Deletions in the CDKL5 5' untranslated region lead to CDKL5 deficiency disorder.

Pathogenic variants in the cyclin-dependent kinase-like 5 (CDKL5) gene are associated with CDKL5 deficiency disorder (CDD), a severe X-linked developmental and epileptic encephalopathy. Deletions affecting the 5' untranslated region (UTR) of CDKL5, which involve the noncoding exon 1 and/or alternatively spliced first exons (exons 1a-e), are uncommonly reported. We describe genetic and phenotypic characteristics for 15 individuals with CDKL5 partial gene deletions affecting the 5' UTR. All individuals presented characteristic features of CDD, including medically refractory infantile-onset epilepsy, global developmental delay, and visual impairment. We performed RNA sequencing on fibroblast samples from three individuals with small deletions involving exons 1 and/or 1a/1b only. Results demonstrated reduced CDKL5 mRNA expression with no evidence of expression from alternatively spliced first exons. Our study broadens the genotypic spectrum for CDD by adding to existing evidence that deletions affecting the 5' UTR of the CDKL5 gene are associated with the disorder. We propose that smaller 5' UTR deletions may require additional molecular testing approaches such as RNA sequencing to determine pathogenicity.

Unraveling the Link: Seizure Characteristics and Ammonia Levels in Urea Cycle Disorder During Hyperammonemic Crises.

BACKGROUND: This retrospective clinical study performed at a single clinical center aimed to identify the prevalence of seizures in individuals with urea cycle disorders (UCDs) with and without hyperammonemic (HA) crises. In addition, we sought to correlate the utility of biochemical markers and electroencephalography (EEG) in detecting subclinical seizures during HA. METHODS: Medical records of individuals with UCDs enrolled in Urea Cycle Disorders Consortium Longitudinal Study (UCDC-LS) (NCT00237315) at Children's National Hospital between 2006 and 2022 were reviewed for evidence of clinical and subclinical seizuress during HA crises, and initial biochemical levels concurrently. RESULTS: Eighty-five individuals with UCD were included in the analyses. Fifty-six of the 85 patients (66%) experienced HA crises, with a total of 163 HA events. Seizures are observed in 13% of HA events. Among all HA events with concomitant EEG, subclinical seizures were identified in 27% of crises of encephalopathy without clinical seizures and 53% of crises with clinical seizures. The odds of seizures increases 2.65 (95% confidence interval [CI], 1.51 to 4.66) times for every 100 µmol/L increase in ammonia and 1.14 (95% CI, 1.04 to 1.25) times for every 100 µmol/L increase in glutamine. CONCLUSIONS: This study highlights the utility of EEG monitoring during crises for patients presenting with clinical seizures or encephalopathy with HA. During HA events, measurement of initial ammonia and glutamine can help determine risk for seizures and guide EEG monitoring decisions.

Global modified-Delphi consensus on comorbidities and prognosis of SCN8A-related epilepsy and/or neurodevelopmental disorders.

OBJECTIVES: We aimed to develop consensus on comorbidities (frequency, severity, and prognosis) and overall outcomes in epilepsy, development, and cognition for the five phenotypes of SCN8A-related disorders. METHODS: A core panel consisting of 13 clinicians, 1 researcher, and 6 caregivers was formed and split into three workgroups. One group focused on comorbidities and prognosis. All groups performed a literature review and developed questions for use in a modified-Delphi process. Twenty-eight clinicians, one researcher, and 13 caregivers from 16 countries participated in three rounds of the modified-Delphi process. Consensus was defined as follows: strong consensus ≥80% fully agree; moderate consensus ≥80% fully or partially agree, <10% disagree; and modest consensus 67%-79% fully or partially agree, <10% disagree. RESULTS: Consensus was reached on the presence of 14 comorbidities in patients with Severe Developmental and Epileptic Encephalopathy (Severe DEE) spanning non-seizure neurological disorders and other organ systems; impacts were mostly severe and unlikely to improve or resolve. Across Mild/Moderate Developmental and Epileptic Encephalopathy (Mild/Moderate DEE), Neurodevelopmental Delay with Generalized Epilepsy (NDDwGE), and NDD without Epilepsy (NDDwoE) phenotypes, cognitive and sleep-related comorbidities as well as fine and gross motor delays may be present but are less severe and more likely to improve compared to Severe DEE. There was no consensus on comorbidities in the SeL(F)IE phenotype but strong conesensus that seizures would largely resolve. Seizure freedom is rare in patients with Severe DEE but may occur in some with Mild/Moderate DEE and NDDwGE. SIGNIFICANCE: Significant comorbidities are present in most phenotypes of SCN8A-related disorders but are most severe and pervasive in the Severe DEE phenotype. We hope that this work will improve recognition, early intervention, and long-term management for patients with these comorbidities and provide the basis for future evidence-based studies on optimal treatments of SCN8A-related disorders. Identifying the prognosis of patients with SCN8A-related disorders will also improve care and quality-of-life for patients and their caregivers.

