2 例 SMC1A 基因突变所致发育性癫痫性脑病 85 型的表型及基因型特点

Phenotypic and genetic features in 2 cases of developmental and epileptic encephalopathy 85 caused by SMC1A mutations

关键词:  SMC1A基因  发育性癫痫性脑病 85 型  发育迟缓

Key words:  SMC1A gene  developmental and epileptic encephalopathy 85  developmental delay

摘要:

目的　总结 2 例SMC1A基因变异所致发育性癫痫性脑病 85 型（DEE85）的表型及基因型特点。方法　收 集 2 例DEE85 患儿的临床资料及外周血，采用全外显子组测序技术筛查致病基因。结果 2 例患儿均为女性，婴儿期起 病，表现为频繁的强直-阵挛发作，伴发育迟缓、面部轻度畸形；脑电图提示广泛或弥漫性慢波，头颅磁共振检查均未发 现中线缺陷；基因检测分别显示SMC1A基因c.511C>T（p.Arg171Ter）、c.138_139insA（p.Phe47IlefsTer5） 新突变。多种 抗癫痫药物治疗仍有发作及发育迟缓。结论 SMC1A基因变异所致DEE85 呈X连锁显性遗传，表现婴儿期起病的难治 性癫痫伴发育迟缓。

Abstract:

Objective To summarize the phenotypic and genetic features of 2 cases of developmental and epileptic encephalopathy 85 (DEE85) caused by SMC1A mutations. Methods Clinical data and peripheral blood of 2 children with DEE85 were collected. The potential pathogenic genes were detected by whole exome sequencing. Results Two female children developed the frequent tonic-clonic seizure in infancy, with developmental delay and mild facial deformity. EEG showed diffuse slow wave. MRI revealed no midline brain defects. Genetic analysis uncovered de novo heterozygous variants of SMC1A gene, c.511C>T (p.Arg171Ter) and c.138_139insA (p.Phe47IlefsTer5). The seizures and developmental delay remained after treated with several antiepileptic drugs. Conclusion DEE85 caused by SMC1A mutations is X-linked dominant inheritance, and presents with infancy-onset refractory epilepsy and developmental delay.