This post has been updated to clarify that the family visited the Mayo Clinic's Michael Ackerman for a second opinion.
After a thirteen-year-old boy died suddenly, doctors diagnosed some 20 of his relatives with Long QT syndrome and implanted a defibrillator in his brother. But, the Wall Street Journal reports, researchers have since found that the family doesn't have Long QT syndrome. Instead, the Journal says this was an instance in which "[m]isuse of a genetic test as well as an incorrect interpretation of the findings" led to a misdiagnosis.
The Mayo Clinic's Michael Ackerman, who the family sought out for a second opinion, tells the paper that that the search for why the boy died was initiated with "good intentions." An autopsy uncovered possible heart-muscle anomalies, but the cause of death couldn't be determined. A cardiologist ordered genetic testing on the boy's brother and that revealed a mutation in a gene that's been linked to Long QT syndrome. The mutation was then uncovered in other family members, and the brother had a defibrillator implanted.
However, Ackerman notes that none of the family members had abnormal electrocardiograms indicative of the syndrome. In addition, he says the variant in the Long QT syndrome-associated gene that this family hasn't actually been linked to disease.
When the boy who died was eventually tested — blood had been collected at autopsy — he was found to have another mutation linked to sudden death.
Ackerman tells the Journal that the "the entire clinical evaluation was a train wreck, where wrong conclusions led to wrong turns and resulted in wrong therapies."