Mutations in ion channel genes have long been implicated in a spectrum of epilepsy syndromes. However, therapeutic decision-making is relatively complex for epilepsies associated with channelopathy. Therefore, in the present study, we used a patient-derived organoid model with a novel SCN2A mutation (p.E512K) to investigate the potential of utilizing such a model as a platform for preclinical testing of anti-seizure compounds. The electrophysiological properties of the variant Nav1.2 exhibited gain-of-function effects with increased current amplitude and premature activation. Immunofluorescence staining of patient-derived cortical organoids (COs) displayed normal neurodevelopment. Multielectrode array (MEA) recordings of patient-derived COs showed hyperexcitability with increased spiking and remarkable network bursts. Moreover, the application of patient-derived COs for preclinical drug testing using the MEA showed that they exhibit differential responses to various anti-seizure drugs and respond well to carbamazepine. Our results demonstrate that the individualized organoids have the potential to serve as a platform for preclinical pharmacological assessment.
Organoids/physiology* ; NAV1.2 Voltage-Gated Sodium Channel/genetics* ; Humans ; Anticonvulsants/pharmacology* ; Epilepsy/drug therapy* ; Mutation ; Cerebral Cortex/drug effects* ; Action Potentials/drug effects* ; Carbamazepine/pharmacology*

OBJECTIVE: To analyze the clinical characteristics and genetic etiology of a child with Christianson syndrome (CS). METHODS: A 1-year-and-5-month-old boy with CS diagnosed at the First Affiliated Hospital of Zhengzhou University in April 2021 was selected as the study subject. Clinical data were retrospectively analyzed. Peripheral blood samples were obtained from the child and his parents, followed by genomic DNA extraction and whole exome sequencing (WES). Candidate variant was validated by Sanger sequencing. This study has been approved by the Medical Ethics Committee of the Hospital of Zhengzhou University (Ethics No. 2024-KY-1103-001). RESULTS: The child has manifested with seizures, microcephaly, and global developmental delay. WES revealed that he has harbored a novel de novo hemizygous nonsense variant of the SLC9A6 gene, namely c.1014G>A (p.W338*). Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was rated as pathogenic. CONCLUSION The hemizygous c.1014G>A nonsense variant of the SLC9A6 gene probably underlay the pathogenesis in this child. Above discovery has expanded mutational spectrum of the SLC9A6 gene and enabled definite diagnosis of the child.
Humans ; Male ; Infant ; Microcephaly/genetics* ; Spasms, Infantile/genetics* ; Sodium-Hydrogen Exchangers/genetics* ; Exome Sequencing ; Intellectual Disability/genetics* ; Genetic Diseases, X-Linked/genetics* ; Mutation ; Seizures/genetics* ; Ataxia ; Epilepsy ; Ocular Motility Disorders

OBJECTIVE: To investigate the clinical phenotype and genotype features of children with Epileptic encephalopathy caused by PCDH19 mutations. METHODS: Four children with epilepsy caused by PCDH19 gene mutations who were treated at Shanghai Children's Medical Center from August 2015 to May 2024 were selected as study subjects. A retrospective study method was used to collect the clinical data of the patients. Peripheral venous blood samples (2 mL each) were collected from the patients and their parents. Genomic DNA was extracted, and whole exome sequencing (WES) was performed, followed by family verification of candidate variants by Sanger sequencing. Pathogenicity of the candidate variants was classified according to the "Genetic Variation Classification Standards and Guidelines" established by the American College of Medical Genetics and Genomics (ACMG). This study was approved by the Medical Ethics Committee of Shanghai Children's Medical Center (Approval No. SCMCIRB-K2020060-1). RESULTS: The patients comprised of 3 females and 1 male, all presenting symptoms before the age of 3. Patients 1-3 exhibited generalized tonic-clonic seizures, while patient 4 manifested focal seizures accompanied by impaired consciousness. In addition to epilepsy, patient 2 showed language delay and patient 3 had frequent panic attacks. WES results identified four pathogenic PCDH19 variants these patients, including 2 previously unreported frameshifting mutations,1 hotspot missense mutation, and 1 mosaic missense mutation with a 32.4% mutation rate. The pathogenic mutation in patient 2 was inherited from her father, while the remaining 3 patients had de novo pathogenic mutations. CONCLUSION Children with PCDH19 gene mutations may exhibit early-onset refractory epilepsy, cognitive impairment, and developmental delay. Females are predominantly affected by the PCDH19 mutations, although males with mosaic mutations can also be affected. The genetic and clinical heterogeneity observed among patients 1-4 indicated the diverse nature of epilepsy related to the PCDH19 gene mutations. PCDH19 gene mutations may be the genetic cause of epilepsy in these affected children, which also enriched the mutational spectrum of the PCDH19 gene.
Child, Preschool ; Female ; Humans ; Infant ; Male ; Cadherins/genetics* ; Epilepsy/genetics* ; Exome Sequencing ; Mutation ; Phenotype ; Protocadherins ; Retrospective Studies

