ON THE outside, seven-month-old Eli Hagar looks just like any other bubbly little boy his age, but his future could depend on the decision of a person he will never meet.
Now his parents are on a mission to raise awareness about his condition and the importance of organ donation.
Elissa and her husband Rodney Hagar both grew up in the Clarence Valley, and moved to Sydney for work about eight years ago.
When their first child entered the world in February, the couple were thrilled.
He was the picture of health when he arrived, but at three weeks he was rushed to hospital in a critical condition.
Doctors soon diagnosed him with cardiomyopathy, which causes the heart muscle to become enlarged, thick, or rigid.
Eli's specific type of cardiomyopathy is called Barth syndrome, which affects fewer than 200 people in the world. He is one of four boys in Australia with the condition, and tragically there is no cure.
Now aged seven months, Eli is fed with a tube at home and receives daily medication to manage his condition.
His weak immune system means the family is usually housebound as they cannot risk falling ill.
"It's a hard because we'd love to be sociable and be normal parents and have Eli interact with other babies, but when he gets sick, he gets really sick," Mrs Hagar said.
"The smallest little thing can set him off, he's really brave and so strong and just keeps pulling through."
While doctors have said there is a chance his condition could improve with medication, Mr and Mrs Hagar are facing the prospect that little Eli will likely need a heart transplant to have a chance at a normal life.
"We try and stay positive and pray that he gets bigger and stronger every day, but it's always there in the back of our minds," Mrs Hagar said.
"We just hope that if we do need to go down that track there will be a heart waiting for us."
Eli's not on the donor list at the moment, but the couple is aware there are very few donors in Australia.
They are hoping to raise awareness of the disease and encourage more people to have a conversation about organ donation, so their son and others can have a fighting chance at life.
"The donor register doesn't matter; at the end of the day the family has to make the call, so have the conversation with those who matter so they know what you want to do," Mrs Hagar said.
"It can save so many lives."