目的 分析CACNA 1 H基因变异所致的癫痫伴肌阵挛-失张力发作患儿的临床表现及遗传学特征。方法 对 1例药物难治性癫痫伴肌阵挛-失张力发作的男性患儿进行临床分析及实验室检查，完善基因测序。结果 男性患儿， 1 岁时出现热性惊厥，2岁4个月出现癫痫发作，表现为肌阵挛、失张力和失神发作，伴有发育落后，予多种抗癫痫药物 治疗效果欠佳，最终加用拉莫三嗪治疗后癫痫控制。基因检测提示患儿CACNA 1 H基因存在杂合错义变异c. 3633 G>A （p. R1215H），为新生变异，既往未见文献报道。根据美国医学遗传学与基因组学学会指南分析该变异为可能致病性变异。 结论 扩充了CACNA1 H基因变异致癫痫伴肌阵挛-失张力发作的基因型。

Objective To analyze the clinical and genetic characteristics of epilepsy with myoclonic-atonic seizure caused by CACNA1 H gene mutation. Method Clinical analysis, laboratory examination and gene sequencing of a case of drug-resistant epilepsy with myoclonic-atonic seizure were retrospectively analyzed. Results At the age of 1 year, the patient had febrile convulsions. At the age of 2 years and 4 months, he had myoclonus, atonic and absence seizures, accompanied by developmental delay. Multiple antiepileptic drugtreatment is ineffective. Finally, he was responsive to lamotrigine. A novel heterozygous variation c. 3633 G > A (p.R 1215 H) in CACNA1H gene was found. According to the guidelines of American Society of Medical Genetics and Genomics, the variation was rated as likely pathogenic, which was consistent with autosomal dominant inheritance. Conclusion This study expanded the genotype of epilepsy with myoclonic-atonic seizure, which is of great significance for the precise treatment of refractory epilepsy.