Tilting at windmills no longer: a data-driven discussion of DTC DNA ancestry tests.

Purpose: Discussions about direct-to-consumer (DTC) DNA ancestry tests have to date been based primarily on conjectures, speculation, and anecdotes, despite the industry being more than a decade old. Representative, empirical data on consumer characteristics; motivations and expectations for testing; intended uses for the information; understanding of results; and behavioral and psychological reactions to the tests are absent. Although the 2010 American Society of Human Genetics white paper clarifies the number and some general characteristics of companies marketing and selling DNA ancestry tests, additional data about the industry's practices have been unavailable.