Like any lively six-year-old, Ava Rees loves chocolate.

But she knows more than a small bite at a time could lead to permanent brain damage.

“At Easter, I can’t have chocolate Easter eggs,” the grade 1 student said.

“It could make my brain go silly and make me go to hospital and die.

“It just makes me upset because I can’t have chocolate, milk and lots of other stuff that’s yummy.”

Ava, from Numurkah in the Goulburn Valley, was born with a genetic condition called maple syrup urine disease that is so rare it affects only one in 150,000 children.

She must follow a strict low-protein diet for life: no meat, no dairy, limited gluten.

Ava has been a patient at the Royal Children’s Hospital since she was a newborn, after her disease was detected by a routine heel prick test.

Mrs Rees was told to rush Ava into Shepparton Hospital’s emergency department, from where she was flown to the Royal Children’s in Melbourne.

“The diagnosis was horrible; the first 12 months was horrible,” Mrs Rees said.

“She has to be on a very strict low-protein diet or she can get brain damage.

“Absolute worst case, if she went off diet, she’d be very ill and end up in a coma. So it’s very, very serious, but easily managed.”

From when she was tiny, Ava learned to say, “I can’t have that because it will hurt my brain.”

The name for the disease stems from a symptom – people with maple syrup urine disease can have sweet-smelling urine, similar to maple syrup, when they get ill.

Ava has a weekly finger prick blood test to check her amino acids, and her diet is tweaked accordingly.

But Mrs Rees said after sending the sample to the Royal Children’s, it took a week to get the results.

Mrs Rees hopes the Good Friday Appeal’s expansion of funding to regional hospitals could mean Ava’s blood samples can be tested locally.

“If we can get results the same day, it would mean we could potentially play around with her diet,” she said. “But we can’t risk that now.”