Early Infantile Epileptic Encephalopathy Research Articles

Early infantile epileptic encephalopathy in the structure of microcephaly-capillary malformation syndrome: a clinical case

The article presents a clinical case of early infantile epileptic encephalopathy diagnosed in a child with a confirmed genetic study of microcephaly-capillary malformation syndrome. The extremely rare occurrence of this syndrome, as well as the small amount of information devoted to the problem of epilepsy in this syndrome, make the presented clinical case relevant and useful for pediatric specialists (neurologists, geneticists, pediatricians). In addition, the article presents the experience of using hormone therapy in the treatment of epilepsy, which also had an effect on the main manifestation of the disease (capillary malformations).

Loss of Function SPTAN1 Variants Result in Ataxia and Intellectual Disability.

SPTAN1 mutations have been reported in association with autosomal dominant early infantile epileptic encephalopathy 5. Individuals present with early-onset seizures and profound intellectual disability. Recent reports suggest a wider spectrum with later-onset seizures and milder developmental delay. Here we describe two patients with loss-of-function variants in SPTAN1. One patient has ataxia and mild intellectual disability stemming from a de novo homozygous p.(Gln1448Pro) variant associated with uniparental disomy 9. The second patient, carrying a heterozygous p.(Asn1839del) allele, exhibits more substantial motor issues, developmental delay, and seizures. Ectopically expressed wild-type or variant-containing forms of sptan1 in zebrafish indicate both variants create loss-of-function alleles, with the p.(Gln1448Pro) likely being hypomorphic. This conclusion is supported by reduced protein abundance and localization of Sptan1 variants in axons of developing embryos. Further, unlike wild-type sptan1, analysis of the p.(Gln1448Pro) variant showed it failed to restore voltage-gated sodium channel localization in sptan1-null axons. Additional behavioral analyses show supplementation with the amino acid D-aspartate improved motility in sptan1-null zebrafish, supporting its use for α-II spectrin-associated motor dysfunction.

Fluoxetine Treatment in Epilepsy of Infancy with Migrating Focal Seizures Due to KCNT1 Variants: An Open Label Study.

Gain-of-function (GoF) variants in KCNT1 encoding for potassium channels are associated with different epilepsy phenotypes, including epilepsy of infancy with migrating focal seizures (EIMFS), other early infantile developmental and epileptic encephalopathies, and focal epilepsy. Fluoxetine blocks currents from both wild-type (WT) and mutant KCNT1 channels with GoF in vitro features. In this study, we tested the hypothesis that treatment with fluoxetine might improve clinical outcome in patients with EIMFS carrying GoF variants in KCNT1 channels showing in vitro sensitivity to fluoxetine blockade. We enrolled three pediatric patients carring de novo KCNT1 genetic variants linked to EIMFS. Functional and pharmacological studies to assess fluoxetine's ability to counteract in vitro variant-induced functional effects were performed with patch-clamp electrophysiology on heterologous channel expression in mammalian Chinese hamster ovary cells. Neuropsychological assessment, electroencephalogram and seizure diary were evaluated at baseline and every 3 months during the study. Electrocardiography and blood levels of medications were monitored for safety. All 3 KCNT1 variants displayed GoF effects in vitro. Exposure to fluoxetine (10μM) blocked both WT and mutant KCNT1 channels, therefore, counteracting variant-induced functional effects. Treatment with fluoxetine caused a variable reduction of seizure frequency (25-75%). Improvement in visual attention, participation, and muscle tone was also reported. No adverse events were reported except for transient dyskinesia in 1 patient, which was probably related to an increase in fluoxetine plasma level. Fluoxetine may be a potential targeted medication in EIMFS caused by KCNT1 GoF variants. Further research is needed to assess its long-term efficacy and safety. ANN NEUROL 2025.

SCN1A pathogenic variants do not have a distinctive blood-derived DNA methylation signature.

