Abstract: This paper retrospectively analyzes the clinical manifestations，neuroelectrophysiology，and genetic testing results of a 7-month-old boy， who was admitted to Department of Pediatrics of Hebei People’s Hospital for treatment in May 2020 because of delayed motor development （four months delayed）. He was with early-onset Charcot-Marie-Tooth disease（CMT）4F caused by a novel mutation of the PRX gene. Genetic testing showed that both the proband and his brother had homozygous frameshift mutation in the PRX gene（NM_181882.3）c.2320_ 2321 delinsTTC（p.V774Ffs * 53），which was respectively inherited from their parents who were carriers.Literature analysis shows that children with this disease often exhibit delayed motor development milestones，symmetrical muscle atrophy at the distal ends of both lower limbs，sensory ataxia，decreased motor nerve conduction velocity，and demyelinating changes.Early genetic testing can help clarify the diagnosis and provide genetic counseling for the family.

Key words: Charcot-Marie-Tooth disease（CMT）4F, Dejerine-Sottas disease, periaxin gene, clinical phenotype

摘要： 回顾分析2020年5月河北省人民医院儿科收治的生后7月龄时因发现运动发育落后4个月入院的男性患儿所在PRX基因新变异致早发型腓骨肌萎缩症4F型1家系临床表现、神经电生理及基因检测结果，显示先证者及胞兄PRX基因（NM_181882.3）均存在纯合移码变异c.2320_2321delinsTTC（p.V774Ffs*53），分别遗传自其携带者父母。结合文献分析，该病患儿常表现为运动发育里程碑落后，双下肢远端对称性肌肉萎缩，感觉性共济失调，运动神经传导速度减慢，脱髓鞘改变，早期基因检测有助于明确诊断及家系遗传咨询。

关键词: 腓骨肌萎缩症4F型, Dejerine-Sottas病, Periaxin基因, 临床表型