November 26, 2013

Should recreational genotyping be illegal?

The US Food and Drug Administration has sent a letter to 23andme, one of the companies that will genotype you and provide lots of information from the sample, telling them to stop. It’s a tricky situation.

This product is a device within the meaning of section 201(h) of the FD&C Act, 21 U.S.C. 321(h), because it is intended for use in the diagnosis of disease or other conditions or in the cure, mitigation, treatment, or prevention of disease, or is intended to affect the structure or function of the body. For example, your company’s website at www.23andme.com/health  (most recently viewed on November 6, 2013) markets the PGS for providing “health reports on 254 diseases and conditions,” including categories such as “carrier status,” “health risks,” and “drug response,” and specifically as a “first step in prevention” that enables users to “take steps toward mitigating serious diseases” such as diabetes, coronary heart disease, and breast cancer. Most of the intended uses for PGS listed on your website, a list that has grown over time, are medical device uses under section 201(h) of the FD&C Act. Most of these uses have not been classified and thus require premarket approval or de novo classification, as FDA has explained to you on numerous occasions.

On the one hand, I can’t see any valid social interest in stopping people from knowing their genotypes if they want to. On the other hand, the FDA has a point about marketing.

They raise two isssues.  The first is that 23andme make lots of (fairly weakly supported) claims about the usefulness of the results in disease prevention. The second is that some of the genotype information is actually clinically relevant and that they have not demonstrated sufficient accuracy in their results. The first issue is essentially a misleading advertising problem; the second is a quality assurance problem.

There are two things that can go wrong with the clinically useful results. The first is simple error: the genotype assay could give the wrong result, or you could be given results from someone else’s sample. This should be low probability, but it’s important to know how low — 1 in a 1000 would definitely be too high.

The second issue is interpretation. Suppose you have a lot of family members with breast cancer, and you suspect a BRCA1 mutation is responsible. You might be relieved if you test negative, and think your risk isn’t especially high, but that’s only a reliable conclusion if your family’s cancer risk was actually due to a BRCA1 mutation, not to some other genetic risk factor.

 

Update: I should probably note that 23andme could fix what I think are the actual problems, but this wouldn’t necessarily satisify the FDA.  The FDA aren’t currently being unreasonable oppressive Luddite statist bureaucrats, but they’re probably happy to be to if that’s the option on offer.

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Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »

Comments

  • avatar

    Worse, say that 1/1000 suggests your kid isn’t yours? Awwwkward.

    10 years ago

    • avatar
      Thomas Lumley

      At least for paternity the genotype assay errors won’t be a big deal since you can measure lots of loci. But even sample-labelling errors can easily be 1/1000 for large-scale research-grade genotyping. Clinical testing has to do much better, and one would want to know where 23andme falls on the continuum.

      10 years ago

  • avatar
    Carol Harris

    I’m actually waiting on my results from 23andMe at the moment. I read through their site and they seem to do their best to tell you the exact state of play in terms of what the numbers mean. I also recall reading somewhere that they try to make it clear that just because you have a higher chance of having a particular disease doesn’t mean you’ll actually get it. They also have a bunch of links through to the research so that you know how many people participated in the study (or studies) etc, etc that they’re basing their results on…

    So far the people that sign up to 23andMe seem to be similar in outlook – curious and taking it all with a grain of salt.

    The FDA is probably more nervous about the fact that 23andMe’s aim is to get enough people signed up to aggregate large pools of data (I think the aim is 2 million people + ) and sell it off to genetic researchers (which is where the profit is). 23andMe also took out a patent in 2008 to allow parents to choose the genetic traits of their offspring.

    I made sure I opted out of everything when I signed up. It probably doesn’t protect me but I did clearly say I did *not* want to participate in any research… :-)

    10 years ago