His parents Rodney and Hayley had noticed their usually energetic little boy was lethargic, in constant pain and grey in colour.

Xavier spent about three weeks in and out of Warrnambool Base Hospital in 2018 with what was first diagnosed as a viral infection.

"But we knew there was something else - it was just parent instinct," Mrs Grant said.

When Xavier underwent a sonogram - an ultrasound of his arteries - his paediatrician Christian Fiedler told the Grants they were going to Melbourne.

They said they'd drive there the next day but Dr Fielder said "no, you're going by plane right now".

Xavier was airlifted to Royal Children's Hospital (RCH) where he was later diagnosed with Kawasaki disease, a rare heart condition after an abnormal immune response to a common germ.

That led to a further diagnosis of coronary heart disease.

"I remember a doctor looked at me and said 'I'm afraid from now your lives are going to change'," Mr Grant said.

Accepting their new fate the Grants returned home to Warrnambool, armed with medication Xavier needed injecting twice a day, every day.

Mrs Grant grew up with a needle phobia - a fear she quickly overcame.

She said they managed to get through the next few years, including the COVID-19 pandemic which caused them significant distress due to Xavier's illness.

"But we kept him in our own bubble... he was tracking really, really well," Mrs Grant said.

That was until October 2023 when Xavier's health declined.

"Our world changed in literally three days," Mrs Grant said.

Xavier didn't present as sick but RCH paediatric cardiologist Lucas Eastaugh found "some deterioration" in a CT scan.

The doctor told the Grants to go home and that he would circle back after he spoke with his team, which included an expert in the USA.

Three days later Xavier was waiting for a date for open heart surgery.

From there it was a waiting game with multiple delayed surgeries and the Grants trying their best to support Xavier and his older sister Sienna.

But finally the day came and on January 24, 2024, Xavier's surgery was a success and the Grants returned home with their "supercharged" son.

"We were told he'd be lethargic but he was just eating and running and playing like normal," Mr Grant said.

"That lasted for four days".

Xavier had a mass of fluid on his left lung.

He was again flown to RCH where he was expected to undergo a routine 40-minute drainage procedure.

But he went into cardiac arrest and the surgeons had to perform CPR.

"Hayley started hyperventilating (when we found out) and I just went blank," Mr Grant said.

He said their son was revived but it was found he also had fluid on his heart.

"We said 'just do what you've got to do'," Mrs Grant said.

"Just get our cheeky boy back."

The following 90 minutes was "brutal" but Xavier survived.

He remained in hospital for more than two weeks, including on his sixth birthday.

"Now we're back home and just taking each day as it comes," Mrs Grant said.

The family spoke to The Standard ahead of the Good Friday Appeal, which has raised funds for the RCH for 93 years.

"I honestly believe we wouldn't be in the position we are in with Xavier, especially being from a country community, if that hospital was not there," Mrs Grant said.

"It's hard to articulate without getting emotional but it is just absolutely amazing."

The Grants urged the community to dig deep for the appeal and thanked everyone at the RCH - from the surgeons and doctors to the cooks, cleaners and support people.

You can donate to the Good Friday Appeal online here.