Autosomal STR Markers for Forensic Genetics: Applications, Challenges, and Future Directions

Area of Science:

• Forensic genetics
• Molecular biology
• Genomic analysis

Background:

• Short tandem repeat (STR) markers are crucial for forensic individualization and kinship verification.
• Traditional length-based capillary electrophoresis (CE) is transitioning to sequence-level analysis via massively parallel sequencing (MPS).
• MPS offers enhanced discriminatory power through detection of internal sequence variants and flanking polymorphisms.

Purpose of the Study:

• To review the molecular mechanisms of STR variability.
• To critically evaluate the shift from CE to MPS in forensic genetics.
• To address analytical challenges and discuss applications in forensic casework.

Main Methods:

• Literature review synthesizing molecular mechanisms of STR variability.
• Critical evaluation of sequencing-based STR analysis.
• Discussion of analytical challenges and forensic applications.

Main Results:

• MPS significantly increases the discriminatory power of STR analysis.
• Challenges include stochastic effects with low-template DNA and PCR inhibition in degraded samples.
• Hierarchical strategies, including mini-STR and MPS, aid in identifying fragmented DNA from mass graves and historical contexts.

Conclusions:

• MPS represents a significant advancement in forensic STR analysis, offering high-resolution capabilities.
• Probabilistic genotyping (PG) evolution emphasizes algorithmic transparency and reproducibility for judicial use.
• Implementing high-resolution STR analysis requires integrating technological advances with practical forensic challenges and considering regional infrastructures.