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Dr. James Watson looks at a reproduction of the structure of DNA, which he helped discover, in this 1962 photograph. Decades later, Watson was one of the first people to have his entire genome sequenced.
When scientists were looking for the first person to test a new, superfast way of deciphering someone's entire genetic blueprint, they turned to James Watson – the guy who shared a Nobel Prize for discovering the structure of DNA.
"They had to sequence someone, so they got me," he says.
The results helped solve a mystery: Watson had never understood why he had so much trouble controlling his blood pressure with beta blockers. "They put me to sleep," he says.
The sequencing revealed that he had genes that made him more sensitive than most people to the drugs. "Now I can take them once a week," he says, "so my blood pressure is better controlled now because of my genome."
This is one of the big benefits doctors expect to get from sequencing: a whole new way to figure out which drugs work for their patients; which don't; which are safe; and which are dangerous.
"The doctors of the future, when you start to prescribe a drug for which you have a genomic variation that would give you a side effect, a flag will pop up and say, 'Maybe you ought to, you know, consider another drug,' " says Robert Green, a geneticist at Harvard Medical School.
Overall, though, Watson didn't end up learning all that much from his DNA. "Really, nothing came up," he says.
Skeptics say that's probably the case for most people at this point. Sequencing gives you all 3 billion letters in your genome, but scientists still know so little about how to interpret the data that most people will get little, if any, useful information out of it.
That's one reason some scientists are sequencing themselves — to learn how to use this flood of information.
When Michael Snyder, who chairs Stanford University's genetics department, decided to become his own sequencing guinea pig, the results were dramatic — and shocking: Snyder learned he was at risk for Type 2 diabetes.
It didn't seem to make sense: Snyder had no family history of diabetes; he wasn't overweight. There was no reason he should get the disease. Still, just to be on the safe side, Snyder asked a colleague who specializes in diabetes to monitor his blood sugar levels. At first, she was skeptical.
"The person doing the test said, 'There's no way you're at risk for Type 2 diabetes.' And I said, 'Well, I don't think so, either. But my genome says there's something interesting about my glucose metabolism, so I think we should do this test,' " Snyder said.
So everyone was stunned when his blood sugar started rising — and then kept rising. Within months, it spiked. They had literally watched him become a diabetic in real time.
"So in fact, my genome, then, did predict I was at risk for a disease, which, by following the various markers for that disease, I did discover I did get," Snyder said.
Snyder jumped on it. He completely transformed his diet and kicked up his exercise. After about six months, his blood sugar gradually fell back to normal.
"That's the power of genomics, is to help you catch things as early as possible. So, some people might say that actually, my genome saved my life," he said.
Stories like Snyder's are feeding the buzz about sequencing and raising the prospect that it could one day become as routine as running through your family history with your doctor, getting your blood pressure checked or testing your cholesterol.
"I think it's going to be part of the every day medicine sooner than most of us can actually imagine," Green says.
For example, genome sequencing could spot who's going to get breast cancer, escape prostate cancer or need to watch their heart. "I think it's one of the most exciting frontiers in science and society," Green says.
But even people pushing those frontiers acknowledge there are limits to what people want to know about themselves.
When Watson was asked to volunteer for sequencing, he had one condition: "I didn't want know its prediction for Alzheimer's," says Watson, who had watched his grandmother die from the incurable brain disease. "There's nothing you can do to prevent it, so why would you want to know?"
Watson told the geneticists they could tell him and even publicize everything else that showed up in his genes, except that.
That type of reaction isn't surprising, says James Evans, a geneticist at the University of North Carolina, Chapel Hill. "Your genome is a complex and not necessarily a real warm and fuzzy place," he says.
Some people will want to know everything. But a lot of people won't. And what do we do if we stumble across something we weren't looking for?
Plus, Evans says, there are plenty of chances for bad or misleading results that could end up doing more harm than good. "Medical tests have the power to help," Evans notes. But they also "have the power to confuse."
In Watson's case, the first interpretation of his genome indicated he should already be dead, killed by a terminal illness.
"It was a nasty condition. I purposefully didn't think about it," he says, "because I figured I would wonder why I wasn't sick. Well, it turns out I shouldn't have been." Doctors quickly realized they had misread his genome. Luckily, Watson hadn't gotten too worked up about the mistake.
But there are also potential drawbacks to getting it right.
Snyder got a glimpse of that himself. After sequencing revealed his high risk for diabetes, his wife tried to increase his life insurance. But because of that high risk, the price shot through the roof.
"So the bottom line is my life insurance ... essentially became prohibitively expensive," Snyder says.
Federal law bans health insurance companies and employers from penalizing people based on genetic information, but the law doesn't apply to life insurance or long-term care insurance — leaving people like Snyder vulnerable to discrimination.
Despite that, Snyder is convinced sequencing has more upsides than downsides. And despite his false alarm, Watson agrees.
"I think many people would benefit from having their DNA told, and that would more than compensate for the occasional mistakes," he says.
Others aren't so sure. They wonder: Is it far too soon for most people to venture into the dark corners of their DNA?
This is the second story in the "$1,000 Genome" series. Our online survey will close after the final story in the series airs on Oct. 5.