Global modified Delphi consensus on diagnosis, phenotypes, and treatment of SCN8A-related epilepsy and/or neurodevelopmental disorders.

OBJECTIVE: We aimed to develop consensus for diagnosis/management of SCN8A-related disorders. Utilizing a modified Delphi process, a global cohort of experienced clinicians and caregivers provided input on diagnosis, phenotypes, treatment, and management of SCN8A-related disorders. METHODS: A Core Panel (13 clinicians, one researcher, six caregivers), divided into three subgroups (diagnosis/phenotypes, treatment, comorbidities/prognosis), performed a literature review and developed questions for the modified Delphi process. Twenty-eight expert clinicians, one researcher, and 13 caregivers from 16 countries participated in the subsequent three survey rounds. We defined consensus as follows: strong consensus, ≥80% fully agree; moderate consensus, ≥80% fully/partially agree, <10% disagree; and modest consensus, 67%-79% fully/partially agree, <10% disagree. RESULTS: Early diagnosis is important for long-term clinical outcomes in SCN8A-related disorders. There are five phenotypes: three with early seizure onset (severe developmental and epileptic encephalopathy [DEE], mild/moderate DEE, self-limited (familial) infantile epilepsy [SeL(F)IE]) and two with later/no seizure onset (neurodevelopmental delay with generalized epilepsy [NDDwGE], NDD without epilepsy [NDDwoE]). Caregivers represented six patients with severe DEE, five mild/moderate DEE, one NDDwGE, and one NDDwoE. Phenotypes vary by age at seizures/developmental delay onset, seizure type, electroencephalographic/magnetic resonance imaging findings, and first-line treatment. Gain of function (GOF) versus loss of function (LOF) is valuable for informing treatment. Sodium channel blockers are optimal first-line treatment for GOF, severe DEE, mild/moderate DEE, and SeL(F)IE; levetiracetam is relatively contraindicated in GOF patients. First-line treatment for NDDwGE is valproate, ethosuximide, or lamotrigine; sodium channel blockers are relatively contraindicated in LOF patients. SIGNIFICANCE: This is the first-ever global consensus for the diagnosis and treatment of SCN8A-related disorders. This consensus will reduce knowledge gaps in disease recognition and inform preferred treatment across this heterogeneous disorder. Consensus of this type allows more clinicians to provide evidence-based care and empowers SCN8A families to advocate for their children.

Seizure Control Outcomes following Resection of Cortical Dysplasia in Patients with DEPDC5 Variants: A Systematic Review and Individual Patient Data Analysis.

