The Quest for the $1,000 Human Genome
The
goal of the $1000 Human Genome is almost certainly a little closer with
the advent of a new generation of DNA sequencers. Nicholas Wade reports
on some of these new developments in the July 18, 2006, issue of the New
York Times article
The Quest for the $1,000 Human Genome.
However,
even as we get closer to this NIH-supported goal, the bigger question
still remains: What impact will access to the complete genome sequence
really have for most people's medical care? The developers of this new
technology acknowledge that there is no real demand for this
information, at least not yet. They are banking that access to complete
genome sequence information will become routinely relevant in
healthcare in the next few years. The jury is still out as to what the
value of this information will be for most people.
So the
question of whether the DNA sequence is likely to be so powerful and
predictive that we all should have our genomes sequenced is a relevant
one. By itself, the sequence is only potentially related to our health;
it yields information about the probabilities of what our health is or
will be, but not what our health actually is now or will be in the
future. A prime example that illustrates this point are the hereditary
cancer syndromes. Even in these families with inherited mutations in
"cancer genes", many (if not most) of the individuals who inherit a
cancer-predisposing mutation never get cancer. The probablilty that
they will eventually develop cancer is higher, to be sure, but they are
not sick simply because they inherited this strongly predisposing
genetic element. This is even more true for the many less potent
genetic elements that we all have that contribute to disease risk. The
real story of health lies in the biological processes and interactions
that are only partially due to the genome.
Our genes are only
half (and sometimes significantly less than half) of our health story,
both present and future. The other major players are all the extrinsic
factors that make up our environment and the consequences of our
behaviors. We are learning more and more about how our genome interacts
with the myriad of elements within the genome itself and the almost
infinite elements that are extrinsic to the genome. These interactions
are more closely related to the health states we experience (both good
and bad) than the sequence alone.
Of course, the DNA sequence
obviously plays an important role--it is the foundation of our biology.
However, the genome functions in an environmental context that
regulates its activities at many levels. The technologies to elucidate
the physiological consequences of these interactions between genes and
environment are developing in parallel with the quest for the
affordable genomic sequence. An understanding of how the genome is
expressed and how non-genomic factors affect expression will ultimately
be more directly relevant to managing the unique and dynamic
physiological circumstances that contribute to a person's state of
health or a particular disease process. As we close in on the quest for
low-cost DNA sequencing, the genome sequence's greatest value may be in
what it contributes to our understanding of the interactions between
our genome and our environment, and thus, our health.
Return to: U of M Home: The Minnesota Gene Pool Home 
Comments
DNA sequence obviously plays an important role... you think?
Posted by: Energy Pill | February 21, 2008 3:47 AM