SCN1A Gene Mutations in Indian Children With Epilepsy: Single Center Experience

Objective: To study prevalence of SCN1A gene mutations in complex seizure disorders. Methods: Retrospective laboratory based study on samples sent for molecular diagnosis in complex seizure disorders. Exome sequencing was performed. Phenotype- genotype correlation was done for patients showing variants in SCN1A gene. Results: 364 samples were evaluated; of which, 54% were of children below 5 years of age. SCN1A mutations were seen in 50 samples of patients with complex seizure disorders; 44 variants were identified. Types of seizure disorders commonly associated were Dravet syndrome and genetic epilepsy with febrile seizures. Conclusions: SCN1A mutations are common in complex seizure disorders, especially Dravet syndrome. Early identification of SCN1A gene in etiology is important for selection of correct antiepileptic and counselling.

Advances in Dravet syndrome / 国际儿科学杂志

Dravet syndrome is a rare and severe developmental epileptic encephalopathy with variable clinical phenotypes.Dravet syndrome is difficult to diagnose and treat, and related comorbidities have a profound impact on the long-term quality of life of patients and their parents.SCN1A is the main pathogenic gene of Dravet syndrome, and SCN1A mutations are found in more than 85% of the patients.In recent years, with the development of genetic testing technology and the accumulation of cases, the understanding of the characteristics of epileptic seizures, comorbidities and SCN1A gene mutation characteristics in Dravet syndrome has gradually deepened.In addition to conventional antiepileptic drugs, new antiepileptic drugs(cannabidiol, fenfluramine)have also shown good antiepileptic effects and are expected to become second-line drugs for the treatment of Dravet syndrome seizures.This article mainly reviews the research progress of unique clinical phenotype, SCN1A gene mutation characteristics and new antiepileptic drugs of Dravet syndrome, in order to deepen clinicians′ understanding of the disease.

Encefalopatías epilépticas de inicio en recién nacidos y lactantes / Epileptic encephalopathies of onset in neonates and infants

Resumen Recientemente la Liga Internacional contra la Epilepsia (ILAE) socializó la clasificación propuesta para síndromes epilépticos de inicio neonatal y hasta los primeros 2 años de edad, dividiéndolos en síndromes epilépticos autolimitados y las encefalopatías epilépticas y del desarrollo (DEEs). En esta revisión nos dedicaremos a las DEEs, definidas como trastornos donde existe deterioro del desarrollo relacionado tanto con la etiología subyacente independiente de la actividad epileptiforme como con la encefalopatía epiléptica. Estas incluyen en el período neonatal la encefalopatía epiléptica infantil temprana o síndrome de Ohtahara y la encefalopatía mioclónica temprana, ahora agrupadas bajo la denominación de encefalopatías epilépticas y del desarrollo infantil temprano (EIDEE). El síndrome de espamos epilépticos infantiles, la epilepsia de la infancia con crisis migratorias y el síndrome de Dravet forman parte de las encefalopatías de inicio en el lactante. La importancia del reconocimiento temprano de las encefalopatías epilépticas radica no solo en el control de las crisis epilépticas, sino en detener el deterioro intentando cambiar el curso de la enfermedad. Es fundamental conocer la etiología evitando medicamentos que puedan exacerbar las crisis y empeorar el curso, aplicando medicina de precisión así como identificando pacientes candidatos a cirugía temprana de epilepsia.

Abstract The International League Against Epilepsy (ILAE) recently socialized the proposed classification for epileptic syndromes of neonatal onset and up to the first 2 years of age, dividing them into self-limited epileptic syndromes and epileptic and developmental encephalopathies (DEEs). In this review we will focus on DEEs, defined as disorders in which there is developmental impairment related to both the underlying aetiology independent of epileptiform activity and epileptic encephalopathy. These include early infantile epileptic encephalopathy or Ohtahara syndrome and early myoclonic encephalopathy in the neonatal period, now grouped under the name of epileptic and early childhood developmental encephalopathies (EIDEE). Infantile epileptic spasms syndrome, childhood epilepsy with migratory crises and Dravet syndrome are part of the infant-onset encephalopathies. The importance of early recognition of epileptic encephalopathies lies not only in the control of epileptic seizures, but also in stopping deterioration by trying to change the course of the disease. It is essential to know the etiology, avoiding medications that can exacerbate seizures and worsen the course, applying precision m edicine as well as identifying candidate patients for early epilepsy surgery.

