Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India.
Amritha Institute of Medical Sciences, Kochi, Kerala, India.
Neurol India. 2021 Nov-Dec;69(6):1701-1705. doi: 10.4103/0028-3886.333508.
Sporadic nonlesional intractable visual-sensitive epilepsies of childhood represent a challenging subset of epilepsies in terms of management and prognostication given a propensity to evolve as epileptic encephalopathy.
To study the genetic heterogeneity of drug-resistant visual sensitive epilepsy of childhood.
A retrospective chart review was conducted on patients in the pediatric age group between 2016 and 2018, with drug-resistant epilepsy (DRE) and video electro encephalography (VEEG) documented reflex photosensitivity, eye-condition sensitivity. Those patients who underwent genetic testing with targeted next-generation sequencing using an epilepsy gene panel were selected.
During the study period, out of 96 patients who underwent genetic testing, 4 patients (4.17%) with sporadic DRE presented with clinical phenotypes ranging from myoclonic-atonic epilepsy, generalized epilepsy with eyelid myoclonia as well as febrile and unprovoked seizures, along with visual sensitivity. Video EEG documented abnormalities ranged from occipital, posterior-cortex and generalized discharges with "eyes-closed state" triggered, self-induced "smart-phone" triggered, photosensitive focal-onset and generalized myoclonic seizures. Accompanying developmental impairment was noted. These patients who were investigated with clinical exome sequencing were detected to have mutations in not only SCN1A genes (pathogenic exonic and intronic variants) but also CHD2 (pathogenic) and CACNA1H genes (a familial febrile-seizure susceptibility variant of unknown significance).
The series highlights the complex genetics of drug-resistant visual-sensitive epilepsy of childhood. Such genotype-phenotype associations throw light on the role of ion-channel and non-ion channel genes on reflex epileptogenesis in this group of patients.
散发性非病灶性难治性儿童视觉敏感癫痫在管理和预后方面代表了一类具有挑战性的癫痫亚组，因为它们有发展为癫痫性脑病的倾向。
研究儿童耐药性视觉敏感癫痫的遗传异质性。
对 2016 年至 2018 年期间儿科年龄组中药物难治性癫痫（DRE）和视频脑电图（VEEG）记录的反射光敏性、眼状态敏感性的患者进行回顾性图表审查。选择接受靶向下一代测序的遗传检测的患者，该检测使用癫痫基因panel 进行。
在研究期间，在接受基因检测的 96 例患者中，有 4 例（4.17%）散发性 DRE 患者表现出从肌阵挛-阵挛性癫痫、以眼睑肌阵挛为特征的全身性癫痫、热性和无诱因癫痫发作以及视觉敏感性的临床表型。视频脑电图记录的异常范围从枕叶、后皮质和广泛性放电，伴有“闭眼状态”触发、自我诱导“智能手机”触发、光敏性局灶性和全身性肌阵挛性癫痫发作。伴有发育障碍。对这些患者进行临床外显子组测序检测到不仅 SCN1A 基因（致病外显子和内含子变异），而且 CHD2（致病）和 CACNA1H 基因（一种家族性热性癫痫易感性的未知意义的变异体）发生突变。
该系列强调了儿童耐药性视觉敏感癫痫的复杂遗传学。这种基因型-表型关联揭示了离子通道和非离子通道基因在这组患者反射性癫痫发生中的作用。
