Their son Charlie, who turned two last month, has a condition known as a STAT1 loss of function mutation and has spent much of his young life undergoing medical treatment.

Things are looking up for the toddler, who will on Sunday celebrate 200 days since undergoing a bone marrow transplant.

But his new sister, who is due to arrive in June or July, has been diagnosed with the same genetic condition.

Mrs Ciavarella said like Charlie, their daughter would have to be isolated as she fights the immunodeficiency disorder.

Doctors initially thought only 10 people worldwide had been diagnosed with the rare illness. 

But the family later received a letter from geneticists stating there were only three known cases. 

According to Mrs Ciavarella, the other two diagnosed babies did not survive.

“We know what we’re going to be up against,” she said of the new arrival.

“We’ve done testing and unfortunately it’s come back to say, against all odds, unfortunately she has the same condition as Charlie.

“The doctors are pretty surprised.”

The first few months of Charlie’s life were spent in limbo as doctors struggled to diagnose his illness.

His condition has required frequent operations, hospital stays in Melbourne and blood tests, but the two-year-old has stayed upbeat throughout the ordeal.

Fortunately, his new sibling already has a bone marrow transplant booked in for October if a suitable donor can be found.

The diagnosis will give the family a head start as they again prepare to battle the illness with their new baby.  

“We know what we’re up against,” Mrs Ciavarella said.

“We don’t have that extra year of waiting.

“We know what to do this time.”

Mrs Ciavarella said the news was as surprising as it was difficult.

“It will definitely impact on how we live our lives over the next few years, for sure,” she said.

But if the support shown to the couple over the past few years is anything to go by, the battle will not be fought alone.

People in their home town of Oxley have found their story so moving that strangers have come up to them in the street and asked how Charlie has been faring.

Friends and family have volunteered their time at their winery and a fundraiser has helped the couple keep their heads above water.

They have frequently travelled to Melbourne for Charlie’s treatment, battling the financial stresses of taking time off work as well as the obvious emotional strain of their situation.

Mrs Ciavarella said Charlie was slowly having his medication reduced as he continues his slow recovery, one step at a time.

“Our focus is getting Charlie back on track and then focusing on this baby,” she said.

“We really appreciate the support and offers of help from the community.

“We haven’t yet been able to discuss what we’re going to do in the future.

“It may involve selling our house and moving closer to treatment.

“It’s all up in the air.

“We feel we couldn’t ask the community for any more and we’re extremely grateful for the help we’ve had so far.”

Mr Ciavarella said the staff at the Royal Children’s Hospital had also been “tremendously supportive”.

“It’s a remarkable hospital,” he said.

“I can’t speak highly enough of them.

“There are networks of support there, everything from music therapists through to play therapists who just help keep the sanity and help people get through the day.”

Charlie’s recovery has also been affected by graft-versus-host disease, which is itself a rare condition.

The medical complication, in basic terms, occurs when transplanted cells attack the host body’s cells.

It has the potential to cause numerous problems, but Charlie appears to have recovered well from the scare.

Mr Ciavarella said life for the young family was slowly starting to return to normal.

“The doctors have reduced his treatment,” he said.

“It’s going to once every two weeks, and after next week it will be once every three weeks.

“We’ve been lucky to be get home a bit more but we’re still keeping him isolated.

“He’s always been full of beans and happy.

“He’s had times where he has felt pretty ill but on the whole he has maintained a really upbeat, happy and resilient sort of attitude.”

While transplant recipients often celebrate the 100 day mark since their operation, the 200 day mark is more symbolic to the Ciavarellas. 

His parents’ long term hope is he will grow up to live a long, normal and healthy life that is free from the need for constant medical treatment. 

“He just turned turned two last month,” Mrs Ciavarella said.

“To him, it’s much more natural to associate and play with doctors and nurses than it is with children.