VUS (Variant of Uncertain Significance)
Definition
This is the situation where the test has detected a change in the DNA, but the role of this change in the development of disease is unconfirmed.
Why it occurs:
There may be insufficient scientific research to confirm or refute an association with disease, or the research may be conflicting.
The human genome contains millions of natural variations. Distinguishing whether a change is a harmless natural difference or a disease-causing variant may not be possible without sufficient evidence.
What the patient should know: 1. A VUS is not a diagnosis. It does not mean "the disease is present." 2. A VUS is not a "clean" result either. It does not mean "there is no disease" either. 3. It can change over time. As science advances, a VUS may be reclassified as "benign" or "pathogenic." For this reason, some laboratories may update the report years later. 4. Testing family members sometimes helps resolve the meaning of a VUS; if the variant is present in affected individuals and absent in healthy ones, its meaning becomes clearer.
Clinical decisions should not be based on a VUS. Important choices such as surgery, medication or pregnancy decisions are not based on a variant of uncertain significance.