TranslucentID: Detecting Individuals with High Confidence in Saturated DNA SNP Mixtures

Abstract

High throughput sequencing (HTS) of complex DNA mixtures with single nucleotide polymorphisms (SNPs) panels can identify multiple individuals in forensic DNA mixture samples. SNP mixture analysis relies upon the exclusion of non-contributing individuals with the subset of SNP loci with no detected minor alleles in the mixture. Few, if any, individuals are anticipated to be detectable in saturated mixtures by this mixture analysis approach because of the increased probability of matching random individuals. Being able to identify a subset of the contributors in saturated HTS SNP mixtures is valuable for forensic investigations. A desaturated mixture can be created by treating a set of SNPs with the lowest minor allele ratios as having no minor alleles. Leveraging differences in DNA contributor concentrations in saturated mixtures, we introduce TranslucentID for the identification of a subset of individuals with high confidence who contributed DNA to saturated mixtures by desaturating the mixtures.