gonadal mosaicism
(goh-NA-dul moh-ZAY-ih-SIH-zum)
A term that refers to the presence of a pathogenic variant that is confined to the ovaries or testes. Gonadal mosaicism occurs when some of the sperm cells in the testes or some of the egg cells in the ovaries carry a pathogenic variant that is not found in other cells of the body. This means that a parent may not develop a genetic condition but could pass it on to one or more of their children. Also called germline mosaicism.