Single nucleotide variant sequencing errors in whole exome sequencing using the Ion Proton System

Errors in sequencing are a major obstacle in the interpretation of next-generation sequencing (NGS) results. In the present study, sequencing errors identified from analysis of single nucleotide variants (SNVs) identified during exome sequencing of human germline DNA were studied using the Thermo Fisher Ion Proton System. Two consanguineous cases were selected for sequencing using the AmpliSeq Exome capture kit, and SNVs found in both cases were validated using Sanger sequencing. A total of 98 SNVs detected by NGS were randomly selected for further analysis. Nine of the analyzed SNVs were shown to be false positives when confirmed by Sanger sequencing. All but one SNV were considered to be homopolymer regions, mainly through the insertion or deletion of nucleotides. The remaining error was considered to be related to the primer. The present results revealed that the majority of the SNV sequencing errors originated from homopolymer insertion/deletion errors, which are commonly observed when using the Ion Torrent system.