You already know that I am not a fan of this genetic testing craze.

Sure, folks are desperate to know where they came from.  (And, it’s clear they don’t trust their grandparents to share!)  Or, they are worried they may have some disease.  (Like knowing what you have without a treatment is going to make you feel much better.)  Some firms even promise to screen your embryo for diseases.

(This may be a good time to review phenotype, genotype, and epigenetic considerations,if you don’t recall what they truly mean.)

These polygenic scores may make sense when genetic factors are important (such as inherited traits) in the phenotype, or even with binary phenotypes.  Phenotype measures have already been found to explain educational achievement (sex, month of birth, prior achievements, as well as parental education and socioeconomic conditions).

Which brings up what may be the latest BS.  At least one researcher, Dr. Robert Plomin (an American psychologist at King’s College in London), is advocating using polygenic tests to see how smart you really are or how well you will do in school. Plomin believes kids should be tested early- to discern if they will have academic failings.  (Others do agree that persistence may be discerned, even if not in agreement with Plomin.)

Drs. Tim Morris,  Neil Davies and George Smith of the University of Bristol are associated with the Avon Longitudinal Study of Adults and Children (aka, Children of the 90s).  Some 7988 folks have had the genomes sequenced, among other tests- plus their academic results were also available.  So, determining their polygenic score wasn’t much of a challenge.  And, guess what?  The correlation between their score and their GCSE (General Certificate of Secondary Education, a UK educational qualification) was 0.4!  (1 is a perfect correlation, 0 denotes absolutely no correlation; 0.8 is the minimum value to claim any real correlation.)

Of course, Dr. Plomin wants us to believe that 0.4 is good enough.  Which reminds me how we approve psychotropic drugs.  (Almost totally based on whimsy.)   The true answer is that something on the order of a million samples must be analyzed to be certain.

But, there’s more genetic (or non-genetic) data to discuss.   Some folks from Harvard Med (Drs. Braden Tierney, Yixuan He, George Church, Aleksandar Kostic, Chirag Patel), along with Dr.  Eran Segal (Weissman Institute, Israel) published their study, The predictive power of the microbiome exceeds that of genome-wide association studies in the discrimination of complex human disease.

As you can tell from the study, our microbiome provides way more information than our genetic coding.  As a result of analyzing some 70 studies for complex conditions and the microbiome, the researchers determined that the microbiome was a better indicator than our genetics for 12 of the 13 conditions that they studied.   (The exception- type I diabetes.) Except it wasn’t clear if the microbiome was the cause or the effect- because microbiomes are just as likely to be changed by our health and lifestyles, so discerning which is the cause or the effect is difficult.

This also means that some sort of protective laws will have to be developed to protect our privacy.  Especially now that it’s clear that  our microbiomes can be used to identify us.  And, right now, only our genetic coding has such protections.

It’s a brave new world out there.

Share this: