Incorporating Nonpedigree Estimates of Relatedness in Modeling the Approximate Likelihood of Pedigree Data for Linkage Analysis

• Activity Number: 561
• Type: Contributed
• Date/Time: Wednesday, August 12, 2015 : 10:30 AM to 12:20 PM
• Sponsor: Section on Statistics in Genomics and Genetics
• Author(s): Fiona Grimson*
• Keywords: genetics ; identity-by-descent (IBD) ; pedigree ; linkage

Abstract

A major topic in statistical genetics is discovering the locations of genes contributing to complex traits through linkage analysis. Using the pedigree structure and data at a genetic marker the likelihood of the marker co-segregating with the disease locus is compared to the likelihood of the data occurring by chance. In most cases, the likelihood must be approximated due to the complexity or size of the pedigree, for example, by using realizations of identity-by-descent on the pedigree. Likelihood approximations based solely on pedigree structure, however, often under-represent the level of relatedness between individuals.

We present a stepwise, scalable approach to modeling the approximate likelihood that incorporates estimates of additional relatedness through identity-by-descent modeling at the population level. We illustrate the performance of the model with a simulation study.