To better understand the underlying genetic mechanisms of AD in NAc, we integrated expression data with previously collected genotypic data to identify eQTLs affecting the expression of hub mRNA and miRNA genes. Only cis-eQTLs (defined within 1 megabases) were considered in our analysis, as our study was underpowered to identify trans-eQTLs. Five hundred and ninety-one significant mRNA hub cis-eQTLs were identified (FDR≤ 0.10). In some cases, a single gene was associated with multiple eQTLs. Thus, the total number of mRNAs for which eQTLs were detected was 383. The full list of the identified mRNA eQTLs is given in S8 Table. The most significant mRNA cis-eQTL signal we detected was for glutamate decarboxylase (GAD1; p = 5.5x10-7), the rate-limiting enzyme in gamma-aminobutyric acid (GABA) biosynthesis (Fig 5). Interestingly, variants in the GAD1 gene have been previously associated with AD in Han Taiwanese men [55].
