Next Generation Sequencing (NGS) using capture or amplicons strategies allows the detection of a large number of mutations increasing the rate of positive diagnosis for the patients. However, most of the detected mutations are Single Nucleotide Variants (SNVs) or small indels. Structural Variants (SVs) are often underdiagnosed in inherited genetic diseases, probably because few user-friendly tools are available for biologists or geneticists to identify them easily. We present here the diagnosis of two brothers presenting a demyelinating motor-sensitive neuropathy: a presumed homozygous c.5744_5745delAT in exon 10 of SACS gene was initially detected, while actually these patients were heterozygous for this mutation and harbored a large deletion of SACS exon 10 in the other allele. This hidden mutation has been detected thanks to the user-friendly CovCopCan software. We recommend to systematically use such a software to screen NGS data in order to detect SVs, such as Copy Number Variations, to improve diagnosis of the patients.

使用捕获或扩增子策略的下一代测序（NGS）可以检测大量突变，从而提高患者的阳性诊断率。但是，大多数检测到的突变是单核苷酸变体（SNV）或小插入缺失。在遗传病中，结构变体（SVs）常常得不到充分的诊断，可能是因为生物学家或遗传学家很难找到易于使用的易于使用的工具。我们在这里介绍了两个兄弟表现出脱髓鞘性运动敏感神经病的诊断：最初检测到SACS基因第10外显子纯合子c.5744_5745delAT ，而实际上这些患者对该突变是杂合的，并且具有SACS的大量缺失其他等位基因中的第10外显子。借助用户友好的CovCopCan软件，已检测到此隐藏突变。我们建议系统地使用这种软件来筛选NGS数据，以检测SV，例如拷贝数变异，以改善患者的诊断。