Selecting microhaplotypes optimized for different purposes.

ABSTRACT

Massively parallel sequencing is transforming forensic work by allowing various useful forensic markers, such as STRPs and SNPs, to be multiplexed providing information on ancestry, individual and familial identification, phenotypes for eye/hair/skin pigmentation, and the deconvolution of mixtures. Microhaplotypes also become feasible with massively parallel sequencing, these are DNA segments (smaller than 300 nucleotides) that are selected to contain multiple SNPs unambiguously defining three or more haplotype alleles occurring at common frequencies. The physical extent of a microhaplotype can thus be covered by a single sequence read making these loci phase-known codominant genetic systems. Such microhaplotypes supply significantly more information than a single SNP can. Our efforts to develop useful sets of microhaplotypes have already identified 182 such loci that we have studied on a large number of human populations from around the world. We present various analyses on 83 populations in our ongoing study for a subset of the best microhaplotypes currently available illustrating their characteristics and potential utility for ancestry, identification, and mixture deconvolution.