There is insufficient evidence regarding the efficacy of epilepsy surgery in patients with pharmacoresistant focal epilepsy and coexistent DEPDC5 (dishevelled EGL-10 and pleckstrin domain-containing protein 5) pathogenic (P), likely pathogenic (LP), or variance of unknown significance (VUS) variants. To conduct a systematic review on the literature regarding the use and efficacy of epilepsy surgery as an intervention for patients with DEPDC5 variants who have pharmacoresistant epilepsy. A systematic review of the current literature published regarding the outcomes of epilepsy surgery for patients with DEPDC5 variants was conducted. Demographics and individual patient data were recorded and analyzed. Subsequent statistical analysis was performed to assess significance of the findings. A total of eight articles comprising 44 DEPDC5 patients with genetic variants undergoing surgery were included in this study. The articles primarily originated in high-income countries (5/8, 62.5%). The average age of the subjects was 10.06 ± 9.41 years old at the time of study. The most common form of epilepsy surgery was focal resection (38/44, 86.4%). Thirty-seven of the 40 patients (37/40, 92.5%) with reported seizure frequency results had improvement. Twenty-nine out of 38 patients (29/38, 78.4%) undergoing focal resection achieved Engel Score I postoperatively, and two out of four patients achieved International League Against Epilepsy I (50%). Epilepsy surgery is effective in patients with pharmacoresistant focal epilepsy and coexistent DEPDC5 P, LP, or VUS variants.

Distinguishing Loss-of-Function and Gain-of-Function SCN8A Variants Using a Random Forest Classification Model Trained on Clinical Features.

Background and Objectives: Pathogenic variants at the voltage-gated sodium channel gene, SCN8A, are associated with a wide spectrum of clinical disease outcomes. A critical challenge for neurologists is to determine whether patients carry gain-of-function (GOF) or loss-of-function (LOF) variants to guide treatment decisions, yet in vitro studies to infer channel function are often not feasible in the clinic. In this study, we develop a predictive modeling approach to classify variants based on clinical features present at initial diagnosis. Methods: We performed an exhaustive search for individuals deemed to carry SCN8A GOF and LOF variants by means of in vitro studies in heterologous cell systems, or because the variant was classified as truncating, and recorded clinical features. This resulted in a total of 69 LOF variants: 34 missense and 35 truncating variants, including 9 nonsense, 13 frameshift, 6 splice site, 6 indels, and 1 large deletion. We then assembled a truth set of variants with known functional effects, excluding individuals carrying variants at other loci associated with epilepsy. We then trained a predictive model based on random forest using this truth set of 45 LOF variants and 45 GOF variants randomly selected from a set of variants tested by in vitro methods. Results: Phenotypic categories assigned to individuals correlated strongly with GOF or LOF variants. All patients with GOF variants experienced early-onset seizures (mean age at onset = 4.5 ± 3.1 months) while only 64.4% patients with LOF variants had seizures, most of which were late-onset absence seizures (mean age at onset = 40.0 ± 38.1 months). With high accuracy (95.4%), our model including 5 key clinical features classified individuals with GOF and LOF variants into 2 distinct cohorts differing in age at seizure onset, development of seizures, seizure type, intellectual disability, and developmental and epileptic encephalopathy. Discussion: The results support the hypothesis that patients with SCN8A GOF and LOF variants represent distinct clinical phenotypes. The clinical model developed in this study has great utility because it provides a rapid and highly accurate platform for predicting the functional class of patient variants during SCN8A diagnosis, which can aid in initial treatment decisions and improve prognosis.

Variability in Serum Concentrations and Clinical Response in Artisanal Versus Pharmaceutical Cannabidiol Treatment of Pediatric Pharmacoresistant Epilepsy.

OBJECTIVE: We hypothesized that serum cannabidiol (CBD) concentrations would be higher in patients taking pharmaceutical- versus artisanal-CBD oil, and higher serum CBD concentrations would correlate with increased side effects and decreased seizure frequency. METHODS: This was a retrospective chart review. We included patients with pharmacoresistant epilepsy, treated with artisanal-CBD or pharmaceutical-CBD (Epidiolex), and with quantitative serum CBD concentrations. We tracked epilepsy diagnosis, artisanal-CBD dosage, pharmaceutical-CBD dose, serum CBD concentration, clobazam concentration, N-desmethylclobazam concentration, seizure history (frequency of motor seizures), response to medication (percentage reduction in motor seizures), and side effects. RESULTS: Forty-two patients met inclusion criteria. Mean serum CBD concentration was 51.1 ng/mL (artisanal group) and 124 ng/mL (pharmaceutical group) (p = 0.022). Patients receiving artisanal-CBD had no change in median overall seizures (IQR, -50% to 50%); the pharmaceutical-CBD group had median 50% reduction (IQR, -90% to no change) (p = 0.199). CONCLUSIONS: Pharmaceutical-CBD achieves higher serum CBD concentrations than artisanal-CBD in pediatric patients with refractory epilepsy. These higher CBD concentrations are associated with increased reported adverse effects, but no detectable difference in seizure frequency.