OBJECTIVE: To explore the clinical features and genetic etiology of a child with a SETD1B gene variant causing seizures and language delay. METHODS: A child with a SETD1B gene variant admitted to the Department of Pediatric Neurology at the Third Affiliated Hospital of Zhengzhou University in September 2022 was selected as the study subject. Clinical data of the child were collected, and peripheral blood samples from the child and her parents were obtained. Whole exome sequencing (WES) was performed for genetic testing, and Sanger sequencing was used for familial validation of the candidate variant. Using "SETD1B" and "epilepsy" as the Chinese and English keywords, relevant cases were retrieved from databases including CNKI, Wanfang Data, OMIM and PubMed, with the search period spanning from database inception to June 2024. RESULTS: The child was a 6-year-old female presenting with myoclonic seizures accompanied by global developmental delay. WES and Sanger sequencing revealed that the child has carried a de novo SETD1B gene variant, namely c.5582G>A (p.Cys1961Tyr). According to the American College of Medical Genetics and Genomics (ACMG) guidelines for sequence variant interpretation, this variant was classified as likely pathogenic (PS2+PM2_Supporting+PP2+PP3). The child was not controlled with effective doses of valproate, levetiracetam, or clonazepam but was successfully managed with low-dose lamotrigine. Follow-up electroencephalography showed normal results, and developmental progress gradually improved. A total of 37 epilepsy cases with SETD1B gene variants were reported across six studies. The predominant seizure types included absence seizures and myoclonic absence seizures, accompanied by delayed language development. The response to pharmacological treatment was generally poor, with no significant difference in incidence between males and females. CONCLUSION SETD1B gene variants may cause neurological disorders with drug-resistant epilepsy and severe clinical manifestations. Lamotrigine is effective in controlling the epileptic seizures.
Humans ; Female ; Child ; Epilepsy/genetics* ; Language Development Disorders/genetics* ; Histone-Lysine N-Methyltransferase/genetics* ; Exome Sequencing ; Male

OBJECTIVE: To investigate the clinical characteristics and genetic etiology of a child with Cortical dysplasia, complex, with other brain malformations 4 (CDCBM4) and epilepsy due to a TUBG1 gene variant. METHODS: A child diagnosed with CDCBM4 and epilepsy at the Children's Medical Center of the Affiliated Hospital of Guangdong Medical University in May 2024 was selected as the study subject. Clinical data were retrospectively analyzed. Peripheral venous blood samples were collected from the child and her parents for genomic DNA extraction. Trio-based whole-exome sequencing (WES) was performed, and candidate variants were validated by Sanger sequencing. According to the Standards and Guidelines for the Interpretation of Sequence Variants established by the American College of Medical Genetics and Genomics (ACMG), candidate variants were classified for pathogenicity. This study was approved by the Medical Ethics Committee of the Affiliated Hospital of Guangdong Medical University (Ethics No.: PJ2021-097). RESULTS: The child, a 4-month-old female infant, had no special facial features, normal limb muscle strength, and increased muscle tone of infantile onset, with generalized tonic-clonic seizures as the main manifestation. During seizures, she exhibited head retroflexion, tightly closed eyes, and tonic convulsions of the limbs, occurring approximately 2-3 times per day. Electroencephalogram suggested bilateral anterior predominant medium-to-high amplitude 7-8 Hz mixed rhythm discharges. Head MRI revealed ventricular system dilatation and pachygyria. Trio-WES results indicated that the child has harbored a TUBG1 gene variant of c.776C>T (p.Ser259Leu). Sanger sequencing verification showed that neither of her parents had carried the same variant, confirming it as de novo in origin. According to the ACMG guidelines, the variant was rated as pathogenic (PS2+PS3+PM2_Supporting+PP3). Combining the child's clinical phenotype, the child was diagnosed as CDCBM4 with epilepsy. CONCLUSION Children with CDCBM4 and epilepsy due to TUBG1 gene variants may show pachygyria or agyria and commonly present with intellectual and motor developmental delays and seizure disorders of variable severity. The heterozygous TUBG1 c.776C>T (p.Ser259Leu) variant is likely the genetic etiology underlying this disorder. The results of this study has expanded the mutational spectrum of the TUBG1 gene associated with CDCBM4 and epilepsy.
Humans ; Female ; Epilepsy/genetics* ; Malformations of Cortical Development/genetics* ; Infant ; Phenotype ; Exome Sequencing ; Microtubule-Associated Proteins/genetics*

