Abstract: Objective　Totally 20 cases of CDKL5 gene mutation positivity，i. e. CDKL5 deficiency disorder（CDD），were found through gene detection in children with recurrent seizures of unknown etiology to summarize the phenotypic characteristics of epilepsy. Methods　A total of 20 children with CDD，who were admitted to the Department of Pediatrics，the First Affiliated Hospital of Tianjin University of Chinese Medicine from April 2016 to December 2021，were included in the study. Their seizure characteristics and evolution were summarized. The whole exon group was sequenced by high-throughput sequencing technology，and the phenotypic analysis was conducted after the gene detection results were obtained. Results　Twenty children with CDD presented with recurrent seizures，including one male and 19 females；17 cases had obvious intellectual and motor development delay. The onset age of epileptic seizure was 2 days to 1 year after birth，and the common types of first seizure were generalized tonic-clonic seizure，focal seizure and tonic seizure. Fourteen children successively experienced epileptic seizure，all of which occurred before 8 months old. In the course of 12 childrens diseases，the electroencephalogram recorded the peak ataxia. All 20 children were treated with antiepileptic drugs. Except for one patient who was treated with sodium valproate alone，the rest of the cases received combination therapy. A total of 19 CDKL5 gene mutation types were found，5 of them have been reported，and the remaining 14 were new mutations. In this study，CDKL5 mutations were divided into eight groups according to the analysis of protein structural regions involved by gene mutation，of which one case was in Group H，with a good prognosis. Conclusion　The phenotypic characteristics of epilepsy in children with CDD are summarized and it is analyzed that its characteristics are related to the mutation types and function of CDKL5 gene.

Key words: CDKL5 gene, epilepsy, epileptic spasm, peak ataxia

摘要： 目的　通过基因检测病因不明的反复癫痫发作患儿，发现20例CDKL5基因变异阳性病例，即CDKL5缺乏症（CDD）患儿，总结其癫痫表型特点。方法　收集2016年4月至2021年12月在天津中医药大学第一附属医院儿科就诊的20例CDD患儿，总结其癫痫发作特点及其演变过程，并运用高通量测序技术对患儿进行全外显子组测序，获得基因检测结果后进行表型分析。结果　20例CDD患儿均以反复癫痫发作就诊，其中男1例，女19例。17例患儿有明显智力、运动发育落后。患儿癫痫发作起病年龄为出生后2d至1岁，首次发作类型以全面强直阵挛发作、局灶性发作和强直发作多见。14例患儿先后出现癫痫性痉挛发作，均在8月龄前出现。12例患儿病程中脑电图记录到高峰失律。20例患儿均应用抗癫痫发作药物治疗，除1例采用丙戊酸钠单药治疗外，余病例均为联合用药。共发现19种CDKL5基因突变类型，5种变异已有报道，其余14种为新突变。按基因突变所累及的蛋白结构区分析，将CDKL5突变分为8组，其中1例为H组，预后较好。结论　总结CDD患儿癫痫表型特点，分析其特点与CDKL5基因突变类型及功能有关。

关键词: CDKL5基因, 癫痫, 癫痫性痉挛, 高峰失律