Research into sudden cardiac death has found more than a quarter of unexplained deaths in young people were linked to a previously undiagnosed genetic mutation.
The findings have opened the way for preventive treatment for surviving family members who may have the same condition.
It's been nearly five years since Rob and Sue Poupouare lost their son to sudden cardiac arrest.
"He was just out at his friends'. He was out at a barbeque and they were just talking and laughing and... and he just collapsed."
Elliot was just 17; cheeky, active and healthy.
"It was just a total shock to us," says Mr Poupouare.
For nearly four years it went unexplained. But new research led by Starship paediatric cardiologist, Jon Skinner, discovered he had a genetic mutation.
"We started to find that indeed there were some young people who died suddenly, where the autopsy was negative, no cause found, and yet through genetic testing we were able to make a diagnosis of a familial condition."
Dr Skinner wants genetic testing to be made a compulsory part of sudden death investigation to give more families closure and to detect other family members who may have inherited heart conditions.
"I don't want to see any more sudden deaths," says Dr Skinner. "The fact of the matter is, we've got people out in the community who are at risk of a sudden death."
With funding from Cure Kids and support from the chief coroner, the study looked at sudden cardiac deaths in 1-35 year olds in Australia and New Zealand from 2010 to 2012. It found 40 percent were unexplained.
After testing, 27 percent of these were linked to genetic mutation.
The Poupouares are now undergoing DNA testing to ensure their daughters and grandchildren aren't at risk.
"It's all about prevention, isn't it?" says Mr Poupouare. "If we'd known Elliot had some sort of sign or something that would have caused his death we'd have done everything we could to have prevented that."
"We're still waiting for the results to see if we might have passed that gene down," says Ms Poupouare.
If they discover that's the case, their family can take immediate medical steps to treat it and help avoid more heartbreak.