无脑回-巨脑回畸形伴早发性癫痫脑病患儿的临床特征及分子遗传学研究

摘要

目的 探讨无脑回-巨脑回畸形伴早发性癫痫脑病患儿的临床特征、预后及潜在的遗传因素,并分析相关基因突变的临床表型.方法 收集2005年12月至2016年12月65例无脑回-巨脑回畸形伴早发性癫痫脑病患儿的临床资料,对其临床资料进行分析,并利用基因二代测序技术行全外显子组测序(WES)分析.结果 65例患儿中单纯无脑回畸形17例(26.1％),单纯巨脑回畸形34例(52.3％),巨脑回畸形并无脑回畸形14例(21.6％).65例患儿伴婴儿痉挛症13例(20.0％),伴大田原综合征9例(13.8％),伴早期肌阵挛脑病3例(4.6％),伴非综合征类早发性癫痫脑病40例(61.6％).6例伴运动障碍(6/65例,9.2％),其中3例表现为肌张力不全,2例为震颤,1例为舞蹈手足徐动症.脑电图表现严重异常,40例为大量多灶性放电.头颅影像学提示单纯巨脑回畸形比例最高(34/65例,52.3％).单纯巨脑回畸形以局限性大脑皮质受累多见(25/34例,73.5％),其中额顶叶受累最多(11/25例,44.0％).61例行拷贝数变异检测和WES分析,发现拷贝数变异1例;2例血小板激活因子乙酰水解酶1B亚单位1(LIS1/PAFAH1B1)基因突变;突触融合蛋白结合蛋白1(STXBP1)基因、Aristaless相关同接源序列(ARX)基因、动力蛋白细胞质1重链1(DYNC1H1)基因突变各1例.随访1～8年[(3.5±1.4)年],20例癫痫发作控制,45例未控制.结论 无脑回-巨脑回畸形伴早发性癫痫脑病患儿以伴婴儿痉挛症、非综合征类早发性癫痫脑病多见,少数合并运动障碍.脑电图多为大量多灶性放电.头颅影像学提示单纯巨脑回畸形居多,以额顶叶受累最多.常见致病基因为LIS1/PAFAH1 B1、STXBP1、ARX.基因突变可同时导致脑回畸形和早发性癫痫脑病共同临床表型,遗传学因素在脑发育畸形伴癫痫患儿中起重要作用.%Objective To study the clinical phenotype and prognosis of children diagnosed with early-onset epileptic encephalopathy (EOEE) and pachygyria-lissencephaly,and to explore the potential genetic factors.Methods The clinical data of 65 children between December 2005 and December 2016 was obtained and analyzed.And the whole exome sequencing was analyzed by using second generation sequencing technology.Results Among 65 children,17 cases (26.1％) were diagnosed as lissencephaly,34 cases (52.3 ％) were pachygyria,and 14 cases (62.6％)were pachygyria with lissencephaly.Thirteen cases (20.0％) were infantile spasms,9 cases (13.8％) were ohtahara syndrome,3 cases (4.6％) were early myoclonic epileptic encephalopathy,and 40 cases (61.6％) were non-symptomatic EOEE.Six cases (6/65 cases,9.2％) were associated with dyskinesia,of whom 3 cases showed dystonia,2 cases of limb tremor,1 case of dancing-like movements.Electroencephalophalogram (EEG) showed serious multifocal discharge,40 cases had massive multifocal discharge.Brain images showed that simple pachygyria was more common (34/65 cases,52.3 ％).Among them,focal pachygyria was more common (25/34 cases,73.5 ％),mostly involving in the frontoparietal lobe (11/25 cases,44.0％).Copy number variations and whole exon sequencing were performed on 61 patients.Copy number variation was detected in 1 patient.There were 2 cases of lissencephaly-1/platelet-activating factor acetylhydrolase isoform 1B (LIS1/PAFAH1B1) mutation,1 case of syntaxin-blinding protein 1 (STXBP1)mutation,1 case of Aristaless-related homeobox (ARX) mutation,and 1 case of dynein cytoplasmic 1 heavy chain 1(DYNC1H1) mutation.The follow-up time varied from 1 year to 8 years [(3.5 ± 1.4) years],in which 20 cases had clinical seizures under control but 45 cases out of control.Conclusion Infantile spasms and non-syndromic EOEEare more common in children diagnosed with EOEE and pachygyria-lissencephaly.A small number of cases have dyskinesia.EEG shows serious abnormalities,mostly multifocal discharge.Brain images show simple pachygyria is more common,mostly involving in the frontoparietal lobe.Common gene mutations are LIS1/PAFAH1B1,STXBP1,ARX.Gene mutations can lead to both clinical manifestations of cortical deformity and EOEE,and genetic factors play an important role in children with brain developmental deformity and epilepsy.