Baby Wil has the will to survive:

After countless health scares and near-misses, this one-year-old boy has defied expectations and is finally going home.

Wil was born with two rare medical conditions which have forced him to spend all but a few weeks of his life in the Melbourne hospital.

He was born by emergency caesarean after a routine ultrasound at 31 weeks detected foetal hydrops.

This is a serious condition where a build-up of fluid in the heart and lungs needs to be drained immediately to prevent further complications.

Soon after, a mystery lung problem required a biopsy which revealed pulmonary interstitial glycogenosis, a condition so rare that only a handful of cases have been reported worldwide.

Infants with pulmonary interstitial glycogenosis have unexplained rapid and laboured breathing.

Even now he's out of hospital, Wil has to have an oxygen tank nearby at all times.

David Armstrong, director of Monash Children's pediatric respiratory medicine, said while Wil had to undergo further treatment, he was confident that he would live a normal life.

"His outlook is excellent. He will still have to visit the hospital every month for an IV treatment, but I'm confident that Wil will have a normal life expectancy," Dr Armstrong said.

What makes Wil's homecoming more remarkable is that only two months ago he was fighting for his life in pediatric palliative care.

"It's always difficult treating a rare disease, but since Wil has begun undergoing treatment we have seen an astonishing turnaround in his fortunes," Dr Armstrong said.

His homecoming is the latest milestone in his recovery, after his first birthday in June and bulking up to 5kg.

For the first time, Melissa Schneider is finally able to relax about her son's future, though she is unsure what she'll do with her newfound free time.

"I really don't know what I am going to do.

"I just look forward to being able to relax and finally have everyone at home."