Search Results (46)

CDKL5 Deficiency Disorder (CDD) is a severe neurodevelopmental encephalopathy characterized by early disruptions of synaptic maturation and network stability, leading to persistent motor, cognitive, and behavioral impairments. Given the role of the endocannabinoid system in synaptic development, neuroinflammation, and neuronal resilience, we investigated whether the sustained enhancement of endogenous 2-arachidonoylglycerol (2-AG) signaling via monoacylglycerol lipase (MAGL) inhibition could mitigate key pathological features in adult Cdkl5 knockout (KO) mice. Using an intermittent 6-week treatment, the MAGL inhibitor JZL184 robustly increased plasma 2-AG levels, reduced MAGL protein levels, and activated CB1-AKT signaling without evidence of receptor desensitization. Despite this clear pharmacodynamic efficacy, behavioral effects were domain-specific: neither dose ameliorated core behavioral deficits, although the higher dose selectively reduced stereotypic jumping and modestly improved cue-dependent associative memory. At the cellular level, JZL184 induced biologically meaningful effects, partially restoring dendritic spine maturation in the primary somatosensory cortex and increasing neuronal survival in the vulnerable CA1 hippocampal region. In contrast, microglial responses were dose-dependent and divergent, with the lower dose exerting anti-inflammatory effects, while the higher dose increased cortical microglial density and Allograft Inflammatory Factor-1 (AIF-1) expression, suggesting engagement of compensatory or off-target mechanisms. Overall, these findings show that MAGL inhibition activates neuroprotective pathways and ameliorates select structural deficits in adult Cdkl5 KO mice, but is insufficient to produce broad behavioral recovery, highlighting the domain-specific effects of selective 2-AG enhancement via MAGL inhibition and the need for developmentally informed or multimodal therapeutic strategies in CDD. Full article

Introduction: Epilepsy syndromes show marked clinical and genetic heterogeneity, with numerous functionally diverse genes involved in their etiology. Next-generation sequencing (NGS) has facilitated the identification of many monogenic epilepsy syndromes and enables earlier, more accurate diagnosis in pediatric patients. Materials and Methods: This study analyzes the molecular profiles of 87 pediatric patients with various forms of epilepsy in whom pathogenic or likely pathogenic variants were identified. Next-generation sequencing (NGS) using multi-gene epilepsy panels or whole-exome sequencing (WES) was performed. Results: A total of 88 pathogenic or likely pathogenic variants were detected in 48 epilepsy-related genes; 30 variants occurred de novo. SCN1A and KCNQ2 were the most frequent contributors (12.6% and 9.2%, respectively). The highest percentage of positive diagnoses (48%) was observed in patients with developmental and epileptic encephalopathy (DEE), with variants identified in genes including ALG13, ATP1A2, CACNA1A, CDKL5, CHD2, GABRG2, ITPA, KCNQ2, PCDH19, SCN1A, SCN2A, SCN3A, SCN8A, SMC1A, SPTAN1, STXBP1, and UBA5. Pathogenic variants in ANKRD11 were found in four patients with KBG syndrome, while other genes appeared sporadically. Conclusions: Targeted massively parallel sequencing is an effective diagnostic tool for pediatric epilepsy. The presence of numerous single-case findings highlights the high genetic heterogeneity of epilepsy. This approach enabled more precise diagnoses that would not have been achieved through clinical evaluation alone, underscoring the importance of genetic testing for prognosis and treatment planning in pediatric patients with unexplained epilepsy. Full article

The Sichuan taimen (Hucho bleekeri) is a flagship species for the Yangtze River and is classified as critically endangered by the IUCN. Successful artificial breeding and conservation efforts are therefore essential for maintaining population stability. The early embryonic stage is the foundation of the entire life cycle and is critical for subsequent survival and growth. Here, we aimed to investigate gene-expression profiles across eight developmental stages through RNA-seq sequencing: fertilized egg, embryonic shield elevation, cleavage, blastula, gastrula, neurula, brain differentiation, and hatching. Time-series analysis revealed remarkable gene-expression changes between the cleavage and embryonic shield elevation, gastrula and blastula, and brain differentiation and hatching stages. The expression levels of cell cycle-related genes—including ccn2d, ccna2, cdk11, cdk17, cdka2, cdkl3, plk1, and others—decreased during embryonic development. Genes associated with muscle development, such as myl9, mylk, and tnnc2, were present in all stages and significantly enriched at hatching, while others were nearly absent during early development. In metabolic pathways, genes related to lipid metabolism and glycolysis were significantly expressed in the hatching stage. Regarding immune-related genes, complement genes were notably enriched at hatching, whereas cfh and cfb were expressed throughout development. Genes involved in adaptive immunity, such as mhc I, mhc II, tcr, and T-cell marker genes, were either not expressed or only weakly expressed in all stages. The results can provide insights into regulatory mechanisms underlying early embryonic development in fishes and provide general knowledge about salmonid development. Full article

