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Insight: New DNA Reader To Bring Promise

Publication Date: 
January 10, 2012
Sharon Begley

Professor Hank Greely spoke with Sharon Begly of Reuters on the hidden costs of a new genome-sequencing machine that can provide a look into a person's genetic information.

After years of predictions that the "$1,000 genome" - a read-out of a person's complete genetic information for about the cost of a dental crown - was just around the corner, a U.S. company is announcing Tuesday that it has achieved that milestone and taken the technology several steps ahead.

The new genome-sequencing machine from Ion Torrent, a division of Life Technologies Corp., in Guilford, Connecticut, is 1,000 times more powerful than existing technology, says CEO and chairman Jonathan Rothberg.


One problem is that the costs only start with the actual sequencing. "The cost of understanding the sequence will be much, much higher," says bioethicist Hank Greely of Stanford University. He participated in a 2010 project that sequenced the full genome of Stanford bioengineer Stephen Quake. The sequencing cost $48,000.

But because it found 2.6 million DNA misspellings and 752 other genetic glitches, says Greely, "it took a few hundred thousand dollars worth of labor from Ph.D. students and faculty working 4,000 to 5,000 hours to understand what the sequence meant" -- that Quake had a higher-than-average risk of sudden cardiac death, a lower risk of Alzheimer's, and a higher risk of prostate cancer.


Although many bioethicists focus on the psychological harm patients might suffer when DNA tests show an elevated risk of cancer, diabetes, Parkinson's, and other diseases, genomics information could also threaten patients' physical health if it is misconstrued. A woman whose DNA sequencing shows she does not carry BRCA mutations that raise her risk of breast cancer "might say, great, I don't need mammograms," says Stanford's Greely. "But a negative BRCA test reduces her risk of breast cancer from 12 percent to 11.96 percent. My dread is less that patients will be damaged psychologically and more that they will misunderstand (genome sequence data) and do stupid things."


A DNA variant that was once thought to be dangerous "might turn out to be benign if countered by another," says Greely. "Whose responsibility will it be to tell you that, years later?" Today's DNA testing companies offer subscriptions that give customers regular updates like that.