and rs11783093 (Figure 3). CHRNA2 expression was predicted with a valid model in two other brain tissues showing nominal significant under-expression in cases compared to controls (dorsolateral prefrontal cortex, P=5.19x10−4; cerebellar hemisphere P=5.30x10−3). That the risk locus for CUD can be linked to CHRNA2 expression is also supported by Won et al.26 who generated high-resolution 3D maps of chromatin contacts (by Hi-C sequencing approach) to capture functional relationships between regulatory and transcribed elements during human corticogenesis. They applied their map to a set of credible SNPs from the large PGC schizophrenia GWAS19 and found physical interaction of the genome-wide significant risk locus on chromosome 8 with the regulatory region of CHRNA2.