Telehealth for patients with rare epilepsies.

Recent developments in technology and exigencies of the COVID-19 pandemic have spurred innovations for telehealth in patients with rare epilepsies. This review details the many ways telehealth may be used in the diagnosis and management of rare, pharmacoresistant epilepsy and documents our experience as measured by surveying caregivers of pediatric patients with epilepsy. Most components of the epilepsy evaluation, including history and examination, neuroimaging, and electroencephalogram (EEG) can be performed or reviewed remotely, assuming similar technique and quality of diagnostic studies. Seizure and epilepsy diagnosis is enhanced through the assistance of caregiver smart phone video recordings and 'ambulatory' EEG. Monitoring patient seizure frequency through paper seizure diaries is now increasingly being replaced by electronic diaries in both clinical and research settings. Electronic seizure diaries have numerous advantages such as data durability, increased accessibility, real-time availability, and easier analysis. Telehealth enhances access to specialized epilepsy care, which has been shown to reduce mortality and improve patient compliance and outcomes. Telehealth can also enable evaluation of patients with rare epilepsy in centers of excellence and enhance enrollment in clinical trials. Reducing mortality risk in patients with epilepsy can be accomplished through remote counseling and addressing psychiatric co-morbidities. Findings from surveying caregivers of children with epilepsy treated at Children's National Hospital showed that 54/56 (96.4%) found that not having to commute to the appointment positively contributed to their telemedicine experience. Overall, most respondents had a positive experience with their telemedicine visit. Almost all respondents (98%) were either 'very happy' or 'happy' with their telemedicine visit and their ability to communicate over telemedicine with the provider and either 'very likely' or 'likely' to want to use telemedicine for some future clinic visits. Telehealth in rare epilepsies is feasible and, in many ways, comparable with traditional evaluation and management.

Telehealth for patients with rare epilepsies Recent technological advancements and constraints caused by the COVID-19 pandemic have spurred innovations for telehealth in patients with rare epilepsies. This review details the many ways telehealth may be used in the diagnosis and management of rare, drug-resistant epilepsy and documents our experience as measured by surveying caregivers of pediatric patients with epilepsy. Most components of the epilepsy evaluation can be performed or reviewed remotely, assuming similar technique and quality of diagnostic studies. Seizure and epilepsy diagnosis is enhanced through the assistance of caregiver smart phone video recordings and 'ambulatory' electroencephalogram (EEG). Monitoring patient seizure frequency through paper seizure diaries is now increasingly being replaced by electronic diaries in both clinical and research settings. Electronic seizure diaries have numerous advantages such as data durability, increased accessibility, real-time availability, and easier analysis. Telehealth enhances access to specialized epilepsy care, which has been shown to reduce mortality and improve patient compliance and outcomes. Telehealth can also enable evaluation of patients with rare epilepsy in centers of excellence and enhance enrollment in clinical trials. Reducing mortality risk in patients with epilepsy can be accomplished through remote counseling and addressing related mental health issues. Findings from surveying caregivers of children with epilepsy treated at Children's National Hospital showed that most respondents found not having to commute to the appointment positively contributed to their telemedicine experience. Almost all respondents were either 'very happy' or 'happy' with their telemedicine visit and their ability to communicate over telemedicine with the provider and either 'very likely' or 'likely' to want to use telemedicine for some future clinic visits. Telehealth in rare epilepsies is feasible and, in many ways, comparable with traditional evaluation and management.

Results of the First GNAO1-Related Neurodevelopmental Disorders Caregiver Survey.

