Kari Stefansson is in a hurry. The president and CEO of deCODE genetics must get across town to see a former colleague at Beth Israel Deaconess hospital before dashing to the airport-and he still needs to squeeze in a promised interview with a journalist. In the cab, he alternates between discussing travel plans in Icelandic with a coworker and expounding on the intersection of disease and human evolution in English with TR associate editor Erika Jonietz.

Changing how genetics is done has kept Stefansson on this hectic pace since 1996, when he left Harvard Medical School and Beth Israel to found deCODE genetics, based in his native Iceland. In 1997 the company proposed construction of the first "phenotype database," a collection of the health records of all 280,000 Icelanders. DeCODE would use information from this centralized health-care database and Iceland's extensive public genealogy records to find disease-causing genes, aided by the relatively homogenous genetics of Iceland's population. This plan helped launch a revolution in population genomics (see "Your Genetic Destiny for Sale"), with a variety of other companies quickly following suit.

Although it's widely imitated, deCODE remains controversial. Editorials in publications from the New York Times to the New England Journal of Medicine attacked and defended the ethics and scientific merits of the proposal. After extensive public debate, Iceland's parliament approved the creation of the Icelandic Health Sector Database in December 1998 and granted deCODE a 12-year license to create and operate the database last January. A vocal minority, including the physician-led group Mannvernd, is still trying to stop the database in the courts, but deCODE has moved ahead. Last July, the company completed a successful initial public offering that raised $244 million.

TR: You were a professor at a leading medical school. Why leave and switch directions so radically to found deCODE?