Primary open-angle glaucoma (POAG), is a heritable common cause of blindness world-wide. To identify risk loci, we conduct a large multi-ethnic meta-analysis of genome-wide association studies on a total of 34,179 cases and 349,321 controls, identifying 44 previously unreported risk loci and confirming 83 loci that were previously known. The majority of loci have broadly consistent effects across European, Asian and African ancestries. Cross-ancestry data improve fine-mapping of causal variants for several loci. Integration of multiple lines of genetic evidence support the functional relevance of the identified POAG risk loci and highlight potential contributions of several genes to POAG pathogenesis, including SVEP1, RERE, VCAM1, ZNF638, CLIC5, SLC2A12, YAP1, MXRA5, and SMAD6. Several drug compounds targeting POAG risk genes may be potential glaucoma therapeutic candidates.

Janey Wiggs, Jonathan Haines and colleagues identify three new susceptibility loci for primary open-angle glaucoma. The association signals map near genes implicated in ocular development (FOXC1), neurodegeneration (ATXN2) and mitochondrial function (TXNRD2). Primary open-angle glaucoma (POAG) is a leading cause of blindness worldwide. To identify new susceptibility loci, we performed meta-analysis on genome-wide association study (GWAS) results from eight independent studies from the United States (3,853 cases and 33,480 controls) and investigated the most significantly associated SNPs in two Australian studies (1,252 cases and 2,592 controls), three European studies (875 cases and 4,107 controls) and a Singaporean Chinese study (1,037 cases and 2,543 controls). A meta-analysis of the top SNPs identified three new associated loci: rs35934224[T] in TXNRD2 (odds ratio (OR) = 0.78, P = 4.05 × 10−11) encoding a mitochondrial protein required for redox homeostasis; rs7137828[T] in ATXN2 (OR = 1.17, P = 8.73 × 10−10); and rs2745572[A] upstream of FOXC1 (OR = 1.17, P = 1.76 × 10−10). Using RT-PCR and immunohistochemistry, we show TXNRD2 and ATXN2 expression in retinal ganglion cells and the optic nerve head. These results identify new pathways underlying POAG susceptibility and suggest new targets for preventative therapies.

Tin Aung, Christopher Hammond and colleagues report the results of a large genome-wide association study of intraocular pressure. They identify four new loci associated with this trait and show that three of these loci are associated with risk of primary open-angle glaucoma. Elevated intraocular pressure (IOP) is an important risk factor in developing glaucoma, and variability in IOP might herald glaucomatous development or progression. We report the results of a genome-wide association study meta-analysis of 18 population cohorts from the International Glaucoma Genetics Consortium (IGGC), comprising 35,296 multi-ancestry participants for IOP. We confirm genetic association of known loci for IOP and primary open-angle glaucoma (POAG) and identify four new IOP-associated loci located on chromosome 3q25.31 within the FNDC3B gene (P = 4.19 × 10−8 for rs6445055), two on chromosome 9 (P = 2.80 × 10−11 for rs2472493 near ABCA1 and P = 6.39 × 10−11 for rs8176693 within ABO) and one on chromosome 11p11.2 (best P = 1.04 × 10−11 for rs747782). Separate meta-analyses of 4 independent POAG cohorts, totaling 4,284 cases and 95,560 controls, showed that 3 of these loci for IOP were also associated with POAG.

Jamie Craig, Puya Gharahkhani and colleagues report results of a genome-wide association study of primary open-angle glaucoma. They identify common variants near ABCA1, AFAP1 and GMDS that are associated with risk of this disease. Primary open-angle glaucoma (POAG) is a major cause of irreversible blindness worldwide. We performed a genome-wide association study in an Australian discovery cohort comprising 1,155 cases with advanced POAG and 1,992 controls. We investigated the association of the top SNPs from the discovery stage in two Australian replication cohorts (932 cases and 6,862 controls total) and two US replication cohorts (2,616 cases and 2,634 controls total). Meta-analysis of all cohorts identified three loci newly associated with development of POAG. These loci are located upstream of ABCA1 (rs2472493[G], odds ratio (OR) = 1.31, P = 2.1 × 10−19), within AFAP1 (rs4619890[G], OR = 1.20, P = 7.0 × 10−10) and within GMDS (rs11969985[G], OR = 1.31, P = 7.7 × 10−10). Using RT-PCR and immunolabeling, we show that these genes are expressed within human retina, optic nerve and trabecular meshwork and that ABCA1 and AFAP1 are also expressed in retinal ganglion cells.