BACKGROUND: We sought to expand our knowledge of the clinical spectrum of GNAO1-related neurodevelopmental disorders through a caregiver survey reviewing medical and developmental history and development of epilepsy and movement disorders. METHODS: An online survey was administered to caregivers of individuals diagnosed with GNAO1 pathogenic variants. RESULTS: Eighty-two surveys were completed. Nearly all (99%) reported the first symptom of concern by age one year with the most frequently identified concerns as hypotonia (68%), developmental delay (67%), seizures (29%), difficulty feeding (23%), and abnormal movements (20%). All caregivers reported developmental delays with a spectrum of severity. Movement disorders (76%) were more common than epilepsy (52%), although 33% reported both. The onset of seizures tended to be earlier than abnormal movements. Nearly half (48%) of those with any seizures, reported they were no longer having recurrent seizures. No single most effective medication for movement disorders or epilepsy was noted. Ten participants have had deep brain stimulator for their movement disorder, and all indicated positive effects. CONCLUSIONS: GNAO1-related neurodevelopmental disorders most often present within the first year of life with nonspecific symptoms of hypotonia or developmental delay. Although associated epilepsy and movement disorders can be severe, GNAO1-associated epilepsy may not always be medically refractory or lifelong.

A Randomized Controlled Trial of SGS-742, a γ-aminobutyric acid B (GABA-B) Receptor Antagonist, for Succinic Semialdehyde Dehydrogenase Deficiency.

We examined safety, tolerability, and efficacy of SGS-742, a γ-aminobutyric acid B (GABA-B) receptor antagonist, in patients with succinic semialdehyde dehydrogenase deficiency. This was a single-center randomized, double-blind crossover phase II clinical trial of SGS-742 versus placebo in patients with succinic semialdehyde dehydrogenase deficiency. Procedures included transcranial magnetic stimulation and the Adaptive Behavior Assessment Scale. Nineteen subjects were consented and enrolled; the mean age was 14.0 ± 7.5 years and 11 (58%) were female. We did not find a significant effect of SGS-742 on the Adaptive Behavior Assessment Scale score, motor threshold, and paired-pulse stimulation. The difference in recruitment curve slopes between treatment groups was 0.003 (P = .09). There was no significant difference in incidence of adverse effects between drug and placebo arms. SGS-742 failed to produce improved cognition and normalization of cortical excitability as measured by the Adaptive Behavior Assessment Scale and transcranial magnetic stimulation. Our data do not support the current use of SGS-742 in succinic semialdehyde dehydrogenase deficiency.Trial registry number NCT02019667. Phase 2 Clinical Trial of SGS-742 Therapy in Succinic Semialdehyde Dehydrogenase Deficiency. https://clinicaltrials.gov/ct2/show/NCT02019667.

Spatiotemporal distribution and age of seizure onset in a pediatric epilepsy surgery cohort with cortical dysplasia.

OBJECTIVE: Focal Cortical Dysplasias (CD) are a common etiology of refractory pediatric epilepsy and are amenable to epilepsy surgery. We investigated the association of lesion volume and location to age of seizure onset among children with CD who underwent epilepsy surgery. METHODS: A retrospective study of epilepsy surgery patients with pathologically-confirmed CD. Regions of interest (ROI) determined preoperative lesion volumes on 1.5 T and 3 T T2 and SPGR MRIs, and location in 7 distributed neural networks. Descriptive and inferential statistics were used. RESULTS: Fifty-five patients were identified: 35 girls (56.5 %). Median age of seizure onset: 19.0 months (range 0.02 months - 16.0 years). Median age of surgery: 7.8 years (range 2.89 months - 24.45 years). CD were frontal (n = 21, 38 %); temporal (n = 15, 27 %); parietal (n = 10, 18 %); occipital (n = 3, 5%); multilobar (n = 6, 11 %). Frontal FCD had seizure onset < 1-year-old (P = 0.10); temporal lobe CD seizure onset was more likely > 5-years-old (P= 0.06). Median lesion volume for CD was 23.23 cm3 (range: 1.87-591.73 cm3). Larger CD lesions were associated with earlier epilepsy (P = 0.01, r = -0.16). We did not find that lesions proximal to early maturing cortical regions were associated with earlier seizure onset. We found an association with CD location in the default mode network (DMN) and age onset < 5years old (P = 0.03). Age of seizure onset was negatively correlated with percent of CD overlapping motor cortex (P = 0.001, r =-0.794) but not with CD overlap of the visual cortex (P = 0.35). There was no effect of CD type on age of epilepsy onset. SIGNIFICANCE: Larger CD lesions are associated with earlier onset epilepsy. CD most commonly occurs within the DMN and Limbic network, and DMN is associated with seizure onset before 5-years-old. Percent of CD overlapping motor cortex correlates with earlier seizure onset. These observations may reflect patterns of brain maturation or regional differences in clinical expression of seizures.