OBJECTIVE: To investigate the clinical phenotypes and genetic variant characteristics in children with epilepsy. METHODS: A total of 91 children with epilepsy admitted to the Women's and Children's Hospital Affiliated to Ningbo University from July 2021 to October 2022 were selected as the study subjects. Peripheral blood samples were collected from the children for whole exome sequencing. Candidate genetic variants were validated by Sanger sequencing and copy number variation sequencing (CNV-seq). The clinical phenotypes and treatment outcomes of the children with epilepsy were followed up, and an analysis of the relationship between genotype and phenotype was conducted. This study was approved by the Women's and Children's Hospital Affiliated to Ningbo University (Ethics No.: EC2020-048). RESULTS: Among the 91 children with epilepsy, 21 cases (23.08%, 21/91) were found to carry pathogenic or likely pathogenic variants. Of these, 18 cases had involved single base variant or insertional deletion, while 3 cases involved copy number variations. The gene with the highest detection rate was PRRT2 (38.10%, 8/21). Among the children with genetic variants, 47.62% (10/21) had onset during infancy, with 8 diagnosed with Benign familial infantile epilepsy (BFIE), 8 with Developmental epileptic encephalopathy (DEE), and 3 with Epileptic encephalopathy (EE). One case of Dravet syndrome (DS) and one case of Infantile spasms (IS) were also noted. The clinical manifestations of children were diverse and primarily included generalized tonic-clonic seizures and focal seizures. Among them, 52.38% (11/21) had exhibited cluster seizures, 23.81% (5/21) showed fever sensitivity, and 14.29% (3/21) experienced status epilepticus. After pharmacological treatment, 42.86% (9/21) of children had achieved complete seizure control, while 61.90% (13/21) had intellectual disability and 19.05% (4/21) had co-morbid autism spectrum disorder. CONCLUSION Pathogenic or likely pathogenic variants were identified in 23.08% of the pediatric epilepsy cases, with the PRRT2 gene being the most frequently involved. Among children carrying genetic variants, 47.62% had seizure onset during infancy. Genetic factors are an important cause of epilepsy, and early genetic testing may facilitate precise diagnosis, treatment, and prognostic evaluation.
Humans ; Female ; Male ; Epilepsy/genetics* ; Child, Preschool ; Child ; Phenotype ; Genotype ; DNA Copy Number Variations/genetics* ; Infant ; Membrane Proteins/genetics* ; Nerve Tissue Proteins/genetics* ; Adolescent ; Exome Sequencing

OBJECTIVE: To explore the clinical characteristics and genetic etiology of a patient with Fliedner-Zweier syndrome (FZS). METHODS: A pregnant woman who was diagnosed with FZS at the Affiliated Women and Children's Hospital of Ningbo University in November 2023 for "intellectual disability, epilepsy, delayed language development and facial abnormalities" was selected as the study subject. Peripheral blood samples were collected from the woman and her husband, whilst amniotic fluid sample was obtained from the fetus. Following extraction of genomic DNA, whole-exome sequencing (WES) and chromosomal karyotyping analysis were performed. Candidate variant was validated by Sanger sequencing. Pathogenicity of the variant was classified based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: EC2023-094). RESULTS: The proband, a 23-year-old woman, was at 19⁺² weeks of gestation and had a history of epilepsy, mild intellectual disability, delayed language development, and subtle facial dysmorphism. Chromosomal analysis showed the she has a normal karyotype. WES revealed that the woman and her fetus both harbored a heterozygous c.1489C>T (p.Gln497Ter) nonsense variant of the SCAF4 gene, which was verified by Sanger sequencing as de novo. Based on the ACMG guidelines, the variant was classified as pathogenic (PVS1+PM2_supporting+PS2_supporting). According to pre-set search strategy, five articles were retrieved. Together with the patient in this study, a total of 69 FZS patients were involved (including 7 from China). The main clinical features have included intellectual disability, epilepsy, behavioral abnormalities, and facial dysmorphism. CONCLUSION The heterozygous c.1489C>T (p.Gln497Ter) variant of the SCAF4 gene probably underlyay the FZS in this patient. Above finding has expanded the mutational spectrum of the SCAF4 gene.
Humans ; Female ; Intellectual Disability/genetics* ; Pregnancy ; Young Adult ; Exome Sequencing ; Epilepsy/genetics* ; Abnormalities, Multiple/genetics* ; Mutation ; Karyotyping