DNA methylation signatures ("episignatures") can be used as biomarkers of genetic aberrations, clinical phenotypes, and environmental exposures in rare diseases. Episignatures are utilized in molecular diagnostics and can clarify variants of uncertain significance. A growing number of disease genes, including epilepsy genes, exhibit robust and reproducible episignatures. However, whether SCN1A, the most prominent epilepsy gene, has one or more episignatures has not yet been determined. We generated genome-wide DNA methylation data and performed episignature analysis on 64 individuals with Dravet syndrome due to pathogenic loss-of-function (LOF) variants in SCN1A and seven individuals with early infantile SCN1A developmental and epileptic encephalopathy due to pathogenic gain-of-function (GOF) variants in SCN1A, relative to a large reference database of controls and rare disease episignature-positive cohorts. We analyzed all samples with LOF variants together and performed separate analyses for missense, nonsense, and GOF variant cohorts. A reproducible blood-derived episignature was not evident in any of the cohorts using current analytical approaches and reference data.

Biallelic Mutations in ADAM22 Presenting as Ohtahara Syndrome in an Indian Family: Expanding the Electroclinical Phenotype of ADAM22 -Related Neurologic Disorder.

Biallelic Mutations in ADAM22 Presenting as Ohtahara Syndrome in an Indian Family: Expanding the Electroclinical Phenotype of ADAM22 -Related Neurologic Disorder.

Developmental phenotype and quality of life in SLC13A5 citrate transporter disorder.

To describe the neurodevelopment and quality of life in SLC13A5 (solute carrier family 13 member 5) citrate transporter disorder (developmental and epileptic encephalopathy 25, DEE25), a rare genetic early infantile epileptic encephalopathy caused by deficiency of a sodium-citrate transporter, characterized by heavy seizure burden in the neonatal period. We analyzed longitudinal neurodevelopmental outcomes from a prospective natural history study of DEE25, using standardized assessments of Mullen Scales of Early Learning, Peabody Developmental Motor Scales, and Vineland Adaptive Behavior Scales. There was significant global impairment across the cohort, with variable quality of life and limited genotype-phenotype correlation. Patient-specific scores were stable across visits with evidence of modest gains in early childhood and static skills in adolescence and adulthood. There is a poor prognosis in terms of multiple measures of age-appropriate development.

De novo genetic variant in epileptic encephalopathy: Importance of specific diagnosis

Introduction: Early infantile epileptic encephalopathies (EIEE) are rare syndromes that affect neurological development. The etiology has been uncertain for a long time, but advances in genetics have identified numerous associated genes. Variants in the CYFIP2 gene have been linked to EIEE. Clinical case: An 11-year-old female born at term without complications, with microcephaly, synophrys, and short neck. No relevant family history. At one month, she developed generalized seizures and delayed neurodevelopment, progressing to severe spastic quadriparesis, requiring gastrostomy and tracheostomy, with paroxysmal discharges on electroencephalogram. She received multiple anticonvulsant medications and ketogenic therapy. Complete individual exome sequencing and analysis of deletions and duplications were requested. Individual complete exome + deletions and duplications analysis (CNV) identified a probably pathogenic heterozygous variant in the CYFIP2 gene variant c.259C>T (p.Arg87Cys) missense type, allelic ratio (VAF) 0.45. The results of this molecular study support the diagnosis of developmental and epileptic encephalopathy de novo. Discussion: Developmental and epileptic encephalopathy (EED) disorders are severe conditions that begin in childhood, characterized by epileptic seizures, abnormalities in the electroencephalogram, and deterioration of neurodevelopment. Genetic EEDs are associated with variants in various genes related to cellular and neuronal functions. The CYFIP2 gene, on chromosome 5q33.3, encodes protein 2 that interacts with FMRP (fragile X mental retardation protein), playing a crucial role in neurological development. De novo variants, such as nonsense mutations and truncation in CYFIP2, are associated with intellectual disability, seizures, and muscle hypotonia. Advancements in genomics are improving the understanding of epilepsy, impacting targeted treatment, prognosis, and patient counseling. Childhood epilepsy has a heterogeneous genetic basis, and some patients without previous diagnosis can now receive one, crucial for the implementation of precision medicine.

