SLC6A1 variant pathogenicity, molecular function and phenotype: a genetic and clinical analysis.

Genetic variants in the SLC6A1 gene can cause a broad phenotypic disease spectrum by altering the protein function. Thus, systematically curated clinically relevant genotype-phenotype associations are needed to understand the disease mechanism and improve therapeutic decision-making. We aggregated genetic and clinical data from 172 individuals with likely pathogenic/pathogenic (lp/p) SLC6A1 variants and functional data for 184 variants (14.1% lp/p). Clinical and functional data were available for a subset of 126 individuals. We explored the potential associations of variant positions on the GAT1 3D structure with variant pathogenicity, altered molecular function and phenotype severity using bioinformatic approaches. The GAT1 transmembrane domains 1, 6 and extracellular loop 4 (EL4) were enriched for patient over population variants. Across functionally tested missense variants (n = 156), the spatial proximity from the ligand was associated with loss-of-function in the GAT1 transporter activity. For variants with complete loss of in vitro GABA uptake, we found a 4.6-fold enrichment in patients having severe disease versus non-severe disease (P = 2.9 × 10-3, 95% confidence interval: 1.5-15.3). In summary, we delineated associations between the 3D structure and variant pathogenicity, variant function and phenotype in SLC6A1-related disorders. This knowledge supports biology-informed variant interpretation and research on GAT1 function. All our data can be interactively explored in the SLC6A1 portal (https://slc6a1-portal.broadinstitute.org/).

Mental health and neurodevelopmental patient-reported outcome measures (PROMs) for children and young people with epilepsy: A systematic review.

Children and young people with epilepsy are at higher risk of mental health disorders and atypical neurodevelopmental outcomes compared to the general population. It is essential to detect such comorbidities early in children with epilepsy and provide appropriate interventions, to improve clinical outcomes. We aimed to identify and evaluate the measurement properties of Patient-Reported Outcome Measures (PROMs) that have been validated specifically to measure mental health and neurodevelopmental outcomes in children and/or young people with epilepsy. We searched Embase, Medline, and PsycINFO in May 2023 for relevant studies. Mental health was defined as psychological symptoms (e.g., anxiety, depression, psychosis) and/or behavioural difficulties (e.g., conduct disorders). Neurodevelopmental outcomes included neurodevelopmental disorder traits such as attention-deficit hyperactivity disorder (ADHD) and autistic spectrum disorders. We assessed methodological quality using Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) guidance. Twelve papers were identified that psychometrically evaluated 13 relevant PROMs (two epilepsy-specific, eleven generic). The appraisal of the PROMs was limited by the availability of only one or two published articles for each, and incomplete psychometric evaluations in some cases. The tool demonstrating the strongest evidence was The Neurological Disorders Depression Inventory-Epilepsy for Youth. The ADHD Rating Scale-IV and The Paediatric Symptom Checklist -17 demonstrated good evidence in favour of at least two measurement properties. This review identified only a small number of mental health and neurodevelopmental PROMs evaluated specifically in paediatric epilepsy. There is a need for further validation of mental health and neurodevelopmental PROMs in children with epilepsy.

Feasibility and acceptability of an ultra-long-term at-home EEG monitoring system (EEG@HOME) for people with epilepsy.

