DMD exon 2 duplication due to a complex genomic rearrangement is associated with a somatic mosaicism
DMD exon 2 duplication due to a complex genomic rearrangement is associated with a somatic mosaicism
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DOI：
10.1016/j.nmd.2021.12.004
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发表时间：
2022-03-23
影响因子：
2.8
通讯作者：
Toda, Tatsushi
中科院分区：
文献类型：
--
作者：
Kubota, Akatsuki;Ishiura, Hiroyuki;Toda, Tatsushi
我们报告一例DMD外显子2重复引起的肌营养不良症患者，表现出明显的不对称性肌肉萎缩。活检肌肉组织的免疫染色显示马赛克染色，表明体细胞镶嵌。聚合酶链反应（PCR）分析显示只有一个断点，长读全基因组测序揭示了重排序列的整个结构。复杂的重排由两个串联重复组成：一个在断点附近显示微同源性，表明微同源性介导的机制，而另一个与侧翼短串联重复相关。长读段测序还表明存在野生型非重复序列，支持体细胞嵌合现象。而互补DNA和蛋白质印迹分析是没有用的，液滴数字PCR（ddPCR）分析显示，平均拷贝数为1.61，能够准确估计的细胞含有重复的比例。长片段测序和ddPCR分析有助于揭示重排和精确拷贝数。(c)2021爱思唯尔有限公司版权所有。
We report the case of a patient with dystrophinopathy caused by DMD exon 2 duplication, showing marked asymmetric muscle atrophy. Immunostaining of the biopsied muscle tissue showed a mosaic staining, suggesting a somatic mosaicism. Polymerase chain reaction (PCR) analysis showed only one breakpoint, and long-read whole-genome sequencing revealed the entire structure of the rearranged sequence. The complex rearrangement was composed of two tandem duplications: one showed a microhomology near the breakpoint, suggesting a microhomology-mediated mechanism, whereas the other was associated with flanking short tandem repeats. The long-read sequencing also suggested the presence of a wild-type nonduplicated sequence, supporting somatic mosaicism. Whereas complementary DNA and western blot analyses were not useful, droplet digital PCR (ddPCR) analysis showed an average copy number of 1.61, enabling accurate estimation of the proportion of cells containing the duplication. Long-read sequencing and ddPCR analysis were useful for revealing the rearrangements and the precise copy number. (c) 2021 Elsevier B.V. All rights reserved.