GRIN1‐related epilepsy in a neonate with response to memantine and vigabatrin

AbstractObjectiveA newborn with GRIN1‐related early infantile developmental and epileptic encephalopathy (DEE) with striking pharmacoresistance is described with emphasis on potential therapy with memantine and vigabatrin.MethodsThe term neonate manifested electrographic and electroclinical seizures from the first day of life with focal tonic seizures with apnea, bradycardia, and desaturations and later developed epileptic spasms and a hyperkinetic movement disorder. Multiple antiseizure medication trials were unsuccessful. Brain magnetic resonance imaging displayed extensive malformations of cortical development.ResultsWhole‐exome sequencing demonstrated a de novo novel GRIN1 variant (1916T > G,p.Phe639Cys), which can be associated with NMDA receptor dysfunction. Gain‐of‐function mutation was suspected based on phenotype correlation. Seizures markedly improved after initiation of memantine, an NMDA‐receptor antagonist. Memantine was complemented by the concurrent use of vigabatrin, initiated 4 days earlier due to emergence of epileptic spasms. Significant reduction in seizures facilitated discharge from neonatal intensive care unit.InterpretationGRIN1‐related disorders occur due to NMDA receptor dysfunction. Patients with gain‐of‐function GRIN1 mutations who present with the phenotype of DEE with extensive bilateral polymicrogyria may benefit from a trial of NMDA‐receptor antagonist therapy and vigabatrin. Further research is warranted to better understand this markedly pharmacoresistant condition and to investigate targeted therapies in GRIN1 DEE.

Novel compound heterozygous P4HTM variants in a girl with developmental and epileptic encephalopathy: First case report of P4HTM variant-associated epileptic encephalopathy

Novel compound heterozygous P4HTM variants in a girl with developmental and epileptic encephalopathy: First case report of P4HTM variant-associated epileptic encephalopathy

Molecular Phenotypes Segregate Missense Mutations in SLC13A5 Epilepsy

Molecular Phenotypes Segregate Missense Mutations in SLC13A5 Epilepsy

Biallelic PIGM Coding Variant Causes Intractable Epilepsy and Intellectual Disability Without Thrombotic Events.

During the past two decades, an emerging group of genes coding for proteins involved in glycosylphosphatidylinositol (GPI) anchor biosynthesis are being implicated in early-infantile epileptic encephalopathy. Amongst these, a hypomorphic promoter mutation in the mannosyltransferase-encoding PIGM gene was described in seven patients to date, exhibiting intractable absence epilepsy, portal and cerebral vein thrombosis and intellectual disability (ID). We describe here three siblings exhibiting intractable epilepsy and ID, found to harbor a homozygous c.224G>A p.(Arg75His) missense variant in PIGM, which segregated with the disease in the family. The variant is evolutionary conserved, extremely rare in general population databases and predicted to be deleterious. Structural modeling of the PIGM protein and the p.(Arg75His) variant indicates that it is located in a short luminal region of the protein, predicted to be hydrophilic. Functional prediction suggests that the entire local region is sensitive to mutations, with the p.(Arg75His) variant in particular. This is the first report of a PIGM coding variant, and the second variant altogether to be described affecting this gene. This phenotype differs from that of patients with the shared PIGM promoter mutation by lack of thrombotic events and no decrease in PIGM cDNA levels or CD59 expression on red blood cells.

A Novel Loss of Function Variant in HCN1 Gene Underlies Early Infantile Epileptic Encephalopathy 24 [EIEE24]

Background: Early infantile epileptic encephalopathy (EIEE) is a rare neurological condition characterized by frequent seizures in the early stages of life, resulting in severely impaired cognitive and motor development. Although the specific causes of EIEE remain unknown, one of the primary causes is gene pathogenicity (even in the absence of consanguinity). Hyperpolarization-activated cyclic nucleotide-gated channels (HCNs) are essential for proper brain function. They are regulated by multiple genes, and mutations in these genes induce channel malfunction, which can result in various severe conditions, including EIEE. Herein, we have reported a patient presenting hallmarks of EIEE. Methods: The patient underwent clinical, radiographic, and genetic analysis. A thorough clinical examination and molecular study were conducted utilizing whole exome sequencing and Sanger sequencing. Results: Whole exome sequencing of the proband revealed a novel de novo nonsynonymous/nonsense variant (c.1468A>T; (p.Lys490Ter) in exon 6 of the HCN1 gene. This variant may cause channel dysfunction via nonsynonymous/nonsense-mediated decay or aberrant protein, which may be associated with EIEE phenotypes. Conclusions: This evidence backs the idea that HCN1 has a vital role in brain development and lose of function can cause a range of debilitating conditions. Still, the functional characterization study of the HCN1 variants will be the fundamental tool for a better understanding of EIEE in the near future.

