Monday, June 11, 2007

DNA Under Pressure

Over at Eye on DNA an MD's op-ed column on genetic association studies is getting a good roasting. The naivete about the interplay of genes and the environment suggested by the original article (which would seem to suggest that environment completely trumps genes) reminded me of an idle speculation I've engaged in recently. Now, in this space I frequently engage in speculation, but this involves a celebrity of sorts, which I don't plan to include often. But I think this speculation is interesting enough to share/expose.

The Old Towne Team has been tearing up the American League East this year, much to the glee of the rabid Red Sox fan who lives down the hall from me. A key ingredient to their success is a very strong starting pitching rotation, and leading that rotation in several stats is Josh Beckett, particularly his American League leading record of 9 wins and 0 losses.

Now, as an aside, I have very little respect for baseball statistics. The rules for most seem arbitrary and the number of statistics endless. I have a general suspicion that baseball statisticians believe that some asylum holds a standard deviant, and that Bayes rule has something to do with billiards. But with Beckett on the mound, good things tend to happen.

Beckett was the prize acquisition last year, but at times he looked like a poor buy. The Sox gave up two prospects for him, one of whom hurled a no hitter and the other ended up as NL Rookie of the Year. Last year Beckett had mixed results, but this year he is on fire.

What hath this to do with genetics? Well, for a short time we lost his services due to an avulsion on one of his pitching fingers, which is the technical term for a deep tear in the skin. Beckett has a long history of severe blisters which knock him out of action periodically.

Genes, or the environment? It could be that he just grips the ball in such a way that anyone would lose their skin. But it could also be that he has polymorphisms in some connective tissue genes which make him just a bit more susceptible to this sort of injury. There are many connective tissue disorders known, with perhaps the best known in connection to sports being Marfan's syndrome. Marfan's leads to a tall and lanky physique, ideal for sports such as basketball and volleyball -- and it was Marfan's that killed Olympic star Flo Hyman. Beckett isn't covered with blisters (at least, no such news has reached the press), but what if it is only in the intense pressure of delivering a fastball that the skin gives way. If this were true, the phenotype would be most certainly due to the genotype -- but only in the context of a very specific environmental factor.

Of course, this is a miserable hypothesis to try to test. Perhaps you would scour amateur and professional baseball for pitchers with similar problems and do a case-control study with other pitchers who don't develop blisters. Or, you would need to collect DNA from his relatives, and also teach them all to pitch just like Josh Beckett in order to see if they too develop blisters and avulsions. It could be a first: a genetics study whose consent form includes permission to be entered into the Major League Baseball Draft!


Anonymous said...

If environment trumped genes, wouldn't animals in a zoo look very different than those in the wild?
Maybe zebras in a zoo wouldn't have stripes...or polar bears wouldn't be white.
That's just plain silly.

Keith Robison said...

It depends on the genes & the environment. To take two examples similar to yours, flamingos will not turn the proper pink unless fed an appropriate diet -- the color comes from their diet, but they have the genes to put the color in the right place. Another example, often shown in textbooks, involves shaving a snowshoe hare and maintaining either a cold pack or hot pack on its back -- cold pack will generate white fur & hot pack dark fur. The same gene-environment interaction (temperature sensitive allele in the melanin pathway) is responsible for the distinctive coat coloring of Siamese cats.