Clinical application of whole-genome low-coverage next-generation sequencing to detect and characterize balanced chromosomal translocations
Clinical application of whole-genome low-coverage next-generation sequencing to detect and characterize balanced chromosomal translocations
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DOI：
10.1111/cge.12844
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发表时间：
2017-04-01
影响因子：
3.5
通讯作者：
Xu, Z.
中科院分区：
文献类型：
--
作者：
Liang, D.;Wang, Y.;Xu, Z.
携带平衡易位的个体具有出生缺陷、复发性自然流产和不孕症的高风险。因此，平衡易位的检测和表征对于揭示携带者的遗传背景和提供适当的遗传咨询是重要的。下一代测序技术（NGS）与其他方法如核型分析和荧光原位杂交（FISH）相比具有很大的优势，已被用于检测疾病相关的断点。在此，为了评估该技术在临床上检测平衡易位的应用，我们对产前不平衡易位病例进行了父母研究。采用两种平行策略，即低覆盖全基因组测序（WGS）、桑格测序和G显带核型分析与FISH相结合，对8个可能存在平衡易位的候选家系进行了调查。G显带分析发现3个平衡易位，FISH检测到2个隐性亚显微平衡易位。一致地，WGS检测到5个平衡易位，并通过桑格测序定位所有断点。对断裂点的分析显示，在四个表面上健康的携带者中，有六个基因被破坏。总之，我们的研究结果表明，低覆盖率WGS可以可靠地检测平衡易位，并可以精确地定位断点相比，传统的程序。WGS在平衡易位携带者的临床诊断中可取代细胞遗传学方法。
Individuals carrying balanced translocations have a high risk of birth defects, recurrent spontaneous abortions and infertility. Thus, the detection and characterization of balanced translocations is important to reveal the genetic background of the carriers and to provide proper genetic counseling. Next-generation sequencing (NGS), which has great advantages over other methods such as karyotyping and fluorescence in situ hybridization (FISH), has been used to detect disease-associated breakpoints. Herein, to evaluate the application of this technology to detect balanced translocations in the clinic, we performed a parental study for prenatal cases with unbalanced translocations. Eight candidate families with potential balanced translocations were investigated using two strategies in parallel, low-coverage whole-genome sequencing (WGS) followed-up by Sanger sequencing and G-banding karyotype coupled with FISH. G-banding analysis revealed three balanced translocations, and FISH detected two cryptic submicroscopic balanced translocations. Consistently, WGS detected five balanced translocations and mapped all the breakpoints by Sanger sequencing. Analysis of the breakpoints revealed that six genes were disrupted in the four apparently healthy carriers. In summary, our result suggested low-coverage WGS can detect balanced translocations reliably and can map breakpoints precisely compared with conventional procedures. WGS may replace cytogenetic methods in the diagnosis of balanced translocation carriers in the clinic.