Navigating the Complexity of Alternating Hemiplegia in Childhood: A Comprehensive Review.

Alternating hemiplegia of childhood (AHC) is a complex neurodevelopmental disorder characterized by paroxysmal and transient events of unilateral or bilateral paresis, usually occurring before 18 months of age. Mutations in the ATP1A3 gene, mainly p.Asp801Asn, p.Glu815Lys, and p.Gly947Arg at the protein level, are found in around 80% of the individuals with AHC. Interestingly, these mutations reflect the degree of severity of the neurological symptoms (p.Glu815Lys > p.Asp801Asn > p.Gly947Arg). Some channels involved in this disorder are N-type voltage-gated calcium channels, ATP-sensitive potassium channels, and the sodium/calcium exchanger. In this context, the management of AHC should be divided into the treatment of attacks, prophylactic treatment, and management of comorbidities commonly found in this group of individuals, including epilepsy, attention-deficit/hyperactivity disorder, aggressive behavior, cognitive impairment, movement disorders, and migraine. The importance of an integrated approach with a multidisciplinary team, such as neuropsychologists and dietitians, is worth mentioning, as well as the follow-up with a neurologist. In the present study, we propose new diagnostic criteria for AHC, dividing it into clinical, laboratory, supporting, and atypical features. Also, we review the location of the mutations in the ATP1A3 protein of individuals with AHC, rapid-onset dystonia-parkinsonism (RDP) variants, and early infantile epileptic encephalopathy (variants with hemiplegic attack). We also include a section about the animal models for ATP1A3 disorders.

The anesthetic management of a child with ohtahara syndrome and severe stridor: a case report

BackgroundOhtahara syndrome is a progressive developmental and epileptic encephalopathy that manifests in the early infantile period. This rare condition is characterized by intractable seizures, psychomotor retardation, and poor prognosis. To date, there are a handful of case reports regarding the anesthetic management of children with Ohtahara syndrome. However, limited reports exist of patients with Ohtahara syndrome who present with difficult airways. This report describes our airway findings and general anesthetic management of a pediatric patient with Ohtahara syndrome undergoing diagnostic bronchoscopy for severe inspiratory stridor.Case presentationA 14-month-old, 9 kg, male patient with Ohtahara syndrome presented with a year-long history of severe inspiratory stridor and was scheduled for bronchoscopy with lavage. On exam, the patient had noisy breathing, was non-verbal with developmental delay, and had poor head control with significant central hypotonia. The patient was induced with ketamine and general anesthesia was maintained with propofol. Bronchoscopic evaluation was completed uneventfully and revealed a diagnosis of laryngotracheomalacia. The patient’s breathing was maintained spontaneously throughout the procedure and no seizures were noted. In the post anesthesia care unit, the patient’s respiratory and cardiovascular function were stable.ConclusionsThis report documents the unusual finding of severe inspiratory stridor in a 14-month-old child diagnosed with Ohtahara syndrome and our anesthetic management during their diagnostic bronchoscopy. Currently, documentation of complex airway pathology present in patients with Ohtahara syndrome is limited and should be further evaluated. This will assist pediatric anesthesiologists as these patients may require careful preoperative assessment, thoughtful airway management, and surgical alternatives on standby.

A retrospective study of the yield of next-generation sequencing in the diagnosis of developmental and epileptic encephalopathies and epileptic encephalopathies in 0-12 years aged children at a single tertiary care hospital in South India.

