SCN4A基因R672G位点突变致低钾性周期性瘫痪伴肌萎缩一家系分析并文献复习  

The clinical and pathological characteristics of a hypokalemic periodic paralysis family with muscle atrophy due to SCN4A R672G mutation and review of literatures

作　　者：夏钰 沙倩倩 朱雯华 乔凯 都爱莲[1] XIA Yu;SHA Qian-qian;ZHU Wen-hua;QIAO Kai;DU Ai-lian(Department of Neurology,Tongren Hospital,School of Medicine,Shanghai Jiaotong University,Shanghai 200336,China;Department of Neurology,Huashan Hospital,Fudan University,Shanghai 200040,China)

机构地区：[1]上海交通大学医学院附属同仁医院神经内科,200336 [2]复旦大学附属华山医院神经内科上海,200040

出　　处：《中国现代神经疾病杂志》2022年第8期717-722,共6页Chinese Journal of Contemporary Neurology and Neurosurgery

基　　金：国家自然科学基金资助项目(项目编号:81971181);上海市自然科学基金资助项目(项目编号:19ZR1449200);上海市长宁区科学技术委员会资助项目(项目编号:CNKW2017Y02)。

摘　　要：目的 报道SCN4A基因R672G位点突变致低钾性周期性瘫痪伴肌萎缩一家系,结合文献总结其临床表现、骨骼肌病理学和MRI特点。方法与结果 男性先证者,27岁,7岁时以反复发作性四肢肌无力为首发表现,后发作频率增加,并逐渐出现下肢肌无力、肌萎缩;其母有类似发作史。发作时血清钾水平降低。长程肌电图提示0~45分钟尺神经复合肌肉动作电位彼幅逐渐降低,长时间运动后小指展肌复合肌肉动作电位波幅下降75.8%,波幅下面积降低67.4%。骨骼肌MRI显示双侧股外侧肌、股内侧肌、腓肠肌、比目鱼肌等水肿。骨骼肌病理学可见肌纤维膜下团块状沉积物,透射电子显微镜可见肌纤维膜下沉积物为排列紊乱的原始肌丝团。基因检测显示,先证者及其母均存在SCN4A基因外显子12 c.2014C>G(Arg672Gly)杂合突变。最终明确诊断为低钾性周期性瘫痪,该家系诊断为SCN4A基因Arg672Cly突变致低钾性周期性瘫痪家系。结论 SCN4A基因R67 2C位点突变致周期性瘫痪可出现肌萎缩和肌纤维膜下肌原纤维沉积的病理表现,肌纤维膜下沉积物的本质尚待进一步研究。Objective To report a family of hypokalaemic periodic paralysis(HypoPP) with muscle atrophy due to SCN4 A gene R672 G mutation.The clinical,pathological and MRI characteristics of HypoPP were summarized combining literatures review.Methods and Results The proband was a 27-year-old male patient who firstly presented periodic muscle weakness from 7 years old.The episode frequency increased with age,and gradually accompanied with muscle atrophy and permanent weakness.His mother has the similar episode but lower frequency.Serum potassium level decreased at the episode.The longterm EMG showed the compound muscle action potential(CMAP) on ulnar nerve gradually decreased from0-45 min.The CMAP in abductor digiti minimi was decreased by 75.8% after long-time exercise test.Muscle MRI showed edema in vastus lateralis,vastus medialis,gastrocnemius lateralis,gastrocnemius medialis,soleus,et al.Muscle pathology showed eosinophilic light-stained sediment under the sarcolemma.Transmission electron microscopy(TEM) showed the sediment under the sarcolemma were primitive myofilaments with disordered arrangement.Gene test showed heterozygous mutation on exon 12 c.2014 C>G(Arg672 Gly) in SCN4 A gene in proband and his mother.Finally,the proband was diagnosed HypoPP,and the family was confirmed HypoPP due to SCN4 A gene R672 G mutation.Conclusions HypoPP due to SCN4 A gene R672 G mutation can have pathological feature of muscle atrophy and sediment of primitive myofilament.The nature of the sediment needs further study.

关 键 词：低钾性周期性瘫痪(非MeSH词) 肌萎缩 钠通道 基因 突变 系谱 

分 类 号：R746[医药卫生—神经病学与精神病学]