Use of cannabidiol in the treatment of epilepsy: Lennox-Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex

SUMMARY OBJECTIVE: The objective of this systematic review with meta-analysis was to evaluate the efficacy, safety, and short- and long-term tolerability of cannabidiol (CBD), as an adjunct treatment, in children and adults with Dravet syndrome (SD), Lennox-Gataut syndrome (LGS), or tuberous sclerosis complex (TSC), with inadequate control of seizures. METHODS: This systematic review was conducted through a search for scientific evidence in the Mediline/PubMed, Central Cochrane, and ClinicalTrials.gov databases until April 2022. Selected randomized clinical trials (RCTs) that presented the outcomes: reduction in the frequency of seizures and total seizures (all types), number of patients with a response greater than or equal to 50%, change in caregiver global impression of change (CGIC) (improvement ≥1 category on the initial scale), adverse events (AEs), and tolerability to treatment. This review followed Preferred Reporting Items for Systematic reviews and Meta-Analyses. RESULTS: Notably, six RCTs were included, with a total of 1,034 patients with SD, LGS, and TSC, of which 3 were open-label extension RCTs. The meta-analysis of the studies showed that the use of CBD as compared with placebo, in patients with convulsive seizures refractory to the use of medications, reduces the frequency of seizures by 33%; increases the number of patients with a reduction ≥50% in the frequency of seizures by 20%; increases the number of patients with absence of seizures by 3%; improves the clinical impression evaluated by the caregiver or patient (S/CGIC) in 21%; increases total AEs by 12%; increases serious AE by 16%; increases the risk of treatment abandonment by 12%; and increases the number of patients with transaminase elevation (≥3 times the referral) by 15%. CONCLUSIONS: This systematic review, with meta-analysis, supports the use of CBD in the treatment of patients with seizures, originated in DS, LGS, and TSC, who are resistant to the common medications, presenting satisfactory benefits in reducing seizures and tolerable toxicity.

Vagus Nerve Stimulation in the Treatment of Dravet Syndrome / 罕见病研究

Dravet syndrome is a epileptic syndrome characterized by drug-resistant epilepsy occuring at childhood. It is often accompanied by status epilepticus and cognitive and language impairment appearing gradually as the disease progresses. The effect of antiepileptic drugs and resection epilepsy surgery on Dravet syndrome is poor although neuromodulation surgery, especially vagus nerve stimulation, is an effective and feasible treatment for Dravet syndrome. In this article we reported a case of Dravet syndrome treated with vagus nerve stimulation, relevant literature was reviewed and summarized at the same time. A total of 141 cases of Dravet treated by vagus nerve stimulation were collected, and the overall effective rate was 53.9%.

Prospective control study of efficacy and safety of ketogenic diet on drug refractory Dravet syndrome / 中华实用儿科临床杂志

Objective To investigate the efficacy and safety of ketogenic diet (KD) and antiepileptic drugs (AEDs) in the children with drug refractory Dravet syndrome (DS).Methods Thirty-two cases of drug refractory DS were enrolled into the Department of Neurology,Shenzhen Children's Hospital Affiliated to Shantou University Medical School from July 2016 to December 2017,and they were divided into 2 groups:KD group and AEDs group (16 cases for each group),respectively.KD was added to as an additional therapy for KD group,and oral AEDs were administered only in AEDs group.In KD group,oral AEDs were not adjusted for the first 3 months.AEDs could be adjusted within a limited range in 2 groups after 3 months.The clinical efficacy,improvement of cognitive function,retention rate and side effects were observed and compared after 3,6,12 months of treatment.The average monthly seizure frequency within 3 months before enrollment was recorded as the baseline.The clinical efficacy was assessed by comparing the seizure frequency of each observation period with the baseline.Results In KD group,after 3,6,12 months' follow-up,KD therapy was maintained in 15,14,12 patients.The number of patients whose seizure reduction over 50％ was 10,12,11 cases,respectively.The number of patients whose seizure reduction over 90％ was 7,9,10 cases,respectively.The number of patients who were seizure free was 3,6,8 cases,respectively.In AEDs group,after 3,6,12 months' therapy,the number of patients whose seizure reduction over 50％ was 6,7,8 cases,respectively,the number of patients whose seizure reduction over 90％ was 3,3,4 cases,respectively.The number of patients who were seizure-free was 2,1,2 cases,respectively.There was a significant difference in the seizure reduction between 2 groups after 6,12 months (P ＜ 0.05).Furthermore,the incidence of status epilepticus (SE) was significantly reduced in KD group,and non-fever related status epilepticus (NFSE) was preferentially improved.There was a significant difference in the incidence of SE between before and after treatment in the KD group (P ＜ 0.05).After 12 months,there was a significant difference in the incidence of SE between 2 groups (P ＜ 0.05).After 6,12 months of treatment,the patients in KD group had significant improvements in adaption,gross motor and language quotients by Gesell Developmental Scale compared to the AEDs group (all P ＜ 0.05).Eleven of 12 children who adhered to the therapy for 1 year in KD group had improvement of developmental quotient ≥ 1 grade,however,7 cases of 16 children in AEDs group had this improvement.The incidence of adverse effect in the KD group and the AEDs group was 37.5％ (6/16 cases) and 56.3％ (9/16 cases),respectively,and the difference was not significant (P ＞ 0.05).Conclusions KD can not only reduce seizure frequency and relieve SE,but also improve the cognitive function of drug refractory DS.The adverse reaction ratio of KD does not increase significantly compared to AEDs.Therefore,KD is effective and safe therapy for children with drug-resistant DS.

