expression and the predicted exon expression was interpreted as being due to an alternative splicing (14). Next, we tested the correlation between rs12442183 genotype and the expression of RGMA transcript variants. We downloaded rs12442183 genotype information from BRAINEAC (15) and reprocessed its corresponding microarray data from GEO (Gene Expression Omnibus) (16) (accession No. GSE60863) (17) with R package ESLiMc. GSE60863 is comprised of 1231 samples originating from 10 brain tissues (occipital cortex, frontal cortex, temporal cortex, hippocampus, intralobular white matter, cerebellar cortex, thalamus, putamen, substantia nigra, and medulla (inferior olivary nucleus)) derived from 134 healthy human brains from UK Biobank (17). These brain samples were confirmed to be free of neurodegenerative disorders and assayed by Affymetrix Human Exon 1.0 ST array. We also used PExFIns (18), an expression quantitative locus (eQTL) analysis software package, to test the association of rs12442183 genotype with RGMA mRNA expression in 423 lymphoblastoid cell lines (LCLs) across 6 global populations, including 73 CEU (Utah residents with northern and western European ancestry), 77 CHB (Han Chinese in Beijing, China), 72 JPT (Japanese in Tokyo, Japan), 80 LWK (Luhya in Webuye, Kenya), 42 MEX (Mexican ancestry in Los Angeles) and 79 YRI (Yoruba in Ibadan, Nigeria).
