Mr. King read that the inexpensive policy would require him to allow his medical data to be submitted to something called the "Medical Information Bureau." (This is a Boston-based organization, to which most American and Canadian insurers now subscribe, which makes medical information collected by one insurance company available to all.) He also had to give the company permission to ask friends and family about his "reputation, personal characteristics, and mode of living." "I went straight sideways," says Mr. King. "I told them 'I'm not signing,' and we left it at that."

Later, Mr. King and his wife decided they could swallow a pretty large invasion of privacy for an extra $360 a year. But when he went back to sign up for the individual plan, his investment counsellor said it was unfortunate he had not had the required "mouth swab" yet. "If he thought I was mad the first time, he knew it this time," recalls Mr. King. "'You want my genetic information for your life insurance policy?' I asked. He dodged around it, saying the swab was for 'other purposes.' I know what an epithelial swab is."

Mr. King's concerns, which led him to opt for the more expensive policy, are doubtless shared by thousands of Canadians. Taking a buccal swab from the skin inside the cheek is, in fact, a common way of taking a DNA sample from a human subject. Marlene Klassen, a spokeswoman for Great-West Life, says that this is not the intent of the procedure; the company is looking for nicotine, cocaine and HIV antibodies, not DNA. "We're not interested in anyone's genetic information," she says. "If genetic testing has already been done, we would request access to that information, but we don't do any of our own testing, and that's consistent with industry practice."

In just a few years, science has discovered genetic keys to an amazing array of diseases and predispositions for diseases. If someone can get hold of your DNA, they can find out how likely you are to get breast cancer, Lou Gehrig's disease or Alzheimer's. Indeed, they can make nearly perfect predictions about some diseases, such as Huntington's. The potential benefits to the insurance industry are self-evident. Last year, an executive from Royal and Sun Alliance Financial admitted to the Ottawa Citizen that his company would use genetic information on individuals if the industry as a whole decided to start demanding it from applicants.

The great fear for insurance companies is that people with strong likelihoods of acquiring dangerous diseases will fleece them by taking out fat policies. (That is one reason they set up the Medical Information Bureau to trade files on previous policyholders.) Some economists have argued that if insurance companies could gene-test policy buyers, it would bring down premiums for the great majority of people--those with no particular "time bomb" in their DNA. But it would also create a whole class of "genetic uninsurables" who would be left helpless to provide for their families through no fault of their own.

Already some governments are trying to act on the issue. In April, British Secretary of State for Health Alan Milburn announced plans to ban insurers from practising "genetic discrimination" against policy applicants. Some U.S. states have already passed similar laws. Charles Black, a senior adviser to the Canadian Life and Health Insurance Association, says that such legislation is illogical. "If two people have equal risks, they certainly should be treated equally," he says. But "discriminating" between risks is what insurance is. "It is not discrimination, surely, to charge different premiums on life insurance for 10-year-olds and 90-year-olds." Or, for that matter, to different genders, or to people whose parents had different lifespans; and that information, now routinely collected, is itself genetic in nature.

For the moment, the status quo is likely to remain in place. That satisfies Mr. Black, who notes that widespread genetic testing, combined with new therapies, may actually reduce the existing number of uninsurables. But it is unlikely to placate those who, like Mr. King, are not necessarily willing to take insurance companies at their reassuring word. "Remember, it's not just my privacy that's involved," he says. "Genetic information about me is genetic information about my progeny. Their interests are at stake too."