Editorial: 10 years on, is genomics all it’s cracked up to be?

August 12, 2010 at 6:29 pm | Posted in Uncategorized | Leave a comment

Chromosomes. Image by George Gastin, Wikimedia

In April, the New York Times published a very interesting series of articles based on commentaries in the New England Journal of Medicine, which appeared to be the first public attempt by scientists to make sense of why, given its fanfair in 2000, the study of the genetic origins of disease has so far failed to furnish us with the medical miracles it seemed to offer.

As the NYT reported: “One recent study found that some 100 genetic variants that had been statistically linked to heart disease had no value in predicting who would get the disease among 19,000 women who had been followed for 12 years. The old-fashioned method of taking a family history was a better guide. Meanwhile, the drug industry has yet to find the cornucopia of new drugs once predicted and is bogged down in a surfeit of information about potential targets for their medicines.”

NYT series “The Genome, 10 years on”

One obstacle to progress identified by the NYT is complexity: it turns out that associations between genes and disease are rarely clear-cut, with diseases like diabetes affected by several variations in a person’s genetic make-up. Genetic combinations only contribute small percentages to the increased chance of having a disease, at least among the common genetic variants.

Epigenetics, a discipline which has emerged only recently, is a further example of how onset of disease may be much more complex than simply a matter of what genes themselves are coding for, because it responds to evidence that the environment itself affects gene expression by switching genes on and off.

These reductive approaches have received particular criticism in a recent paper from Professors Ana Soto and Carlos Sonnenschein (featured in July’s H&E), who argue that communication between tissue types is more important than gene mutation in understanding diseases such as cancer.

There is much talk in the NYT interviews and responding letters about how genomics has been successful because of its influence on the way drugs have been developed. This does not, however, necessarily mean that if the money poured into genomics had not instead been invested somewhere else, that there would not have been comparatively more success.

Obviously, understanding the genetic origins of disease is a good thing; nor is it our place to allocate research money. However, we would do well not to be blinded by the lights of new technologies; if family histories work better than genomics for anticipating disease, then that is important; if the environment causes illness, then investment needs to be allocated there as well.

One interesting outcome of genomics is it looks like giving birth to “enviromics” – a translation of the techniques for examining the genetic variations which result in disease, but applying them to human / environment interactions. Early indications suggest this could shed new light on the origins of diseases such as diabetes, as we explain in May’s H&E (see second article).

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