BACKGROUND: Variations in the WWOX gene have been identified as the leading cause of several central nervous system disorders. However, most previous reports have focused on the description of clinical phenotype, neglecting functional verification. Herein, we presented a case of a patient with developmental epileptic encephalopathy (DEE) caused by WWOX gene variation.
METHODS: Our patient was a 13-month-old girl with abnormal facial features, including facial hypotonia, arched eyebrows, a broad nose, and a depressed nasal bridge. She also had sparse and yellow hair, a low anterior hairline, and a short neck. Before the age of 8 months, she was suffering from mild seizures. Her developmental delay gradually worsened, and she suffered infantile spasms. After treatment with vigabatrin, seizures subsided. WWOX gene homozygous variation c.172+1G>C was identified using whole exome sequencing. Further minigene assay confirmed that the variation site affected splicing, causing protein truncation and affecting its function.
CONCLUSIONS: Clinical phenotype and minigene results suggest that WWOX gene homozygous variation c.172+1G>C can cause severe DEE. We also concluded that vigabatrin can effectively treat seizures.

BACKGROUND: Voltage-gated sodium channels are involved in the initial depolarisation of neurones. As such, they play important roles in neurotransmission. Variants in the genes encoding these channels may lead to altered functionality and neurodevelopmental disorders. Pathogenic variants of SCN8A, which encodes the voltage-gated Na+ channel Nav1.6, have been associated with various encephalopathies characterised by developmental delay and epileptic seizures. Herein, we discuss the genotype-phenotype associations in a group of 17 novel Polish patients with SCN8A mutations, further expanding the molecular and phenotypic spectrum of SCN8A-related diseases.
METHODS: The participants were recruited from five clinical centres in Poland. Pathogenic and likely pathogenic SCN8A variants were identified using a next-generation sequencing (NGS) panel and exome sequencing, respectively. Magnetic resonance imaging (MRI) and electroencephalography (EEG) recordings were performed to obtain relevant clinical data on brain malformations and epileptic seizures.
RESULTS: Three phenotypes were observed in the study group: developmental and epileptic encephalopathy, early onset epileptic encephalopathy, and neurodevelopmental disorders without epilepsy. Patients in the first two phenotypic subgroups presented with epileptic seizures within the first few months of life. Their semiology evolved with age, comprising mostly tonic, clonic, and tonic-clonic seizures, with eyelid myoclonia, myoclonic seizures, and epileptic spasms. The most prevalent neurological feature was developmental delay. Alterations in muscle tone were more frequent than in previous reports.
CONCLUSIONS: Seventeen patients with 11 novel mutations in SCN8A had alterations in muscular tone accompanied by typical features of SCN8A-related encephalopathies (i.e., developmental delay and a wide range of seizures).

Developmental Epileptic encephalopathies (DEEs) are severe neurological conditions where cognitive functions appear modulated by both seizure and interictal epileptiform activity. Cannabidiol (CBD) has been shown to be highly effective in the treatment of drug-resistant seizures in patients with DEEs. Along with its antiseizure effects, CBD demonstrated clinical beneficial effects in patients\' quality of life, sleep and numerous adaptive behaviors. However, based on the available phase III studies, the indications for this treatment have so far been restricted to Lennox-Gastaut syndrome (LGS), Dravet syndrome (DS) and tuberous sclerosis complex (TSC) by regulatory authorities. We present the case of a 30-year-old girl with a rare genetic DEE, experiencing relevant seizure frequency reduction together with striking improvement in sleep quality, mood, behavior, language and motor skills after introducing off-label CBD.

OBJECTIVE: An early genetic diagnosis can guide the time-sensitive treatment of individuals with genetic epilepsies. However, most genetic diagnoses occur long after disease onset. We aimed to identify early clinical features suggestive of genetic diagnoses in individuals with epilepsy through large-scale analysis of full-text electronic medical records (EMR).
METHODS: We extracted 89 million time-stamped standardized clinical annotations using Natural Language Processing from 4,572,783 clinical notes from 32,112 individuals with childhood epilepsy, including 1,925 individuals with known or presumed genetic epilepsies. We applied these features to train random forest models to predict SCN1A-related disorders and any genetic diagnosis.
RESULTS: We identified 47,774 age-dependent associations of clinical features with genetic etiologies a median of 3.6 years prior to molecular diagnosis. Across all 710 genetic etiologies identified in our cohort, neurodevelopmental differences between 6-9 months increased the likelihood of a later molecular diagnosis fivefold (P<0.0001, 95% CI=3.55-7.42). A later diagnosis of SCN1A-related disorders (AUC=0.91) or an overall positive genetic diagnosis (AUC=0.82) could be reliably predicted using random forest models.
CONCLUSIONS: Clinical features predictive of genetic epilepsies precede molecular diagnoses by up to several years in conditions with known precision treatments. An earlier diagnosis facilitated by automated EMR analysis has the potential for earlier targeted therapeutic strategies in the genetic epilepsies.

