Novel variants of SYNGAP1 associated epileptic encephalopathy: two cases report and literature review  

作　　者：Xingying Zeng Yong Chen Xiongying Yu Yuanyuan Che Hui Chen Zhaoshi Yi Jie Qin Jianmin Zhong 

机构地区：[1]Molecular Diagnostic Laboratory,Children’s Hospital of Jiangxi Province,Nanchang 330006,China [2]Department of Neurology,Children’s Hospital of Jiangxi Province,Nanchang 330006,China

出　　处：《Acta Epileptologica》2023年第1期56-63,共8页癫痫学报（英文）

基　　金：Written informed consent was obtained from the children’s guardians to publish their cases,and the Research Ethics Committee of Children’s Hospital of Jiangxi Province provided approval for this study(approval number is JXSETYY-YXKY-20210035).

摘　　要：Background SYNGAP1 is a signifcant genetic risk factor for global developmental delay,autism spectrum disorder,and epileptic encephalopathy.De novo loss-of-function variants in this gene cause a neurodevelopmental disorder,for example,early-onset and drug-refractory seizures.We report two children with global developmental delay and epileptic encephalopathy,which are caused by SYNGAP1 gene novel mutations,and drug treatment is efective.Case presentation We report a boy and a girl presented with global developmental delay when they were young babies;as they grew up,cognitive impairment and social-communication disorder became more and more prominent;unfortunately,the patients developed into various seizure types,including eyelid myoclonia,myoclonic and absences when the boy was 1 year 8 mouths old and the girl was 3 years old.The two patients were found two previously unknown mutations by high throughput sequencing[c.3271_c.3272insT;(p.L1091L fs^(*)62),c.2515A>T(p.K839^(*))]in exon 15 of the SYNGAP in the proband.Sanger sequencing confrmed the heterozygous nature,and neither of their parents carried the same mutation.The girl treated with valproic acid and prednisone became seizure-free,and valproic acid and levetiracetam combined with clonazepam were infuential in the other.Conclusions The global developmental delay and epileptic encephalopathy of the children were probably due to the pathogenic mutation of the SYNGAP1 gene,and prednisone and clonazepam may be efective in achieving seizure-free.

关 键 词：SYNGAP1 EPILEPSY PREDNISONE CLONAZEPAM Case report 

分 类 号：R742.1[医药卫生—神经病学与精神病学]