Genetic and genomic testing for medical purposes is becoming increasingly common. But what should a doctor do if a patient undergoing testing for a disease-causing mutation in one gene is discovered to have another, unrelated mutation for a different, unsuspected condition? The American College of Medical Genetics and Genomics today issued recommendations regarding this very situation (called an “incidental finding”). The results may surprise some people.
ScienceInsider summarized the results nicely in a post earlier today:
Fourteen genetics experts, with the backing of the American College of Medical Genetics and Genomics (ACMG), are proposing a radical shift in how and what patients learn about what's in their DNA. They argue that anyone whose genome is sequenced for any medical reason should automatically learn whether 57 of their genes put them at risk of certain cancers, potentially fatal heart conditions, and other serious health problems. The information would be provided whether [or not] patients want it—and often when they're seeking care from a doctor for something else entirely—because, the experts say, knowing the makeup of this DNA could save an individual's life. The recommendations apply to sequencing children's DNA as well, even if there's no preventive care available until adulthood.
Stanford genetic counselor Kelly Ormond was a member of the task force that came up with the guidelines. She elaborated the thinking of the group and the reasons behind the changes to me in a recent conversation:
We believe that there are a number of conditions that a patient would wish to know about, including BRCA1, colon cancer risk and others. This information should be given regardless of the age of the patient because it’s useful information. If the patient is a child, it’s possible that steps can be taken to reduce the risk or to incorporate screening to detect the disease as the child matures. There’s another reason, though. If a child has a mutation that clearly confers increased risk, it’s likely that he or she inherited that mutation from the parents. Informing the parents of their child’s mutation may allow them to undergo relevant screening, and hopefully keep them healthier, as well.
The college’s recommendations are just that: recommendations. Doctors can still make their own judgment calls, or even discuss with the patient or parents prior to the test the types of information they’d like to receive (in some cases, this may mean opting for a lab to process the genetic sample that doesn’t divulge any incidental findings). And the “should be informed” list is limited to those mutations that meet two criteria: They must carry a significantly increased risk of disease and there must be something that can be done clinically to mitigate this risk. Diseases (such as Huntington’s or Alzheimer’s disease, for example) for which there is a clear genetic cause, but no treatment or cure, are not included on the list.
Previously: When it comes to your genetic data, 23andMe's Anne Wojcicki says: Just own it, Film to document Stanford student's decision to be genetically tested for Huntington's disease, and How genome testing can help guide preventative medicine