Dr. Grossman’s Blog

In glaucoma, cells in the optic nerve die, preventing the brain from understanding what patients see.

Scientists have long believed that there is a link between a gene named WDR36 and glaucoma, but have been unable to determine what the gene does and why some people with variations of the gene get glaucoma while others don’t.

University of Alberta geneticist, Dr. Michael Walter, has published results of a new study which help to explain this link. 

“Our results suggest that glaucoma is polygenetic, which means there have to be changes in several different genes in order for WDR36 to cause the disease,” said Walter, a professor and chair of the Department of Medical Genetics in the Faculty of Medicine & Dentistry.  This finding helps explain why only some people who have WDR36 gene variations get glaucoma.

“Only 10 per cent of glaucoma cases are caused by known genes, so the genes involved in this polygenetic interaction may help to explain the other 90 per cent,” said Walter, who is also a professor in the Department of Ophthalmology.

The WDR36 gene normally helps make ribosomes, specialized molecules that make the proteins necessary to keep the cell functioning.  Dr. Walter suspects that changes to WDR36 will affect ribosome production, and in turn affect the cell’s ability to function.

In addition to this mutation, changes also have to happen to the STI1 gene, which normally packages the proteins produced by WDR36′s ribosomes.  Glaucoma occurs when WDR36 isn’t producing ribosomes properly and STI1 isn’t packaging those proteins properly.  Both mutations must be present to cause the disease.

This DNA detective work may have a tangible impact on preventing and treating glaucoma, as it may help doctors learn to treat the disease rather than just the symptoms.

Learn more about glaucoma

SOURCE:  “Genetic Sleuth Solves Glaucoma Mystery”, University of Alberta Express News, March 20, 2009, http://www.expressnews.ualberta.ca/article.cfm?id=10052.