Purpose: Genome-wide association studies (GWAS) have revealed plenty of putative loci of ocular disorders, and the relationship among ocular disorders manifesting vision loss has been widely studied. However, genetic pleiotropy correlations remain unknown in eye diseases.
Methods: The GWAS summary statistics of age-related macular disorder (AMD), cataract and glaucoma were leveraged to dissect the genetic pleiotropy from three aspects: genomic pleiotropy, regional pleiotropy and variant-level pleiotropy. A meta-analysis using three approaches was performed. Cell types related to disease risk were unveiled using retina and anterior chamber angle single cell RNA (scRNA) seq profiles and retina single cell ATAC (scATAC) seq data. Causal pleiotropic genes of the above three diseases were prioritized base on the colocalization between retina-specific/cell-type-specific annotations and credible sets. In addition, we assessed the protein-protein network of candidate causal genes as well as the druggability.
Results: Genetic correlations were corroborated and eleven pleiotropic regions were identified between the pairs of AMD, cataract and glaucoma. Ten pleiotropic loci were jointly identified, including three pleiotropic loci intersecting with retina-specific eQTL SNPs and enhancer regions as well as six pleiotropic loci resided in HiChIP loops or cell-type-specific peaks. Six loci were replicated using the Finggen GWAS data of corresponding diseases. Muller cell, astrocyte, vascular endothelium and fibroblast were identified in cell-type trait association analysis. Through the strategy we have formulated, thirty genes causally associated with three traits were prioritized, which enriched in the pathways of nerve development and cell communication.
Conclusions: The genetic pleiotropy of AMD, cataract and glaucoma was detailedly characterized in our study which provides potential drug targets for ocular disorders.