Genome-wide studies account for small percentage of POAG genetic risk factors

This literature review found that while genome-wide association studies have been a valuable tool in the hunt for genetic risk factors for primary open-angle glaucoma (POAG), the identified loci, including high-penetrance genes found in family studies, still account for less than 10 percent of POAG.

The authors reviewed findings from genome-wide association studies for POAG and found that the CDKN2B-AS1 locus on chromosome 9 is undoubtedly a major genetic risk factor for glaucoma. This locus, as well as the SIX1/SIX6 locus, were identified through analysis of vertical cup-to-disc ratio in normal populations and have since demonstrated a reproducible association with POAG itself. The CAV1/CAV2 locus is also reproducibly associated, although the effect size is small in most Caucasian populations investigated to date.

They conclude that further loci remain to be identified. This will likely be achieved through a variety of methodologies including genome-wide studies and more traditional family-based studies.