Global developmental delay and epileptic encephalopathy caused by SPTAN1 gene mutations in 3 cases and literature review / 中华神经科杂志

Objective:To summarize the clinical manifestations, gene variations,and treatment of cases with SPTAN1 gene variations characterized by global developmental delay or epileptic encephalopathy. Methods:Three patients with SPTAN1 gene mutations which caused developmental epileptic encephalopathy type 5 admitted to the Department of Pediatrics, Xiangya Hospital, Central South University from August 2019 to September 2021 were collected. The studies till December 2021 were searched with keywords of " SPTAN1" and "developmental and epileptic encephalopathy 5" in both English and Chinese databases of China National Knowledge Infrastructure, Wanfang, Online Mendelian Inheritance in Man, and PubMed. The clinical manifestations, genetic variations, treatments and prognosis of patients with SPTAN1 gene variations were summarized. Results:All 3 patients presented with global developmental delay, infant onset. Patient 1 showed early-onset epileptic encephalopathies and microcephaly. Patient 2 had an atrial septal defect. Cranial magnetic resonance imaging (MRI) of patient 3 showed cerebellar hypoplasia.Antiepileptic seizure therapy was partially effective, but failed to control the spasm. Development was slightly improved after rehabilitation training and other treatments, but still lagged behind the children of the same age. The SPTAN1 gene mutations of the 3 cases were heterozygous mutations, c.6923_6928dup, c.6619_6621delGAG and c.6749T>C, respectively. c.6749T>C was not reported in the previous literature. Thirteen case reports, including 69 patients, were collected. Sixty-seven patients had heterozygous mutations, inherited in an autosomal dominant fashion, including 35 missense mutations, 12 deletion mutations, 11 repetition mutations, 9 nonsense mutations, and the rest 2 patients had compound heterozygous missense mutations. A total of 38 different variation sites were reported. The phenotypes of 69 patients from the previous studies mainly included intellectual impairment (32/69), seizures (30/69), developmental delay (28/69), progressive microcephaly (27/69), hypotonia (23/69), poor visual attention (15/69), spastic quadriplegia (9/69), and gastrointestinal abnormalities (7/69). The primary type of seizures was epileptic spasm. Cranial MRI abnormalities mainly included cerebellar and brainstem atrophy, corpus callosum dysplasia, myelin dysplasia, and brain atrophy. Previous reports showed that a variety of anti-seizure drugs were effective for epileptic seizures. The prognosis varied greatly. Severe cases could be fatal, and mild cases only manifested as mild mental retardation or movement disorders. Conclusions:SPTAN1 gene mutation leads to developmental epileptic encephalopathy type 5, the phenotypes of which include intellectual impairment, global developmental delay, infantile spasms, and head deformity.Antiepileptic drugs and functional training can improve the symptoms, but the prognosis is still poor. This study expands the SPTAN1 gene variant spectrum, enriches the mutant spectrum of SPTAN1 gene associated with developmental epileptic encephalopathy type 5.

Clinical and genetic analysis of children with developmental and epileptic encephalopathy 8 caused by ARHGEF9 gene variants / 中华神经科杂志

Objective:To analyze the clinical characteristics and genetic variation of 2 children with developmental and epileptic encephalopathy 8 (DEE8).Methods:Whole-exome sequencing (WES) was performed to determine the potential variants in the probands. Candidate variants identified by WES were validated by Sanger sequencing and quantitative real-time polymerase chain reaction. X chromosome inactivation (XCI) detection was performed in the proband 1′s mother and proband 2 to detect the allelic expression difference of ARHGEF9. Results:Both of the cases showed global developmental delay. Proband 1 presented with delayed motor and speech development, intellectual disability, and seizures. Electroencephalography of proband 1 showed slow background activity, with spikes, spike and waves in bilateral frontal and midline regions during sleep. While proband 2 showed delay in acquisition of language, motor skills, and cognition, but no seizures. It was identified that proband 1 carried a novel maternally derived heterozygous splicing variant (c.925-2A>T) in ARHGEF9 by WES, which was verified in Sanger sequencing. The XCI in proband 1′s mother was observed, and the expression ratio of mutant ARHGEF9 and wild-type was 0∶100%. A novel exon 3-10 heterozygous deletion of ARHGEF9 was identified in proband 2, and this variant was not found in his unaffected parents. Conclusions:DEE8 disorders are relatively rare. Most of the patients have varying degrees of neurodevelopmental phenotype, but epilepsy is not a specific clinical manifestation. ARHGEF9 gene deletion and splicing variation may be the genetic cause of the 2 probands, and above findings have enriched the spectrum of variation and phenotype of DEE8.

