Forensic STR (Autosomal and Y-STR) Analysis of Genotypes and SNPs
High throughput sequencing of STRs and Y-STRs provides both allele calls and sequence variants. Identifying SNPs in STRs is new in the field of forensics. The resulting iso-alleles (a locus that appears homozygous in length-based measurements such as CE, but is heterozygous by sequence) can aid in identification of individuals and relatives in single source samples and has the potential for improving the assignment of alleles to contributors during the analysis of mixtures.
High-throughput sequencing data for forensic applications such as, STRs, Y-STRs, mtDNA, or all three simultaneously, can be analyzed by selecting a built-in panel (Promega PowerSeq chemistries) or by loading a panel for custom chemistries. Autosomal and Y-STR analysis includes conventional forensic nomenclature and is concordant with CE genotyping results. Contact info@softgenetics.com for a copy of the concordance study.
GeneMarkerHTS software capabilities include simultaneous analysis and reporting of mtDNA and STR chemistries. Review and save reports for the different data types -- no need to scroll through pages of results to locate the area(s) of interest.
STR Analysis Screen
Figure 1: The STR Analysis screen has histograms and a Results Table. The histograms show the depth of coverage for each marker, with any iso-alleles being represented by a different color. The Results Table includes columns for the allele name, forward counts, reverse counts, total counts, and sequence.
Visualization of Iso-Alleles
Figure 2: Example of an iso-allele, which is a locus that appears homozygous in length-based measurements (such as CE), but is heterozygous by sequence.
Minimum Recommended processing hardware:
- 64-bit Windows OS 12 GB RAM 2.4GHz Dual Quad Core Processor
Reference Material:
- Evaluation of GeneMarkerHTS for improved alignment of mtDNA MPS data, haplotype determination, and heteroplasmy assessment. Mitchell M. Holland, Erica D. Pack, Jennifer A. McElhoe. Forensic Science International: Genetics 28 (2017) 90–98.
- haracterization of NIST Human Mitochondrial DNA SRM-2392 and SRM-2392-I Standard Reference Materials by Next Generation Sequencing. Sarah Riman, Kevin M. Kiesler, Lisa A. Borsuk, Peter M. Vallone. Forensic Science International: Genetics
- Harnessing the Power of Massively Parallel Sequencing in Forensic Analysis: Validation of PowerSeq™ CRM Nested System data with GeneMarker®HTS software - by Dr. Seth Faith's group (Battelle and Ohio BCI)
- International Journal of Legal Medicine Article
- GeneMarker®HTS Software Brochure
- Concordance Study