Pathogenic variant and variant of uncertain significance (VUS)

A pathogenic variant is a change in a gene's DNA sequence that is known, based on scientific and clinical evidence, to cause or significantly raise the chance of a particular health condition. A variant of uncertain significance (VUS) is a gene change that has been identified but where current evidence is not sufficient to classify it as either disease-causing or harmless. Genetic laboratories classify variants using standard criteria, and classifications can change over time as more evidence becomes available — a VUS may later be reclassified as pathogenic or as benign. Receiving a VUS result on a genetic test can feel unsettling; genetic counselling can help explain what is and is not yet known, and whether retesting family members or waiting for reclassification is useful, rather than acting on an uncertain result as though it were definite.

Also known as: VUS, variant of uncertain significance, disease-causing variant

Last reviewed: 9 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.