NCM 2022: STRspy-ing hidden variation in forensic DNA profiles using the MinION device

Short tandem repeats (STRs) are the gold standard for human identification in forensic investigations. Despite the power and reliability of current typing techniques, sequence-level information within and around STRs are masked in conventional length-based profiles. To harness the advantages of the portable MinION device in forensic genetics, we developed STRspy, a novel method capable of generating accurate length- and sequence-based allele designations for autosomal STRs from ONT reads. Here, we expand on STRspy to enable simultaneous profiling of autosomal and Y-STRs as well as flanking SNPs in casework-relevant samples. STRspy predicted the correct alleles across all 22 autosomal and 23 Y-STRs and identified SNPs in the flanking regions with a high level of accuracy. These results demonstrate that STRspy can produce accurate profiles for the largest combined autosomal and Y-STR amplification panel, further increasing the forensic potential of the MinION device in future applications.