Three sets of candidate gene analyses were also undertaken: 204 endophenotype-general candidate genes selected from the neuroSNP data base (Saccone et al., 2009) because they are involved in neural systems or substance-metabolizing pathways that might reasonably be expected to affect one or more of the endophenotypes; 92 genes from the Consortium on the Genetics of Schizophrenia (COGS) that have received considerable support as relevant to schizophrenia endophenotypes (Greenwood et al., 2013), some of which are in the set of endophenotypes we examined as well; and endophenotype-specific genes that were different for each endophenotype. Only two findings emerged as significant, GABRA1 for delta power and GRIK3 for overall startle. GABRA1 encodes for a GABA receptor and has been associated with alcohol misuse (Dick et al., 2006). However, it has not been previously linked to delta power and, in MTFS analyses, it was not associated with alcohol use or misuse (Irons et al., 2014; McGue et al., 2013; Vrieze et al., 2013). GRIK3, one of the COGS genes selected for its relevance to schizophrenia, is involved in the glutamate system. It has