Neurodevelopmental disorders (NDDs) are defined as a group of conditions that result from impaired brain development. Disorders that are commonly classified under NDDs include intellectual disability (ID), autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), communication and learning disorders, developmental delay (DD), brain malformations, cerebral palsy, Down syndrome, schizophrenia, and childhood epilepsies. A significant hinderance in the development of targeted treatments for NDDs are gaps in understanding how underlying genetic changes alter cellular physiology and how these changes may converge or diverge across NDDs with similar symptoms. Here, we focus on the genetic overlap between epilepsy, ASD, and other NDDs to identify common cellular and molecular mechanisms that may inform future treatments for each of these disorders individually or together. We describe several genes—including CDKL5, TSC1/2, SCN1a, and TANC2—that have been associated with epilepsy, ASD, or other NDD phenotypes that play a critical role in regulating one or more stages of brain development or function but differ widely in their disease-causing mechanisms. We also describe genotype–phenotype relationships. Finally, how a gene may cause NDDs through distinct functional pathways, or where different types of pathogenic variants within the same gene can have significantly different phenotypic outcomes is detailed. Full article

The ketogenic diet (KD) is a metabolic intervention characterized by high fat and very low carbohydrate intake, showing significant metabolic, neuroprotective, and therapeutic effects. However, its efficacy varies widely due to individual genetic and epigenetic factors. This review synthesizes current knowledge of genes most strongly associated with KD response, including polymorphisms in FTO, APOA2, PPAR, SCN1A, KCNQ2, STXBP1, CDKL5, the MODY gene group, and SLC2A1, which shape outcomes across lipid metabolism, energy expenditure, inflammation, and neurotransmission. Epigenomic modifications induced by a KD, such as changes in DNA methylation and histone acetylation involving BDNF, SLC12A5, KLF14, and others, modulate functional metabolic and neurological effects. Sex and age further modulate KD effects through distinct patterns of gene activation and hormonal interactions. These variables together impact metabolic and neurological outcomes and are critical for developing personalized nutrition and disease management strategies. Based on the reviewed evidence, genetic and epigenetic profiling can help identify patients who are likely to benefit from a KD (e.g., GLUT1DS, PDH deficiency) and those in whom a KD may be ineffective or harmful (e.g., SCOT or SLC2A1-independent defects). The review concludes that genetic and epigenetic profiling is recommended for personalized dietary interventions. Full article

CDKL5 deficiency disorder (CDD) is a rare developmental epileptic encephalopathy (DEE) caused by mutations in cyclin-dependent kinase-like 5 (CDKL5). The clinical manifestations include early and severe epilepsy, intellectual disability, motor abnormalities, and cortical visual impairments. The pathophysiological mechanisms underlying CDD are not fully understood, and current treatments are limited to symptomatic management and do not target the underlying cause. Characterizing the downstream molecular pathways that are disrupted by CDKL5 deficiency may provide a more complete understanding of the underlying molecular mechanisms and yield therapeutic strategies. Previous studies have focused on mapping the differential expression of protein-coding genes and post-translational modifications of CDKL5 targets, but the role of non-coding RNAs (ncRNAs) in CDD is unknown. Here we performed small RNA sequencing to define the short non-coding RNA landscape in the hippocampus of mice in the Cdkl5 exon 6 deletion mouse model (12-week-old heterozygous mice). Our findings catalog extensive bi-directional alterations in the expression of multiple ncRNA species including microRNAs, tRNAs, piwi-RNAs, snoRNAs, and snRNAs. We further validated two dysregulated miRNAs, namely, miRNA-200c-3p and miRNA-384-3p, in CDD mice. The findings reveal that the loss of this single gene has an extensive impact on the non-coding transcriptional landscape in CDD. Such dysregulated ncRNAs may hold potential as biomarkers and could provide valuable insights into underlying disease mechanisms. Full article

