Deadly heart condition can now be genetically screened

Elka Johansson was born with a big heart. It was inherited from her mother. And it had the potential to kill her.

Diagnosed with dilated cardiomyopathy at six weeks of age, by the time she was 17, Ms Johansson was on the operating table undergoing a heart transplant.

The doctors didn't know if I would make it to my 18th birthday 

Elka Johansson

Just three years earlier, in 2000, the condition had killed her mother Stefka Warbanoff at the painfully young age of 39.

Elka Johansson inherited a potentially fatal heart condition from her mother. Photo: Simon O'Dwyer

"The doctors didn't know if I would make it to my 18th birthday," said Ms Johansson, now 30. "I probably had weeks to months."

Now scientists from the Victor Chang Cardiac Research Institute have identified a genetic mutation behind the deadly heart condition which affects about one in 2000 Australians.

"We've got unique information about this gene, known as TTN, which when there is a mutation results in a shortened titin protein," said cardiologist Diane Fatkin.

Cardiologist Diane Fatkin in the lab. Photo: Victor Chang Cardiac Research Institute

The largest known protein in the human body, titin is a major building block of heart muscles.

"It means that next time someone finds one of these mutations, doctors will be more confident in making a diagnosis," Professor Fatkin said.

Fifteen years in the making, it is a breakthrough which will allow early intervention to prevent the onset of the condition.

Identifying the genetic mutation associated with dilated cardiomyopathy paves the way for the development of a non-invasive diagnostic test. Professor Fatkin, head of the inherited heart diseases laboratory at the Victor Chang Cardiac Research Institute, said this could be as simple as a blood test or cheek swab.

An estimated one in four patients diagnosed with dilated cardiomyopathy carry a genetic clue to their condition in their DNA.

Testing means the condition can now be traced well before symptoms surface, bringing certainty to families who wish to be genetically screened.

For Ms Johansson, her heart transplant means she no longer has the condition she was born with. But there remains a 50 per cent chance that she could pass the condition on if she has children.

She said news that there was now a diagnostic test for the condition would bring peace of mind to people like her who carry the genetic mutation.

"The fear of passing it on is real for people with dilated cardiomyopathy," she said. "Everyone wants a healthy child, so it's really important."

A heart muscle disease, dilated cardiomyopathy is a condition where the heart's main pumping chamber, the left ventricle, is enlarged and weakened. The condition is considered a major risk factor for heart failure, strokes and sudden death.

"The whole reason for doing the genetic research is to enable people at risk to be identified early before they have established disease, so that we can do prevention," Professor Fatkin said.