Glaucoma genes sighted

5 April 2016

Published in Nature Genetics: A major genome-wide association study has identified five previously-unknown genetic areas or 'loci' associated with an increased risk of developing primary angle closure glaucoma (PACG).

The study involved 229 scientists from 25 countries, including Australia, which highlights the size and global reach of these kind of studies.

While less common than open angle glaucoma, PACG disease is a major cause of blindness affecting an estimated 15 million people worldwide. Of these, around 80% live in Asia.

And as is the case for the other two forms of glaucoma - open angle glaucoma and exfoliation glaucoma - the disease clusters among related people suggesting a strong genetic component.

Expanding a previous smaller study, the researchers used DNA from more than 40,000 individuals from 24 countries across Asia, Australia, Europe, North America, and South America.

Their research confirmed three loci previously reported in the smaller study, and they found five new loci that were associated with an increased risk of developing PACG.

Through the analysis of these genes, the researchers were able to implicate a number of biochemical pathways in the development the disease. Their further investigation could lead to a better understanding of the mechanisms that underlie PACG.

However, the authors also write that the now eight identified loci can only explain a small fraction of the genetic component that leads to disease. This is not unusual for a complex disease.

For example, a recent analysis of the genetic basis of rheumatoid arthritis increased the number of potential genetic loci that play a role in developing the condition to 101.

Four universities from Australia were involved in the glaucoma study: The University of Sydney, the University of Melbourne, Flinders University and the University of Tasmania.