Background: Developmental and Epileptic Encephalopathy (DEE) is a severe and heterogeneous neurological disorder in infancy/early childhood. DEE’s genetic and phenotypic variability complicates diagnosis and treatment. This retrospective study aimed to identify genetic variants and explore genotype–phenotype correlations in children with DEE using a targeted epilepsy gene panel (TGP) and Whole Exome Sequencing (WES). Patients and Methods: Medical records of children who underwent custom-designed 55-gene TGP and WES were reviewed. The diagnostic yield of each method was determined based on the detection of pathogenic (P) and likely pathogenic (LP) variants. Results: A total of 129 patients (66 males, 63 females) underwent TGP, which identified P/LP variants in 29 cases (22.48%). Variants were detected in SCN1A, KCNQ2, STXBP1, CDKL5, PCDH19, PLCB1, WWOX, SCN2A, FGF12, HCN1, SCN8A, and SLC35A2. WES further identified several variants in children with West syndrome. A TSC1 variant was detected in a patient without cutaneous stigmata of tuberous sclerosis complex. The NALCN variant in a patient was linked to Infantile Hypotonia with Psychomotor Retardation and Characteristic Facies 1. A CTBP1 variant associated with extremely rare Hypotonia, Ataxia, Developmental Delay, and Tooth Enamel Defect Syndrome was detected in another patient. A PIEZO2 variant—associated with Marden–Walker syndrome—was found in a child with Early Infantile Developmental and Epileptic Encephalopathy. Conclusions: These findings highlight the extensive genetic heterogeneity and phenotypic variability of DEE. WES demonstrates substantial value in identifying novel gene-disease associations and may be considered as a first-tier diagnostic tool in epilepsy and DEE. Full article

Background: Lennox–Gastaut syndrome (LGS) is a severe childhood-onset developmental and epileptic encephalopathy characterized by treatment-resistant seizures and significant morbidity. Despite multiple approved anti-seizure medications (ASMs), optimal seizure control remains elusive. This has led to ongoing interest in newer ASMs, including those not specifically approved for LGS. This review evaluates the emerging evidence on the use of these agents in LGS management. Methods: We conducted a comprehensive literature search of PubMed, Web of Science, and Embase to identify studies examining perampanel, brivaracetam, cenobamate, ganaxolone, and stiripentol in LGS populations. Both randomized controlled trials and observational studies were included. Results: Perampanel was studied in approximately 300 patients across one Phase 3 trial and seven observational studies, showing responder rates of 26–69% with particular efficacy for generalized tonic–clonic and myoclonic seizures, though behavioral side effects (irritability, aggression) were dose-related concerns. Brivaracetam demonstrated inconsistent efficacy in 59 patients across six studies (0–61.5% responder rates) but offered better behavioral tolerability than levetiracetam. Cenobamate showed exceptional promise in 223 patients across seven studies with 50–85% responder rates and significant polypharmacy reduction, though requiring careful titration. Ganaxolone demonstrated efficacy in LGS-like CDKL5 deficiency phenotypes with 28.2% drop seizure reduction versus placebo. Stiripentol showed potential benefit for generalized seizures in limited LGS data. Conclusions: Several newer ASMs show therapeutic promise in LGS. Perampanel offers the most extensive evidence base, cenobamate demonstrates exceptional efficacy potential, while brivaracetam provides an alternative for levetiracetam-intolerant patients. Further controlled studies are needed to define optimal treatment algorithms. Full article

Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder, which is a developmental and epileptic encephalopathy occurring in 1 in every 40,000 to 60,000 live births, was the subject of this computational investigation. This study provided a comprehensive list of missense variants (156) seen in the human population within the CDKL5 protein. Furthermore, the list of CDKL5 binding partners was updated to include four new entries. Computational modeling resulted in 3D structure models of twenty-four CDKL5-target protein complexes. The CDKL5 stability changes upon the above-mentioned missense mutations that were modeled, and it was shown that the corresponding folding free energy changes (ΔΔG_folding) caused by pathogenic variants are much larger than the ΔΔG_folding caused by benign variants. The same observation was made for the binding free energy change (ΔΔG_binding). This resulted in a protocol that allowed for the reclassification of missense variants with unknown or conflicting significance into pathogenic or benign. It was demonstrated that such reclassification is more reliable than using leading tools for pathogenicity predictions, since the latter failed to correctly predict known pathogenic/benign variants. Furthermore, the study demonstrated that pathogenicity is linked with the disturbance of thermodynamics quantities such as ΔΔG_folding and ΔΔG_binding, paving the way for development of therapeutic solutions. Full article

Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is a severe X-linked neurodevelopmental condition characterized by early-onset, intractable epilepsy, motor and cognitive impairment, and autistic-like features. Although constitutive Cdkl5 knockout (KO) models have established the importance of CDKL5 during early brain development, CDKL5’s role in the mature brain remains poorly defined. Here, we employed an inducible, conditional KO model in which Cdkl5 is selectively deleted from forebrain glutamatergic neurons in adult mice to investigate the postdevelopmental functions of CDKL5. Using a total of 48 adult male mice, including Cdkl5^flox/Y(Cre⁺) (n = 30) and Cdkl5^flox/Y(Cre⁻) littermate controls (n = 18), we found that tamoxifen-induced Cdkl5 deletion led to prominent behavioral impairments, including deficits in motor coordination, reduced sociability, and impaired hippocampus-dependent spatial memory, while behavioral features such as hyperactivity and stereotypic jumping, typically present in germline KOs, were absent. Sensory functions, including olfaction and pain perception, were also preserved. At the cellular level, the loss of Cdkl5 resulted in a marked reduction in excitatory synapse density in the cortex and hippocampus, accompanied by increased numbers of immature dendritic spines and decreased mature spines. Neuronal loss in the hippocampal CA1 region and selective microglial activation in the cortex were also observed. These alterations closely resemble those seen in constitutive KO models, underscoring the ongoing requirement for CDKL5 expression in excitatory neurons for maintaining synaptic integrity and neuronal homeostasis in the adult brain. This study underscores the importance of temporally controlled models for investigating the mechanisms underlying CDD pathophysiology in the adult brain. Full article

Zebrafish is a well-recognized model for studying human genetic disorders. Recently, we proposed the homozygous cdkl5^sa21938 mutant zebrafish as a model of CDKL5 deficiency disorder (CDD), a developmental epileptic encephalopathy with diverse symptoms. This study aimed to explore Cdkl5-associated molecular mechanisms in zebrafish and assess their similarity to those in mammals. We conducted RNA sequencing on whole cdkl5^−/− zebrafish and wild-type siblings at 5 and 35 days post-fertilization (dpf) to compare their gene expression profiles. Most significant differentially expressed genes (DEGs) were related to muscle, neuronal, and visual systems which are affected in CDD. Gene Ontology analysis revealed downregulated DEGs enriched in muscle development, extracellular matrix, and actin cytoskeleton functions at both stages, while upregulated DEGs were enriched in eye development functions at 35 dpf. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed enrichment of downregulated DEGs in focal adhesion and extracellular matrix (ECM)-receptor interaction pathways at both stages. Neuronal development DEGs were mainly downregulated at both stages, while synaptic signaling DEGs were upregulated at 35 dpf. Crossing cdkl5^−/− mutants with the Hb9:GFP transgenic line showed fewer motor neuron cells with shorter axons compared to the wild type, which may explain the impaired motor phenotype observed in zebrafish and CDD patients. Moreover, we identified key downregulated DEGs related to cartilage development at both stages and bone development at 35 dpf, potentially explaining the skeletal defects seen in zebrafish and CDD individuals. In conclusion, Cdkl5 loss in zebrafish leads to dysregulation of genes involved in CDKL5-associated functions in mammals, providing new insights into its less studied functions and phenotypes. Full article

Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is an X-linked rare neurodevelopmental disorder associated with severe sleep disturbances. However, little is known about the mechanisms underlying sleep disturbances in CDD patients. Here, we employed the electroencephalogram (EEG) recording to characterize sleep–wake behaviors and EEG activity in male CDKL5-deficient mice. We found that young adult and middle-aged Cdkl5 knockout (KO) mice recapitulated sleep phenotypes in patients with CDD, including difficulties in initiating and maintaining sleep, reduction in total sleep time, and frequent night awakenings. Cdkl5 KO mice exhibited pre-sleep arousal, but normal circadian rhythm and homeostatic sleep response. Conditional knockout (cKO) of Cdkl5 in glutamatergic neurons resulted in reduced sleep time and difficulty in sleep maintenance. Further, the rate of age-associated decline in sleep and EEG activity in Cdkl5 KO mice was comparable to that of wild-type littermates. Together, these results confirm a causative role for CDKL5 deficiency in sleep disturbances observed in CDD patients and establish an animal model for translational research of sleep treatment in CDD. Moreover, our results provide valuable information for developing therapeutic strategies and identifying sleep and EEG parameters as potential biomarkers for facilitating preclinical and clinical trials in CDD. Full article