Relationship between mutation characteristics of SCN1A gene in Dravet syndrome and its clinical phenotype and drug efficacy / 中华实用儿科临床杂志

Objective To explore the relationship between different mutation characteristics and clinical phenotype of children with Dravet syndrome (DS) with SCN1A gene mutation,and to summarize the drug efficacy.Methods The clinical data of children diagnosed as DS from the Department of Pediatrics Neurology,the Third Affiliated Hospital of Zhengzhou University from January 2014 to May 2018 were collected.The peripheral blood DNA of the children was detected by adopting next generation sequencing for epilepsy-related gene-panel,while the parents' were screened by using Sanger sequencing for family verification.Multiple ligation-dependent probe amplification technology was used to detect large fragment variation of SCN1A gene if the mutations of the children were negative.The Gesell scale and cavity Wechsler intelligence scale for children(C-WISC) were used to evaluate the intelligence of children.Results A total of 50 cases of DS were collected,38 cases of them were positive for SCN1A mutation,and the mutation rate was 76.0％ (38/50 cases),of which,the missense mutation[50.0％ (19/38 cases)] and frameshift mutation[28.9％ (11/38 cases)] were dominant.The average onset age of 50 patients was 6 months,of which onset of seizures was triggered by fever(temperature ＞ 37.5 ℃) in 68.0％ (34/50 cases)of children,the history of seizures in hot baths was found in 60.0％ (30/50 cases) of children,status epilepticus was found in 74.0％ (37/50 cases),cluster-like episodes was found in 80.0％ (40/50 cases),≥2 seizure types was found in 92.0％ (46/50 cases).Mental retardation was found in most of the children,of which 30.0％ (15/50 cases) were mild mental retardation,38.0％ (19/50 cases) were moderate mental retardation,14.0％ (7/50 cases)were severe intelligence retardation.Interictal abnormalities of electroencephalogram(EEG) before 1 year old was found in 24.0％ (12/50 cases),and the average age of EEG abnormalities was 30.12 months old;the top three drug efficacy rates were 70.0％ (28/40 cases) of Topiramate,48.0％ (24/50 cases) of Sodium Valproate,45.7％ (16/35 cases) Clonazepam or Clobazam.The time of onset of myoclonus and atypical absence of the truncation mutation group was earlier than that of the missense mutation group(14.75 months vs.21.20 months;16.82 months vs.26.00 months),and the difference was statistically significant (P ＜ 0.05).The proportion of clustered episodes in the truncation mutation group was higher than that in the missense mutation group [94.7％ (18/19 cases)vs.63.2％ (12/19 cases)],and the difference was statistically significant (P ＜0.05).There was no significant correlation between the SCN1A gene mutation (type and position) and age of onset,type of seizure,proportion of convulsion persistence,the mental development or abnormal proportion of EEG and seizure frequency before 1 year old(all P ＞ 0.05).Conclusions The SCN1A gene mutation rate is high in children with DS,and the SCN1A gene mutation characteristics has a certain correlation with DS clinical phenotype.Topiramate is the most effective drug among children with DS.

