# De novo mutation

National Cancer Institute (NCI)

## Source

National Cancer Institute (NCI). *De novo mutation*.

A genetic alteration that is present for the first time in one family member as a result of a variant (or mutation) in a germ cell (egg or sperm) of one of the parents, or a variant that arises in the fertilized egg itself during early embryogenesis. Also called de novo variant, new mutation, and new variant