Ancestry/Phenotype SNP Analysis & Integration with Established Forensic Markers

Using a literature-based candidate group of over 100 SNPs, the proposed study will continue the development of a panel of ancestry and phenotype markers with SBE technology. Single Base primer Extension (SBE) is an effective and sensitive technology that can type over 30 loci throughout the genome in a single reaction, using the capillary electrophoresis (CE) equipment currently available in forensic DNA laboratories. DNA samples, collected from anonymous volunteers along with corresponding ancestry and phenotype survey information, and spectrophotometric skin color data, and additional samples of known ancestry, will be analyzed to assess the predictive value of the candidate SNPs, with the goal of identifying the optimal panel of SNPs to efficiently assess an unknown individual's characteristics. Once this panel is established, a method of analyzing an individual sample of unknown origin will be determined and tested. This method will be needed to convey an appropriate level of confidence in the result. Additionally, being able to statistically combine the ancestry/phenotype SNP data with the ancestry information that exists with STR, YSTR, and/or mitochondrial DNA data, will allow for greater confidence and increase the utility of existing data. To accomplish this, select volunteer samples will be genotyped in these conventional forensic marker systems, and different statistical models will be evaluated as methods of combining the information. Lastly, the possibility of developing a next-generation sequencing technology that can assay STR, YSTR, autosomal SNP, and mitochondrial DNA markers on the same platform at the same time will be explored. The next-generation technology evaluation is expected to include the Pacific Biosciences RS and Illumina HiScan platforms. Combining forensic DNA markers both statistically and technologically will maximize the evidence and the efficiency of analysis. The results of this study, including the final ancestry/phenotype panel design (that can be validated in any forensic DNA laboratory) and the statistical analysis model, will be freely available on STRbase (http://www.cstl.nist.gov/strbase/SNP.htm) as well as in peer-reviewed publications.
ca/ncf