背景:SMC1A的致病性截短变体,位于染色体Xp11.2,已知会导致婴儿发作性癫痫和女孩严重的智力残疾。一些研究报告了SMC1A截断与癫痫发作聚类之间的相关性;然而,相关的脑电图(EEG)模式仍然未知。
方法:我们调查了一名12岁女孩,她在4个月大的时候出现了癫痫。病人起病不明,强直-阵挛性癫痫发作,每周发生几次。她在2岁时的发作间脑电图显示阵发性,广义的,高振幅慢波,而癫痫样放电很少。患者的发作间脑电图逐渐恶化;在11岁时,弥漫性连续尖峰波放电主要在左颞区观察到,在清醒状态下尤为明显。虽然发病未知,在多种抗癫痫药物下每周持续发作一次,患者自9岁起没有出现癫痫聚集性发作.全基因组测序揭示了SMC1A中从头已知的无义变体(c.2923C>T,p.R975*)。
结论:我们的患者在婴儿期和儿童早期出现发作间脑电图轻度异常,尽管癫痫发作频繁。值得注意的是,随着时间的推移,患者的脑电图检查结果逐渐恶化,这与癫痫发作聚集的改善不一致。
BACKGROUND: Pathogenic truncating variants in SMC1A, which is located on chromosome Xp11.2, are known to cause infantile-onset epilepsy and severe intellectual disability in girls. Several studies have reported a correlation between SMC1A truncations and seizure clustering; however, the associated electroencephalogram (EEG) patterns remain largely unknown.
METHODS: We investigated an 12-year-old girl who had developed epilepsy at the age of 4 months. The patient experienced unknown onset, tonic-clonic seizures that occurred in clusters several times a week. Her interictal EEG at the age of 2 years showed paroxysmal, generalized, high-amplitude slow waves, whereas epileptiform discharges were scarce. The patient\'s interictal EEG gradually deteriorated; at the age of 11 years, diffuse continuous spike-and-wave discharges were predominantly observed in the left temporal region and were particularly obvious in the awake state. Although the unknown onset, tonic seizures occurring weekly persisted under multiple antiepileptic medications, the patient did not experience seizure clustering since the age of 9 years. Whole-genome sequencing revealed a de novo known nonsense variant in SMC1A (c.2923C > T, p.R975*).
CONCLUSIONS: Our patient presented with a mild abnormality in the interictal EEG during infancy and early childhood despite frequent seizure clustering. Notably, the patient\'s EEG findings gradually deteriorated over time, which was inconsistent with the amelioration of seizure clustering.