Detection of sequence-tagged sites to reveal mechanisms of multi-step mutations at multi-copy Y-STRs in father-son pairs.

The case report demonstrates that co-examining various forensic markers with different technologies can strengthen the connection between father-son pairs with multi-step mutations observed at multi-copy Y-chromosomal short tandem repeats (Y-STRs). We detect 33 autosomal STRs and 94 identity-informative single nucleotide polymorphisms (iSNPs) using capillary electrophoresis (CE) and/or next-generation sequencing (NGS) to confirm the relationship within pedigrees. Meanwhile, this study reveals that the mechanisms behind the mutations observed in these cases involve STR slippage (identified using NGS or Sanger sequencing methods) and/or chromosomal structure rearrangement (identified using sequence-tagged site analyses).

Simultaneous sequencing of 102 Y-STRs on Ion Torrent ™ GeneStudio ™ S5 System.

The Precision ID NGS System from Thermo Fisher Scientific is a mainstream next-generation sequencing (NGS) platform used in forensic laboratories to detect almost all commonly used forensic markers, except for Y-chromosomal short tandem repeats (Y-STRs). This study aimed to: 1) develop a Y-STR panel compatible with the automatic workflow of the NGS system using Ion AmpliSeq Technology, 2) evaluate the panel performance following the SWGDAM guidelines, and 3) explore the possibility of using a combination workflow to detect autosomal STRs and Y-STRs (AY-STR NGS workflow). The GrandFiler Y-STR Panel was successfully designed using the 'separating' and 'merging' strategies, including 102 Y-STRs and Amelogenin with an average amplicon length of 133 bp.

Ion Torrent ™ Genexus ™ Integrated Sequencer and ForeNGS Analysis Software-An automatic NGS-STR workflow from DNA to profile for forensic science.

The Ion Torrent ™ Genexus ™ Sequencer (Genexus) is a highly integrated instrument that can automate library construction, templating, and sequencing in a single-instrument run. By programing the ForeNGS Analysis Software (FNAS), we bridged the gap between sequencing and genotyping without manual intervention. FNAS can automatically transfer sequencing output files from Genexus, analyze the repeat and flanking regions aligned to the GRCh38 assembly, name the alleles according to the ISFG guidelines, and generate user-friendly interactive profiles.