Children with refractory epilepsy demonstrate alterations in myocardial strain.

OBJECTIVE: To test whether children with epilepsy have impairments in myocardial mechanics compared to controls without epilepsy. METHODS: Children with refractory epilepsy with epilepsy duration of at least 3 years underwent echocardiography including conventional measurements and speckle tracking to assess longitudinal and circumferential strain. Parent-completed surveys, capturing critical aspects of the children's seizure history and cardiac risk factors, complemented retrospective chart reviews, which also included antiepileptic drug history. Normal echocardiograms from controls, matched for age and gender, were obtained from our institutional database and evaluated for strain. RESULTS: Forty-one patients (median age = 10 years, interquartile range [IQR] = 5-15; 58.5% male) were enrolled. Epilepsy etiology included genetic (n = 26), structural (n = 6), genetic and structural (n = 5), infection (n = 3), and unknown (n = 1). No cardiac structural abnormalities were identified. Both longitudinal and circumferential strain were impaired (P < .03) in patients compared to controls (median [IQR] = 22.7% [21.2-24.2] vs 23.6% [22.2-26.1] and 22.0% [20.3-25.4] vs 24.5% [22.3-27.0], respectively), indicating decreased myocardial deformation/contraction. Shortening fraction was higher in patients (37.6% [35.7-39.7] vs 34.9% [32.5-38.7], P = .009); mitral valve E wave inflow velocity (84.8 cm/s [78.4-92.8] vs 97.2 cm/s [85.9-105.8], P = .005) and tissue Doppler lateral E' wave (13.9 cm/s [12.3-16.1] vs 17.3 cm/s [15.4-18.5], P < .001) were decreased compared to controls. Findings were similar in the pairs with epilepsy patients distinguished by the ability to independently ambulate. There was no difference between patients and controls in ejection fraction. Among the epilepsy patients, there were no associations between cardiac measurements and epilepsy characteristics, including seizure type and frequency and cardiotoxic antiseizure medication exposure after correction for multiple comparisons. SIGNIFICANCE: Children with refractory epilepsy had impaired systolic ventricular strain compared to controls, not correlated with epilepsy history. Further studies are needed to determine the significance of these changes.

Measure thrice, cut twice: On the benefit of reoperation for failed pediatric epilepsy surgery.

OBJECTIVE: To determine whether clinical outcomes are improved after repeat surgery for medically refractory epilepsy in children. METHODS: This is a single-center retrospective cohort analysis of all patients who received repeat resective surgery for ongoing seizures from 2000-2017. From a total of 251 consecutive individual epilepsy surgical patients for focal resection, 53 patients met study inclusion criteria and had adequate follow-up documented. RESULTS: Median age of seizure-onset was 2.0-years-old (IQR 0.3-5.5 years). The median age at first epilepsy surgery was 6.3-years-old (IQR 2.9-9.2 years) and at second epilepsy surgery was 8.4-years-old (IQR 4.7-12.6 years). Overall, 53 % (n = 28) of this series achieved Engel Class I (seizure freedom); with improved seizure control (Engel Class I-II) in 83 % (n = 44) of the cohort. 64 % (n = 34) had one reoperation; 26 % (n = 14) had two; and 9% (n = 5) had three. Pathology: 58 % (n = 31) had focal cortical dysplasia; 13 % (n = 10) tumor; 9% (n = 5) encephalitis; 6% (n = 3) gliosis; 4% (n = 2) mesial temporal sclerosis; and 2% (n = 1) hemimegalencephaly. Tumor pathology was associated with increased chance (p = 0.01) for seizure freedom (90 % of tumor patients had Engel Class I outcome). MTS had worse outcome with both patients having ongoing seizures (Engel II-IV). There were 6 patients who developed post-operative hemiparesis; one was unplanned but resolved. SIGNIFICANCE: Reoperation for pediatric epilepsy surgery can lead to seizure freedom in many cases and improved seizure control in most cases. Reoperation for brain tumor pathology is associated with a high rate of seizure freedom.

