September 19th, 2011

“Doc, I Got My Whole Genome Scanned – Now What?”

When Walmart announced that it would stock personal genetic kits, the FDA balked and Walmart held off. But that doesn’t mean patients can’t still order a personal whole genome scan online.

So what do you do if and when your patient shows you a commercially produced report of a personal whole genome scan? Do you treat the results as part of the medical record and manage accordingly? Or do you cite recently reported quality control problems and lack of formal FDA regulation? Or do you refer the patient to a genetic counselor?

With this week’s issue of Nature reporting another 16 new loci for hypertension, the list of genotypes associated with a multitude of phenotypes – from height to Alzheimer’s disease – continues to burgeon. Even though genetic risk scores only modestly predict common complex diseases (e.g. median C statistics of 0.55-0.60 for coronary heart disease), this fact is often lost on the lay media and, in turn, the average public consumer.

So if your next patient showed up in clinic with a genome scan report in hand, what would be your approach?

3 Responses to ““Doc, I Got My Whole Genome Scanned – Now What?””

  1. Louis Krut, MB.ChB. MD says:

    Suggest they lock it up and throw away the key.
    As you indicate, this subject becomes more complex by the day. Our naivety about the whole gene world becomes more evident with every genotype revelation, and these are coming up with increasing frequency. We are looking into a bottomless pit. If we seek help from knowledge of genes we need to be looking into this in some other way. Taking the easy option of identifying what we believe to be markers has not been helpful.

    Competing interests pertaining specifically to this post, comment, or both:

  2. As a clinical geneticist, I sometimes have patients bring in a lot of genetic data from 23andMe or some other company. It actually doesn’t take much time to explain how meaningless the data are for guiding medical intervention that will improve patient outcomes. One blanket statement usually suffices. The real concern arises when patients, without any prior genetic counseling, find out that they are carriers of rare recessive alleles and are forced to confront a vast array of high-tech reproductive choices such as preimplantation genetic diagnosis (in vitro blastocyst single cell biopsy with DNA amplification for genetic diagnosis).

    Competing interests pertaining specifically to this post, comment, or both:

  3. Vikki Stefans, MD, MS says:

    The commerical services may occasionally pick up an important finding, but a tactful way to put it is that their value for most users is 99% entertainment. They may motivate people to do the best they can with their genes, or to boost flagging self-esteem if they actually have some risk factors for obesity and find it even harder than average to lose weight or keep it off; it is important to make sure users understand that what they do in terms of lifestyle is more, not less important, given most of the genetic risks the services present to them. I have heard people who assume that because genes can’t be directly changed, attempts to reduce risks are futile. The other little trick you might try is to show them how one actually looks up information on snps in the medical literature, which may be complicated enough to discourage them, especially when they see how much conflicting evidence there may be and how effects vary by population.