STRspy2.0: Unlocking the Potential of Long Reads for Forensic DNA Profiling.

Area of Science:

• Forensic Science
• Genomics
• Bioinformatics

Background:

• Forensic identification traditionally uses length-based short tandem repeat (STR) analysis across autosomal and Y chromosomes, requiring separate reactions and offering limited resolution.
• Next-generation sequencing (NGS) provides higher discriminatory power but is often costly and confined to specialized laboratories.
• Nanopore sequencing, particularly the portable MinION, presents an opportunity for accessible, real-time genetic analysis.

Purpose of the Study:

• To develop a bioinformatics tool for simultaneous autosomal and Y-STR profiling using nanopore sequencing reads.
• To ensure compatibility of nanopore-derived STR profiles with existing forensic databases.
• To enhance the accessibility of advanced STR profiling for forensic applications, especially in resource-limited environments.

Main Methods:

• Development of STRspy2.0, a software tool designed to analyze nanopore sequencing data for both autosomal and Y-STR loci.
• Validation of STRspy2.0 using 54 multiplexed control libraries.
• Testing STRspy2.0 on 41 mock casework samples, including blood, swabs, and bone.

Main Results:

• STRspy2.0 achieved high accuracy, with F1-scores of 100% for control libraries and 99.75% for casework samples.
• The method successfully generated simultaneous autosomal and Y-STR profiles from nanopore sequencing reads.
• The generated profiles demonstrated compatibility with established length-based forensic STR databases.

Conclusions:

• STRspy2.0 offers a robust and accurate solution for simultaneous autosomal and Y-STR profiling via nanopore sequencing.
• The portability and cost-effectiveness of the MinION platform, combined with STRspy2.0, democratize advanced STR analysis.
• This approach enhances forensic identification capabilities, particularly for laboratories with limited resources or requiring field-deployable solutions.