Genetic testing fumbles, revealing 'dark side' of precision medicine

Enthusiasm for precision medicine, from the White House down to everyday physicians, is at an all-time high. But serious problems with the databases used to interpret patients’ genetic profiles can lead to “inappropriate treatment” with “devastating consequences,” researchers at the Mayo Clinic warned on Monday.

Their report describes the cases of some two dozen people who were told they had a potentially fatal illness and one who had a heart defibrillator surgically implanted but, it turns out, never needed it. The individuals were family members who underwent genetic testing after a young relative died of a heart syndrome. Test results indicated that they carried a mutation in a heart-related gene — and the database that the testing company used indicated it caused a serious disorder.

A reanalysis by Dr. Michael Ackerman, a genetic cardiologist at Mayo, and colleagues with a more modern genetic database, however, indicated that in fact the mutation is harmless, and the invasive treatment was unnecessary. “This is the proverbial dark side of genetic testing and precision medicine,” said Ackerman. Because databases that companies use to interpret DNA tests are riddled with errors, “we’re starting...