Progress of add-on stiripentol therapy in children with Dravet syndrome / 国际儿科学杂志

Dravet syndrome ( DS) , known as severe myoclonic epilepsy of infancy, is a devastating disorder characterized by intractable epilepsy and poor neurodevelopmental outcome. Seizures are refractory to conventional antiepileptic therapy, therefore resulting in heavy psychological pressure and burden. Stiripentol ( STP) is a novel antiepileptic drug, which has been proposed to achieve better seizure control in DS. It acts as a direct GABA receptor agonist by increasing the GABAergic transmission and by prolongating the opening peri-od of the receptor dependent chloride channels. In addition, STP inhibits several isoenzymes of the cytochrome P450 system in the liver involved in the metabolism of other antiepileptics, thus potentiating their effects. By summarizing the relevant researches at home and abroad, we describe an on-going work in the anticonvulsant mechanisms and efficacy of STP, to provide an alternative treatment of DS.

Prospective control study of efficacy and safety of ketogenic diet on drug refractory Dravet syndrome / 中华实用儿科临床杂志

Objective@#To investigate the efficacy and safety of ketogenic diet (KD) and antiepileptic drugs(AEDs) in the children with drug refractory Dravet syndrome (DS).@*Methods@#Thirty-two cases of drug refractory DS were enrolled into the Department of Neurology, Shenzhen Children′s Hospital Affiliated to Shantou University Medical School from July 2016 to December 2017, and they were divided into 2 groups: KD group and AEDs group (16 cases for each group), respectively.KD was added to as an additional therapy for KD group, and oral AEDs were administered only in AEDs group.In KD group, oral AEDs were not adjusted for the first 3 months.AEDs could be adjusted within a limited range in 2 groups after 3 months.The clinical efficacy, improvement of cognitive function, retention rate and side effects were observed and compared after 3, 6, 12 months of treatment.The average monthly seizure frequency within 3 months before enrollment was recorded as the baseline.The clinical efficacy was assessed by comparing the seizure frequency of each observation period with the baseline.@*Results@#In KD group, after 3, 6, 12 months′ follow-up, KD the-rapy was maintained in 15, 14, 12 patients.The number of patients whose seizure reduction over 50% was 10, 12, 11 cases, respectively.The number of patients whose seizure reduction over 90% was 7, 9, 10 cases, respectively.The number of patients who were seizure free was 3, 6, 8 cases, respectively.In AEDs group, after 3, 6, 12 months′ therapy, the number of patients whose seizure reduction over 50% was 6, 7, 8 cases, respectively, the number of patients whose seizure reduction over 90% was 3, 3, 4 cases, respectively.The number of patients who were seizure-free was 2, 1, 2 cases, respectively.There was a significant difference in the seizure reduction between 2 groups after 6, 12 months (P<0.05). Furthermore, the incidence of status epilepticus (SE) was significantly reduced in KD group, and non-fever related status epilepticus (NFSE) was preferentially improved.There was a significant difference in the incidence of SE between before and after treatment in the KD group (P<0.05). After 12 months, there was a significant difference in the incidence of SE between 2 groups (P<0.05). After 6, 12 months of treatment, the patients in KD group had significant improvements in adaption, gross motor and language quotients by Gesell Developmental Scale compared to the AEDs group (all P<0.05). Eleven of 12 children who adhered to the therapy for 1 year in KD group had improvement of developmental quotient ≥ 1 grade, however, 7 cases of 16 children in AEDs group had this improvement.The incidence of adverse effect in the KD group and the AEDs group was 37.5%(6/16 cases) and 56.3%(9/16 cases), respectively, and the difference was not significant (P>0.05).@*Conclusions@#KD can not only reduce seizure frequency and relieve SE, but also improve the cognitive function of drug refractory DS.The adverse reaction ratio of KD does not increase significantly compared to AEDs.Therefore, KD is effective and safe therapy for children with drug-resistant DS.