Studies on the genetic yield of developmental and epileptic encephalopathy and Epileptic encephalopathies using next-generation sequencing techniques are sparse from the Indian subcontinent. Hence, the study was conducted to assess the yield of genetic testing and the proportion of children where a positive genetic yield influenced treatment decisions. In this retrospective observational study, electronic medical records of children (0-12 years) with suspected genetic epilepsy who underwent genetic testing using whole exome sequencing, focused exome sequencing and epilepsy gene panels were retrieved. Genetic yield was ascertained based on the detection of pathogenic and likely pathogenic variants. A total of 100 patients with epilepsy underwent genetic testing. A yield of 53.8% (42/78) was obtained. Pathogenic variants were identified in 18 (42.8%) cases and likely pathogenic variants in 24 (57.1%) cases. Yield was 66.6% each through whole exome sequencing, focused exome sequencing and 40% through Epilepsy gene panels (p = .07). Yield was not statistically significant across different age groups (p = .2). It was however found to significantly vary across different epilepsy syndromes with maximum yield in Epilepsy in infancy with migrating focal seizures in 2 (100%), followed by developmental and epileptic encephalopathy unspecified in 14 (77.7%), Dravet syndrome in 14 (60.8%), early infantile developmental and epileptic encephalopathy in 3 (60%), infantile epileptic spasm syndrome in 5 (35.7%), and other epileptic encephalopathies in 4 (30.7%) cases (p = .04). After genetic diagnosis and drug optimization, drug-refractory proportion reduced from 73.8% to 45.3%. About half of the cases achieved seizure control. A reasonably high yield of 53.8% was obtained irrespective of the choice of panel or exome or age group using next-generation sequencing-based techniques. Yield was however higher in certain epilepsy syndromes and low in Infantile epileptic spasms syndrome. A specific genetic diagnosis facilitated tailored treatment leading to seizure freedom in 28.6% and marked seizure reduction in 54.7% cases.

Population-based study of rare epilepsy incidence in a US urban population.

This study was undertaken to estimate incidence of rare epilepsies and compare with literature. We used electronic health record text search to identify children with 28 rare epilepsies in New York City (2010-2014). We estimated cumulative incidence and compared with literature. Eight of 28 rare epilepsies had five or more prior estimates, and our measurements were within the published range for all. The most common were infantile epileptic spasms syndrome (1 in 2920 live births), Lennox-Gastaut syndrome (1 in 9690), and seizures associated with tuberous sclerosis complex (1 in 14 300). Fifteen of 28 had fewer than five prior estimates, and of these, we provided additional estimates for early infantile developmental and epileptic encephalopathy (1 in 32 700), epilepsy with myoclonic-atonic seizures (1 in 34 100), Sturge-Weber syndrome plus seizures/epilepsy (1 in 40 900), epilepsy in infancy with migrating focal seizures (1 in 54 500), Aicardi syndrome plus seizures/epilepsy (1 in 71 600), hypothalamic hamartoma with seizures (1 in 225 000), and Rasmussen syndrome (1 in 450 000). Five of 28 rare epilepsies had no prior estimates, and of these, we provided a new estimate for developmental/epileptic encephalopathy with spike-and-wave activation in sleep and/or continuous spikes and waves during sleep (1 in 34 100). Data were limited for the remaining 12 rare epilepsies, which were all genetic epilepsies, including PCDH19, CDKL5, Alpers disease, SCN8A, KCNQ2, SCN2A, GLUT1 deficiency, Phelan-McDermid syndrome, myoclonic epilepsy with ragged-red fibers, dup15q syndrome, ring chromosome 14, and ring chromosome 20. We estimated the incidence of rare epilepsies using population-based electronic health record data and literature review. More research is needed to better estimate the incidence of genetic epilepsies with nonspecific clinical features. Electronic health records may be a valuable data source for studying rare epilepsies and other rare diseases, particularly as genetic testing becomes more widely adopted.

ATP1A2-related epileptic encephalopathy and movement disorder: Clinical features of three novel patients.

Variants in the ATP1A2 gene exhibit a wide clinical spectrum, ranging from familial hemiplegic migraine to childhood epilepsies and early infantile developmental epileptic encephalopathy (EIDEE) with movement disorders. This study aims to describe the epileptology of three unpublished cases and summarize epilepsy features of the other 17 published cases with ATP1A2 variants and EIDEE. Medical records of three novel patients with pathogenic ATP1A2 variants were retrospectively reviewed. Additionally, the PUBMED, EMBASE, and Cochrane databases were searched until December 2023 for articles on EIDEE with ATP1A2 variants, without language or publication year restrictions. Three female patients, aged 6 months-10 years, were investigated. Epilepsy onset occurred between 5 days and 2 years, accompanied by severe developmental delay, intellectual disability, drug-resistant epilepsy, severe movement disorder, and recurrent status epilepticus. All individuals had pathogenic variants of the ATP1A2 gene (ATP1A2 c.720_721del (p.Ile240MetfsTer9), ATP1A2c.3022C > T (p.Arg1008Trp), ATP1A2 c.1096G > T (p.Gly366Cys), according to ACMG criteria. Memantine was p) rescribed to three patients, one with a reduction in ictal frequency, one with improvement in gait pattern, coordination, and attention span, and another one in alertness without significant side effects. This study reinforces the association between ATP1A2 variants and a severe phenotype. All patients had de novo variants, focal motor seizures with impaired awareness as the primary type of seizure; of the 11 EEGs recorded, 10 presented a slow background rhythm, 7 multifocal interictal epileptiform discharges (IED), predominantly temporal IEDs, followed by frontal IED, as well as ten ictal recordings, which showed ictal onset from the same regions mentioned above. Treatment with antiseizure medication was generally ineffective, but memantine showed moderate improvement. Prospective studies are needed to enlarge the phenotype and assess the efficacy of NMDA receptor antagonist therapies in reducing seizure frequency and improving quality of life.

