BARDEN Ridge parents Michelle and Dean Ramsay felt helpless when their three-year-old daughter Chloe was diagnosed with mitochondrial disease in December 2014.
But they have managed to find a "silver lining", with Dean due to run the Gold Coast Marathon this Sunday to raise money for the Australian Mitochondrial Disease Foundation to help find a cure and spare other parents what they have been through.
Michelle said Chloe had been suffering symptoms for months before she was correctly diagnosed.
"I always knew that something wasn't quite right; she was a lot slower in hitting milestones than other kids," she said.
"The first thing the doctor said was that there was no cure and the disease was fatal. It was surreal, you don't want to believe it; we were just devastated."
Since then they have been taking it day by day.
Chloe is on a high-fat diet and is taking supplements to stop her muscles weakening.
"On the outside she is a happy, cheeky little girl but on the inside she's fighting a battle."
One thing that has helped them get them through is the outpouring of support they have received.
Chloe's preschool Play 'n' Around Early Learning Centre at Illawong held a disco on Friday to raise funds.
Vision Personal Training at Bangor has joined in holding an event for the foundation's annual fundraiser, "stay in bed day".
Dean and Michelle's sister Katie are hoping to raise $5000 for the foundation when they take part in the Gold Coast Marathon.
Michelle said they had raised $3500 already.
"We didn't expect the support — everyone has really jumped on board," she said.
"We're just blown away."