In the coming era of personal genomics — when we all can decode our genes cheaply and easily — political candidates may be pressed to disclose their own DNA, like tax returns or lists of campaign contributors, as voters seek new ways to weigh a leader's medical and mental fitness for public office.

The technology is advancing so quickly that the next generation of presidential hopefuls may be judged not just on the content of their character but also on the possibilities revealed in their genes, highlighting the tension between privacy and public life.

"DNA is not an issue in this campaign, but in the next campaign it will be bigger," says George Annas, a leading authority on bioethics and human rights at Boston University. "It's coming."

While still high, the cost of high-speed genetic analysis is falling fast. It took 13 years and $2.7 billion to determine all the DNA in the first complete human genome, finished in 2006.

Earlier this month, a Mountain View, Calif., company called Complete Genomics announced that by next year it will be able to read out an entire personal genome for $5,000.

So far, hundreds of diagnostic tests are on the market, with hundreds more on the way. Mail-order genetic testing services are legion.

At the last World Economics Forum in Davos, Switzerland, DNA test kits were handed out as party favors to 1,000 world leaders.

Political demands for DNA disclosure may be only a matter of time, experts say.

Even so, candidates don't have to make their medical records public and often have good reasons to conceal them, especially if, like many genetic tests, they only reveal the possibility of a future problem.

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