Integrated analysis of proteome-wide and transcriptome-wide association studies identified novel genes and chemicals...

Vertigo is a leading symptom of various peripheral and central vestibular disorders. Although genome-wide association studies (GWASs) have identified multiple risk variants for vertigo, how these risk variants contribute to the risk of vertigo remains unknown. Discovery proteome-wide association study (PWAS) was first performed by integrating the protein quantitative trait loci from the dorsolateral prefrontal cortex (DLPFC) in the Banner Sun Health Research Institute dataset (n = 152) and GWAS summary of vertigo (n = 942 613), followed by replication PWAS using the protein quantitative trait loci from the DLPFC in Religious Orders Study or the Rush Memory and Aging Project dataset (n = 376). Transcriptome-wide association studies (TWASs) were then performed by integrating the same GWAS datasets of vertigo (n = 942 613) with mRNA expression reference from human fetal brain, and DLPFC. Chemical-related gene set enrichment analysis (GSEA) and Gene ontology/Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were finally conducted to further reveal the pathogenesis of vertigo. Permutation-based empirical P values were calculated in PWAS, TWAS, and GSEA. By integrating the GWAS of vertigo and two independent brain proteomes from human DLPFC, three genes were identified to genetically regulate protein abundance levels in vertigo, and were not previously implicated by GWAS, including MTERFD2 (P _Banner = 0.045, P _ROSMAP = 0.031), MGST1 (P _Banner = 0.014, P _ROSMAP = 0.018), and RAB3B (P _Banner = 0.045, P _ROSMAP = 0.035). Compared with TWAS results, we identified overlapping genes RAB3B (P _TWAS = 0.017) and MTERFD2 (P _TWAS = 0.003) that showed significant associations with vertigo at both proteome-wide and transcriptome-wide levels. Chemical-related GSEA identified multiple chemicals that might be associated with vertigo, such as nickel (P = 0.007), glycidamide (P = 0.005), and proanthocyanidins (P = 0.015). Our study provides novel clues for understanding the biological mechanism of vertigo, and highlights several possible risks and therapeutic chemicals for vertigo.