A multi-disciplinary clinic for SCN8A-related epilepsy.

OBJECTIVE: We endeavored to evaluate a cohort of patients diagnosed with SCN8A-related epilepsy in a multi-disciplinary clinic and to create a bio-repository. METHODS: We recruited patients with epilepsy due to SCN8A variants at Children's National Medical Center, through family organizations, or SCN8A.net. Study procedures included medical record review, review of EEG and MRI data, clinical evaluation, the Vineland Adaptive Behavior Scales, Third Edition (VABS-3), DNA extraction, and preparation of peripheral blood mononuclear cells. RESULTS: Seventeen patients (9 months - 19 years) completed the study. Age at seizure onset was 1 day to 4 years old (median age 4 months). Epilepsy phenotype ranged from mild epilepsy to severe developmental and epileptic encephalopathy. Medications targeting the voltage-gated sodium channel were most often effective, while levetiracetam resulted in worsening seizures and/or developmental regression in 7/16 (p < 0.05). VABS-3 scores were below age expectations for most children; older children had lower scores. Neurological examination revealed hypotonia (13), spastic quadriparesis (1), ataxia (9), dyskinesia (2)/ dystonia (7), and four non-ambulatory. CONCLUSIONS: This is the first report of a large series of patients with epilepsy due to SCN8A variants evaluated in a single multi-disciplinary clinic. By utilizing a more comprehensive and consistent evaluation, we clarify specific seizure and epilepsy types, describe a distinct epilepsy phenotype in a patient with a nonsense variant, delineate patterns of developmental delay, language, and swallow function (specifically anomic aphasia and flaccid dysarthria), identify and characterize movement disorders, report common findings on physical exam, and demonstrate clinical worsening with levetiracetam.

Novel variants and phenotypes widen the phenotypic spectrum of GABRG2-related disorders.

PURPOSE: Next-generation sequencing (NGS) has made genetic testing of patients with epileptic encephalopathies easier - novel variants are discovered and new phenotypes described. Variants in the same gene - even the same variant - can cause different types of epilepsy and neurodevelopmental disorders. Our aim was to identify the genetic causes of epileptic encephalopathies in paediatric patients with complex phenotypes. METHODS: NGS was carried out for three patients with epileptic encephalopathies. Detailed clinical features, brain magnetic resonance imaging and electroencephalography were analysed. We searched the Human Gene Mutation Database for the published GABRG2 variants with clinical description of patients and composed a summary of the variants and their phenotypic features. RESULTS: We identified two novel de novo GABRG2 variants, p.P282T and p.S306F, with new phenotypes including neuroradiological evidence of neurodegeneration and epilepsy of infancy with migrating focal seizures (EIMFS). One patient carried previously reported p.P83S variant with autism spectrum disorder (ASD) phenotype that has not yet been described related to GABRG2 disorders and a more severe epilepsy phenotype than reported earlier. In all, the literature search yielded twenty-two articles describing 27 different variants that were divided into two categories: those with self-limiting epilepsies and febrile seizures and those with more severe drug-resistant epileptic encephalopathies. CONCLUSION: This study further expands the genotypic and phenotypic spectrum of epilepsies associated with GABRG2 variants. More knowledge is still needed about the influence of the environment, genetic background and other epilepsy susceptibility genes on the phenotype of the specific GABRG2 variants.

Spatially clustering de novo variants in CYFIP2, encoding the cytoplasmic FMRP interacting protein 2, cause intellectual disability and seizures.

