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 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: