Objective: To analyze the genotypes and clinical phenotypes of patients with epilepsy associated with IQSEC2 gene variants. Methods: The genotypes, seizure types, electroencephalogram, neuroimage of 6 patients with IQSEC2 gene variants in the Department of Pediatrics, Peking University First Hospital from July 2019 to October 2021 were analyzed. Results: There were 5 males and 1 female. Six variants were de novo, including 2 frameshift variants (c.3801_3808dup/p.Q1270Rfs*130, c.1459_1460delAT/p.M487Vfs*2), 2 nonsense variants (c.3163C>T/p.R1055*, c.1417G>T/p.E473*), 1 in-frame deletion (c.2295_2297del/p.N765del) and 1 missense variant (c.2293A>G/p.N765D). Age at seizure onset ranged from 3 months to 2 years and 5 months. Multiple seizure types were observed, including epileptic spasms in 5 patients, focal seizures in 5 patients, tonic seizures in 3 patients, myoclonic seizures in 3 patients, atypical absence seizures in 2 patients and atonic seizures in 2 patients. All 6 patients showed global developmental delay before seizure onset. There were other clinical manifestations, including autistic features in 3 patients, microcephaly in 3 patients, dystonia in 2 patients and binocular esotropia in 1 patient. The electroencephalogram showed slow background activity and hypsarrhythmia in all 6 patients. Brain magnetic resonance imaging showed abnormal in 5 patients and normal in 1 patient. Five patients were diagnosed with infantile spasms. Among them, 4 patients had late-onset infantile spasms. One patient was unclassified developmental epileptic encephalopathy. The age of last follow-up ranged from 3 years and 2 months to 7 years and 2 months. All 6 patients still had seizures after multiple anti-seizure medications. Conclusions: The seizure onset of patients with IQSEC2 gene variants usually begins after 1 year of age. The common seizure types include epileptic spasms and focal seizures. Patients usually have a global developmental delay before seizure onset. IQSEC2 variants could be related to developmental and epileptic encephalopathy, and most patients are diagnosed with late onset infantile spasms. Epilepsy associated with IQSEC2 gene variants is usually refractory.
目的： 分析IQSEC2基因变异相关癫痫患儿的基因型与临床表型特点。 方法： 收集2019年7月至2021年10月在北京大学第一医院儿科就诊的6例IQSEC2基因变异癫痫患儿的临床资料，对其基因型特点和癫痫发作表现、脑电图、头颅影像学等结果进行回顾性分析。 结果： 6例患儿中男5例、女1例。6例IQSEC2基因变异均为新生变异，其中移码变异2例（c.3801_3808dup/p.Q1270Rfs*130、c.1459_1460delAT/p.M487Vfs*2），无义变异2例（c.3163C>T/p.R1055*、c.1417G>T/p.E473*），框内缺失变异1例（c.2295_2297del/p.N765del）、错义变异1例（c.2293A>G/p.N765D）。癫痫起病年龄为3月龄至2岁5月龄。癫痫发作类型多样，包括癫痫性痉挛、局灶性发作各5例，强直发作、肌阵挛发作各3例，不典型失神发作、失张力发作各2例。6例患儿癫痫起病前均有全面发育迟缓，其他临床表现有孤独症样表现3例，小头畸形3例，肌张力减低2例，双眼内斜视1例。6例脑电图背景活动均减慢，发作间期均表现为高度失律。头颅磁共振成像显示异常5例，正常1例。5例诊断为婴儿痉挛症，其中4例为晚发型婴儿痉挛症；1例为不能分类的发育性癫痫性脑病。末次随访年龄3岁2月龄至7岁2月龄，6例均联合多种抗癫痫发作药物治疗，仍有反复发作。 结论： IQSEC2基因变异相关癫痫多数在1岁后起病，发作类型主要为癫痫性痉挛和局灶性发作，癫痫起病前均有全面性发育迟缓，符合发育性癫痫性脑病，多数表型为晚发型婴儿痉挛症，均为药物难治性癫痫。.