BACKGROUND: Recent technological advancements offer new ways to monitor and manage epilepsy. The adoption of these devices in routine clinical practice will strongly depend on patient acceptability and usability, with their perspectives being crucial. Previous studies provided feedback from patients, but few explored the experience of them using independently multiple devices independently at home. PURPOSE: The study, assessed through a mixed methods design, the direct experiences of people with epilepsy independently using a non-invasive monitoring system (EEG@HOME) for an extended duration of 6 months, at home. We aimed to investigate factors affecting engagement, gather qualitative insights, and provide recommendations for future home epilepsy monitoring systems. MATERIALS AND METHODS: Adults with epilepsy independently were trained to use a wearable dry EEG system, a wrist-worn device, and a smartphone app for seizure tracking and behaviour monitoring for 6 months at home. Monthly acceptability questionnaires (PSSUQ, SUS) and semi-structured interviews were conducted to explore participant experience. Adherence with the procedure, acceptability scores and systematic thematic analysis of the interviews, focusing on the experience with the procedure, motivation and benefits and opinion about the procedure were assessed. RESULTS: Twelve people with epilepsy took part into the study for an average of 193.8 days (range 61 to 312) with a likelihood of using the system at six months of 83 %. The e-diary and the smartwatch were highly acceptable and preferred to a wearable EEG system (PSSUQ score of 1.9, 1.9, 2.4). Participants showed an acceptable level of adherence with all solutions (Average usage of 63 %, 66 %, 92 %) reporting more difficulties using the EEG twice a day and remembering to complete the daily behavioural questionnaires. Clear information and training, continuous remote support, perceived direct and indirect benefits and the possibility to have a flexible, tailored to daily routine monitoring were defined as key factors to ensure compliance with long-term monitoring systems. CONCLUSIONS: EEG@HOME study demonstrated people with epilepsy' interest and ability in active health monitoring using new technologies. Remote training and support enable independent home use of new non-invasive technologies, but to ensure long term acceptability and usability systems will require to be integrated into patients' routines, include healthcare providers, and offer continuous support and personalized feedback.

Biallelic variants in PIGN cause Fryns syndrome, multiple congenital anomalies-hypotonia-seizures syndrome, and neurologic phenotypes: A genotype-phenotype correlation study.

PURPOSE: Biallelic PIGN variants have been described in Fryns syndrome, multiple congenital anomalies-hypotonia-seizure syndrome (MCAHS), and neurologic phenotypes. The full spectrum of clinical manifestations in relation to the genotypes is yet to be reported. METHODS: Genotype and phenotype data were collated and analyzed for 61 biallelic PIGN cases: 21 new and 40 previously published cases. Functional analysis was performed for 2 recurrent variants (c.2679C>G p.Ser893Arg and c.932T>G p.Leu311Trp). RESULTS: Biallelic-truncating variants were detected in 16 patients-10 with Fryns syndrome, 1 with MCAHS1, 2 with Fryns syndrome/MCAHS1, and 3 with neurologic phenotype. There was an increased risk of prenatal or neonatal death within this group (6 deaths were in utero or within 2 months of life; 6 pregnancies were terminated). Incidence of polyhydramnios, congenital anomalies (eg, diaphragmatic hernia), and dysmorphism was significantly increased. Biallelic missense or mixed genotype were reported in the remaining 45 cases-32 showed a neurologic phenotype and 12 had MCAHS1. No cases of diaphragmatic hernia or abdominal wall defects were seen in this group except patient 1 in which we found the missense variant p.Ser893Arg to result in functionally null alleles, suggesting the possibility of an undescribed functionally important region in the final exon. For all genotypes, there was complete penetrance for developmental delay and near-complete penetrance for seizures and hypotonia in patients surviving the neonatal period. CONCLUSION: We have expanded the described spectrum of phenotypes and natural history associated with biallelic PIGN variants. Our study shows that biallelic-truncating variants usually result in the more severe Fryns syndrome phenotype, but neurologic problems, such as developmental delay, seizures, and hypotonia, present across all genotypes. Functional analysis should be considered when the genotypes do not correlate with the predicted phenotype because there may be other functionally important regions in PIGN that are yet to be discovered.

A prospective 5-year longitudinal study detects neurocognitive and imaging correlates of seizure remission in self-limiting Rolandic epilepsy.

