A two-time cancer-surviving grandmother from Brisbane has won her "David and Goliath" battle against a US biotech firm that wanted to patent the BRCA-1 cancer gene.

Myriad Genetics had argued it held the patent over the BRCA-1 and BRCA-2 genes which, if present, dramatically increase a woman's chance of developing breast and ovarian cancer.

But Yvonne D'Arcy, 69, argued the genes existed in nature, so were discovered rather than invented.

The company succeeded twice in the Federal Court, but the High Court overturned those decisions as it ruled unanimously in Ms D'Arcy's favour.

Ms D'Arcy said the High Court challenge had been a "David and Goliath" battle, and said the ruling would make testing for the BRCA-1 gene more accessible.

"I'm only a little person, but it's not the size of the dog in the fight, it's the size of the fight in the dog," she said.

"For all those people who do have the genetic footprint for breast cancer or any cancer basically, it's a win for them because now they're forewarned," she said, speaking from Brisbane.

"The testing will be a lot cheaper and it will be more available ... rather than using only Myriad's agents at a price that nobody really can afford.

"I'm just hoping that other countries will see sense and follow us and the Americans."

Does identification equal invention?

The main legal issue was whether the identification of the gene by Myriad Genetics could be recognised legally as an invention.

At the heart of the case was the concern that ownership of the gene patent could stifle the research and development of treatments for genetic diseases.

Sorry, this video has expired Breast cancer survivor hails High Court win in gene patent case

The court found that while the discovery of the gene was a product of human action, to consider it an invention would stretch the law too far.

The ruling is in line with the US Supreme Court ruling that genes are not inventions, but discoveries.

Myriad Genetics had argued that patents ensured innovation could be commercialised for everyone's benefit.

Before the Australian case, in 2013 the United States Supreme Court also ruled against the patent.

Specifically the US Court ruled that naturally occurring DNA was a product of nature and not patentable.

But the court did recognise synthetic DNA created in a laboratory, known as cDNA, was not a product of nature and could be patented.

Myriad Genetics' lawyers said the law in the US did not reflect the law in Australia and the legal test in the US differed, asking only if the material "is a product of nature".

Invention claimed not within concept of 'manufacture'

In Australia, what is known in legal terminology as "the manufacture test" applies.

This arose from a case in 1959, when the court ruled in favour of patenting a new type of weed killer that did not harm crops, but was made from already known compounds.

Myriad Genetics said the patent applies to a product, an isolated nucleic acid, that is chemically, structurally and functionally different to naturally occurring DNA.

More information on human gene patenting: The BRCA-1 and BRCA-2 genes were isolated and sequenced by researchers at Utah University in Salt Lake City in 1994

The BRCA-1 and BRCA-2 genes were isolated and sequenced by researchers at Utah University in Salt Lake City in 1994 Myriad Genetics was assigned the patents on the isolated sequences and the cDNA variants

Myriad Genetics was assigned the patents on the isolated sequences and the cDNA variants At the time of the US Supreme Court ruling there were concerns about future investment in medical research when patents could be at risk. But there were also claims the ruling could free up research in the area.

At the time of the US Supreme Court ruling there were concerns about future investment in medical research when patents could be at risk. But there were also claims the ruling could free up research in the area. In Australia there have already been calls for the Federal Government to legislate against gene patents.

Myriad said under Australian law the emphasis was on the differences in the structure and function of the genetic material, and not the similarities, as it would be in the US.

The company believed the US ruling supported the Australian patent, as the material in use was isolated from the gene, creating a "non-naturally occurring molecule".

But on Wednesday the High Court ruled that the invention claimed did not fall within the concept of "manufacture".

In a summary of the case, the court found: "While the invention claimed might be, in a formal sense, a product of human action, it was the existence of the information stored in the relevant sequences that was an essential element of the invention as claimed."

But some in the industry questioned the significance of the ruling, saying future patents would not target the same sort of material.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 6 minutes 37 seconds 6 m Australian breast cancer survivor beats huge US firm over BRCA-1 patent bid ( Tracy Bowden )

"Innovation in relation to gene sequences has moved on from claiming those sequences perse, to more in relation to how they can be used," Patent Attorney Grant Shoebridge said.

"Patents in the future or patents which are being drafted now, which relate to gene sequences, will predominantly have claims directed to how those sequences are used.

"This decision does not affect those claims."

Mr Shoebridge said there was also "no evidence to suggest that gene patents stifle research".

"There was a Senate inquiry in relation to that - no evidence whatsoever," he said.

Actress Angelina Jolie drew attention to the BRCA-1 gene in 2013 when she revealed she had a double mastectomy after she learned she carried the gene, which has killed several women in her family.