Objectives: To study the clinical phenotype and genetic features of 16p11.2 microdeletion-related epilepsy in children.
Methods: The medical data of 200 children with epilepsy who underwent a genetic analysis of epilepsy by the whole exon sequencing technology were collected retrospectively, of whom 9 children with epilepsy had 16p11.2 microdeletion. The clinical phenotype and genetic features of the 9 children with 16p11.2 microdeletion were analyzed.
Results: The detection rate of 16p11.2 microdeletion was 4.5% (9/200). The 9 children with 16p11.2 microdeletion were 3-10 months old. They experienced focal motor seizures with consciousness disturbance, and some of the seizures developed into generalized tonic-clonic seizures. The interictal electroencephalogram showed focal or multifocal epileptiform discharge, and all 9 children responded well to antiepileptic drugs. The 9 children had a 16p11.2 deletion fragment size of 398-906 kb, and the number of deleted genes was 23-33 which were all pathogenic mutations. The mutation was of maternal origin in 2 children, of paternal origin in 1 child, and de novo in the other children.
Conclusions: 16p11.2 microdeletion can be detected in some children with epilepsy. Most of the 16p11.2 microdeletion is de novo mutation and large gene fragment deletion. The onset of 16p11.2 microdeletion-related epilepsy in children is mostly within 1 year of life, and the epilepsy is drug-responsive.
目的: 探究16p11.2微缺失相关儿童癫痫的临床表型与遗传学特征。方法: 回顾性收集200例应用全外显子测序技术进行癫痫遗传学分析的癫痫患儿，其中9例癫痫患儿为16p11.2微缺失，分析9例16p11.2微缺失患儿的临床表型及遗传学特征。结果: 16p11.2微缺失检出率为4.5%（9/200）。9例患儿为3~10月龄的婴儿；癫痫发作形式为局灶运动性发作伴意识障碍，部分进展为全身强直-阵挛发作；发作间期脑电图为局灶或多灶性痫样放电，对抗癫痫药物反应良好。9例患儿16p11.2缺失片段大小在398~906 kb之间，缺失基因数为23~33个，且均为致病性变异，其中2例为母源性来源，1例为父源性来源，余均为新发变异。结论: 16p11.2微缺失在癫痫患儿中有一定的检出率，16p11.2微缺失多为新发变异，且为基因大片段缺失；16p11.2微缺失相关儿童癫痫多在出生1年内起病且为药物反应性癫痫。.
Keywords: 16p11.2 microdeletion; Child; Epilepsy; Whole exon sequencing technology.