variant of unknown significance

Definition of variant of unknown significance
National Cancer Institute

variant of unknown significance

(VAYR-ee-unt … UN-none sig-NIH-fih-kunts)
A change in a gene’s DNA sequence that has an unknown effect on a person’s health. There is usually not enough information about a variant of unknown significance to know whether it increases a person’s risk of developing a disease, such as cancer. Also called unclassified variant, variant of uncertain significance, and VUS.

Source: NCI Dictionary of Cancer Terms