Image caption The US Supreme Court is being asked to judge whether human genes can be patented

The US Supreme Court has heard arguments questioning whether the human genome can be claimed as intellectual property.

The case relates to a lawsuit filed by the American Civil Liberties Union in 2009, and centres on whether companies should be able to patent genes.

US authorities have been awarding patents on genes to universities and medical companies for almost 30 years.

The case may have far-reaching repercussions for future gene research.

Currently, researchers and private companies work to isolate genes in order to use them in tests for gene-related illnesses, and in emerging gene therapies.

According to researchers at Weill Cornell Medical College in the US, patents now cover some 40% of the human genome.

The ACLU lawsuit, filed in conjunction with the Public Patent Foundation, relates to seven patents on two human genes held by US firm Myriad Genetics.

'Products of ingenuity'

The genes are linked to breast and ovarian cancer, and Myriad has developed a test to look for mutations in these genes that may increase the risk of developing cancer.

The company argues that the genes patented were "isolated" by them, making them products of human ingenuity and therefore patentable.

Analysis Nearly every cell in your body contains a copy of your genetic code - your blueprint for life. But a long-running battle over who owns that information has repeatedly been played out in the courts. The ramifications of any decision by the Supreme Court are uncertain. Would removing the right to patent lead to biotech companies fleeing the field and damage research? Or would it lead to more breakthroughs by allowing anyone to study any part of the genome? One thing is certain: A deeper understanding of how genes affect health is already starting to transform medicine. It is helping to deliver targeted drugs to the right patients as well as tests for cancer risk genes. The status of gene patenting will shape medical research for years to come.

The ACLU rejects this argument, saying that genes are products of nature, and therefore can't be patented under US laws.

Speaking immediately after the hearing, the ACLU's lawyer, Christopher Hansen, said: "Myriad did not invent the human genes at issue in this case, and they should not be allowed to patent them.

"The patent system was designed to encourage innovation, not stifle scientific research and the free exchange of ideas, which is what these patents do."

His co-counsel on the case, Daniel Ravicher, said granting patents on genes was "morally offensive".

"Genes are the foundation of life, they are created by nature, not by man," he said.

In 2010 a New York federal court ruled in favour of the ACLU, but an appeals court has on two separate occasions sided with Myriad.

The Supreme Court rejected the appeal court's conclusions, and is now reconsidering the case.

A ruling from the court is expected in June.

The outcome may have significant repercussions for the multi-billion-dollar US pharmaceuticals industry.

Companies like Myriad argue that without patents, the development of genetic tests and therapies will stall as researchers will not be able to recoup the huge levels of investment needed.

"Countless companies and investors have risked billions of dollars to research and develop scientific advances under the promise of strong patent protection," said Peter Meldrum, the president and chief executive of Myriad.

In statements submitted to the Supreme Court, Myriad said the materials and methods protected by the patents took years to develop.

"This was the product of creative, human ingenuity, resulting in significant new applications for human health that were previously unavailable," it said.