暂无摘要。

Mutations in the SCN8A gene, encoding the voltage-gated sodium channel NaV1.6, are associated with a range of neurodevelopmental syndromes. The p.(Gly1625Arg) (G1625R) mutation was identified in a patient diagnosed with developmental epileptic encephalopathy (DEE). While most of the characterized DEE-associated SCN8A mutations were shown to cause a gain-of-channel function, we show that the G1625R variant, positioned within the S4 segment of domain IV, results in complex effects. Voltage-clamp analyses of NaV1.6G1625R demonstrated a mixture of gain- and loss-of-function properties, including reduced current amplitudes, increased time constant of fast voltage-dependent inactivation, a depolarizing shift in the voltage dependence of activation and inactivation, and increased channel availability with high-frequency repeated depolarization. Current-clamp analyses in transfected cultured neurons revealed that these biophysical properties caused a marked reduction in the number of action potentials when firing was driven by the transfected mutant NaV1.6. Accordingly, computational modeling of mature cortical neurons demonstrated a mild decrease in neuronal firing when mimicking the patients\' heterozygous SCN8A expression. Structural modeling of NaV1.6G1625R suggested the formation of a cation-π interaction between R1625 and F1588 within domain IV. Double-mutant cycle analysis revealed that this interaction affects the voltage dependence of inactivation in NaV1.6G1625R. Together, our studies demonstrate that the G1625R variant leads to a complex combination of gain and loss of function biophysical changes that result in an overall mild reduction in neuronal firing, related to the perturbed interaction network within the voltage sensor domain, necessitating personalized multi-tiered analysis for SCN8A mutations for optimal treatment selection.

Genetic advances over the past decade have enhanced our understanding of the genetic landscape of childhood epilepsy. However a major challenge for clinicians ha been understanding the rationale and systematic approach towards interpretation of the clinical significance of variant(s) detected in their patients. As the clinical paradigm evolves from gene panels to whole exome or whole genome testing including rapid genome sequencing, the number of patients tested and variants identified per patient will only increase. Each step in the process of variant interpretation has limitations and there is no single criterion which enables the clinician to draw reliable conclusions on a causal relationship between the variant and disease without robust clinical phenotyping. Although many automated online analysis software tools are available, these carry a risk of misinterpretation. This guideline provides a pragmatic, real-world approach to variant interpretation for the child neurologist. The focus will be on ascertaining aspects such as variant frequency, subtype, inheritance pattern, structural and functional consequence with regard to genotype-phenotype correlations, while refraining from mere interpretation of the classification provided in a genetic test report. It will not replace the expert advice of colleagues in clinical genetics, however as genomic investigations become a first-line test for epilepsy, it is vital that neurologists and epileptologists are equipped to navigate this landscape.

Loss of function variants in the Cyclin-dependent kinase-like 5 gene (CDKL5) causes CDKL5 deficiency disorder (CDD). Most cases of CDD are due to a de novo missense or truncating variants. The CDKL5 gene was discovered in 1998 as part of the genomic mapping of the chromosome Xp22 region that led to the discovery of the serine-threonine kinases STK9. Since then, there have been significant advancements in the description of the disease in humans, the understanding of the pathophysiology, and the management of the disease. There have been many lessons learned since the initial description of the condition in humans in 2003. In this article, we will focus on pathophysiology, clinical manifestations, with particular focus on seizures because of its relevance to the medical practitioners and researchers and guidelines for management. We finalize the manuscript with the voice of the parents and caregivers, as discussed with the 2019 meeting with the Food and Drug Administration.

OBJECTIVE: Validated measures capable of demonstrating meaningful interventional change in the CDKL5 deficiency disorder (CDD) are lacking. The study objective was to modify the Rett Syndrome Gross Motor Scale (RSGMS) and evaluate its psychometric properties for individuals with CDD.
METHODS: Item and scoring categories of the RSGMS were modified. Caregivers registered with the International CDKL5 Clinical Research Network uploaded motor videos filmed at home to a protected server and completed a feedback questionnaire (n = 70). Rasch (n = 137), known groups (n = 109), and intra- and inter-rater reliability analyses (n = 50) were conducted.
RESULTS: The age of individuals with CDD ranged from 1.5 to 34.1 years. The modified scale, Gross Motor-Complex Disability (GM-CD), comprised 17 items. There were no floor or ceiling effects and inter- and intra-rater reliability were good. Rasch analysis demonstrated that the items encompassed a large range of performance difficulty, although there was some item redundancy and some disordered categories. One item, Prone Head Position, was a poor fit. Caregiver-reported acceptability was positive. Scores differed by age and functional abilities.
CONCLUSIONS: GM-CD appears to be a suitable remotely administered measure and psychometrically sound for individuals with CDD. This study provides the foundation to propose the use of GM-CD in CDD clinical trials. Longitudinal evaluation is planned.

Dravet syndrome (DS), also known as severe myoclonic epilepsy of infancy, is a rare and drug-resistant form of developmental and epileptic encephalopathies, which is both debilitating and challenging to manage, typically arising during the first year of life, with seizures often triggered by fever, infections, or vaccinations. It is characterized by frequent and prolonged seizures, developmental delays, and various other neurological and behavioral impairments. Most cases result from pathogenic mutations in the sodium voltage-gated channel alpha subunit 1 (SCN1A) gene, which encodes a critical voltage-gated sodium channel subunit involved in neuronal excitability. Precision medicine offers significant potential for improving DS diagnosis and treatment. Early genetic testing enables timely and accurate diagnosis. Advances in our understanding of DS\'s underlying genetic mechanisms and neurobiology have enabled the development of targeted therapies, such as gene therapy, offering more effective and less invasive treatment options for patients with DS. Targeted and gene therapies provide hope for more effective and personalized treatments. However, research into novel approaches remains in its early stages, and their clinical application remains to be seen. This review addresses the current understanding of clinical DS features, genetic involvement in DS development, and outcomes of novel DS therapies.