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A new study led by QIMR Berghofer Medical Research Institute and Harvard Medical School has significantly increased understanding of the genetics of glaucoma, identifying 44 previously unknown genes linked to a person’s risk of developing the degenerative eye disease.
The findings of the large, international study take the total number of genes now known to increase a person’s glaucoma risk to 127. The research also shows that most of the genes are shared across different ethnic ancestry groups.
The findings have been published in the journal ‘Nature Communications’. “Glaucoma causes a progressive degeneration of the optic nerve. It is the leading cause of irreversible blindness globally, affecting more than 75 million people,” read the study on Thursday.
The head of QIMR Berghofer’s Statistical Genetics group and co-senior researcher on the study, Professor Stuart MacGregor, said the 44 identified risk genes uncover new biological processes, such as immune function, associated with glaucoma.
“Glaucoma is one of the most strongly genetic human diseases, which is why we are looking at the genetic architecture of the disease to find clues on how to prevent and treat it,” Professor MacGregor said.
“We’re hopeful that understanding the biological processes and knowing which genes control them could help scientists develop new drugs in the future,” MacGregor said.
Lead researcher Associate Professor Puya Gharahkhani, from QIMR Berghofer’s Statistical Genetics group, said they examined data from more than 34,000 people across five continents and compared it to genetic information from almost 350,000 people without glaucoma.
“Glaucoma rates are highest in people of African and Asian ancestry, but the largest genetic studies of glaucoma in the past have focused on people of European ancestry,” Associate Professor Gharahkhani said.
“Those studies showed genetic tests could be used to help identify who would benefit from sight-saving early monitoring or treatment, but because of the narrow scope of the genetic data, we weren’t sure until now that the genetic indicators applied to people of different ancestries.
“By combining data from around the globe, our study suggests genetic tests could work well across a wide range of ancestries to identify people at risk of glaucoma.”
Co-senior author and Professor of Ophthalmology at Harvard Medical School, Janey Wiggs, said there are currently no treatments to prevent glaucoma.
“More than 50 per cent of glaucoma cases are not diagnosed until irreversible optic nerve damage has occurred,” Professor Wiggs, who is also Associate Chief of Ophthalmology Clinical Research at Massachusetts Eye and Ear, said.
“Available drugs can only slow disease progression during the early stages, so identifying improved means by which we can diagnose the disease earlier is an exciting development – especially since we now know this would be effective globally.” Professor MacGregor said the researchers hoped to build on the study to identify even more genes associated with glaucoma.