CYFIP2, encoding the evolutionary highly conserved cytoplasmic FMRP interacting protein 2, has previously been proposed as a candidate gene for intellectual disability and autism because of its important role linking FMRP-dependent transcription regulation and actin polymerization via the WAVE regulatory complex (WRC). Recently, de novo variants affecting the amino acid p.Arg87 of CYFIP2 were reported in four individuals with epileptic encephalopathy. We here report 12 independent patients harboring a variety of de novo variants in CYFIP2 broadening the molecular and clinical spectrum of a novel CYFIP2-related neurodevelopmental disorder. Using trio whole-exome or -genome sequencing, we identified 12 independent patients carrying a total of eight distinct de novo variants in CYFIP2 with a shared phenotype of intellectual disability, seizures, and muscular hypotonia. We detected seven different missense variants, of which two occurred recurrently (p.(Arg87Cys) and p.(Ile664Met)), and a splice donor variant in the last intron for which we showed exon skipping in the transcript. The latter is expected to escape nonsense-mediated mRNA decay resulting in a truncated protein. Despite the large spacing in the primary structure, the variants spatially cluster in the tertiary structure and are all predicted to weaken the interaction with WAVE1 or NCKAP1 of the actin polymerization regulating WRC-complex. Preliminary genotype-phenotype correlation indicates a profound phenotype in p.Arg87 substitutions and a more variable phenotype in other alterations. This study evidenced a variety of de novo variants in CYFIP2 as a novel cause of mostly severe intellectual disability with seizures and muscular hypotonia.

Inhaled TRIM72 Protein Protects Ventilation Injury to the Lung through Injury-guided Cell Repair.

Studies showed that TRIM72 is essential for repair of alveolar cell membrane disruptions, and exogenous recombinant human TRIM72 protein (rhT72) demonstrated tissue-mending properties in animal models of tissue injury. Here we examine the mechanisms of rhT72-mediated lung cell protection in vitro and test the efficacy of inhaled rhT72 in reducing tissue pathology in a mouse model of ventilator-induced lung injury. In vitro lung cell injury was induced by glass beads and stretching. Ventilator-induced lung injury was modeled by injurious ventilation at 30 ml/kg tidal volume. Affinity-purified rhT72 or control proteins were added into culture medium or applied through nebulization. Cellular uptake and in vivo distribution of rhT72 were detected by imaging and immunostaining. Exogenous rhT72 maintains membrane integrity of alveolar epithelial cells subjected to glass bead injury in a dose-dependent manner. Inhaled rhT72 decreases the number of fatally injured alveolar cells, and ameliorates tissue-damaging indicators and cell injury markers after injurious ventilation. Using in vitro stretching assays, we reveal that rhT72 improves both cellular resilience to membrane wounding and membrane repair after injury. Image analysis detected rhT72 uptake by rat alveolar epithelial cells, which can be inhibited by a cholesterol-disrupting agent. In addition, inhaled rhT72 distributes to the distal lungs, where it colocalizes with phosphatidylserine detection on nonpermeabilized lung slices to label wounded cells. In conclusion, our study showed that inhaled rhT72 accumulates in injured lungs and protects lung tissue from ventilator injury, the mechanisms of which include improving cell resilience to membrane wounding, localizing to injured membrane, and augmenting membrane repair.

Mutation in an alternative transcript of CDKL5 in a boy with early-onset seizures.

Infantile-onset epilepsies are a set of severe, heterogeneous disorders for which clinical genetic testing yields causative mutations in ∼20%-50% of affected individuals. We report the case of a boy presenting with intractable seizures at 2 wk of age, for whom gene panel testing was unrevealing. Research-based whole-genome sequencing of the proband and four unaffected family members identified a de novo mutation, NM_001323289.1:c.2828_2829delGA in CDKL5, a gene associated with X-linked early infantile epileptic encephalopathy 2. CDKL5 has multiple alternative transcripts, and the mutation lies in an exon in the brain-expressed forms. The mutation was undetected by gene panel sequencing because of its intronic location in the CDKL5 transcript typically used to define the exons of this gene for clinical exon-based tests (NM_003159). This is the first report of a patient with a mutation in an alternative transcript of CDKL5 This finding suggests that incorporating alternative transcripts into the design and variant interpretation of exon-based tests, including gene panel and exome sequencing, could improve the diagnostic yield.