Direct-to-consumer genetic testing is an emerging, highly publicized industry, despite considerable skepticism among experts. Advances in sequencing and genomics have revealed some correlations between particular genetic sequences and certain diseases, physical characteristics, and behaviors, though these relationships are not perfectly understood. Nevertheless, entrepreneurs have seized on these correlations to sell tests that purport to indicate whether the customer has an increased risk of a disease or other characteristic. Similarly, associations of genetic sequences with specific geographical locations have led to commercial “ancestry tests.”

Evaluating the claims of these companies is difficult, since their technologies are typically kept private and there is minimal oversight. Medical tests are supposed to be supervised by a physician, and testing laboratories need to be licensed. California has worked with Navigenics and 23andMe, two of the best-known companies, to ensure that they are operating legally in the state, but these Internet-based businesses raise regulatory concerns that cross state boundaries.

This industry may contribute to an over-emphasis on genes as determinants, possibly at the expense of environmental, economic and social considerations. A further concern is the possible use of DNA databases developed by private companies, whose business plans include profiting from the compiled data. Finally, although the companies insist that they will respect the privacy of their customers, there is no effective guarantee.