Toronto — Women in Ontario who have a high risk of developing breast cancer will soon have access to a new screening test, but it is one that could put the province on a collision course with an American company.

The test involves a gene sequence that has been patented, and Health Minister Tony Clement said Monday the Ontario government will ignore threats of legal action from Utah-based Myriad Genetics, which holds the patent.

The blood-screening process — known as DHPLC — is for those women with a family history of breast or ovarian cancer and who therefore might have a genetic mutation that raises their risk of getting the disease.

Mr. Clement, who called gene patenting "abhorrent," said accepting Myriad's claim would mean more costly tests.

"We do not accept their claim and we are disregarding that claim," said Mr. Clement.

"This is a fight for access for women who might have a predisposition to breast or ovarian cancer."

The tests cost about $1,100 each but Myriad, which also holds gene patents for screening of colon and prostate cancers, wants all tests done at its own laboratory at triple the cost.

A company spokesman said all patent holders in Canada should be "greatly concerned" that Ontario can "selectively" decide to ignore certain patents.

"Myriad has a duty to protect its intellectual property and we will have to take necessary steps to enforce our valid, issued Canadian patents," said Bill Hockett, a company vice-president.

"It could certainly include legal action."

Mr. Hockett called criticism of the fees charged by Myriad "short-sighted," saying the company's testing is cost effective when other factors such as accuracy are factored in.

While several European countries are fighting Myriad in court, the British Columbia government last fall stopped doing tests involving the two genes amid legal concerns about infringing the patents.

Instead, B.C. intends to have about 200 of the tests conducted in Ontario each year.

The federal government has previously washed its hands of the dispute, saying Ontario and Myriad can battle it out in court if they want.

Mr. Clement said the province will fight if the company does sue.

"We will go to the highest court in the land on this."

Dr. Ron Carter, a genetic specialist based in Hamilton, said Myriad wants "a complete monopoly" on any use of the genetic information.

"You have to do the test their way with their equipment at their site and you get their answer."

About 11 per cent of Canadian women who live to the age of 90 will develop breast cancer — with the likelihood increasing further with age. Carrying the genetic defect raises the risk to between 35 and 80 per cent.

About five to 10 per cent of breast cancers are hereditary and more than a thousand Ontario women request genetic screening each year.

Confirmation of the mutation allows for preventative therapies, more intensive screening, earlier diagnosis, or even the removal of still healthy breasts or ovaries.

Ontario will spend $1.2-million on the screening, which is said to be 95 per cent accurate, about 10 per cent better than existing tests.

The screening will be conducted at seven regional hospital laboratories beginning in April, making Ontario the first province in Canada to roll out the testing on such a wide scale.