LEGIT - Latent Environmental & Genetic InTeraction (LEGIT) Model
Constructs genotype x environment interaction (GxE) models
where G is a weighted sum of genetic variants (genetic score)
and E is a weighted sum of environments (environmental score)
using the alternating optimization algorithm by
Jolicoeur-Martineau et al. (2017) <arXiv:1703.08111>. This
approach has greatly enhanced predictive power over traditional
GxE models which include only a single genetic variant and a
single environmental exposure. Although this approach was
originally made for GxE modelling, it is flexible and does not
require the use of genetic and environmental variables. It can
also handle more than 2 latent variables (rather than just G
and E) and 3-way interactions or more. The LEGIT model produces
highly interpretable results and is very parameter-efficient
thus it can even be used with small sample sizes (n < 250).
Tools to determine the type of interaction (vantage
sensitivity, diathesis-stress or differential susceptibility),
with any number of genetic variants or environments, are
available <arXiv:1712.04058>. The software can now produce
mixed-effects LEGIT models through the lme4 package.
