Clinical Genetics Has a Big Problem That's Affecting People's Lives

For Heidi Rehm, it looked like a straightforward case. Her lab at Partners Healthcare offers tests for genetic diseases. They had received a blood sample from a fetus after a doctor conducting an ultrasound spotted signs of Noonan syndrome—an inherited disorder involving heart problems and stunted growth. The fetus turned out to have a mutation in PTPN11, a gene that affects the risk of Noonan syndrome.

Rehm found that another team of scientists had published on that very same mutation before. (Not every mutation of PTPN11 increases the rick of Noonan syndrome.) They found that it was more common among Noonan patients than in healthy people, and had billed it as “pathogenic”—that is, likely to cause disease. Rehm reported it as such to the doctor who sent her the sample.

Sometime later, she was listening to a talk by a colleague who had found the same mutation in a patient with Noonan syndrome and, based on the same published study, had also classified it as pathogenic. But this time, the patient—an adult—had contacted the researchers behind...