Consumer DNA databases have grown significantly, allowing users to discover relatives they never knew they had. The relative-finder tool can now reveal unexpected family connections, such as a half-sibling or first cousin, through an email notification.

AncestryDNA has nearly 30 million kits, surpassing other genealogy databases combined. Other companies, including 23andMe and MyHeritage, also have sizable databases, with 14 million and 9.6 million kits, respectively.

Further details about the impact of at-home DNA tests on American family trees are available, including surprising discoveries made by those who have taken the tests.