Recent guidelines from the American College of Medical Genetics and Genomics (ACMG) regarding the return of incidental findings continue to generate controversy. At the heart of much of the controversy lies a single question: what makes a medical finding truly “incidental”?
Implicit in the new recommendations is a mandate to laboratories that when genome-scale sequencing is performed, the resultant data be actively and systematically queried for specific types of mutations in a selected set of genes. How can such a call for an active search be reconciled with the designation of those results as “incidental”? And why is this not tantamount to a call for overt screening for mutations in those genes? The details of how genome-scale sequencing is carried out, as well as long-established norms of clinical medical practice, are critical to resolving these questions.