent with a haploinsufficiency mechanism. Pathogenic missense mutations act through destabilization of the protein domain, making it prone to aggregation or degradation. The presence or absence of early seizures may reflect ascertainment bias in the literature as well as the broad recruitment strategy of the DDD study.
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Affiliation(s)
- Mohnish Suri
- Nottingham Regional Genetics ServiceNottingham University Hospitals NHS TrustCity Hospital Campus, The Gables, Hucknall RoadNottinghamNG5 1PBUK
| | - Jochem M G Evers
- European Bioinformatics Institute (EMBL-EBI)Wellcome Genome Campus, HinxtonCambridgeCB10 1SDUK
| | - Roman A Laskowski
- European Bioinformatics Institute (EMBL-EBI)Wellcome Genome Campus, HinxtonCambridgeCB10 1SDUK
| | - Sinead O'Brien
- MRC Cognition and Brain Sciences Unit15 Chaucer RoadCambridgeCB2 7EFUK
| | - Kate Baker
- MRC Cognition and Brain Sciences Unit15 Chaucer RoadCambridgeCB2 7EFUK.,Department of Medical GeneticsUniversity of CambridgeCambridge Biomedical CampusCambridgeCB2 0QQUK
| | - Jill Clayton-Smith
- Manchester Centre for Genomic MedicineSt Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester Academic Health Science CentreManchesterM13 9WLUK
| | - Tabib Dabir
- Northern Ireland Regional Genetics CentreBelfast Health and Social Care TrustBelfast City HospitalLisburn RoadBelfastBT9 7ABUK
| | - Dragana Josifova
- South East Thames Regional Genetics CentreGuy's and St Thomas' NHS Foundation TrustGuy's HospitalGreat Maze PondLondonSE1 9RTUK
| | - Shelagh Joss
- West of Scotland Genetics ServiceQueen Elizabeth University HospitalLaboratory Medicine BuildingGlasgowG51 4TFUK
| | - Bronwyn Kerr
- Manchester Centre for Genomic MedicineSt Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester Academic Health Science CentreManchesterM13 9WLUK
| | - Alison Kraus
- Yorkshire Regional Genetics ServiceDepartment of Clinical GeneticsLeeds Teaching Hospitals NHS TrustChapel Allerton HospitalChapeltown RoadLeedsLS7 4SAUK
| | - Meriel McEntagart
- South West Thames Regional Genetics CentreSt George's Healthcare NHS TrustSt George's University of LondonCranmer TerraceLondonSW17 0REUK
| | - Jenny Morton
- West Midlands Regional Clinical Genetics Service and Birmingham Health PartnersBirmingham Women's and Children's NHS Foundation TrustBirmingham Women's HospitalMindelsohn Way, EdgbastonBirminghamB15 2TGUK
| | - Audrey Smith
- Yorkshire Regional Genetics ServiceDepartment of Clinical GeneticsLeeds Teaching Hospitals NHS TrustChapel Allerton HospitalChapeltown RoadLeedsLS7 4SAUK
| | - Miranda Splitt
- Northern Genetics ServiceNewcastle upon Tyne Hospitals NHS Foundation TrustInstitute of Human GeneticsInternational Centre for LifeCentral ParkwayNewcastle upon TyneNE1 3BZUK
| | - Janet M Thornton
- European Bioinformatics Institute (EMBL-EBI)Wellcome Genome Campus, HinxtonCambridgeCB10 1SDUK
| | | | - Caroline F Wright
- Wellcome Trust Sanger InstituteWellcome Genome Campus, HinxtonCambridgeCB1 8RQUK.,University of Exeter Medical SchoolRoyal Devon & Exeter HospitalBarrack RoadExeterEX2 5DWUK
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