Moving toward System Genetics through Multiple Trait Analysis in Genome-Wide Association Studies

TLDR

Genotype‑phenotype mapping relies on association studies, yet most genetic epidemiology analyses focus on single traits despite the frequent collection of correlated multiple traits. The paper reviews methods for multiple‑trait analysis in genome‑wide association studies. The review covers traditional multivariate equation models and newer network‑theory‑based graphical approaches.

Abstract

Association studies are a staple of genotype-phenotype mapping studies, whether they are based on single markers, haplotypes, candidate genes, genome-wide genotypes, or whole genome sequences. Although genetic epidemiological studies typically contain data collected on multiple traits which themselves are often correlated, most analyses have been performed on single traits. Here, I review several methods that have been developed to perform multiple trait analysis. These methods range from traditional multivariate models for systems of equations to recently developed graphical approaches based on network theory. The application of network theory to genetics is termed systems genetics and has the potential to address long-standing questions in genetics about complex processes such as coordinate regulation, homeostasis, and pleiotropy.