Abstract:
Next-generation sequencing (NGS) is a valuable tool, but has limitations in sequencing through repetitive runs of single nucleotides (homopolymers). Pathogenic germline variants in WRAP53 encoding telomere Cajal body protein 1 (TCAB1) are a known cause of dyskeratosis congenita. We identified a significant NGS error in WRAP53, c.1562dup, p.Ala522Glyfs*8 (rs755116516 G>-/GG/GGG) that did not validate by Sanger sequencing. This error occurs because rs755116516 G>-/GG/GGG (Chr17:7,606,714) is polymorphic, and variants at this site challenge the ability of NGS to accurately call the correct number of nucleotides in a homopolymer run. This was further complicated by the fact that chr17:7,606,721 (rs769202794) is multiallelic G>A, C, T, and that chr17:7,606,722 is also multiallelic (rs7640C>A/G/T and rs373064567C>delC). In addition to the expert interpretation of potentially clinically actionable variants, it recommended that all variants in regions of the genome with homopolymers be validated by Sanger sequencing before clinical action.
摘要:
下一代测序(NGS)是一种有价值的工具,但在通过单核苷酸(均聚物)的重复运行的测序中具有局限性。WRAP53中编码端粒Cajal体蛋白1(TCAB1)的致病性种系变体是先天性角化障碍的已知原因。我们在WRAP53中发现了一个重大的NGS错误,c.1562dup,p.Ala522Glyfs*8(rs755116516G>-/GG/GGG)未通过Sanger测序验证。发生此错误是因为rs755116516G>-/GG/GGG(Chr17:7,606,714)是多态的,和该位点的变体挑战NGS在均聚物运行中准确调用正确数量的核苷酸的能力。由于chr17:7,606,721(rs769202794)是多等位基因G>A,C,T,并且chr17:7,606,722也是多等位基因的(rs7640C>A/G/T和rs373064567C>delC)。除了对潜在的临床可操作变体的专家解释之外,它建议在临床行动之前通过Sanger测序验证基因组区域中具有均聚物的所有变异体.