Incidentalome

The incidentalome is the phenomenon of all possible incidental findings.The term was coined as an extension of incidentaloma which refers to the incidental, often radiographic findings of masses or tumors whose significance and prognosis is therefore poorly understood. In the genomic era, the lack of prior probabilities regarding the clinical import of each genetic variant creates the likelihood of a large proportion of false positives, if genetic testing is not placed on a systematic quantitative basis.

"If practitioners pursue unexpected genomic findings without thought, there may be untoward consequences. Specifically, physicians will be overwhelmed by the complexity of pursuing unexpected genomic measurements, patients will be subject to unnecessary follow-up tests, causing additional morbidity, and the cost of genomic medicine will increase substantially with little benefit to patients or physicians, thus casting into question the benefit of genomic-based medicine." [1]

The incidentalome raises a challenge for both the FDA approval of panels (e.g. SNP chips) of genetic tests as well as the substance of medical education in the genomic era. At this time, whether for screening a hundred genetic variants or even a full genomic, there are no clinical standards or regulatory requirements to post the overall risk of false positives on such testing (see, for example, Familywise Error Rate).