Privacy, politicians, and genetic testing

Ronald Bailey opines about coming pressures for politicians to release their genetic test results:

Again, it's just as easy to obtain a DNA sample from a presidential candidate as it would be to get one from a celebrity like Winfrey. Green and Annas are most worried that competing campaigns might engage in "genetic McCarthyism." That is, campaigns will seek to obtain DNA from their adversaries and then release genetic data that suggests that their opponents are somehow unhealthy. Such a tactic could be used to confuse the public because genetic information is easy to misinterpret and to misrepresent. Consequently, Green and Annas argue that "future presidential candidates should resist calls to disclose their own genetic information. We recommend that they also pledge that their campaigns will not attempt to obtain or release genomic information about their opponents." They reject the idea of making it a federal crime to sequence a candidate's DNA without consent. Oddly, Green and Annas overlook the plausible scenario in which some media organization surreptitiously obtains DNA from candidates, and then sequences it and reports the results.

This last scenario, the sneaky approach, pretty much makes it inevitable that genetic test results for future candidates (or anyone else of sufficient interest) will be public. Congress could simply make it illegal to release any record of a person’s genetic information. But this would extend the privacy right much further, with respect to publicly obtained information, than it currently goes – and far into the territory where the First Amendment pushes back.

If it were only politicians, that would be trouble enough. But these kind of data may be used in the same manner as many kinds of “junk science” today. Imagine a custody battle, in which the father hires a private investigator to get a mother’s genome. With two variants that yield a 15 percent higher risk of schizophrenia, will the mother’s genetic risk be held against her? Or think of corporate boards, looking for a way to dismiss a CEO without paying that golden parachute. Could a genetic test result showing a higher risk for early Alzheimer’s give them a reason to invoke a “health” clause in the contract?

Why does this entire topic look like “junk science?” I can think of a couple of reasons. First, genetic information today is essentially meaningless at the individual level. Consider Bailey’s description of his own 23andMe results:

The genetic screening company reports that 24 out of 100 people with my genotype will get type 2 diabetes between the ages 20 and 79. The average risk is 21.9 per 100 people. With regard to macular degeneration, 9.5 out of 100 people with my genotype will get it between the ages of 43 and 79. The average risk for people of European ethnicity is 7 out of 100. And 0.94 out 100 people with my genotype will get Crohn's disease between the ages of 20 and 79. The average risk for people of European ethnicity is 0.43 out of 100. I will save for a future article the good news that I also have a number of genetic markers that indicate lower risks for many other conditions. This is the kind of risk information that genetic screening tests will reveal.

These “risks” are based on single genotypes, mostly replicated in more than a single study, but not analyzed with any combination of other genotypes. We simply don’t have a way to predict a person’s lifetime risk of chronic disease, based on the entire genome. A person who has one known risk allele may have any number of unknown protective alleles. So saying that a person has a XX risk for condition YY is highly misleading. At best, the strongest such variants suggest a higher relative risk, all other things – including environment, diet, and past disease history – being held constant.

Second, there is no natural limit to what a genetic test might be claimed to find. Genes affect health, sure, but they also affect personality, IQ, and behavior. Once a person’s genetic data are made public, they are hostage to every future study that might show one (or more) genetic variants are associated with some trait.

This is not only about the candidate for President, where the public is judging their future health. This is about a sitting President, whose public genome data show a newfound association with a personality disorder.

Maybe, as George Church hopes, we are headed for a future where these things won’t matter. But I think it will be a rough road.