Whole-Genome Linkage Analysis with Whole-Exome Sequencing Identifies a Novel Frameshift Variant in NEFH in a Chinese Family with Charcot-Marie-Tooth 2: A Novel Variant in NEFH for Charcot-Marie-Tooth 2
Whole-Genome Linkage Analysis with Whole-Exome Sequencing Identifies a Novel Frameshift Variant in NEFH in a Chinese Family with Charcot-Marie-Tooth 2: A Novel Variant in NEFH for Charcot-Marie-Tooth 2
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DOI：
10.1159/000487754
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发表时间：
2018-01-01
影响因子：
3
通讯作者：
Liu, Qiji
中科院分区：
文献类型：
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作者：
Bian, Xianli;Lin, Pengfei;Liu, Qiji
背景：腓骨肌萎缩症（CMT）是最常见的周围神经系统退行性疾病。发现50多个基因/位点与该病相关。我们发现了一个常染色体显性CMT 2家族。目的：揭示该家系的致病基因，并进一步研究该变异体的功能。方法：对所有家系成员进行全基因组连锁分析，对2名家系成员进行全外显子组测序。将神经丝轻多肽和野生型或突变型神经丝重多肽（NEFH）共转染到SW 13（Vim-）细胞中。用吗啉代反义寡核苷酸构建了nefh基因敲低的斑马鱼模型。结果：我们确定了一个新的插入变异（c.3057insG）在NEFH的家庭。该变体导致蛋白质中终止密码子的丢失和延长的41个氨基酸。免疫荧光结果显示，突变的NEFH破坏神经丝网络，并诱导NEFH蛋白聚集。在斑马鱼中敲除nefh导致轻微或严重卷曲的尾巴。nefh基因敲除的胚胎运动能力受损甚至缺失，运动神经元轴突发育缺陷。异常表型和轴突发育缺陷可以通过注射人野生型而不是人突变体NEFH mRNA来挽救。结论：我们在NEFH中鉴定了一种新的止损变体，该变体可能是CMT 2的致病性，结果为CMT中神经丝异常组装的作用提供了进一步的证据。(C)2018 S. Karger AG，巴塞尔
Background:Charcot-Marie-Tooth disease (CMT) is the most common neurodegenerative disorder of the peripheral nervous system. More than 50 genes/loci were found associated with the disease. We found a family with autosomal-dominant CMT2. Objective: To reveal the pathogenic gene of the family and further investigate the function of the variant. Methods: DNA underwent whole-genome linkage analysis for all family members and whole-exome sequencing for 2 affected members. Neurofilament light polypeptide and wild-type or mutant neurofilament heavy polypeptide (NEFH) were co-transfected into SW13 (vim-) cells. The nefh-knockdown zebrafish model was produced by using morpholino antisense oligonucleotides. Results: We identified a novel insertion variant (c.3057insG) in NEFH in the family. The variant led to the loss of a stop codon and an extended 41 amino acids in the protein. Immunofluorescence results revealed that mutant NEFH disrupted the neurofilament network and induced aggregation of NEFH protein. Knockdown of nefh in zebrafish caused a slightly or severely curled tail. The motor ability of nefh-knockdown embryos was impaired or even absent, and the embryos showed developmental defects of axons in motor neurons. The abnormal phenotype and axonal developmental defects could be rescued by injection of human wild-type but not human mutant NEFH mRNA. Conclusions: We identified a novel stop loss variant in NEFH that is likely pathogenic for CMT2, and the results provide further evidence for the role of an aberrant assembly of neurofilament in CMT. (C) 2018 S. Karger AG, Basel