Global population variability in Qiagen Investigator HDplex STRs

Area of Science:

• Forensic Genetics
• Population Genetics
• Human Genetics

Background:

• Standard forensic analyses rely on 15-24 core short tandem repeats (STRs).
• Complex identification and relationship testing may require additional STRs for enhanced discrimination power.
• Supplementary STRs offer potential improvements in forensic casework.

Purpose of the Study:

• To evaluate the forensic utility of 10 supplementary STRs from the Qiagen Investigator HDplex kit.
• To determine allele frequency distributions and identify rare alleles in diverse human populations.
• To assess the combined discriminatory power of HDplex with other STR kits through simulations.

Main Methods:

• Genotyping of 10 supplementary STR loci (SE33, D2S1360, D3S1744, D4S2366, D5S2500, D6S474, D7S1517, D8S1132, D10S2325, D21S2055) in 941 individuals.
• Analysis of allele frequency distributions across seven population groups within the HGDP-CEPH panel.
• Simulation of combined STR kits to predict increased relationship testing power.

Main Results:

• The evaluated HDplex STRs are highly informative and demonstrate comparable forensic discrimination power across all studied populations.
• At least six of the nine novel loci showed above-average forensic discrimination power in each population group.
• Potential allele mobility overlaps were identified between specific HDplex loci and other established STRs.

Conclusions:

• The supplementary STRs in the HDplex kit are valuable additions to forensic genetic analysis.
• These STRs provide significant discriminatory power across diverse populations, aiding in complex identification scenarios.
• Combining HDplex with other multiplex STR kits can substantially increase the power for relationship testing in challenging cases.