Relationship between mutation characteristics of SCN1A gene in Dravet syndrome and its clinical phenotype and drug efficacy / 中华实用儿科临床杂志

Objective@#To explore the relationship between different mutation characteristics and clinical phenotype of children with Dravet syndrome (DS) with SCN1A gene mutation, and to summarize the drug efficacy.@*Methods@#The clinical data of children diagnosed as DS from the Department of Pediatrics Neurology, the Third Affi-liated Hospital of Zhengzhou University from January 2014 to May 2018 were collected.The peripheral blood DNA of the children was detected by adopting next generation sequencing for epilepsy-related gene-panel, while the parents′ were screened by using Sanger sequencing for family verification.Multiple ligation-dependent probe amplification technology was used to detect large fragment variation of SCN1A gene if the mutations of the children were negative.The Gesell scale and cavity Wechsler intelligence scale for children(C-WISC) were used to evaluate the intelligence of children.@*Results@#A total of 50 cases of DS were collected, 38 cases of them were positive for SCN1A mutation, and the mutation rate was 76.0%(38/50 cases), of which, the missense mutation[50.0%(19/38 cases)] and frameshift mutation[28.9%(11/38 cases)] were dominant.The average onset age of 50 patients was 6 months, of which onset of seizures was triggered by fever(temperature>37.5 ℃) in 68.0%(34/50 cases)of children, the history of seizures in hot baths was found in 60.0%(30/50 cases) of children, status epilepticus was found in 74.0%(37/50 cases), cluster-like episodes was found in 80.0%(40/50 cases), ≥2 seizure types was found in 92.0%(46/50 cases). Mental retarda-tion was found in most of the children, of which 30.0% (15/50 cases) were mild mental retardation, 38.0% (19/50 cases) were moderate mental retardation, 14.0% (7/50 cases)were severe intelligence retardation.Interictal abnormalities of electroencephalogram(EEG) before 1 year old was found in 24.0%(12/50 cases), and the average age of EEG abnormalities was 30.12 months old; the top three drug efficacy rates were 70.0% (28/40 cases) of Topiramate, 48.0% (24/50 cases) of Sodium Valproate, 45.7% (16/35 cases) Clonazepam or Clobazam.The time of onset of myoclonus and atypical absence of the truncation mutation group was earlier than that of the missense mutation group(14.75 months vs.21.20 months; 16.82 months vs.26.00 months), and the difference was statistically significant(P<0.05). The proportion of clustered episodes in the truncation mutation group was higher than that in the missense mutation group [94.7%(18/19 cases)vs.63.2%(12/19 cases)], and the difference was statistically significant (P<0.05). There was no significant correlation between the SCN1A gene mutation (type and position) and age of onset, type of seizure, proportion of convulsion persistence, the mental development or abnormal proportion of EEG and seizure frequency before 1 year old(all P>0.05).@*Conclusions@#The SCN1A gene mutation rate is high in children with DS, and the SCN1A gene mutation characteristics has a certain correlation with DS clinical phenotype.Topiramate is the most effective drug among children with DS.

Latest progress on clinical treatment of Dravet syndrome / 中华实用儿科临床杂志

Dravet syndrome (DS) is an epileptic (developmental) encephalopathy which onsets in infancy,most DS children are drug resistant.However,the emergence of new antiepileptic drugs is providing more options to treat DS.In the recent years,the efficacy of nonpharmacologic therapies (such as neurostimulation and ketogenic diet) had been also confirmed in DS.Now,the latest progress on clinical treatment of DS was elaborated.Besides that,the therapies on neuropsychological damages and how to prevent and deal with the status epilepticus and sudden unexpected death in children with DS were briefly introduced.

Clues to differentiate Dravet syndrome from febrile seizures plus at the first visit

Objective: To investigate the clinical clues to differentiate between Dravet syndrome (DS) and febrileseizures plus (FS+). Methods: From September 2001 to March 2014, 44 consecutive patients whowere diagnosed with DS or FS+, were recruited. We retrospectively analyzed the characteristics of thefirst seizure and findings of patients exhibiting seizures during hot water immersion at the first visit.Comparisons between the two groups were analyzed. Results: Thirty-two DS and 12 FS+ patientswere enrolled. The most prevalent body temperature classification in the DS group was afebrile(43.8% vs. 25%, p=0.001), followed by 37-37.9oC (31.3% vs. 8.3%, p=0.02), and that in the FS+group was at 39oC or above (33.3% vs. 9.4%, p=0.001). The most prevalent seizure type in the DSgroup was focal motor seizures (43.8% vs. 25%, p=0.001), followed by alternating hemiconvulsiveseizures (12.5% vs. 0%, p=0.005), and that in the FS+ group was generalized clonic and/or tonic-clonicseizures (83.3% vs. 37.5%, p=0.002). Compared with the FS+ group, there was a greater prevalenceof vaccination-related seizure as the first presenting feature among the DS patients (46.9% vs. 8.3%,p<0.001). During hot water immersion, myoclonic seizure was seen significantly in the DS group(46.4% vs. 25.5%, p=0.013).Conclusions: Afebrile and mild body temperature variation below 38oC, focal motor seizure oralternating hemiconvulsive seizure types, and vaccination-related first seizure were found to be cluesfor highly suspected DS.

