Mayo researchers urge caution with genetic testing


A new paper from the Mayo Clinic urges more careful use and interpretation of genetic testing, with one of its authors noting, “We’re starting to see a lot of fumbles.”

It highlights the case of the sudden death of a 13-year-old boy that an autopsy failed to explain. In turn, more than 20 relatives underwent genetic testing for heart problems that could put them at risk. The tests indicated they had potentially deadly genetic heart rhythm condition called long QT syndrome, a serious disorder according to the database the testing company used.

The boy’s brother even had a defibrillator implanted in his chest that later was determined to be unnecessary, reports STAT.

When Michael Ackerman, a genetic cardiologist at Mayo, and colleagues re-evaluated the findings with a more modern genetic database, they determined that none of the boy's relatives tested had long QT syndrome; he died of a different genetic mutation not found in any of his family members.

"The medical community and community at large need to get a better grasp on genetic testing and precision medicine rather than just using them as buzzwords,” Ackerman said, according to CNN. “When used properly, these tests are incredibly helpful. But we must become wiser users of genetic testing and even wiser interpreters of the genetic test results so that we can make wise conclusions."

Errors can occur when DNA letters in a sequence differ from the “reference human genome,” considered the “correct” DNA spellings. When there is an anomaly, doctors search databases to determine whether the misspelling is linked to disease or is considered benign. Unfortunately, databases often disagree, while others are out of date.

And mutations might affect different populations differently, the CNN story points out.

Minority groups tend to be underrepresented in genetic databases and may not be well served by the prevailing research, a recent study published in Health Affairs pointed out.