OBJECTIVE: Self-limiting Rolandic epilepsy (RE) is the most common epilepsy in school-age children. Seizures are generally infrequent, but cognitive, language, and motor coordination problems can significantly impact the child's life. To better understand brain structure and function changes in RE, we longitudinally assessed neurocognition, cortical thickness, and subcortical volumes. METHODS: At baseline, we recruited 30 participants diagnosed with RE and 24-healthy controls and followed up for 4.94 ± 0.8 years when the participants with RE were in seizure remission. Measures included were as follows: T1-weighted magnetic resonance brain imaging (MRI) with FreeSurfer analysis and detailed neuropsychological assessments. MRI and neuropsychological data were compared between baseline and follow-up in seizure remission. RESULTS: Longitudinal MRI revealed excess cortical thinning in the left-orbitofrontal (p = 0.0001) and pre-central gyrus (p = 0.044). There is a significant association (p = 0.003) between a reduction in cortical thickness in the left-orbitofrontal cluster and improved processing of filtered words. Longitudinal neuropsychology revealed significant improvements in the symptoms of developmental coordination disorder (DCD, p = 0.005) in seizure remission. CONCLUSIONS: There is evidence for altered development of neocortical regions between active seizure state and seizure remission in RE within two clusters maximal in the left-orbitofrontal and pre-central gyrus. There is significant evidence for improvement in motor coordination between active seizures and seizure remission and suggestive evidence for a decline in fluid intelligence and gains in auditory processing.

A cross-sectional survey of healthcare professionals supporting children and young people with epilepsy and their parents/carers: which topics are raised in clinical consultations and can healthcare professionals provide the support needed?

BACKGROUND AND PURPOSE: Children and young people (CYP) with epilepsy see healthcare professionals (HCPs) for management of their seizures but may require information, advice and support with a range of broader topics. The purpose of the survey was to identify from HCPs, which topics CYP with epilepsy and their parents/carers ask about other than seizure management, and how adequately HCPs feel able to support them with these topics. METHOD: A cross-sectional online survey was used to collect data. Adverts which included a link to the survey were shared via social media channels, professional networks and United Kingdom (UK)-based epilepsy networks. Eighty-eight HCPs in the UK (who worked with CYP with epilepsy and their parents/carers) completed the survey. Quantitative data are presented descriptively. Qualitative data (free-text responses) were reflexively thematically analysed. RESULTS: CYP with epilepsy and their parents/carers were reported to ask HCPs for information, advice and support about a range of topics, most commonly, cognition and mental health. CYP were reported as also frequently asking about aspects of their social life while parents/carers commonly asked about sleep. HCPs varied in how able they felt to adequately support families about these topics, as well as in their views about which resources could be most useful. Having insufficient time and a lack of suitable services and resources to refer to, or draw upon, were key barriers to HCPs being able to support CYP and their families. DISCUSSION: Findings highlight the broad array of topics CYP with epilepsy and their families are reported as seeking support for. HCPs identified gaps in services and their abilities to meet those needs. There appeared to be a mismatch between the support that families were seeking and the ability of HCPs to meet these needs. Findings have implications for how HCPs could best be supported to deal with topics raised by CYP and families in clinic, highlighting the potential usefulness of informational resources on key topics for HCPs, parents/carers and CYP.

'No one's ever said anything about sleep': A qualitative investigation into mothers' experiences of sleep in children with epilepsy.

INTRODUCTION: Sleep problems in children with epilepsy (CWE) are common. However, little is known about parental experiences and feelings about managing sleep in their CWE. To provide the most appropriate services' provision, it is essential that the lived experience of parents of this patient group and the issues and problems that they face in managing their child's sleep is understood. METHOD: In 2018, nine mothers of CWE (aged 5-15 years) were interviewed about their perceptions and experiences around their child's sleep, sleep problems and their management, the impact of sleep difficulties on the child and their family and available support. RESULTS: Four themes were identified that represented the nature of the child's sleep problems, including settling and night-waking issues, parasomnias and child anxiety around sleep. Seven themes represented mothers' experiences of managing their child's sleep and any associated problems, including the longstanding challenging nature of child sleep issues, management strategies adopted, challenges related to managing sleep over time, the link between sleep and seizures, the negative impact of poor sleep on daytime functioning, role of antiseizure medication and maternal concerns about child sleep. One theme represented the perceived lack of information, help and support available. CONCLUSIONS: Findings suggest there are unmet needs in supporting parents to deal with sleep, sleep problems and their management in CWE. PATIENT OR PUBLIC CONTRIBUTION: This individual study was conducted under the umbrella of the CASTLE research programme (see https://castlestudy.org.uk/). Parents who have lived experience of parenting a child with epilepsy were co-applicants for the programme and were involved in the original conception, aims, design and funding application for the research programme (including the project reported in this paper) and advised on project design. Mothers of CWE who have lived experience of managing sleep and sleep problems in their child were participants who shared their experiences through the interviews, which formed the data of the current study.

