Testing Your Genes for Future Diseases

There used to be a company 23andMe that sequenced your genome using your saliva sample and then sent you back a list of diseases you might get in the future. The intention was that people start taking preventive steps early in life for specific possibilities.

In 2013, Tyler Cowen wrote a blog explaining why he decided against getting such a test done. Even though he knew the risk of not getting himself tested:

“An absence of negative information might have encouraged me to slack on exercise, to the detriment of my eventual health outcomes.”

But, on the other hand:

 “I thought the “worry cost” of negative information would exceed the benefit of whatever specific preventive measures I might take.”

But 23andMe was shut down. Why? As more and more people started using its services to make medical choices, the US government was forced to step in to check the accuracy of these tests. One finding:

“The interpretation of 23andme results involves examining a large number of odds ratios.”

It was a statistical assessment, in other words. Or more bluntly, what they reported back to you could be wrong. Both as false positives and as false negatives. The error rate was too high by the standards of US regulators.

On the other hand, 23andMe and other similar companies coordinated with sites like openSNP.org where customers could “publish their (anonymized) test results, find others with similar genetic variations, learn more about their results, get the latest primary literature on their variations and help scientists find new associations”. While one can see the upside of such data sharing for both customers and scientists, the data was not always detailed enough. Could the missing data undercut conclusions drawn? Alternately, could we ever secure against the “inevitably unethical uses to which eugenics will be put”, as Cowen wondered.

And in places like the West where health costs are (largely) covered by the state, Megan Molteni wonders:

“Will they confuse doctors, scare patients, and drive up unnecessary costs?”

So where are we headed? Towards a future where the data gets better, and patients and doctors learn to handle the conclusions as probabilities? Or is ignorance going to be bliss, because as Eugene Wei wrote:

“It's disheartening how much of life's happiness depends on ignorance or self-deception.”