What is a gene variant?
A gene variant is a small difference in a gene's spelling that makes one person's version slightly different from another's.
Everyone has the same set of genes, but the exact spelling differs in tiny ways from person to person. These small differences are called variants. Most are harmless and simply make us individuals — different eye colour, different caffeine tolerance.
A few variants raise or lower the risk of certain conditions. When a genetic test 'finds something', it has usually found a specific variant whose effect has been studied.
Last reviewed 29 May 2026 · reviewed by someone with genetics training