(CBS News) How far would you be willing to go to satisfy your need to know? Far enough to find out your likelihood of dying from a terrible disease? These days that's more than an academic question, as Tracy Smith reports in our Cover Story:
There are now more than a thousand genetic tests, for everything from baldness to breast cancer, and the list is growing. Question is, do you really want to know what might eventually kill you?
That knowledge, some scientists say, could ruin the life you have now.
For instance, Nobel Prize-winning scientist James Watson - one of the first people to map their entire genetic makeup - is said to have asked NOT to be told if he was at higher risk for Alzheimer's.
"If I tell you, particularly incorrectly, that you have an increased risk of getting a terrible disease, that could weigh on your mind, that could make you anxious," said Dr. Robert C. Green of Boston's Brigham and Women's Hospital. "That could be the filter through which you see the rest of your life as you wait for that disease to hit you. It could really mess you up."
"Every ache and pain," Smith suggested, could be interpreted as "the beginning of the end."
"That's right. If you ever worried you were at risk for Alzheimer's disease, then every time you can't find your car in the parking lot, you think the disease has started."
Dr. Green is a Harvard geneticist who has been pondering this issue for years. He led a study of people who wanted to know if they were at a higher genetic risk for Alzheimer's. It was thought that people who got bad news would, for lack of a better medical term, freak out.
But Green and his team found that there was "no significant difference" between how people handled good news and possibly the worst news of their lives. People who ask for the information usually can handle the information, good or bad, said Green.
in fact, most people think they can handle it: According to a CBS News poll, 58 percent of Americans said they would want to know if they carried a gene for an incurable disease.
Dr. William Harbour, of Miami's Bascom Palmer Eye Institute, is a pioneer in treating ocular melanoma - eye cancer. He's also developed a new genetic test that divides patients into two classes of survivability:
Class I or Class II.
Very simply, Class I cancer cells act like normal cells and can be killed. In Class II, the cells have mutated and have begun to spread throughout the body. There is no cure for Class II.
As far as accuracy goes, compared to other genetic tests out there, where does Dr. Harbour's stand? He replied, "I'm told by my colleagues in other fields of oncology that this is perhaps the most accurate prognostic test of any cancer. Certainly among the most accurate of any cancer."
Now, when his patients inevitably ask if the disease will kill them, Harbour has a more accurate answer.
Sunni Ziroff already knew she had ocular cancer when she first saw Dr. Harbour. He gave her the option of peering into her future.
"And so what did that mean to you, class I versus class II?" Smith asked.
"Whether you live or die, quite honestly," Ziroff said. "I mean, you don't know. It scares you and sets you straight up where you want to know. To me, I did."