The Y-Chromosome in Forensic and Public Health Genetics

Abstract

Unlike the autosomes and X-chromosome, the Y-chromosome does not recombine with a homologous partner, save obligatory recombination with the X-chromosome in the pseudoautosomal regions. Because of the lack of recombination, the male-specific region of the Y is inherited clonally from father to son. This inheritance pattern influences the way the Y-chromosome can be used forensically and in public health genetics. Chapter 1 of this dissertation details the history and use of the Y-chromosome in forensic genetics. The second half of the chapter examines the properties of a new estimator of population-specific FST on the Y-chromosome and its use in calculating the forensic match probability, as well as a comparison of the kappa method and an evolutionary model for match probability calculation. The Y-chromosome has recently been used for forensic familial searching using a commercial DNA database. Chapter 2 presents a policy analysis of forensic familial searching in commercial DNA databases. Due to its small size and a number of analytic challenges, the Y-chromosome has largely been ignored in genetic association studies. One of the major analytic challenges is how to adjust for population stratification on the Y-chromosome, as relatedness is different between the Y and autosomes. Chapter 3 examines associations between SNPs on the Y-chromosome and obesity in Hispanic men, adjusting for autosomal and Y-chromosome principal components.