Development of a Comprehensive Massively Parallel Sequencing Panel of Single Nucleotide Polymorphism and Short Tandem Repeat Markers for Human Identification

Massively parallel sequencing (MPS) technologies allow for the detection of an unparalleled amount of genetic information with unprecedented speed and relative ease. These qualities make the technology desirable for generating DNA profiles that may be uploaded into forensic offender, arrestee, and family reference database files. This doctoral dissertation research was conducted under the hypothesis that MPS, with its exquisitely high throughput, can provide a system whereby reference samples can be typed for a large battery of markers, providing more discrimination power for forensic DNA typing and offering increased opportunities to develop investigative leads. The design and implementation of large marker panels for the typing of reference samples will reduce debates on the best core markers for forensic utility, generate innovation because focus will not be solely on a core set of autosomal STRs, promote the development of better systems that can analyze more challenging samples, and enable sharing of data across laboratories worldwide. The primary goal of this project was to develop the capability of typing reference samples for a large battery of markers: 84 autosomal, Y-chromosome, and X-chromosome short tandem repeats (STRs), Amelogenin, and 275 human identity single nucleotide polymorphisms (SNPs), in a single multiplex analysis. To that end, a bioinformatic software package, STRait Razor, was developed to detect STR alleles in raw MPS data. A proof-of-concept study was performed to evaluate the efficacy of using MPS to type forensically relevant markers, using a PCR multiplex-based SNP assay. The proposed comprehensive capture-based MPS panel then was designed and extensively tested. Finally, the benefits of the additional genetic data afforded by MPS, as opposed to traditional methods, were illustrated through the characterization of intra-repeat nucleotide variation within Y-chromosome STR alleles. The results of this dissertation research indicate that MPS is capable of providing robust genetic data from a wide variety of forensically-relevant STR and SNP loci in a single analysis. To date, the comprehensive MPS panel developed during the course of these studies is the most potentially informative assay for reference sample testing for human identification.