OBJECTIVES: To summarize the clinical and genetic characteristics of epilepsy with intellectual disability caused by SETD1B gene variants in children. METHODS: A retrospective analysis was conducted on the clinical data of three children with SETD1B gene variants diagnosed and treated at the Department of Pediatric Neurology of Xiangya Hospital of Central South University. Relevant literature was reviewed to summarize the clinical characteristics of this condition. RESULTS: All three children presented with symptoms during infancy or early childhood, including mild intellectual disability and myoclonic seizures, with two cases exhibiting eyelid myoclonia. After treatment with three or more antiepileptic drugs, two cases achieved seizure control or partial control, while one case remained refractory. Each of the three children was found to have a heterozygous variant in the SETD1B gene (one deletion, one frameshift, and one missense variant). To date, 54 cases with SETD1B gene variants have been reported, involving a total of 56 variants, predominantly missense variants (64%, 36/56). The main clinical manifestations included varying degrees of developmental delay (96%, 52/54) and seizures (81%, 44/54). Among the 44 patients with seizures, myoclonic (20%, 9/44) and absence seizures (34%, 15/44) were common, with eyelid myoclonia reported in six cases. Approximately one-fifth of these patients had poorly controlled seizures. CONCLUSIONS The primary phenotypes associated with SETD1B gene variants are intellectual disability and seizures, and seizures exhibit distinct characteristics. Eyelid myoclonia is not uncommon.
Humans ; Intellectual Disability/complications* ; Epilepsy/complications* ; Male ; Female ; Histone-Lysine N-Methyltransferase/genetics* ; Child, Preschool ; Child ; Retrospective Studies

OBJECTIVE: To analyze the characteristics of genetic variants among children with refractory epilepsy (RE). METHODS: One hundred and seventeen children with RE who had presented at the Affiliated Jinhua Hospital of Zhejiang University School of Medicine from January 1, 2018 to November 21, 2019 were selected as the study subjects. The children were divided into four groups according to their ages of onset: < 1 year old, 1 ~ 3 years old, 3 ~ 12 years old, and >= 12 years old. Clinical data and results of trio-whole exome sequencing were retrospectively analyzed. RESULTS: In total 67 males and 50 females were included. The age of onset had ranged from 4 days to 14 years old. Among the 117 patients, 33 (28.21%) had carried pathogenic or likely pathogenic variants. The detection rates for the < 1 year old, 1 ~ 3 years old and >= 3 years old groups were 53.85% (21/39), 12.00% (3/25) and 16.98% (9/53), respectively, with a significant difference among the groups (χ² = 19.202, P < 0.001). The detection rates for patients with and without comorbidities were 33.33% (12/36) and 25.93% (21/81), respectively (χ² = 0.359, P = 0.549). Among the 33 patients carrying genetic variants, 27 were single nucleotide polymorphisms (SNPs) or insertion/deletions (InDels), and 6 were copy number variations (CNVs). The most common mutant genes were PRRT2 (15.15%, 5/33) and SCN1A (12.12%, 4/33). Among children carrying genetic variants, 72.73% (8/11) had attained clinical remission after adjusting the medication according to the references. CONCLUSION 28.21% of RE patients have harbored pathogenic or likely pathogenic variants or CNVs. The detection rate is higher in those with younger age of onset. PRRT2 and SCN1A genes are more commonly involved. Adjusting medication based on the types of affected genes may facilitate improvement of the remission rate.
Infant ; Female ; Male ; Humans ; Child ; Infant, Newborn ; Child, Preschool ; DNA Copy Number Variations ; Drug Resistant Epilepsy/genetics* ; Retrospective Studies ; Polymorphism, Single Nucleotide

OBJECTIVE: To explore the genetic basis for a child featuring global developmental disorder with epilepsy. METHODS: A child who had presented at Guangzhou Women and Children's Medical Center in July 2022 was selected as the study subject. Clinical data was collected. Potential variant was detected by whole exome sequencing (WES). Candidate variant was validated by Sanger sequencing and bioinformatic analysis. RESULTS: The child, a three-year-old ethnic Zhuang Chinese girl, had presented with global developmental disorder and epilepsy, for which rehabilitation therapy was ineffective. Genetic testing revealed that she has harbored a homozygous c.821T>C (p.Leu274Pro) missense variant of the PIGW gene, for which both of her parents and sister were heterozygous carriers. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as variant of uncertain significance. CONCLUSION The homozygous c.821T>C (p.Leu274Pro) variant of the PIGW gene probably underlay the onset of disease in this child. Above finding has enriched the mutational spectrum of the PIGW gene.
Child, Preschool ; Female ; Humans ; Computational Biology ; Developmental Disabilities ; Epilepsy/genetics* ; Genetic Testing ; Homozygote