[Clinical features of epilepsy in children with IRF2BPL gene variation].

Objective: To summarize the genotype and phenotype of epilepsy in patients with interferon regulatory factor 2 binding protein-like (IRF2BPL) gene variants. Methods: Data of 6 epilepsy patients with IRF2BPL gene variants seen from May 2017 to September 2020 in the Department of Pediatrics of Peking University First Hospital were retrospectively collected. The clinical characteristics and genetic test results were analyzed. Results: A total of 6 patients with IRF2BPL gene variants (1 boy and 5 girls) were identified. The age of seizure onset was from 3.5 to 7.0 months. Epileptic spasms were observed in 6 patients, tonic seizures and tonic-spasms were observed in 1 patient and focal seizure was observed in 1 patient. All 6 patients presented with developmental delay, 5 patients presented with hypotonia, and 2 patients presented with dysphagia. Microcephaly,nystagmus,chorea and athetosis were observed in 1 patient. The electroencephalography (EEG) showed slow background activity in 2 patients. Hypsarrhythmia was observed in all 6 patients. Focal epileptic discharges were observed in 2 patients. Epileptic spasms were monitored in all 6 patients. Focal seizure and tonic-spasm were monitored in 2 patients respectively. The brain magnetic resonance imaging (MRI) showed cerebral atrophy and dysplasia of the corpus callosum in 1 patient, delayed myelination in 2 patients and normal in 3 patients. Two patients had missense variants c.1280C>T/p.L474F and c.1420C>T/p.S427L, 3 patients had frameshift variants c.232delG/p.V78Sfs*73, c.244del/p.A82Pfs*70 and c.283-308del/p.Ala95Thrfs*29, 1 patient had non-frameshift deletion variant c.1453-c.1455delTTC/p.F485del, and all of the 6 cases had de novo variants. All patients were diagnosed with infantile spasms. The last follow-up age ranged from 1 year to 3.8 years. Four patients achieved seizure-free and 2 patients still had frequent seizures after the treatment with antiepileptic drugs (adrenocorticotropic hormone, topiramate, and vigabatrin). Conclusions: IRF2BPL gene variants are mainly de novo. The age of seizure onset is mainly in infancy, and epilepsy and developmental delay are the main clinical manifestations. Infantile spasm is the main phenotype, some patients have hypotonia and dysphagia. Cerebral atrophy can be observed in a few patients.目的： 总结干扰素调节因子2结合蛋白样（IRF2BPL）基因变异相关的癫痫患儿临床表型及基因变异特点。 方法： 回顾性分析2017年5月至2020年9月北京大学第一医院儿科就诊的6例IRF2BPL基因变异癫痫患儿的病例资料，对其临床表型和基因检测结果进行分析。 结果： 6例患儿中男1例、女5例，均以癫痫发作起病，起病年龄为3.5~7.0月龄；均有痉挛发作，1例兼有强直发作和强直-痉挛发作，1例有局灶性发作；均有发育落后，肌张力低下5例，吞咽困难2例，小头、眼球震颤、手足舞动见于同1例。脑电图背景活动慢2例，6例均有高峰失律，2例有局灶性痫样放电；6例均监测到痉挛发作，1例监测到局灶性发作，1例监测到强直痉挛发作。头颅磁共振成像1例显示脑萎缩和胼胝体发育不良，2例髓鞘化延迟，3例正常。6例患儿IRF2BPL基因错义变异2例（c.1280C>T/p.L474F、c.1420C>T/p.S427L），移码变异3例（c.232delG/p.V78Sfs*7、c.244del/p.A82Pfs*70、c.283-308del/p.Ala95Thrfs*29），框内缺失变异1例（c.1453-c.1455delTTC/p.F485del），6例均为新生变异。6例均诊断为婴儿痉挛症。末次随访年龄1岁至3岁10个月，经抗癫痫药物治疗4例发作缓解，分别用促肾上腺皮质激素、托吡酯、氨己烯酸，2例尝试多种抗癫痫药仍有发作。 结论： IRF2BPL基因变异以新生变异为主，多在婴儿期起病，主要表现为癫痫发作和发育迟缓，以婴儿痉挛症表型最常见，部分可出现肌张力低下和吞咽困难，少数患儿可有脑萎缩。.