PCDH19 gene mutations lead to epilepsy with mental retardation limited to females in 2 cases and literature review / 中南大学学报(医学版)

Epilepsy with mental retardation limited to females (EFMR) is a syndrome characterized by early onset heat-sensitive epilepsy of infancy or early childhood and generally limited to females,which previously reported that the cadherin gene superfamily subtype protocadherin 19 (PCDH19)gene is its pathogenic gene.We retrospectively analyzed the clinical data for 2 cases of EFMR patients with PCDH19 mutation diagnosed by Department of Pediatric Neurology of Xiangya Hospital,Central South University in 2015.Literature on PubMed,OMIM and HGMD relevant to this syndrome was reviewed,and the clinical characteristics were summarized accordingly.The 2 cases are consistent with the typical clinical manifestations of EFMR caused by PCDH19 mutations.Their seizures are heat sensitive,with or without screaming,and expressed in various forms.Cognitive impairment or autism-like performance were often identified in these patients,hematuria metabolic diseases screening was normal,no abnormal MRI imaging of the head,and de novo PCDH19 gene mutations were found in their epilepsy gene chip sequencing.It is noteworthy that this disease is very similar to the clinical manifestations of the Dravet syndrome due to the mutations of the neurotype sodium channel αl subunit SCN1A.Therefore,in female patients whose clinical manifestations resemble to Dravet syndrome but SCN1A gene test were negative,EFMR with PCDH19 mutation should be taken into consideration.Early PCDH19 gene testingis of great significance because it not only helps clinicians to understand and analyze the prognosis of this disease,but also offers genetic counseling to the parents.

Study on the causative genes and analysis of genotypes and phenotypes of Dravet syndrome / 中华实用儿科临床杂志

Objective To identify the rare causative genes of Dravet syndrome (DS) in patients who do not have SCN1A mutation and to analyze genotypes and phenotypes of DS patients with different rare causative genes.Methods DS patients were collected from the Pediatric Department of Peking University First Hospital from February 2005 to August 2016.SCN1A and PCDH19 gene mutations were screened by Sanger sequencing and multiple ligation-dependant probe amplification (MLPA).Next generation sequencing (NGS) for epilepsy-related gene-panel was applied to SCN1A and PCDH19 mutation-negative patients.The phenotypes of DS patients with different rare causative genes were analyzed.Results Six hundred and seventy patients with DS were collected and 556 patients (83.0％)carried SCN1A mutations and 6 patients with PCDH19 mutations.Epilepsy-related gene-panel was applied to remain 108 patients without SCN1A or PCDH19 mutation,and among them 12 patients were detected with 6 rare causative genes,with heterozygous mutations in GABRA1 mutations in 3,GABRG2 in 2 cases,GABRB2 mutations in 2 cases and SCN2A mutation in 1 case,complex heterozygous mutations in TBC1D24 in 2 cases and ALDH7A1 in 2 cases.The clinical phenotypes of 6 patients with PCDH19 mutations were featured by clustering of repeated seizures with short periods of times,only 1 case had an episode of status epilepticus.Patients with GABRB2 mutations had a relatively better outcome of seizure control.Many episodes of myoclonic status were emerging as hallmark features in patients with TBC1D24 mutations.Vitamin B had a dramatic therapeutic effect in patients with ALDH7A1 mutations.The clinical phenotypes of DS patients with GABRG2,SCN2A and GABRA1 had no obvious specificity.Conclusions The rare causative genes in DS patients include PCDH19,GABRG2,SCN2A,GABRA1,GABRB2,TBC1D24 and ALDH7A1.The finding of causative genes GABRB2 and TBC1D24 may enrich the gene spectrum of DS.Patients with PCDH19 mutations are featured by clustering of repeated seizures with short periods of time and rare status epilepticus.Patients with GABRB2 mutations have a relatively better outcome of seizure control.Many episodes of myoclonic status are emerging as hallmark features in patients with TBC1D24 mutations.