Noninvasive mobile EEG as a tool for seizure monitoring and management: A systematic review.

In the last two decades new noninvasive mobile electroencephalography (EEG) solutions have been developed to overcome limitations of conventional clinical EEG and to improve monitoring of patients with long-term conditions. Despite the availability of mobile innovations, their adoption is still very limited. The aim of this study is to review the current state-of-the-art and highlight the main advantages of adopting noninvasive mobile EEG solutions in clinical trials and research studies of people with epilepsy or suspected seizures. Device characteristics are described, and their evaluation is presented. Two authors independently performed a literature review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A combination of different digital libraries was used (Embase, MEDLINE, Global Health, PsycINFO and https://clinicaltrials.gov/). Twenty-three full-text, six conference abstracts, and eight webpages were included, where a total of 14 noninvasive mobile solutions were identified. Published studies demonstrated at different levels how EEG recorded via mobile EEG can be used for visual detection of EEG abnormalities and for the application of automatic-detection algorithms with acceptable specificity and sensitivity. When the quality of the signal was compared with scalp EEG, many similarities were found in the background activities and power spectrum. Several studies indicated that the experience of patients and health care providers using mobile EEG was positive in different settings. Ongoing trials are focused mostly on improving seizure-detection accuracy and also on testing and assessing feasibility and acceptability of noninvasive devices in the hospital and at home. This review supports the potential clinical value of noninvasive mobile EEG systems and their advantages in terms of time, technical support, cost, usability, and reliability when applied to seizure detection and management. On the other hand, the limitations of the studies confirmed that future research is needed to provide more evidence regarding feasibility and acceptability in different settings, as well as the data quality and detection accuracy of new noninvasive mobile EEG solutions.

ZMYND11 variants are a novel cause of centrotemporal and generalised epilepsies with neurodevelopmental disorder.

ZMYND11 is the critical gene in chromosome 10p15.3 microdeletion syndrome, a syndromic cause of intellectual disability. The phenotype of ZMYND11 variants has recently been extended to autism and seizures. We expand on the epilepsy phenotype of 20 individuals with pathogenic variants in ZMYND11. We obtained clinical descriptions of 16 new and nine published individuals, plus detailed case history of two children. New individuals were identified through GeneMatcher, ClinVar and the European Network for Therapies in Rare Epilepsy (NETRE). Genetic evaluation was performed using gene panels or exome sequencing; variants were classified using American College of Medical Genetics (ACMG) criteria. Individuals with ZMYND11 associated epilepsy fell into three groups: (i) atypical benign partial epilepsy or idiopathic focal epilepsy (n = 8); (ii) generalised epilepsies/infantile epileptic encephalopathy (n = 4); (iii) unclassified (n = 8). Seizure prognosis ranged from spontaneous remission to drug resistant. Neurodevelopmental deficits were invariable. Dysmorphic features were variable. Variants were distributed across the gene and mostly de novo with no precise genotype-phenotype correlation. ZMYND11 is one of a small group of chromatin reader genes associated in the pathogenesis of epilepsy, and specifically ABPE. More detailed epilepsy descriptions of larger cohorts and functional studies might reveal genotype-phenotype correlation. The epileptogenic mechanism may be linked to interaction with histone H3.3.

SCN8A heterozygous variants are associated with anoxic-epileptic seizures.