Lennox–Gastaut syndrome (LGS) is a severe childhood-onset developmental and epileptic encephalopathy characterized by multiple drug-resistant seizure types, cognitive impairment, and distinctive electroencephalographic patterns. Current treatments primarily focus on symptom management through antiseizure medications (ASMs), dietary therapy, epilepsy surgery, and neuromodulation, but often fail to address the underlying pathophysiology or improve cognitive outcomes. As genetic causes are identified in 30–40% of LGS cases, precision therapeutics targeting specific molecular mechanisms are emerging as promising disease-modifying approaches. This narrative review explores precision therapeutic strategies for LGS based on molecular pathophysiology, including channelopathies (SCN2A, SCN8A, KCNQ2, KCNA2, KCNT1, CACNA1A), receptor and ligand dysfunction (GABA/glutamate systems), cell signaling abnormalities (mTOR pathway), synaptopathies (STXBP1, IQSEC2, DNM1), epigenetic dysregulation (CHD2), and CDKL5 deficiency disorder. Treatment modalities discussed include traditional ASMs, dietary therapy, targeted pharmacotherapy, antisense oligonucleotides, gene therapy, and the repurposing of existing medications with mechanism-specific effects. Early intervention with precision therapeutics may not only improve seizure control but could also potentially prevent progression to LGS in susceptible populations. Future directions include developing computable phenotypes for accurate diagnosis, refining molecular subgrouping, enhancing drug development, advancing gene-based therapies, personalizing neuromodulation, implementing adaptive clinical trial designs, and ensuring equitable access to precision therapeutic approaches. While significant challenges remain, integrating biological insights with innovative clinical strategies offers new hope for transforming LGS treatment from symptomatic management to targeted disease modification. Full article

CDKL5 deficiency disorder (CDD), a developmental encephalopathy caused by mutations in the cyclin-dependent kinase-like 5 (CDKL5) gene, is characterized by a complex and severe clinical picture, including early-onset epilepsy and cognitive, motor, visual, and gastrointestinal disturbances. This disease still lacks a medical treatment to mitigate, or reverse, its course and improve the patient’s quality of life. Although CDD is primarily a genetic brain disorder, some evidence indicates systemic abnormalities, such as the presence of a redox imbalance in the plasma and skin fibroblasts from CDD patients and in the cardiac myocytes of a mouse model of CDD. In order to shed light on the role of oxidative stress in the CDD pathophysiology, in this study, we aimed to investigate the therapeutic potential of Coenzyme Q10 (CoQ10), which is known to be a powerful antioxidant, using in vitro and in vivo models of CDD. We found that CoQ10 supplementation not only reduces levels of reactive oxygen species (ROS) and normalizes glutathione balance but also restores the levels of markers of DNA damage (γ-H2AX) and senescence (lamin B1), restoring cellular proliferation and improving cellular survival in a human neuronal model of CDD. Importantly, oral supplementation with CoQ10 exerts a protective role toward lipid peroxidation and DNA damage in the heart of a murine model of CDD, the Cdkl5 (+/−) female mouse. Our results highlight the therapeutic potential of the antioxidant supplement CoQ10 in counteracting the detrimental oxidative stress induced by CDKL5 deficiency. Full article

Background: The fimbria-fornix is a nerve fiber bundle that connects various structures of the limbic system in the brain and plays a key role in cognition. It has become a major target of deep brain stimulation (DBS) to treat memory impairment in both dementia patients and animal models of neurological diseases. Previously, we have reported the beneficial memory effects of chronic forniceal DBS in mouse models of intellectual disability disorders. In Rett syndrome and CDKL5 deficiency disorder models, DBS strengthens hippocampal synaptic plasticity, reduces dentate inhibitory transmission or increases adult hippocampal neurogenesis that aids memory. However, the underlying neuronal circuitry mechanisms remain unknown. This study we explored the neural network circuits involved in forniceal DBS treatment. Methods: We used acute forniceal DBS-induced expression of c-Fos, an activity-dependent neuronal marker, to map the brain structures functionally connected to the fornix. We also evaluated the mouse behavior of locomotion, anxiety, and fear memory after acute forniceal DBS treatment. Results: Acute forniceal DBS induces robust activation of multiple structures in the limbic system. DBS-induced neuronal activation extends beyond hippocampal formation and includes brain structures not directly innervated by the fornix. Conclusions: Acute forniceal DBS activates multiple limbic structures associated with emotion and memory. The neural circuits revealed here help elucidate the neural network effect and pave the way for further research on the mechanism by which forniceal DBS induces benefits on cognitive impairments. Full article