DNA Revolution-Hype or Hope?

by jeeg 6. June 2010 15:13

 

 

 

 

 

 

 

 

 

 

 Thus suggests Sharon Begley of Newsweek in her recent article DNA As Crystal Ball: Buyer Beware.   Begley points to a study in the May 12, 2010 issue of the Journal of the American Medical Association that reported the findings of a full genome association study of more than 35,000 people.  There, Seshadri et al. identify two new genetic loci for Alzheimer’s disease (AD) that reach genome-wide statistical significance.  Nevertheless, the study finds that the new loci are“not clinically significant” for predicting individual risk of developing AD—”one of the most heritable common, complex disorders, with a heritability of 60% to 80%.”  At first glace this seems counterintuitive: how could a study finding two new genetic causes of AD fail to aid clinicians in their efforts to predict AD in individuals?  As Begley writes:

The finding that adding Alzheimer’s-risk genes to plain old age, sex, and apoE [another gene associated with AD] status does not improve the accuracy of disease prediction seems to defy everything the public is being told about the dawn of a new era of personalized medicine, in which knowing our genomes will tip us off about what diseases we are most at risk for.

Commenting on the same study, an editorial in the same issue of JAMA questioned

. . . the value of continued attempts to find genetic effects of diminishing importance remains uncertain.  Important questions are whether these small effect sizes have any value in understanding disease pathogenesis and what truly are the clinical implications of this line of study?

While many today tout the predictive ability of genome-wide analysis (so-called genomics), findings like those of Seshardi and collogues stand as a sobering reminder that, as geneticist David Altschuler of Harvard Medical School put it, such prognostications are “overhyped.”  It is important to remember that genes alone do not determine the course of our lives—that countless other factors, both biological and environmental, impact our chances for developing this or that disease.  Relying on oversimplified gene-disease associations as the basis for predictive models sets a dangerous president—especially in an age when genetic tests are marketed directly to consumers.

 

By Andrew Thibedeau

Comments

6/19/2010 12:30:09 AM #

Miley

This new info on gene development seems exciting. Do you have any other sources about the future of this topic?

Miley United States |

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