Anoxic-epileptic seizures (AES) are rare outcomes of common childhood reflex anoxic syncope that trigger a true epileptic seizure. The term AES was coined by Stephenson in 1983, to differentiate these events from convulsive syncopes and the more common reflex anoxic syncopes. A genetic susceptibility for AES has been postulated; but, its molecular basis has up to now been elusive. We report here two illustrative cases and show the association of de novo SCN8A variants and AES. One of them had focal or generalized seizures and autonomic symptoms triggered by orthostatism; the second had breath-holding spells triggered by pain or exercise leading to tonic-clonic seizures; both had repeatedly normal EEGs and a family history of reflex syncope. The data of three additional AES patients further suggest, for the first time, a link between SCN8A pathogenic variants and AES. The neurodevelopment of four patients was abnormal. Four of the five SCN8A mutations observed here were previously described in patients with seizure disorders. Seizures responded particularly well to sodium channel blockers. Our observation enriches the spectrum of seizures linked with SCN8A pathogenic variants.

Epilepsy-specific patient-reported outcome measures of children's health-related quality of life: A systematic review of measurement properties.

OBJECTIVE: To identify and appraise published evidence of the measurement properties for epilepsy-specific patient-reported outcome measures (PROMs) of children's health-related quality of life (HRQoL). METHODS: We searched multiple databases for studies evaluating the measurement properties of English-language epilepsy-specific PROMs of children's HRQoL. We assessed the methodological quality using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidance. We extracted data about the content validity, construct validity, internal consistency, test-retest reliability, proxy reliability, responsiveness, and precision, and assessed the measurement properties with reference to standardized criteria. RESULTS: We identified 27 papers that evaluated 11 PROMs. Methodological quality was variable. Construct validity, test-retest reliability, and internal consistency were more commonly assessed. Quality of Life in Childhood Epilepsy (QoLCE) questionnaires are parent-reported and evaluated more than other PROMs; QoLCE-55 has good and replicated evidence for structural and construct validity and internal consistency. Health-Related Quality of Life Measure for Children with Epilepsy (CHEQoL) has both child and parent-reported versions and good evidence of content, structural, and construct validity. SIGNIFICANCE: This review identified two leading candidate epilepsy-specific PROMs for measuring health-related quality of life in children. Establishing evidence of the responsiveness of PROMs is a priority to help the interpretation of meaningful change scores.

Phenotypic and genetic spectrum of epilepsy with myoclonic atonic seizures.

OBJECTIVE: We aimed to describe the extent of neurodevelopmental impairments and identify the genetic etiologies in a large cohort of patients with epilepsy with myoclonic atonic seizures (MAE). METHODS: We deeply phenotyped MAE patients for epilepsy features, intellectual disability, autism spectrum disorder, and attention-deficit/hyperactivity disorder using standardized neuropsychological instruments. We performed exome analysis (whole exome sequencing) filtered on epilepsy and neuropsychiatric gene sets to identify genetic etiologies. RESULTS: We analyzed 101 patients with MAE (70% male). The median age of seizure onset was 34 months (range = 6-72 months). The main seizure types were myoclonic atonic or atonic in 100%, generalized tonic-clonic in 72%, myoclonic in 69%, absence in 60%, and tonic seizures in 19% of patients. We observed intellectual disability in 62% of patients, with extremely low adaptive behavioral scores in 69%. In addition, 24% exhibited symptoms of autism and 37% exhibited attention-deficit/hyperactivity symptoms. We discovered pathogenic variants in 12 (14%) of 85 patients, including five previously published patients. These were pathogenic genetic variants in SYNGAP1 (n = 3), KIAA2022 (n = 2), and SLC6A1 (n = 2), as well as KCNA2, SCN2A, STX1B, KCNB1, and MECP2 (n = 1 each). We also identified three new candidate genes, ASH1L, CHD4, and SMARCA2 in one patient each. SIGNIFICANCE: MAE is associated with significant neurodevelopmental impairment. MAE is genetically heterogeneous, and we identified a pathogenic genetic etiology in 14% of this cohort by exome analysis. These findings suggest that MAE is a manifestation of several etiologies rather than a discrete syndromic entity.

Meta-analysis of response inhibition in juvenile myoclonic epilepsy.

