Development of an accurate genomic ancestry prediction strategy to enable the accounting of Australian and Japanese historical military remains

Unrecovered War Casualties - Army (UWC-A) is part of the Australian Defence Force (ADF) and investigates unaccounted for Australian soldiers from previous conflicts. In the Asia-Pacific region of WWII, DNA is often the only method available to predict the ancestry of remains. UWC-A specifically apply mtDNA/Y-DNA lineage testing which is estimated to predict ancestry accurately for only 23.4% of cases. This research presents a population-specific ancestry prediction strategy targeted to meet UWC-A needs and may ultimately lead to direct identification through further familial testing. STRUCTURE analyses indicated that all samples representing the UWC-A scenario (n = 195; British and Japanese samples) were correctly assigned. The use of the Ghaiyed population-specific panel (GPSP) showed an increase in thelowest membership profile for each group greater than was observed for other ancestry panels. This comparison demonstrated an increase in the minimum membership proportion in each group (14.3% for British and 18.1% for Japanese individuals). The Genomic Differentiation Index (GDI) indicated that the optimum differentiation between the GBR and JPT groups could be achieved using the GPSP. Six phenotype SNPs were used for the prediction of blue/brown eye colour and light/dark hair. This ancestry/phenotype prediction strategy will be evaluated on a historically relevant sample in the future.