Later, the company launched a media campaign to attract DNA donors on a larger scale. Family histories are part of the database. These actions allow deCODE to combine genetic information with the genealogical and health records of each Icelander in order to create a comprehensive database. With so much personal information available to a private enterprise, scientists and policy makers are watching the endeavor closely to see how the ethical, legal, and business aspects are resolved. Most Icelanders can trace their ancestry back 1200 years.
Homogeneity is a big plus in studying genetic disorders of populations.
Iceland's population is relatively small - about 275,000 people. Detailed individual medical records have been maintained by public health services since 1915. There is an advantage to having genealogical data when studying a group's DNA, e.g. a list of people with a common disease can be run through the genealogical database to look for clues to genetic and environmental causes for the disease. The country is isolated geographically, with little migration from other places ever since a few hundred Vikings and some Celts arrived almost 1200 years ago. In addition, over the centuries, a series of disasters such as plague and famine, have minimized the opportunity for new genetic input into the country's gene pool.