

UC Berkeley Students Denied Genetic Test Results - miked
http://www.futurepundit.com/archives/007406.html

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carbocation
There is a discussion to be had about whether or not the students should
receive their test results. However, the author does not seem to fully
understand what he's discussing.

First, there is the issue of our limited genetic knowledge. Genetic tests are
currently based on a sample of 1 out of every ~3000 nucleotides in your
genome. Therefore, although they do cover the vast majority of common
variants, they cannot tell the full story. You may have a detected SNP that
predisposes you to some risk of disease, but at the same time you may have a
rare variant - not picked up by the tests - that is virtually guaranteed to
protect you from the same disease. This is not trivial, as rare variants are
common (everyone has lots of rare variants; however, few people _share_ the
same rare variants).

Furthermore, most SNPs that are associated with disease have not been
demonstrated to be _causal_ for disease. In fact, I'm aware of only a small
number of SNPs that are not in exons (coding regions of genes) that are
nevertheless known to be causal: one is rs12740374, which causes a decrease in
LDL production via a novel pathway.

I suppose my point is that there is a large ethical debate that hinges on our
scientific knowledge of the limitations of genetic testing. This author seems
not to know about this, or not to care, and instead has chosen to write a
polemic. I find this unfortunate.

~~~
AngryParsley
_There is a discussion to be had about whether or not the students should
receive their test results._

An extremely one-sided discussion. Genetic testing is already very useful, and
it's only going to get more useful.

 _First, there is the issue of our limited genetic knowledge._

Our knowledge is incomplete, but it's far from useless. Genetic testing lets
us know what foods or drugs are particularly harmful or beneficial. It lets
people know of future disease risks. Knowing about these risks helps people
change their lifestyles to reduce risk, or at least plan for the future. While
today's test results aren't 100% accurate, they give the best probability
estimate based on currently available science. To say that no information is
better than this is absurd.

People don't want to restrict other diagnostic tests, even though they can be
similarly inaccurate. It's simple technophobia that causes newer tests to be
regarded with suspicion.

Also, there's the issue of rights. It's my DNA. I have trillions of copies of
it in my body. I am literally made of this stuff. If human beings have any
right over their own bodies then they should be able to read their DNA.

~~~
carbocation
I'm not sure that we're talking about the same type of genetic testing.
Perinatal genetic testing is highly useful, because you can literally save a
person's life by early knowledge of genetic diseases.

Getting GWAS data from 23andMe, on the other hand, is generally not so much
useful as it is entertaining.

The best probability estimate for most adult diseases still comes from history
and the physical exam, not from genetic tests.

> Also, there's the issue of rights. It's my DNA. I have trillions of copies
> of it in my body. I am literally made of this stuff. If human beings have
> any right over their own bodies then they should be able to read their DNA.

I am most sympathetic to that argument.

~~~
AngryParsley
_Getting GWAS data from 23andMe, on the other hand, is generally not so much
useful as it is entertaining._

I mostly agree, although 23andMe did tell me something very useful. I have the
two G alleles for rs4680. (<http://www.snpedia.com/index.php/Rs4680>) One
research paper said I am likely to respond well to Modafinil. I now find
Modafinil extremely useful. While 23andMe is mostly for the coolness factor
right now, it's only going to get better. For a small fraction of people, data
from services like 23andMe is undeniably useful, since it will tell them
things we do know with high probability (drug interaction/metabolism, early-
onset Alzheimer's from ApoE4, etc).

 _The best probability estimate for most adult diseases still comes from
history and the physical exam, not from genetic tests._

I meant that genetic testing along with a physical exam is more useful than
just a physical exam.

~~~
carbocation
In medicine we often ask, "How would this test change management?" As it turns
out, buying the 23andMe test and then taking modafinil is more expensive than
taking modafinil, but it doesn't seem to change management. With or without
the 23andMe test, you could have tried modafinil. I wouldn't consider your
story a success for 23andMe (though I would consider it a success for you, and
for modafinil; cheers!).

We are getting closer to clinical utility of these tests. I'm no Luddite. But
I think that these tests need to be thought about like every other medical
test. (See <http://www.nejm.org/doi/full/10.1056/NEJMoa0706728> for why I say
that we're not quite there yet, but getting closer for some phenotypes.)

It's one thing to say that you have a right to your raw genetic data; like I
said, I'm sympathetic to it from a rights-based standpoint, though not a
clinical one for reasons that bhickey has brought up. It's another thing to
say (not implying that _you_ are saying this) that companies should be allowed
to make clinical claims about you based this data. That interpretive step
merits thoughtful consideration, and probably regulation.

