GABRA2 and alcohol dependence: These trilinear components of the resting EEG have been used in a COGA study to reduce multiple testing of electrodes and frequency bands, where significant linkage/linkage disequilibrium and association was found between a trilinear beta EEG phenotype and GABRA2, a GABAA receptor gene, later found to be also associated with alcoholism (Edenberg et al. 2004; Porjesz et al. 2002a).