Yet, rare diseases affect more than two million Australians, including one little Port Macquarie boy, Joshua Marshman.

“We are the forgotten people – the ones that people don’t see.

“We aren’t popular like cancer or heart disease, we are unknown, unsupported, never funded – invisible,” says Joshua’s mum Lynda Gamack.

“We battle daily to keep our children alive ...

“We fall through the cracks in every sense of the word.”

Ms Gamack was hoping today’s designated Rare Disease Day would help raise awareness of the plight of those suffering in silence.

Ten-year-old Joshua is among the 10 per cent of Australians diagnosed with a rare disease.

His debilitating metabolic condition is so rare, and so complex, it is considered a medical mystery.

Labelled as glutaric acidemia type II, Josh’s condition is an inherited disorder which interferes with his body’s ability to break down proteins and fats to produce energy.

Rare diseases are defined as a condition, syndrome or disorder that affects 1 in 10,000 people or less and are either life-threatening or chronically debilitating.

But Josh’s disease is so rare, its likelihood is less than 1 in 100,000, according to doctor Kaustuv Bhattacharya, his genetic metabolic disorders specialist.

Josh’s condition includes a number of underlying problems, likened to many diseases rolled into one.

Dr Bhattacharya said rare disease professionals struggled to secure the funding needed to pursue much needed research for patients like Joshua.

“For some of the more well known conditions there is funding, support and events,” he said.

“But these orphan conditions are not well known and therefore not well funded.”

The low prevalence of each disease means local medical expertise is rare, knowledge is scarce, care offering inadequate, and research limited.

Very few cures exist.

Fighting Joshua’s rare disease is an all encompassing daily battle for his family, said Ms Gamack.

“He is a very sick little boy,” she said.

“The disease effects nearly every organ in his body.”

He spends weekends recuperating from the week at school and even a common cold can leave him violently ill.

“The senior paediatricians and health professionals don’t know what to do with us – they learn from us, but we are never offered new medicines or treatment,” Ms Gamack said.

“We are the unseen.”

Dr Bhattacharya said there was a long way to go to increase awareness of rare diseases.

“Research in these areas is  extremely difficult to get off the ground because investment is limited,” Dr Bhattacharya said.

“We really do rely on charity and collaborations with others around the world.”