The legal question at the heart of the US Supreme Court’s debate over the patenting of human genes has practical ramifications that could ripple into the lives of every American -- not just women at risk for rare breast cancer.

Dorothy Warburton, Ph.D./Newscom BRCA 2 (breast cancer) gene on chromosome 13.

What the high court decides could affect who will conduct your medical tests, how those tests are interpreted, how and how fast drugs can be developed -- and what your doctor can tell you about your health, experts say.

That’s because all of those issues are entangled in the case involving a Utah company, Myriad Genetics, which controls the patents on variations of two human genes, known as BRCA1 and BRCA2. Women with mutations in those genes are at much higher risk for getting breast and ovarian cancer.

“This is important,” says patent expert Arti Rai, the Elvin R. Latty professor of law at Duke University School of Law, and an affiliate of Duke’s Institute for Genome Sciences and Policy. If the court rules against Myriad, “this may make it easier for you to get second opinions,” about diagnostic tests, she said.

Myriad owns the patents to the genetic sequences, as well as any mutations along those genes. The American Civil Liberties Union, which has brought the case on behalf of a coalition of patients, researchers and doctors, argues that that means that if genes from a particular person are analyzed or separated from other biological material, regardless of how or for what reason, that would constitute patent infringement.

The industry has countered for years -- and won on this argument -- that they don't patent the genes, but the man-made molecules based on those genes.

Myriad’s current exclusive right to the testing means all BRCA tests are conducted by Myriad. There’s no second opinion or confirmation by an independent second source and Myriad can set its own price free of competition.

If the court rules in favor of Myriad, that won’t change. “They have had a monopoly over all genetic testing for breast cancer for nearly two decades,” says bioethicist Arthur Caplan, an NBC News contributor and director of medical ethics at New York University’s Langone Medical Center. “Doctors and patients have complained bitterly that Myriad’s high-priced tests have limited access for many women.” The tests can cost up to $3,500, although a statement on Myriad's website says the company offers a financial assistance program for low-income or uninsured women.

Moreover, since only Myriad can perform the tests, it can, and does, keep any data it gleans from tests results, such as geographic and demographic patterns, or new genetic variants it may find. It has stopped sharing this data publicly, keeping it as its own trade secret so nobody else can use it to conduct research or develop therapies or tests.

“Now [Myriad] controls this database, including gene variants that may have unknown clinical significance,” says Michael S. Watson, executive director of the American College of Medical Genetics. So even though they don’t have patents on such data, “they control the marketplace.”

Such control could keep costs high for patients and insurers, and strangle competing research. For example, when new BRCA-related variants were uncovered, Myriad didn’t include them in its standard BRCA testing. Rather, it created a supplemental test, called BART, available at an extra charge of $700, to cover these mutations. So if a woman wants to cover all the BRCA bases, her doctor would have to order both tests.

The ACLU argues that genes are simply part of nature and therefore not patentable in the first place.

A ruling in favor of Myriad could also hamper the promise of “personalized medicine” based on our individual genetic makeups. Soon, some scientists say, it will be practical for doctors to order the sequence of each person’s genome to look for disease-related gene variations. But if big parts of the genome have been locked under patent protection, what would a doctor be able to do with that information?

Take, for example, the case of muscular dystrophy, a genetic disorder that weakens the body’s muscles. A number of patents related to mutations in the dystrophin gene have been issued. If a parent were to have a young child’s genome sequenced, the doctor may not able to communicate any important results relating to the dystrophin gene because the right to do that belongs to the companies or individuals who control the intellectual property. The doctor, or the genome sequencing company, could be sued.

“That has enormous implications for a family,” says Watson. “They could have another child who's affected. Care could be approached differently if they knew they had [genetic] features of muscular dystrophy."

Many academic research scientists say that so-called “gene patents” hamper their ability to share information, slowing the pace of invention for new therapies for dreaded diseases, or making that research too expensive.

“Myriad’s early patent arguably hindered the willingness of others to aggressively explore better tests for a terrible disease,” Caplan said. “Other patents on other gene sequences could have the same effect.”

Anybody trying to develop a drug related to a patented gene sequence would have to deal with the patent holder, adding costs, time, and legal complications, possibly delaying or even preventing innovation.

Supporters of such patenting argue that striking down Myriad’s intellectual property claims could actually hinder the development of life-saving therapies because companies wouldn’t take the financial risk to pursue them. Medical science could stall. A ruling for Myriad by the Supreme Court, could help spark, or at least protect, the innovation engine, ultimately saving patient lives, its backers claim.

Besides, they say, there is no such thing as a patent on a human gene. No one's patenting nature; they're patenting man-made molecules derived from human genetic information that are used to test for increased risk of breast cancer and ovarian cancer, argued Karen Dow, a San Diego partner in the law firm Sughrue Mion PLLC, who has long experience in the biotechnology industry, but is not involved in the current case.

In the BRCA case, an appeals court has agreed with this argument and upheld the patents.

But major medical societies fear what impact a ruling in favor of Myriad could have.

“The care available to patients should not be restricted because the naturally occurring building blocks of human biology have been inappropriately patented,” Dr. Jeremy A. Lazarus, president of the American Medical Association, said in a statement to NBC News. “Opportunities for scientific research and medical care based on human genes must remain available to all and exclusive to none.”

Brian Alexander is co-author, with Larry Young, of "The Chemistry Between Us: Love, Sex and the Science of Attraction."

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