Improving the strategy to identify historical military remains:a literature review and Y-STR meta-analysisOA

The identification of historical military remains by Unrecovered War Casualties—Army(UWC-A)currently relies on Y-chromosome Short Tandem Repeat(Y-STR)testing when maternal relatives are not available,or when a mitochondrial DNA match does not provide sufficient certainty of identification.However,common Y-STR profiles(using Yfiler™)between sets of remains or families often prevent identification.To resolve these cases,an investigation of additional Y-DNA markers is needed for their potential inclusion into the DNA identification strategy.The number of genetic transmissions between missing soldiers and their living relatives needs to be considered to avoid false exclusions between paternal relatives.Analysis of 236 World War Ⅰ/Ⅱ(WWI/Ⅱ)era pairs of relatives identified up to seven genetic transmissions between WWII soldiers and their living relatives,and nine for WWI.Previous Y-STR meta-analyses were published approximately 10 years ago when rapidly mutating markers were relatively new.This paper reports a contemporary literature review and meta-analysis of 35 studies(which includes 23 studies not previously used in meta-analysis)and 23 commonly used Y-STR's mutation rates to inform the inclusion of additional loci to UWC-A's DNA identification strategy.Meta-analysis found mutation data for a given Y-STR locus could be pooled between studies and that the mutation rates were significantly different between some loci(at P＜0.05).Based on this meta-analysis,we have identified two additional markers from PowerPlex® Y23 for potential inclusion in UWC-A's identification strategy.Further avenues for potential experimental exploration are discussed.