de novo pathogenic variants

Definition of de novo variant
National Cancer Institute

de novo variant

(deh NOH-voh VAYR-ee-unt)
A term used to describe a change in the DNA sequence of a gene that is seen for the first time in a person and has not appeared in previous generations. A de novo variant can explain how a person can have a genetic condition that did not occur in his or her parents. A de novo variant can occur in an egg or sperm cell of a parent, in the fertilized egg soon after the egg and sperm unite, or in another type of cell during embryo development. A person who has a de novo variant may pass the mutation to his or her child. Some de novo variants may lead to cancer or other diseases. Also called de novo mutation, new mutation, and new variant.

Source: NCI Dictionary of Cancer Terms