Improving early detection and treatment of rare diseases is the focus of a new plan being funded by the federal government.

When Kane Blackman's son started experiencing severe symptoms of an unknown condition, he was told his child was delayed and would eventually catch up.

It was then suggested his son probably had cerebral palsy.

Finally, he was diagnosed with Angelman Syndrome, a rare genetic disease affecting one in 15,000 Australians. It prevents speech, causes seizures, impacts motor co-ordination and requires a lifetime of care.

Not only was the diagnosis a total enigma to Mr Blackman and his wife but also too for the medical fraternity they were dealing with, creating a "diagnostic odyssey" lasting two years.

Mr Blackman, deputy chair of Rare Voices Australia, joined Health Minister Greg Hunt and Labor health spokesman Chris Bowen in Parliament House on Wednesday to launch the nation's first strategic action plan for rare diseases.

The plan will also be given up to $3.3 million by the government over three years to help speed up diagnosis and improve treatment of the illnesses.

Rare diseases affect less than five in every 10,000 people, but there are more than 7000 of them.

They affect about two million Australians today, with half having received at least one incorrect diagnosis. Some 300,000 still have no idea what they are suffering from.

Rare Voices Australia chief executive Nicole Millis says it can be a heartbreaking journey from diagnosis of a rare disease to finding out there is no treatment option.

"For many rare diseases there is no research at all happening, think about how isolating or lonely that makes people feel," she said.

"We don't even measure rare disease in our health system."

On average Australians with rare diseases wait up to four years longer for access to government-funded treatment, in contrast to comparable countries, Ms Millis says.

The rare disease action plan has been developed over ten years to help policymakers better assist the medical community in facilitating more research, more funding for treatment options and clinical trials.

It sets out solutions to help families struggling with diagnosis and highlights the need for better data gathering from hospitals and staff.

Ms Millis says Australia's healthcare system currently does not make the best use of what data is available and does not measure or track rare disease.

Mr Blackman described the government's commitment to the action plan as a beacon of light for the rare disease community.