Genetic testing for all? As Australia weighs preventive DNA checks, should NZ follow its lead?
In Australia, a group of experts is pushing for nationwide preventive gene testing. Image / Getty Images
Would you want to be screened for genes that indicate a higher risk of you developing a serious health problem such as cancer or heart disease? At the moment, publicly funded genetic testing is available only to people with a family history of certain conditions. The other option, going with a private company such as i-screen for a comprehensive DNA profile, comes with a price tag.
In Australia, a group of experts is pushing for nationwide preventive gene testing. Researchers at Monash University are working to develop a programme that would be available through the public health system.
Their recently completed pilot study, DNA Screen, offered free genomic testing to 10,000 Australians aged 18-40. A saliva swab test checked for 10 medically actionable genes linked to hereditary breast and ovarian cancer, Lynch syndrome (which ups the risk of developing cancer, particularly bowel, at a young age) and familial hypocholesterolaemia, which increases the chance of early cardiovascular disease.
Of the 165 participants identified as carrying a high-risk genetic variant, 133 weren’t aware of any family history of the disease. “If they had gone to a doctor, they wouldn’t have qualified for genetic testing,” says public health researcher Jane Tiller.
Among the group was a woman in her 20s, Zoe, who had lost her mother to breast cancer but had been told she was too young for breast screening and not eligible for gene testing. Enrolling in the DNA Screen programme, she discovered she had a high-risk BRCA2 gene variant.
“As a result she had an MRI and discovered she had stage 2 breast cancer,” says Tiller. “She had no symptoms and it wouldn’t have been caught at such an early stage if she hadn’t had the genetic test. Zoe will have a double mastectomy and survive this cancer. We don’t know what would have happened if not for our study but it’s very likely she would have had a much worse outcome.”
It’s believed one in 50 Australians are carrying a high-risk genetic variant, and identifying them would save money as well as lives. Tiller hopes to scale up the DNA Screen programme, testing 100,000 people this time, to get a clearer idea of how it could be taken nationwide.
There are still several issues to work through. One key point is that people found to have these 10 medically actionable, high-risk genes will need genetic counselling along with further tests and possible treatment. The health system will need to be ready to respond.
“That takes resources and has costs,” says Tiller. “If you are found to have Lynch syndrome you will require a yearly colonoscopy, but the chances of you developing bowel cancer are small, and if you do, it will be found at an early stage.
“The difference in cost between that and treating someone for stage 4 bowel cancer is significant.