For a study, researchers sought to uncover genetic variations linked to pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG) in unrelated individuals and to learn more about the genetic and potentially causative links between PDS and risk factors.

There were 574 instances of PG or PDS and 52,627 European-descent controls. Genome-wide association studies were done in four cohorts and meta-analyzed in three stages: a discovery meta-analysis in three cohorts, replication in the fourth cohort, and meta-analysis of all four cohorts to boost statistical power. To examine if refractive error and intraocular pressure had a causal influence on PDS, two-sample Mendelian randomization was performed. The relationship between genetic variations and PDS, as well as whether myopia has a causal influence on PDS.

There was a significant relationship for PDS/PG at two new loci. These locations and subsequent studies suggest the genes gamma-secretase activator protein (GSAP) (lead SNP: rs9641220, P = 6.0×10-10) and glutamate metabotropic receptor 5 (GRM5)/TYR (lead SNP: rs661177, P = 3.9×10-9) as key illness risk factors. Mendelian randomization revealed that negative refractive error (myopia) directly influenced PDS (P = 8.86×10-7). 

SNPs in the GSAP and GRM5/TYR genes have been linked to the development of PDS and PG. Even though myopia is an established risk factor, this study analyzes genetic data to show that myopia is a cause of PDS and PG in part.