Fulgent Genetics, Temple City, California.
Fulgent Genetics, Temple City, California.
J Mol Diagn. 2020 May;22(5):670-678. doi: 10.1016/j.jmoldx.2020.02.001. Epub 2020 Feb 21.
When a potential disease-causing variant is detected in a proband, parental testing is used to determine the mode of inheritance. This study demonstrates that next-generation sequencing (NGS) is uniquely well suited for parental testing, in particular because of its ability to detect clinically relevant germline mosaicism. Parental variant testing by NGS was performed in a clinical laboratory for 1 year. The detection of mosaicism by NGS was compared with its detection by Sanger sequencing. Eight cases of previously unrevealed mosaicism were detected by NGS across eight different genes. Mosaic variants were differentiated from sequencing noise using custom bioinformatics analyses in combination with familial inheritance data and complementary Sanger sequencing. Sanger sequencing detected mosaic variants with allele fractions ≥8% by NGS, but could not detect mosaic variants below that level. Detection of germline mosaicism by NGS is invaluable to parents, providing a more accurate recurrence risk that can alter decisions on family planning and pregnancy management. Because NGS can also confirm parentage and increase scalability, it simultaneously streamlines and strengthens the variant curation process. These features make NGS the ideal method for parental testing, superior even to Sanger sequencing for most genomic loci.
当在先证者中检测到潜在的致病变异时，可进行父母检测以确定遗传模式。本研究表明，下一代测序（NGS）非常适合用于父母检测，特别是因为其能够检测到临床相关的种系嵌合体。在临床实验室中进行了为期 1 年的 NGS 父母变异检测。通过 NGS 检测嵌合体的能力与 Sanger 测序进行了比较。在八个不同的基因中，NGS 检测到了以前未发现的 8 例嵌合体。通过定制的生物信息学分析与家族遗传数据和补充的 Sanger 测序相结合，区分嵌合变体与测序噪声。Sanger 测序可以检测到 NGS 检测到的等位基因分数≥8%的嵌合变体，但无法检测到低于该水平的嵌合变体。NGS 检测种系嵌合体对父母来说是非常有价值的，可以提供更准确的复发风险，从而改变计划生育和妊娠管理的决策。因为 NGS 还可以确认亲子关系并提高可扩展性，所以它同时简化和加强了变异的管理过程。这些特征使 NGS 成为父母检测的理想方法，即使对于大多数基因组位点，也优于 Sanger 测序。
