majority of known environmental factors have been found to have a heritable component – and these genetic underpinnings, when shared with the outcome of interest, may represent gene-environment correlations (rGE) (Plomin et al., 1977; Rutter et al., 2006; Scarr and McCartney, 1983).When not controlled for, these correlations can produce spurious GxE effects. In the context of gene-finding efforts, controls for rGE will be necessary prior to examining GxE. This may be accomplished by isolating those genes that jointly influence risk for AD and increase likelihood of early initiation of alcohol use.