BACKGROUND: Patients with juvenile myoclonic epilepsy (JME) show evidence of cognitive impulsivity that may be linked to later adverse psychosocial outcomes. Here, we quantify the strength of association and estimate effect size (ES) of response inhibition by pooling available evidence in a meta-analysis. METHODS: We conducted a systematic review of the literature using Ovid MEDLINE and Ovid EMBASE databases (covering 2001-2019) with a search strategy using combinations of the specific Medical Subject Headings (MeSH) terms 'juvenile myoclonic epilepsy, cognitive impulsivity, response inhibition, Stroop, cognition, personality, traits' using the 'explode' feature where possible. We also searched within references of retrieved articles. We included studies reporting ESs describing established measures of response inhibition in teenage and adult patients with JME. RESULTS: Using the ESs pooled from 16 studies comprising 1047 patients and controls, we found ESs for response inhibition to be homogeneous with a significant moderate mean ES of d = 0.50 (95% confidence interval [CI]: 0.37-0.63). CONCLUSIONS: We confirm that reduced response inhibition is a consistently observed homogeneous trait in patients with JME.

Trait impulsivity correlates with active myoclonic seizures in genetic generalized epilepsy.

BACKGROUND: Juvenile myoclonic epilepsy (JME) is a common subtype of genetic generalized epilepsy (GGE) arising in adolescence and is often associated with executive function (EF) deficits. Some EF components like response inhibition have been extensively evaluated in JME, but few studies have focused upon trait impulsivity or compared between GGE subtypes. The aim of the present study was to compare the association of trait impulsivity in JME with other GGE subtypes. METHODS: Patients with GGE aged between 14 and 40 years (n = 137) were divided into those with JME (n = 92) and those with other GGEs (n = 45: 8 childhood absence epilepsy (CAE), 22 juvenile absence epilepsy (JAE), and 15 epilepsy with generalized tonic-clonic seizures only (EGTCS)). The study participants were recruited through medical records of the general population of Buskerud County and the neighboring municipalities, covering 477,000 people or 9.1% of Norway's total population. All participants underwent a clinical interview including the Barratt Impulsiveness Scale (BIS), an established measure of trait impulsivity. We controlled for other potential predictors of BIS score using analysis of covariance (ANCOVA). RESULTS: There were no differences between JME and other types of GGE for BIS scores, but the presence of myoclonic seizures within the last year, irrespective of GGE subtype, was independently associated with significantly increased behavioral impulsivity. CONCLUSIONS: This study demonstrates that trait impulsivity in GGE is most strongly related to the recent occurrence of myoclonic seizures rather than GGE subtype.

Mapping epilepsy-specific patient-reported outcome measures for children to a proposed core outcome set for childhood epilepsy.

OBJECTIVE: The objectives of the study were to (1) map questions in epilepsy-specific patient-reported outcome measures (PROMs) of children's health-related quality of life (HRQoL) to a proposed core outcome set (COS) for childhood epilepsy research and (2) gain insight into the acceptability of two leading candidate PROMs. METHOD: We identified 11 epilepsy-specific PROMs of children's HRQoL (17 questionnaire versions) in a previous systematic review. Each item from the PROMs was mapped to 38 discrete outcomes across 10 domains of the COS: seizures, sleep, social functioning, mental health, cognition, physical functioning, behavior, adverse events, family life, and global quality of life. We consulted with three children with epilepsy and six parents of children with epilepsy in Patient Public Involvement and Engagement (PPIE) work to gain an understanding of the acceptability of the two leading PROMs from our review of measurement properties: Quality of Life in Childhood Epilepsy (QOLCE-55) and Health-Related Quality of Life Measure for Children with Epilepsy (CHEQOL). RESULTS: Social Functioning is covered by all PROMs except DISABKIDS and G-QOLCE and Mental Health is covered by all PROMs except G-QOLCE and Hague Restrictions in Childhood Epilepsy Scale (HARCES). Only two PROMs (Epilepsy and Learning Disability Quality of Life (ELDQOL) and Glasgow Epilepsy Outcome Scale (GEOS-YP)) have items that cover the Seizure domain. The QOLCE-55 includes items that cover the domains of Physical Functioning, Social Functioning, Behavior, Mental Health, and Cognition. The CHEQOL parent and child versions cover the same domains as QOLCE-55 except for Physical Functioning and Behavior, and the child version has one item that covers the discrete outcome of Overall Quality of Life and one item that covers the discrete outcome of Relationship with parents and siblings. The QOLCE-55 parent version was acceptable to the parents we consulted with, and CHEQOL parent and child versions were described as acceptable to our child and parent advisory panel members. SIGNIFICANCE: Mapping items from existing epilepsy-specific PROMs for children is an important step in operationalizing our COS for childhood epilepsy research, alongside evaluation of their measurement properties. Two leading PROMS, QOLCE-55 and CHEQOL, cover a wide range of domains from our COS and would likely be used in conjunction with assessment tools selected for specific study objectives. The PPIE work provided practical insights into the administration and acceptability of candidate PROMs in appropriate context. We promote our COS as a framework for selecting outcomes and PROMs for future childhood epilepsy evaluative research.

