Resolving individuals contributing trace amounts of DNA to highly complex mixtures using high-density SNP genotyping microarrays

PLoS Genet. 2008 Aug 29;4(8):e1000167. doi: 10.1371/journal.pgen.1000167.

Abstract

We use high-density single nucleotide polymorphism (SNP) genotyping microarrays to demonstrate the ability to accurately and robustly determine whether individuals are in a complex genomic DNA mixture. We first develop a theoretical framework for detecting an individual's presence within a mixture, then show, through simulations, the limits associated with our method, and finally demonstrate experimentally the identification of the presence of genomic DNA of specific individuals within a series of highly complex genomic mixtures, including mixtures where an individual contributes less than 0.1% of the total genomic DNA. These findings shift the perceived utility of SNPs for identifying individual trace contributors within a forensics mixture, and suggest future research efforts into assessing the viability of previously sub-optimal DNA sources due to sample contamination. These findings also suggest that composite statistics across cohorts, such as allele frequency or genotype counts, do not mask identity within genome-wide association studies. The implications of these findings are discussed.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Computer Simulation
  • Genetics, Medical*
  • Genome, Human
  • Genotype
  • Humans
  • Oligonucleotide Array Sequence Analysis / methods*
  • Polymorphism, Single Nucleotide*