By detecting those genes, for example the genes that predispose women to breast cancer, doctors can offer preemptive treatment. It sounds simple enough, but there's a catch: a woman may have that gene, but strange as it seems, it's really the property of a biotech company that has taken out a patent on it.
So far, nearly 10,000 human genes have been patented, all of them now in question based on a court ruling this past week.
Because, as "60 Minutes correspondent Morley Safer reports, whether you like it or not, under current law a vital part of who you are actually belongs to someone else.
Lisbeth Ceriani and Genae Girard were both diagnosed with breast cancer.
Ms. Girard was diagnosed at age 36, Ms. Ceriani at 42. Breast cancer at a relatively young age is often hereditary.
"Because of my age and the disease was already very aggressive in me, they thought there is most likely a genetic component at play," Ceriani told Safer.
The way to find out is through a test called BRAC Analysis, a blood test in which lab technicians at a company called Myriad Genetics examine two genes that exist in all of us.
If mutations - irregularities - are found, it means the risk of getting breast cancer and ovarian cancer is extremely high: breast cancer five times more likely, ovarian cancer as much as 40 times more likely.
Since a positive result usually means the removal of ovaries before cancer can develop, doctors told Ceriani she needed to get tested.
"I did try to have the test done several times," she said. "My insurance actually covers the test and would pay for the test. But the lab won't accept my insurance."
Myriad Genetics charges about $3,200 for the test, and most insurance policies do cover it. But Myriad won't accept Ceriani's plan because it won't pay the full amount.
"I don't have the $3,200 to pay for that test," she explained. "And I spent days trying to track down what is going on. If my insurance covers it, there must be someplace else I can bring this test. I mean it's a simple blood test, it's not a complicated procedure. And after all the research, I found out why and learned Myriad is the only game in town and they want it all."
Myriad Genetics controls all testing on the two breast cancer genes because they own the genes, lock stock and barrel. They patented them and no one else can legally test for them, or look at them, or even develop potential therapies that are based on them without Myriad's consent.
When it comes to inherited breast cancer, it's Myriad or nothing.
Just ask Genae Girard. Since doctors suspected that her cancer was also genetic she too got tested and her results were positive. Doctors recommended that she have a double mastectomy and have her ovaries removed.
"Which was a very tough decision. I mean, I'm still in my 30s and this is going to change my life whether or not I ever wanna have children. And that was a big deal," she said.
So she did the obvious: sought a second opinion - another genetic sequencing from a different lab.
But her doctor told her that wasn't possible.
"I think Myriad Laboratory is a very reputable company. But I know for a fact that there's human error that exists in laboratories and I would have felt a lot better about these decisions if I had that," she said.
"So, whether you like it or not, Myriad owns that gene that's in both of you," Safer remarked.
"Yes," Girard replied.
"No one invented my gene. They didn't change or alter my gene," Ceriani told Safer. "All they're doing is looking at it. It's crazy."