SCN1A Variants in Patients with Dravet Syndrome / 대한소아신경학회지

PURPOSE: The aim of this study is to examine the SCN1A variants in Korean patients with Dravet syndrome. METHODS: We conducted a retrospective study of clinically confirmed thirty-nine patients with Dravet syndrome who visit our hospital from January 2007 to May 2015. We analyzed the SCN1A variants by direct sequencing. We analyzed and classified SCN1A variants according to ACMG/AMP (American College of Medical Genetics and Genomics and the Association for Molecular Pathology) guideline. RESULTS: A total thirty-nine patients (female 22, male 17) were included. Among them, twenty patients (51.2%) with Dravet syndrome had pathogenic or likely pathogenic SCN1A mutations including fifteen truncating mutations (12 nonsense and 3 splice region mutations), 5 missense mutations. The remained variants in nineteen patients with Dravet syndrome classified into ten variants of unknown significances, and 9 benign variants. In our study, truncation mutations are located whole span of SCN1A protein, while half of missense mutations are located at higher density on pore loop (S5-S6) regions. CONCLUSION: Unlike previous known study, lower positive rate of SCN1A mutation of Dravet syndrome was revealed in our study. The importance of parental test (trio test) and other additional tests have been emphasized.

SCN1A Variants in Patients with Dravet Syndrome / 대한소아신경학회지

PURPOSE: The aim of this study is to examine the SCN1A variants in Korean patients with Dravet syndrome. METHODS: We conducted a retrospective study of clinically confirmed thirty-nine patients with Dravet syndrome who visit our hospital from January 2007 to May 2015. We analyzed the SCN1A variants by direct sequencing. We analyzed and classified SCN1A variants according to ACMG/AMP (American College of Medical Genetics and Genomics and the Association for Molecular Pathology) guideline. RESULTS: A total thirty-nine patients (female 22, male 17) were included. Among them, twenty patients (51.2%) with Dravet syndrome had pathogenic or likely pathogenic SCN1A mutations including fifteen truncating mutations (12 nonsense and 3 splice region mutations), 5 missense mutations. The remained variants in nineteen patients with Dravet syndrome classified into ten variants of unknown significances, and 9 benign variants. In our study, truncation mutations are located whole span of SCN1A protein, while half of missense mutations are located at higher density on pore loop (S5-S6) regions. CONCLUSION: Unlike previous known study, lower positive rate of SCN1A mutation of Dravet syndrome was revealed in our study. The importance of parental test (trio test) and other additional tests have been emphasized.

SCN1A Gene Mutation and Adaptive Functioning in 18 Vietnamese Children with Dravet Syndrome

BACKGROUND AND PURPOSE: Dravet syndrome is a rare and severe type of epilepsy in infants. The heterogeneity in the overall intellectual disability that these patients suffer from has been attributed to differences in genetic background and epilepsy severity. METHODS: Eighteen Vietnamese children diagnosed with Dravet syndrome were included in this study. SCN1A variants were screened by direct sequencing and multiplex ligation-dependent probe amplification. Adaptive functioning was assessed in all patients using the Vietnamese version of the Vineland Adaptive Behavior Scales, and the results were analyzed relative to the SCN1A variants and epilepsy severity. RESULTS: We identified 13 pathogenic or likely pathogenic variants, including 6 that have not been reported previously. We found no correlations between the presence or type of SCN1A variants and the level of adaptive functioning impairment or severity of epilepsy. Only two of nine patients aged at least 5 years had an adaptive functioning score higher than 50. Both of these patients had a low frequency of convulsive seizures and no history of status epilepticus or prolonged seizures. The remaining seven had very low adaptive functioning scores (39 or less) despite the variability in the severity of their epilepsy confirming the involvement of factors other than the severity of epilepsy in determining the developmental outcome. CONCLUSIONS: Our study expands the spectrum of known SCN1A variants and confirms the current understanding of the role of the genetic background and epilepsy severity in determining the developmental outcome of Dravet syndrome patients.

