Several small independent studies have reported evidence for association of single DISC1 single-nucleotide polymorphisms (SNPs) (coding and non-coding) or haplotypes with SZ, BD, rMDD and other neuropsychiatric traits, including autism spectrum disorder, cognition, normative cognitive ageing, anxiety and structural and functional brain imaging phenotypes.9, 12, 13 Rare amino-acid substitution variants in DISC1 have been reported in cases of SZ,10, 11 BD,14 rMDD,13 autism spectrum disorder15 and agenesis of the corpus callosum,16 as has an increased burden of rare missense variants in exon 11 of DISC1 for schizoaffective disorder,17 and for DISC1 pathway genes in SZ.10 In contrast, a meta-analysis of all known common variants within the DISC locus, from a total of 11 626 cases and 15 237 controls that involved the testing of 1241 SNPs, found no evidence that common variants at the DISC locus are significantly associated with SZ.18 Moreover, the DISC1 locus has not reached genome-wide significance in large-scale meta-analyses of linkage studies of SZ,19 nor have its common variants in large-scale genome-wide association studies of SZ, BD or rMDD.20, 21, 22 A recent exon-based study that