PIGT-CDG, a disorder of the glycosylphosphatidylinositol anchor: description of 13 novel patients and expansion of the clinical characteristics.

PURPOSE: To provide a detailed electroclinical description and expand the phenotype of PIGT-CDG, to perform genotype-phenotype correlation, and to investigate the onset and severity of the epilepsy associated with the different genetic subtypes of this rare disorder. Furthermore, to use computer-assisted facial gestalt analysis in PIGT-CDG and to the compare findings with other glycosylphosphatidylinositol (GPI) anchor deficiencies. METHODS: We evaluated 13 children from eight unrelated families with homozygous or compound heterozygous pathogenic variants in PIGT. RESULTS: All patients had hypotonia, severe developmental delay, and epilepsy. Epilepsy onset ranged from first day of life to two years of age. Severity of the seizure disorder varied from treatable seizures to severe neonatal onset epileptic encephalopathies. The facial gestalt of patients resembled that of previously published PIGT patients as they were closest to the center of the PIGT cluster in the clinical face phenotype space and were distinguishable from other gene-specific phenotypes. CONCLUSION: We expand our knowledge of PIGT. Our cases reaffirm that the use of genetic testing is essential for diagnosis in this group of disorders. Finally, we show that computer-assisted facial gestalt analysis accurately assigned PIGT cases to the multiple congenital anomalies-hypotonia-seizures syndrome phenotypic series advocating the additional use of next-generation phenotyping technology.

Core Health Outcomes in Childhood Epilepsy (CHOICE): Development of a core outcome set using systematic review methods and a Delphi survey consensus.

OBJECTIVE: Establishing a core set of outcomes to be evaluated and reported in intervention trials aims to improve the usefulness of health research. There is no established core outcome set (COS) for childhood epilepsies. The aim of this study was to select a COS to be used in evaluative research of interventions for children with rolandic epilepsy (RE). METHODS: We followed guidance from the COMET (Core Outcome Measures in Effectiveness Trials) Initiative. First, we identified outcomes that had been measured in research through a systematic review. Second, young people with RE, parents, and professionals were invited to take part in a Delphi survey in which participants rated the importance of candidate outcomes. Last, a face-to-face meeting was convened to seek consensus on which outcomes were critical to include and to ratify the final COS. RESULTS: From 37 eligible papers in the review, we identified and included 48 candidate outcomes in the survey. We sent invitations to 165 people registered to take part in the survey; of these, 102 (62%) completed Round 1, and 80 (78%) completed Round 2 (three young people, 16 parents, 61 professionals). In Round 2 we included four additional outcomes suggested by participants in Round 1. The consensus meeting included two young people, four parents, and nine professionals who were eligible to vote and ratified the COS as 39 outcomes across 10 domains. SIGNIFICANCE: Our methodology was a proportionate and pragmatic approach toward producing a COS for evaluating research on interventions aiming to improve the health of children with RE.

Parental mosaicism in epilepsies due to alleged de novo variants.