Clinical characteristics of a case of developmental and epileptic encephalopathy caused by PPP3CA gene mutation and literature review / 中华神经科杂志

Objective:To improve clinicians′ understanding of developmental and epileptic encephalopathy (DEE) caused by PPP3CA gene mutation. Methods:Clinical data of a patient with DEE diagnosed in the First Department of Neurology, Hebei Children′s Hospital in September 2018 were collected. The whole-exome sequencing of the proband′s family was performed, and the characteristics of gene mutation were analyzed. Literature review was carried out based on the reported cases related to PPP3CA gene. Results:The proband, a 3 months and 20 days old girl, was admitted to the hospital with a history of paroxysmal confusion with extremities shaking for 2 days. The clinical manifestations included frequent epilepsy seizures and hypoevolutism. Brain magnetic resonance imaging showed that the bilateral frontotemporal extracerebral space was slightly wider. The video electroencephalography showed hyperarrhythmia and a cluster of spastic seizures. Whole exome sequencing of the family revealed that the proband had a heterozygous de novo frameshift truncating mutation in the PPP3CA gene: c.1255-1256delAG (p.Ser419Cysfs*31). From the establishment of the database to May 2022, 8 foreign literatures and 1 Chinese literature were retrieved, and a total of 21 children with PPP3CA gene mutation were reported, with clinical developmental delay, cognitive dysfunction and abnormal electroencephalography activity. Conclusions:The frameshift truncating mutation of the PPP3CA gene (c.1255-1256delAG) is the hereditary etiology of this patient. For cases of frequent seizures with poor efficacy of antiepileptic drugs, and developmental delay, genetic testing should be performed to confirm diagnosis and treatment.

Developmental and epileptic encephalopathy with dyskinesia caused by the FRRS1L gene mutation: a case report and literature review / 中华实用儿科临床杂志

The clinical characteristics and gene mutation profiles of a child who was treated in Xuzhou Children′s Hospital, Xuzhou Medical University in June 2022 due to developmental and epileptic encephalopathy (DEE) combined with dyskinesia caused by the FRRS1L gene mutation was analyzed retrospectively.A male case 1 year and 9 months old presented developmental delay since childhood, hypotonia at the age of 6 months, treatment-resistant seizures (focal clonic seizures) at the age of 1 year and 7 months that were unable to be controlled by antiepileptic drugs, and developmental regression and abnormal movements of the hands and feet during the attack.Whole exome sequencing showed 2 heterozygous variants (missense mutation and deletion mutation) in the FRRS1L gene of the child.The missense mutation c. 754C>T (p.R252C) located in the 4 th exon was inherited from his mother, and the deletion mutation c. 438_c.459del (p.I146fs*4) located in the 2 th exon was inherited from his father, thus constituting a compound heterozygous mutation.Through literature review, all 6 relevant literatures involving 31 children with DEE were published in foreign countries.They presented similar clinical manifestations to this case, but the genotypes were different, all of which were homozygous mutations.The FRRS1L gene mutation can lead to DEE, which is characterized by the autosomal recessive inheritance pattern, refractory epilepsy onset in infancy, developmental regression and prominent dyskinetic movements with hyperkinesia, and poor long-term prognosis.

Research progress of voltage-gated Calcium channel gene mutations associated with epilepsy in children / 中华实用儿科临床杂志

Abnormal expression and dysfunction of voltage-gated Calcium channels (VGCCs) can give rise to a variety of neurological disorders in children, including epilepsy, migraine and ataxia.In the past, only CACNA1A, CACNA1H, CACNA2D2 and CACNB4 were considered associated with epilepsy in children.In recent years, an increasing number of VGCCs gene associated with epilepsy in children have been found, especially developmental and epileptic encephalopathy genes.This study aims to review the research progress of VGCCs gene mutations associated with epilepsy in children.

