Microhaplotypes: the next generation DNA marker

Microhaplotypes (microhaps) are biomarkers less than 300 nucleotides long that display multiple allelic combinations. The main advantages of microhaps over conventional short tandem repeats (STRs) include the absence of stutter, same-size alleles within each locus, lower mutation rate, and ancestry informative alleles. These forensically relevant loci can yield a power of discrimination similar to STRs while enhancing human identification (HID), mixture deconvolution and biogeographic ancestry prediction. Sanger sequencing does not allow determining the cis/trans relationship among closely related SNPs while massively parallel sequencing (MPS) allows determining the parental haplotypes at each locus by clonally sequencing of each DNA molecule if they are included in the same amplicon. Currently, STR panels are used for mixture deconvolution and SNP assays are used for ancestry inference. Microhaplotypes can be used for both functions allowing, for example, to infer the ancestry of a minor contributor to a mixture (DNA intelligence). In this presentation we discuss the current status of the research conducted in the GW-FMB lab on this new multi-function DNA marker and its potential impact to the field of in forensic genetics.

Learning Objectives:

1. Molecular basis of microhaplotypes

2. Informativeness and power of discrimination of microhaplotypes

3. Mixture deconvolution via microhaplotypes