To explore further the functional role of the GWS variants identified, we tested association of these loci with gene expression (cis-eQTL: variants located ±1Mb from the transcription site start of the gene tested) considering the 13 tissues related to the central nervous system (CNS) available in GTEx V77. After applying a FDR 5% correction accounting for the number of variants, genes, and tissues tested, we observed 257 significant eQTLs (of 2,514 tests) conducted with respect to the GWS loci observed in the EUR samples (Supplemental Table 6). The eight GWS variants observed in EUR are associated with the expression of 52 genes, of which 27 are protein-coding. However, most of the eQTLs relate to two variants: rs2532252 on chromosome 17 is associated with the expression of 30 different genes; rs2777888 on chromosome 3 is associated with the expression of 14 different genes. Figure 3 shows the strength of the eQTLs identified with respect to protein-coding genes across the 13 brain tissues investigated. Due to the strong LD with the loci identified in the EUR analysis, similar eQTL results were observed with respect to the variants identified in the trans-ancestry meta-analysis.
