Friday, February 11, 2011

The human genome birth month

Ten years ago this week, Nature and Science published results of the first pass at sequencing the human genome.  And now Nature and Science are feting the event with commentaries from people who were central to the initial effort, as well as assessments of where we are now. Science in fact will have 4 issues celebrating the birth month of the human genome sequence, not just a single issue. We will blog about a few of these commentaries in the next few days.

A News Focus from the Feb 4 issue of Science asks how all we've learned in the last 10 years is being translated into clinical practice.  Titled "Waiting for the Revolution", the message is that if physicians saw some practical use for genetic information, they'd be using it, but they don't and they aren't.  One consistent message from those who defend the commitment of time and money on genetic research is that it's early days yet, and we can't expect miracles overnight.  The practical use of genetics that genetics enthusiasts frequently cite is sequencing of tumors to allow an informed choice of treatment.

There are a few noted clinical decisions that can be made based on genetic analysis, but they are far fewer than had been hoped (or promised) 10 years ago.  The amount of genetic information that can be collected on any individual continues to far outweigh its usefulness for disease prediction or clinical applicability.  For example, should individuals with a history of deep-vein blood clots be tested for known genetic risk factors, factor V Leiden and prothrombin gene variants?  According to the News piece,
Both genes influence such clotting. People who have had such clots should be treated with anticoagulants anyway, regardless of genetic status, the panel concluded. And in a second group—relatives of people who have had clots but who themselves have not—the panel judged that it would be too risky to treat preemptively with anticoagulants (which can cause hemorrhaging) based on genetic status alone.
And the same is true for many other conditions.  Treat it when it happens, but preventive treatment is not useful, or is even risky, so genotyping is an unnecessary added cost.  Researchers have been looking for genes for diabetes for decades, with little success, for example.  A colleague of ours recently told Ken that although he's been working in the field of heart disease and lipid research genetics for decades, focusing on ApoE (one of the best candidate genes that has been studied ad nauseum), he still cannot put any of the knowledge about ApoE into his internal medicine practice.  

But let's say they find genes for whatever their favorite disease (an outcome that isn't at all guaranteed).  In what sense will that help prevent or treat it?   Does it really matter as a rule?  If you just eat better, exercise and don't smoke, your risk of heart attack will drop by far more than even the most enthusiastic gene-O-hyper can claim.  Enthusiasts will say that genetics will transform medicine to target treatment, itself based on molecular technologies, to each individual's particular risk.  The truth will be a mix, and each person has his or her own view on where the balance, and the distribution of resources, should lie.

Stepping back, we can say that it's always true that most work in a field is pedestrian, unremarkable, journeyman-like but not spectacular.  A century (or more) later we may remember the 'genius' but forget the unheard-of peons in a given field.  Our era is distinguished by its materialistic greed and immodesty, but is otherwise the same as it's always been.  There will be expensive trails of cow-droppings, but there will also be gains, some of them important.  They may or may not correlate to the bravado of those today who boast about their successes, lobby for funds, and so on.  Most of our work will be tiny, incremental, incidental, or irrelevant.

A century from now there may or may not be blogs in which reflection can be seen to look back on the early 21st century to point out where the remarkable insights were.  But we can be sure that then, as now, there will be both the remarkable minority, and the pedestrian majority.

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