Early onset epileptic and developmental encephalopathy and MOGS variants: a new diagnosis in the whole exome sequencing (WES) ERA : Report of a new patient and review of the literature.

Mannosyl-oligosaccharide glucosidase - congenital disorder of glycosylation (MOGS-CDG) is determined by biallelic mutations in the mannosyl-oligosaccharide glucosidase (glucosidase I) gene. MOGS-CDG is a rare disorder affecting the processing of N-Glycans (CDG type II) and is characterized by prominent neurological involvement including hypotonia, developmental delay, seizures and movement disorders. To the best of our knowledge, 30 patients with MOGS-CDG have been published so far. We described a child who is compound heterozygous for two novel variants in the MOGS gene. He presented Early Infantile Developmental and Epileptic Encephalopathy (EI-DEE) in the absence of other specific systemic involvement and unrevealing first-line biochemical findings. In addition to the previously described features, the patient presented a Hirschprung disease, never reported before in individuals with MOGS-CDG.

Identification of CYFIP2 Arg87Cys Ligands via In Silico and In Vitro Approaches.

The advancement of next-generation sequencing has enabled the identification of specific mutations associated with early infantile epileptic encephalopathies (EIEEs). In EIEE, epileptic spasms and seizures that occur since early childhood lead to impaired neurological development. The CYFIP2 p.Arg87Cys variant was recently related to EIEE. CYFIP2 participates in the Wave Regulatory Complex (WRC), which is related to the regulation of actin dynamics. The variant residue is at the interface between the CYFIP2 protein and WAVE1 protein inside the WRC. Thus, the weakening of this interaction induced by the residue modification, which also causes the flexibilization of the loop 80-110 within the CYFIP2 structure, allows the constant activation of the WCR. This study aimed to identify ligands for CYFIP2 p.Arg87Cys and potential therapy targets using in silico in vitro approaches. Models of different CYFIP2 versions were constructed, and molecular docking analyses were conducted. A total of 3946 ligands from the PDE3 and Drugbank databases were screened, leading to the identification of 11 compounds that selectively bind to the variant protein. The impact of binding in CYFIP2 was also evaluated using a thermal stability assay. These findings contribute to a better understanding of CYFIP2's functional role in pathology and can guide more in vitro experiments, facilitating the development of targeted therapies for CYFIP2-related conditions.

Type 1 early infantile epileptic encephalopathy: A case report and literature review.

Variants in the Aristaless-related homeobox (ARX) gene lead to a variety of phenotypes, with intellectual disability being a steady feature. Other features can include severe epilepsy, spasticity, movement disorders, hydranencephaly, and ambiguous genitalia in males. X-linked Ohtahara syndrome or Type 1 early infantile epileptic encephalopathy (EIEE1) is a severe early-onset epileptic encephalopathy with arrested psychomotor development caused by hemizygous mutations in the ARX gene, which encodes a transcription factor in fundamental brain developmental processes. We presented a case report of a 2-year-old boy who exhibited symptoms such as microcephaly, seizures, and severe multifocal epileptic abnormalities, and genetic techniques such as autozygosity mapping, Sanger sequencing, and whole-exome sequencing. We confirmed that the patient had the NM_139058.3:c.84C>A; p.(Cys28Ter) mutation in the ARX gene. The patient with EIEE1 had physical symptoms and hypsarrhythmia on electroencephalogram. Genetic testing identified a causative mutation in the ARX gene, emphasizing the role of genetic testing in EIEE diagnosis.