"The devil's in the detail": Release of an expanded, enhanced and dynamically revised forensic STR Sequence Guide

Area of Science:

• Forensic genetics
• Genomics
• Molecular biology

Background:

• The 2016 STR sequence template file by the International Society for Forensic Genetics (ISFG) provided minimal nomenclature requirements.
• Previous versions relied on older genome assemblies, potentially limiting accuracy with newer sequencing technologies.
• Forensic geneticists require standardized, up-to-date sequence information for accurate DNA profiling.

Purpose of the Study:

• To comprehensively revise and audit the forensic STR sequence template file using the latest GRCh38 human genome assembly.
• To expand the characterized forensic STR list with supplementary markers for future massively parallel sequencing (MPS) panels.
• To provide a dynamically updated resource for forensic scientists utilizing MPS technology.

Main Methods:

• Sequence alignment and annotation comparing GRCh37 and GRCh38 human genome assemblies.
• Matching of MPS-based allele descriptions to established repeat region structures.
• Auditing and updating of STR sequence data based on the GRCh38 reference genome.

Main Results:

• A comprehensively revised STR sequence template file is now available, audited against the GRCh38 genome assembly.
• The updated list includes supplementary autosomal, X-, and Y-chromosome microsatellites.
• The revised guide addresses complexities in sequence alignment and annotation for forensic STRs.

Conclusions:

• The updated STR sequence guide facilitates accurate analysis of forensic STR data, especially with MPS technologies.
• The dynamic FTP format and change log on the STRidER website ensure users have access to the latest information.
• This resource supports the adoption of new STR markers and enhances the capabilities of forensic DNA profiling.