Global study reveals new key genetic targets linked to glaucoma risk

Researchers were able to identify another 185 previously unknown genes linked to glaucoma risk. Image credit: ©Anusorn - stock.adobe.com

An international research effort on glaucoma, led by Queensland Institute of Medical Research (QIMR) Berghofer, in Brisbane, Queensland, Australia, has linked hundreds of previously-unknown genes to a risk of developing the disease.¹ These findings could be the first step in preventing the retinal damage that causes blindness, QIMR Berghofer said in a statement.²

Previous studies identified over 100 loci for primary open-angle glaucoma, with two key glaucoma-associated traits showing high heritability: intraocular pressure and optic nerve head excavation damage, quantified as the vertical cup-to-disc ratio.¹ But because a large portion of glaucoma heritability is unknown, researchers at QIMR Berghofer undertook the large-scale multitrait genome-wide association study (GWAS). The study population included data from UK Biobank (UKB), Mass General Brigham Biobank, the Canadian Longitudinal Study on Aging (CLSA) and previously-published GWAS.¹  “For genetic data, approximately 488,000 participants were genotyped with more than 800,000 markers,” the researchers noted.¹

The study advanced the understanding of glaucoma by including European ancestry combining primary open-angle glaucoma and its two associated traits to substantially improve genetic discovery power. By building on previous research, researchers were able to identify another 185 previously unknown genes linked to glaucoma risk, bringing the total number to 312 genes.²

Glaucoma, the leading cause of irreversible blindness, affects more than 75 million people globally.¹ Early diagnosis and treatment are imperative since around half of all cases are not diagnosed until after permanent optic nerve damage has occurred.

Professor Stuart MacGregor, head of QIMR Berghofer’s Statistical Genetics Laboratory, served as lead researcher on the study. He said the discoveries “could rapidly advance effective treatment to finally prevent retina and optic nerve damage.”²

“Glaucoma robs your sight by stealth,” Professor MacGregor said in a statement.² “You don’t realise what’s happening until you’ve already suffered permanent damage and loss of vision.” Early detection could drastically change the outcomes for patients who would otherwise suffer permanent vision loss from glaucoma.

The research also revealed new connections between glaucoma risk,diabetes and immune diseases, such as multiple sclerosis. “Some of our drug discovery work suggests that certain existing treatments for other diseases, such as the diabetes drug Metformin, may have potential for use in glaucoma,” Professor MacGregor said.

The full study is available to read in Nature Genetics.

References

1. Han, X., Gharahkhani, P., Hamel, A.R. et al. Large-scale multitrait genome-wide association analyses identify hundreds of glaucoma risk loci. June 29, 2023. Accessed July 10, 2023. Nat Genet (2023); https://doi.org/10.1038/s41588-023-01428-5

2. Genetic discovery could help prevent irreversible blindness in people with glaucoma. News release. QIMR Berghofer, July 3, 2023. Accessed July 10, 2023. https://www.qimrberghofer.edu.au/news/genetic-discovery-could-help-prevent-irreversible-blindness-in-people-with-glaucoma/