Severe early onset epilepsies are often caused by de novo pathogenic variants. Few studies have reported the frequency of somatic mosaicism in parents of children with severe epileptic encephalopathies. Here we aim to investigate the frequency of mosaicism in the parents of children with epilepsy caused by alleged de novo variants. We tested parental genomic DNA derived from different tissues for 75 cases using targeted next-generation sequencing. Five parents (6.6%) showed mosaicism at minor allele frequencies of 0.8%-29% for the pathogenic variant detected in their offspring. Parental mosaicism was observed in the following genes: SCN1A, SCN2A, SCN8A, and STXBP1. One of the identified parents had epilepsy himself. Our results show that de novo events can occur already in parental tissue and in some cases can be detected in peripheral blood. Consequently, parents affected by low-grade mosaicism are faced with an increased recurrence risk for transmitting the pathogenic variant, compared to the overall recurrence risk for a second affected child estimated at approximately 1%. However, testing for parental somatic mosaicism will help identifying those parents who truly are at higher risk and will significantly improve genetic counseling in the respective families.

The spectrum of intermediate SCN8A-related epilepsy.

OBJECTIVE: Pathogenic variants in SCN8A have been associated with a wide spectrum of epilepsy phenotypes, ranging from benign familial infantile seizures (BFIS) to epileptic encephalopathies with variable severity. Furthermore, a few patients with intellectual disability (ID) or movement disorders without epilepsy have been reported. The vast majority of the published SCN8A patients suffer from severe developmental and epileptic encephalopathy (DEE). In this study, we aimed to provide further insight on the spectrum of milder SCN8A-related epilepsies. METHODS: A cohort of 1095 patients were screened using a next generation sequencing panel. Further patients were ascertained from a network of epilepsy genetics clinics. Patients with severe DEE and BFIS were excluded from the study. RESULTS: We found 36 probands who presented with an SCN8A-related epilepsy and normal intellect (33%) or mild (61%) to moderate ID (6%). All patients presented with epilepsy between age 1.5 months and 7 years (mean = 13.6 months), and 58% of these became seizure-free, two-thirds on monotherapy. Neurological disturbances included ataxia (28%) and hypotonia (19%) as the most prominent features. Interictal electroencephalogram was normal in 41%. Several recurrent variants were observed, including Ile763Val, Val891Met, Gly1475Arg, Gly1483Lys, Phe1588Leu, Arg1617Gln, Ala1650Val/Thr, Arg1872Gln, and Asn1877Ser. SIGNIFICANCE: With this study, we explore the electroclinical features of an intermediate SCN8A-related epilepsy with mild cognitive impairment, which is for the majority a treatable epilepsy.

Psychosocial complications in juvenile myoclonic epilepsy.

Juvenile myoclonic epilepsy (JME) constitutes about 10% of all epilepsies. Because of executive dysfunction, people with JME may be prone to impulsivity and risk-taking behavior. Our aim was to investigate whether psychosocial issues associated with impulsivity are more prominent in people with JME than in those with other types of genetic generalized epilepsy (GGE). Patients with GGE were recruited retrospectively through the Drammen Hospital records in Buskerud County, Norway, 1999-2013. They were invited to a semi-structured interview, either at the hospital or at home. Ninety-two patients with JME and 45 with other types of GGE were interviewed. Variables were evaluated in terms of their association with JME versus other GGE diagnosis using a logistic regression model. Juvenile myoclonic epilepsy was associated with use of illicit recreational drugs and police charges, although with borderline significance (odds ratio [OR] 3.4, p = 0.087 and OR 4.2, p = 0.095); JME was also associated with being examined for attention-deficit hyperactivity disorder (ADHD) in females (OR 15.5, p = 0.015), a biological parent with challenges like addiction or violent behavior (OR 3.5, p = 0.032), and use of levetiracetam (OR 5.1, p = 0.014). After controlling for group differences, we found psychosocial complications to be associated with JME, potentially influencing the lives of the individuals and their families to a greater extent than the seizures per se. Thus, JME should be considered a disorder of the brain in a broader sense than a condition with seizures only.