Abstract：
Pathogenic variants of the SCN2A gene (MIM 182390) are associated with several epileptic syndromes ranging from benign familial neonatal-infantile seizures (BFNIS) to early infantile epileptic encephalopathy. The aim of this work was to describe clinical features among five patients with concomitant SCN2A gene variants and cryptogenic epileptic syndromes, thus expanding the SCN2A spectrum of phenotypic heterogeneity. De novo variants were identified in four patients, while one inherited variant was identified in a patient with an unaffected carrier biological father with somatic mosaicism. Two of five patients were diagnosed with a neonatal epileptic encephalopathy. The remaining three patients manifested a focal epileptic syndrome associated with autistic spectrum disorders (ASD) or with a variable degree of intellectual disability (ID), one of them displaying a hitherto unreported atypical late onset epilepsy. Overall, the pattern of clinical manifestations among these patients suggest that any observed neurological impairment may not be directly related to the severity of the electroclinical pattern, but instead likely associated with the mutation itself. Moreover, our results highlight the importance of SCN2A mutational screening in cases of ID/ASD with or without epilepsy.
摘要：
SCN2A基因（MIM182390）的致病变异与几种癫痫综合征有关，范围从良性家族性新生儿-婴儿癫痫发作（BFNIS）到早期婴儿癫痫性脑病。这项工作的目的是描述5例伴有SCN2A基因变异和隐源性癫痫综合征的患者的临床特征。从而扩大了表型异质性的SCN2A谱。在四名患者中发现了从头变异，而在一名未受影响的携带者生物父亲患有体细胞镶嵌的患者中发现了一种遗传变体。五名患者中有两名被诊断出患有新生儿癫痫性脑病。其余三名患者表现为与自闭症谱系障碍（ASD）或不同程度的智力障碍（ID）相关的局灶性癫痫综合征。其中之一显示迄今未报告的非典型晚发性癫痫。总的来说,这些患者的临床表现模式表明，任何观察到的神经功能缺损可能与电临床模式的严重程度没有直接关系，但可能与突变本身有关。此外，我们的结果强调了在有或没有癫痫的ID/ASD病例中进行SCN2A突变筛查的重要性.
