While researching the long-suspected gene linked to glaucoma, WDR36, Michael Walter, PhD, and team discovered that the gene STL1 is only one of many other genes in which mutations must take place in order for WDR36 to cause glaucoma.

To obtain these results, the investigators researched a yeast gene similar to WDR36 that is much easier to experiment with. They introduced the suspected WDR3g variation into the yeast gene and tested its ability to function and discovered that WDR36 wasn't working alone.

"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 Dr Walter, professor and chairman, Department of Medical Genetics, professor, Department of Ophthalmology, Medicine & Dentistry, University of Alberta.

This explains why only some people who have WDR36 gene variations get glaucoma. This also may lead to further research to uncover the other genetic accomplices.

"Only 10% of glaucoma cases are caused by known genes, so the genes involved in this polygenetic interaction may help to explain the other 90%," Dr Walter said.