Clinical and genetic study of developmental and epileptic encephalopathy in argentinean pediatric patients / Estudio clínico y genético de encefalopatía epiléptica y del desarrollo en pacientes pediátricos argentinos

Abstract Introduction: The aim of this study was to extend our knowledge of the genetic background of Argentinean pediatric patients with developmental and epileptic encephalopathy (DEE) applying a next generation sequencing (NGS) panel. Methods: Thirty one patients with DEE were studied, including these phenotypes: Dravet syndrome (n:7), Dravet like syndrome (n:3), West syndrome (WS) (n:6), WS that evolved to Lennox-Gastaut syndrome (LGS) (n:4), epilepsy of infancy with migrating focal seizures (n:2), continuous spikes and waves during slow sleep evolving to LGS (n:1), LGS (n:1), myoclonic status in non-progressive encephalopathy (n:1), myoclonic atonic epilepsy (n:1), epileptic encephalopathy with multifocal spikes (n:1) and unclassified epileptic encephalopathy (n:4). Fifty-two genes frequently associated with DEE were studied by NGS in genomic DNA from peripheral blood. Results: Relevant variants were detected in 12 cases; 6 novel pathogenic or likely pathogenic variants, 6 previously reported as pathogenic and 1 variant of unknown sig nificance. Single-nucleotide heterozygous variants were identified in the SCN1A (5), GABRG2 (1), STXBP1 (2) genes, a mosaic variant in SCN2A (1) and a homozygous variant in SCN1B (1). Additionally, a heterozygous deletion involving the SCN1A, SCN2A and SCN3A genes (1), and the most frequent triplet repeat expansion in the ARX gene (1) were detected. Discussion: Genetic diagnosis was made in 39% of patients. We emphasize the importance of considering mosaic variants, copy number variants and hereditary forms when designing and interpreting molecular studies, to optimize diagnosis and management of patients. Approximately 42% of the de tected variants were novel, expanding the knowledge of the molecular basis of DEEs in Latin-American patients.

Resumen Introducción: El objetivo del estudio fue ampliar el conocimiento de las bases moleculares de las encefalopatías epilépticas y del desarrollo (EED) en pacientes pediátricos argentinos aplicando un panel de secuenciación de nueva generación (NGS). Métodos: Se analizaron 31 pacientes con los fenotipos clínicos de síndrome de Dra vet (n:7), síndrome símil Dravet (n:3), síndrome de West (SW) (n:6), SW que evoluciona a síndrome de Lennox Gastaut (SLG)(N:4), epilepsia de la infancia con crisis focales migratorias (n:2), actividad de punta onda continua durante el sueño que evolucionan a SLG (n:1), SLG (n:1), encefalopatía no progresiva con estatus mioclónico (n:1), epilepsia mioclónica atónica (n:1), encefalopatía epiléptica con espigas multifocales (n:1) y encefalopatía epiléptica indeterminada (n:4). Se estudiaron los 52 genes más frecuentemente asociados a EED a través de NGS, en ADN extraído de sangre periférica. Resultados: Se identificaron variantes relevantes en 12 casos, de las cuales 5 fueron nuevas y 6 previamente reportadas como patogénicas o posiblemente patogénicas, mien tras que una variante fue clasificada como de significado incierto. Variantes heterocigotas, de nucleótido único, se identificaron en los genes SCN1A (5), GABRG2 (1), STXBP1 (2), una variante en mosaico en SCN2A (1) y otra homocigota en SCN1B (1). Además, se detectó una deleción que involucra a los genes SCN1A, SCN2A y SCN3A (1) y la expansión de repeticiones de tripletes más frecuente en el gen ARX (1). Discusión: Se alcanzó el diagnóstico molecular en el 39% de los pacientes. Remarcamos la importancia de considerar variantes en mosaico, variantes en el número de copias y formas heredadas al momento de diseñar e interpretar los estudios moleculares, de tal forma de optimizar el diagnóstico y seguimiento de los pacientes con EED. Cabe destacar, que el 42% de las variantes detectadas fueron nuevas, ampliando nuestro conocimiento sobre las bases mole culares de las EED en población latino americana.