Cystic fibrosis (CF) patients and their families are celebrating after the Federal Government listed a drug on the Pharmaceutical Benefits Scheme (PBS) that will help treat some people with the genetic disease.

Health Minister Peter Dutton said the Government has approved the listing of ivacaftor, the first medicine to treat the underlying cause of CF in patients with a specific gene mutation.

It will be available from December for patients aged six and over with the G551F gene mutation and will be marketed as Kalydeco.

Cystic fibrosis is the most common life-threatening genetic condition affecting young people in Australia.

It affects the lungs and digestive system, with patients struggling to breathe because of mucus clogging their lungs. There is currently no cure.

"With this new treatment many patients can experience an improved quality of life with reductions in respiratory and gastrointestinal complications, improved lung function and fewer hospitalisations," Mr Dutton said.

Cystic Fibrosis Australia chief executive Michelle Skinner told ABC News 24 the drug significantly reduces the symptoms of CF.

"The medications that [patients] take are significantly reduced," she said.

"[The result is] less time having quite invasive treatments, less hospitalisations and a much, much better quality of life for children and adults with CF."

The CF gene was first discovered in 1989 and medical experts consider ivacaftor to be the most important development in the treatment of the disease since.

The Government has approved $174.5 million over the next four years to fund ivacaftor on the PBS.

Without the Government subsidy, about 200 Australian families would be looking at costs of more than $250,000 a year to use the treatment, according to the Cystic Fibrosis Australia.