Landmark legal action challenging a patent over breast cancer gene BRCA1 is being launched in Australia today.

The Australian action follows a lawsuit in the United States against patent holder Myriad Genetics.

Both the US and Australian legal cases are attempting to remove patents from human genes altogether.

The lawyers are trying to prove that patents should not have been awarded over human genes because they say these genes occur in nature, and therefore are a discovery, not an invention.

In March, the Federal District Court in New York ruled that patents should not have been granted to Myriad Genetics on two human genes, BRCA1 and 2.

Melbourne-based company Genetic Technologies Limited (GTL) has the exclusive licence from Myriad to do the BRCA1 and 2 testing in Australia. The tests show whether a woman is more susceptible to developing breast and ovarian cancer.

The action being launched in Australia's Federal Court today aims to deem GTL's monopoly on the gene mutation invalid.

The case is being brought against four biotech companies, including GTL and Myriad, by law firm Maurice Blackburn, national consumer group Cancer Voices and Yvonne D'Arcy, a Brisbane woman with breast cancer.

Lawyer Rebecca Gilsenan says there are many dangers to having a monopoly on this patent.

"There's a philosophical and ethical issue about commercialising the human body and its genetic material," she said.

"Beyond that though, there's a practical concern and that is that the patent owner has a right to prevent people from studying and testing for the gene mutation.

"Gene patents can have the effect that they stifle research, they can stifle the development of treatments that researchers might otherwise develop and they can impede access to diagnostic testing for that gene mutation."

Ms Gilsenan says GTL's monopoly could lead to Australian women paying significant sums of money to test for BRCA1 and 2, which are responsible for up to 10 per cent of cases of breast cancer.

"The patent owner has the right to be the exclusive tester, if you like, and therefore it can drive up the cost, it can create delays," Ms Gilsenan said.

"It means there's no competition and therefore nobody could develop an improved test so there's all sorts of consequences - mainly cost and quality."

In the US, Myriad Genetics charges women about $3,700 to test for BRCA1 and 2, and the company does not allow second opinions.

In Australia, GTL has "gifted" its intellectual property rights to institutions and does not impose royalties.

But in 2003 and 2008, GTL sent legal letters to Westmead Hospital and the Peter MacCallum Cancer Institute in Victoria, telling them to stop testing for the BRCA1 and 2 genes.

GTL withdrew the threat after a public outcry, but the situation remains uncertain for medical researchers.

Patent law expert at the Australian National University, Dr Luigi Palombi, says the court action being launched today is extremely significant.

"It is important because for the first time in Australian legal history, the Australian courts are going to rule on whether an isolated biological material, such as the human gene which has been removed from the human body, is an invention," he said.

"For the last 20-odd years the Australian patent office [IP Australia] has been granting patents on all manner of genes and biological material such as plants, plant genes, viral genes - all manner of biological material.

"Having patents over what really amounts to raw fundamental data prevents others from using those materials in new and useful and inventive ways.

"It will mean a message will go out to the patent office immediately that it can no longer continue to pursue a policy that's led to the grants of these kind of patents. It will force biotechnology companies to start innovating in different ways."

At least 20 per cent of human genes are patented in Australia, and the outcome of this legal action is likely to have implications for other genetic patents.