Mutation screening of SCN1A 3′ untranslated region on Dravet syndrome patients and functional analysis of the variant / 中华神经科杂志

Objective To conduct mutation screening of SCN1A 3′ untranslated region (UTR) on Dravet syndrome (DS) patients without mutations in the SCN1A coding region and promoter region, and functional analysis of the variant from DS patients.Methods Twenty-eight DS patients without mutations in the SCN1A coding region and promoter region were screened for SCN1A 3′ UTR mutations using PCR and direct sequencing.Functional analysis of the detected mutation was done via luciferase assay, mRNA stability analysis and RNA electrophoretic mobility shift assay (RNA-EMSA).Results A novo variant (c.*20A>G) in SCN1A 3′ UTR was found in one DS patient.The variant (c.*20A>G) reduced the luciferase gene xpression by 30% through increasing the affinity of pluripotent embryonal carcinoma cell line NT2/cytoplasmic protein binding and reducing luciferase gene mRNA stability (t=8.5,P<0.01).Conclusions A functional variant was detected from one patient with DS.This variant negatively regulated the gene expression by increasing the affinity of pluripotent embryonal carcinoma cell line NT2/cytoplasmic protein binding and reducing mRNA stability.

The relationship between vaccination and febrile seizure、GEFS+ and Dravet syndrome / 国际儿科学杂志

Vaccination in children suffering neurological diseases is a troublesome issue that people es-pecially pediatricians are reluctant to mention. Due to worrying about the emergence of adverse reactions and concerning on the heat induced seizure,doctors and parents tend to cancel or do not recommend these children to be vaccinated. Additionally,the heat sensitive seizures,such as febrile seizure( FS) ,generalized epilepsy with fe-brile seizure plus(GEFS+),Dravet syndrome account for the largest proportion of the seizure related disease and epilepsy syndrome. Their pathogenesis has been proved relating to the mutation of SCN gene of the sodium channel. For children with FS,GEFS+,and Dravet syndrome,vaccination may lead to fever,which even may bring about convulsions,but it will not result in worse prognosis.

Clinical features and gene mutations analysis in 62 children with early - onset epileptic encephalopathy of un-known causes / 中华实用儿科临床杂志

Objective To study the clinical features and gene mutations of early - onset epileptic encephalo-pathy(EOEE)of unknown causes and to identify pathogenic mutations of EOEE by next generation sequencing. Methods The clinical data of 62 cases diagnosed with unexplained EOEE between June 2013 and June 2015 were ob-tained and analyzed. Specimens were collected from the selected children and their parents. Next generation sequencing was used to detect epilepsy - related genes,and Sanger sequencing was performed to verify the results and confirm the source of the parents,further to identify suspected pathogenic mutations of EOEE. Results Among 62 cases with unex-plained EOEE,37 cases(61% )were diagnosed as non - specific EOEE,17 cases(27% )with West syndrome,6 ca-ses(10% )with Dravet syndrome,1 case(1% )with Ohtahara syndrome,1 case(1% )with early myoclonic epileptic encephalopathy. The pathogenic mutations were not detected among 17 cases with West syndrome and the early myoclonic epileptic encephalopathy. Among 37 cases with non - specific EOEE,suspected pathogenic mutations were detected in 7 cases. Three cases of missense mutations for PCDH19 gene,1 case of frame - shift mutation and 1 case of splice site mutation for CDKL5 gene,1 case of denovo nonsense mutation for KCNQ2 gene,and 1 case of missense muta-tion for GRIN2A gene were detected. Among 6 children with Dravet syndrome,2 cases of frame - shift mutations and 1 case of missense mutation for SCN1A gene were detected,of which 2 cases were of frame - shift mutations,1 case was denovo mutation,1 case of missense mutation for SCN1A gene and 1 case of missense mutation for SCN1A combined with SCN9A gene were detected. One case of denovo nonsense mutation for STXBP1 gene was detected. After treatment, 22 cases with clinical seizures were under control,and 40 cases were out of control. Conclusions The clinical pheno-types for children with unexplained EOEE were varied. SCN1A,SCN9A,STXBP1,PCDH19,CDKL5,KCNQ2 and GRIN2A genes detected in China are in accordance with those reported internationally and some gene sites are denovo mutations which have not been reported. The SCN9A gene may be the new pathogenic mutation for Dravet syndrome. And the KCNQ2 gene nonsense mutation may be the lethal mutation.