Population Genetic Issues for Forensic Y-chromosome Markers

As submitted by the proposer: There is a growing use for genetic markers on the Y chromosome for forensic identification. Current use is mainly for STR markers, but there is increasing attention to SNP markers. The importance of sound methods for interpreting matching Y-profiles is reflected in the SWGDAM “Guidelines Interpretation Guidelines for Y-Chromosome STR Typing” and in several scientific publications in Forensic Science International:Genetics. This proposal describes analyses designed to extend the work describe briefly in the SWGDAM guidelines, and to address some of the uncertainty on the effects of population structure on match probability calculations. This dissertation will build on recent advances in estimating the population structure parameter theta carried out under NIJ award 2011-DN-BX-K541, whereby haplotype matching within populations is compared to matching within pairs of populations. These methods will be extended and applied to three recebt large publicly-available datasets: Xu et al (Mol Genet Genomics 290:141-150), Willuweit and Roewer (For Sci Int:Genetics 15:43-48) and Shi et al. (Mol. Biol. Evol. 27:385-393). The findings will be compared to those derived from the US-YSR dataset, not publicy available, used in the SWGDAM Guidelines. The work on Y-STR data conducted in the proposed dissertation will then be extended to SNP data available from the dbGaP repository maintained by NIH. Those data have many more markers but on a more narrow range of ancestries. The combined work will lead to recommendations for the US forensic community. This project contains a research and/or development component, as defined in applicable law. ca/ncf