Long-read targeted sequencing uncovers clinicopathological associations for C9orf72-linked diseases.
Long-read targeted sequencing uncovers clinicopathological associations for C9orf72-linked diseases.
复制标题
DOI：
10.1093/brain/awab006
复制
发表时间：
2021-05-07
期刊：
影响因子：
--
通讯作者：
van Blitterswijk M
中科院分区：
文献类型：
--
作者：
DeJesus-Hernandez M;Aleff RA;Jackson JL;Finch NA;Baker MC;Gendron TF;Murray ME;McLaughlin IJ;Harting JR;Graff-Radford NR;Oskarsson B;Knopman DS;Josephs KA;Boeve BF;Petersen RC;Fryer JD;Petrucelli L;Dickson DW;Rademakers R;Ebbert MTW;Wieben ED;van Blitterswijk M
C9orf72是额颞叶变性和运动神经元疾病最常见的遗传原因，为了检测C9orf72中六核苷酸扩增的长度，我们采用了一种靶向无扩增长读测序技术：No-Amp测序。在我们的横断面研究中，我们评估了28个具有良好特征的C9orf72扩增携带者的小脑组织。我们获得了3507个符合目标的圆形一致测序读数，其中814个桥接了C9orf72重复扩增（23%）。重要的是，我们观察到使用No-Amp测序和Southern blotting获得的扩增大小之间存在显著相关性（P = 5.0 × 10−4）。有趣的是，我们还发现了较小扩张个体的显著生存优势（P = 0.004）。此外，我们发现，较小的扩增量与含有内含子1b （P = 0.003）、多聚（GP）蛋白（P = 1.3 × 10−5）和多聚（GA）蛋白（P = 0.005）的C9orf72转录本水平较高显著相关。对扩增物的组成进行仔细检查，发现其GC含量极高（中位数：100%），主要由GGGGCC重复序列组成（中位数：96%），表明扩增后的C9orf72重复序列相当纯净。综上所述，我们的研究结果表明，No-Amp测序是一种强大的工具，可以发现相关的临床病理关联，突出了c9orf72相关疾病中小脑扩增重复序列的大小所起的重要作用。DeJesus-Hernandez等人采用了一种创新的长读测序方法来检测扩展的C9orf72重复序列的长度，该重复序列代表了额颞叶痴呆和肌萎缩侧索硬化症最常见的遗传原因。较小的扩张尺寸为患者的生存带来了好处。
To examine the length of a hexanucleotide expansion in C9orf72, which represents the most frequent genetic cause of frontotemporal lobar degeneration and motor neuron disease, we employed a targeted amplification-free long-read sequencing technology: No-Amp sequencing. In our cross-sectional study, we assessed cerebellar tissue from 28 well-characterized C9orf72 expansion carriers. We obtained 3507 on-target circular consensus sequencing reads, of which 814 bridged the C9orf72 repeat expansion (23%). Importantly, we observed a significant correlation between expansion sizes obtained using No-Amp sequencing and Southern blotting (P = 5.0 × 10−4). Interestingly, we also detected a significant survival advantage for individuals with smaller expansions (P = 0.004). Additionally, we uncovered that smaller expansions were significantly associated with higher levels of C9orf72 transcripts containing intron 1b (P = 0.003), poly(GP) proteins (P = 1.3 × 10− 5), and poly(GA) proteins (P = 0.005). Thorough examination of the composition of the expansion revealed that its GC content was extremely high (median: 100%) and that it was mainly composed of GGGGCC repeats (median: 96%), suggesting that expanded C9orf72 repeats are quite pure. Taken together, our findings demonstrate that No-Amp sequencing is a powerful tool that enables the discovery of relevant clinicopathological associations, highlighting the important role played by the cerebellar size of the expanded repeat in C9orf72-linked diseases. DeJesus-Hernandez et al. employ an innovative long-read sequencing method to examine the length of the expanded C9orf72 repeat that represents the most common genetic cause of frontotemporal dementia and amyotrophic lateral sclerosis. Smaller expansion size confers a survival benefit for patients.