家族性婴儿重症肌阵挛癫癎患儿电压门控性钠通道α1亚基基因的遗传特征

Genetic characteristics of SCN1A gene in familial severe myoclonic epilepsy in infancy

目的探讨家族性婴儿重症肌阵挛癫癎（SME）患儿电压门控性钠通道α1亚基（SCN1A）基因的遗传特征。方法对我院诊断的具有热性惊厥或癫痈家族史的SME患儿及其亲属进行临床资料及外周血标本收集，提取DNA，PCR方法扩增SCN1A基因外显子，应用变性高效液相色谱（denaturing high performance liquid chromatography，DHPLC）筛查，对发现“异源峰”者进行测序分析。结果具有热性惊厥或癫癎家族史的SME患儿14例，其中一级亲属具有阳性病史者5例，2例存在SCN1A基因突变，为遗传性突变（c．4284＋2T〉C和c．1216G〉T）；二级亲属具有阳性病史者9例，2例存在SCN1A突变，为新生突变。结论SCN1A基因是SME的重要致病基因，具有相同基因遗传基础的个体可以表型不同。应把一级亲属具有热性惊厥或癫癎病史的SME患者作为SCN1A遗传性突变筛查的重点，有助于发现遗传性SME。

Objective To explore the inheritance characteristics of SCN1A gene in familial severe myoclonic epilepsy in infancy. Methods The clinical information and blood of the patients and their relatives who had febrile seizure （FS） or epilepsy history were collected. Blood genome DNA were extracted. All exons of SCN1A gene were PCR amplified and screened with denaturing high performance liquid chromatography （DHPLC） technology, and sequence analysis was performed. Results Fourteen SME patients had FS or epilepsy family history. Five were found positive history in first class relatives and 2 of them had inherited mutations of SCNIA（ c. 4284 ＋ 2T 〉 C and c. 1216G 〉 T） ; Other 9 were found positive history in second class relatives and 2 of them had de novo mutations of SCN1A. Conclusions SCN1A is the pathogenic gene for SME. The same mutation of SCN1A gene can be related to different clinical phenotypes. SME patients whose first class relatives with FS or epilepsy history should be taken as the focus of SCN1A inherited mutation screening.