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目的:对1例热性惊厥患儿及其父母进行相关基因检测，分析其可能的致病原因和遗传学特征。方法:抽取患儿外周静脉血4 mL分别行染色体核型分析以及n FMR1基因的变异检测，同时留取患儿及父母外周静脉血各2 mL予神经系统panel针对性进行基因检测和分析，对发育迟缓、智力障碍、语言发育迟缓、癫痫及特殊面容相关基因进行特异性捕获、测序。n 结果:患儿常规染色体核型分析(400条带)显示核型无异常。检测范围内n FMR1基因CGG重复序列区域未见异常扩增。基因测序显示患儿n MEF2C基因(chr5：88 027 545)存在c.864+1delG杂合变异，为调控区域的剪切变异。该变异可能导致蛋白质功能受到影响。患儿父母该位点均未检测到变异，提示患儿n MEF2C基因变异为新发变异(n de novo)。根据美国医学遗传学与基因组学学会遗传变异标准与指南，n MEF2C基因c.864+1delG变异判定为致病性变异(PVS1+PS2+PM2)。n 结论:MEF2C基因是染色体5q14.3缺失综合征的致病关键基因，为常染色体显性遗传方式。患儿染色体5q14.3区段n MEF2C基因c.864+1delG变异可能为患儿热性惊厥的原因。n “,”Objective:To explore the genetic basis for a child with febrile seizures.Methods:Peripheral venous blood samples were taken from the child and his parents for the analysis of chromosomal karyotype and dynamic variant of the n FMR1 gene. The family trio was also subjected to target capture and next generation sequencing (NGS) with a gene panel related to developmental retardation, mental retardation, language retardation, epilepsy and special facial features.n Results:The child was found to have a normal karyotype by conventional cytogenetic analysis (400 bands). No abnormal expansion was found with the CGG repeats of the n FMR1 gene. NGS revealed that the child has carried a heterozygous c. 864+ 1 delG variant of the n MEF2C gene, which may lead to abnormal splicing and affect its protein function. The same variant was found in neither parent, suggesting that it has a n de novo origin. Based on the American College of Medical Genetics and Genomics standards and guidelines, c. 864+ 1delG variant of n MEF2C gene was predicted to be pathogenic(PVS1+ PS2+ PM2).n Conclusion:MEF2C, as the key gene for chromosome 5q14.3 deletion syndrome which was speculated as a cause for febrile seizures, has an autosomal dominant effect. The c. 864+ 1delG variant of the n MEF2C gene may account for the febrile seizures in this patient.n