Evaluation of high density SNP Microarrays to Obtain Phenotypic and Ancestry Information from Skeletal Remains

As submitted by the proposer: Identifying skeletal remains typically begins by developing a biological profile using anthropological methods to reduce the number of potential comparisons. However, an accurate biological profile relies on relatively complete adult remains, with limited applicability to fragmentary or juvenile skeletons. The ability to estimate ancestry and information such as eye and hair color would provide additional probative details towards a potential match. ldentitas Inc. customized an lllumina single nucleotide polymorphism (SNP) chip to provide over 200,000 SNP markers able to generate information on sex, ancestry, hair color and eye color. The forensic application of the ldentitas v1 Forensic Chip has been tested with soft tissue but its efficacy has yet to be tested on skeletal remains. Since some of the most challenging unidentified cases are skeletonized individuals, the goal of this two year, three stage research is to test the ability of this new technology to identify ancestral markers and phenotypic characteristics with molecular data from bone samples. Samples will be obtained from the William Bass Donated Skeletal Collection at the University of Tennessee-Knoxville, which consists of self-donated contemporary skeletal remains. Donor biographical and physical information accompanies each skeleton, including self-reported race, hair and eye color. Blood and bone samples from three individuals will be tested to assess the success rates for SNP assays using a range of input DNA amounts. Next, sex and ancestry will be estimated from 15 skeletons (five self-reported Black, Hispanic, and White) using standard anthropological methods. These skeletons will also undergo DNA testing and analysis with the ldentitas v1 Forensic Chip for a direct comparison of molecularly derived estimations of sex, ancestry, hair and eye color. An additional ten skeletons will be sampled to further evaluate the SNP chip's ability to accurately predict phenotypic expression of hair and eye color. The results from the DNA testing and anthropological methods will be compared with the self-reported information. This study will establish the level of input DNA required from bone samples for the ldentitas v1 Forensic Chip and the chip's utility and accuracy to predict ancestry, sex, and phenotypic characteristics from skeletal remain. In particular, this research will enable the medico-legal community to maximize their capabilities to identify fragmentary, incomplete, or juvenile remains by providing additional probative information for their most difficult cases. Interim and final financial and progress reports will also be submitted and data will be archived on designated Forensic Anthropology Center project computers. ca/ncf