Twins help find genes for blindness

Several studies from the Queensland Institute of Medical Research (QIMR) have found new genes that affect eyesight, all thanks to twins.

In Australia, there are approximately 293,000 blind and visually impaired people.

Dr Stuart MacGregor from QIMR's Genetics and Population Health Division said, "Using data collected from over 1,000 sets of twins, our research has uncovered genes that affect eyesight as part of several conditions. We discovered a new gene for myopia (long or short sightedness), new genes affecting glaucoma risk, and a gene that causes optic nerve hypoplasia – one of the leading causes of blindness in children.

The findings were part of an international study in collaboration with Professor David Mackey's research team from the Centre for Eye Research Australia.

Dr MacGregor said "One of the major causes of glaucoma is decreased cornea thickness. Our research is the first to identify a gene that influences cornea thickness.

"Another risk factor is for glaucoma is intraocular pressure, which is tested in regular eye exams as the puff of air onto the eye. We identified genes that influence the pressure inside the eye.

"This type of work can lead to genetic tests that can analyse the risk of blindness, and help doctors to monitor people who may have a higher risk of conditions such as glaucoma."

Dr MacGregor said twin research provides invaluable information. "Identical twins are nature's clones. Despite having the same genes, the environment can make them very different. Comparing identical and non-identical twins, we can determine how much of who we are is determined by our genes and how much is influenced by environment.

"Our work addresses the question of nature versus nurture. We are helping to understand how small changes in genes can have large impacts on our health.

"Large-scale genetic tests like these can increase our understanding of a range of diseases, and we need lots of twins to participate in these studies.

"The Queensland Twin Registry, QTwin recruits twins, identical and non-identical for studies like this to determine disease risk and many other factors."

(Source: Queensland Institute of Medical Research)