Discovery and characterization of highly polymorphic ultra-short STRs for human identification via shotgun sequencing

Conventional forensic STRs are 100–450 bp long, which exceeds the ~150 bp read length typical of shotgun sequencing. This study systematically assesses the limitations of standard STR markers in SGS data and identifies novel ultra-short STRs that retain high polymorphism while being compatible with short reads. The work addresses a key bottleneck in analyzing low-template and highly degraded DNA samples, where current human identification methods are often inadequate. By expanding the set of usable markers, these findings could improve forensic workflows and broaden the application of SGS in genotyping.