Google Inc-funded 23andMe launched on Monday and began offering a DNA saliva test for $999 per person, which would help U.S. users of the online site learn about disease risk, inherited traits and their ancestry.

Eventually users, who sign up for the saliva test online and receive it by mail, will also be able to participate in research.

Those who are tested may choose to learn their risk for developing certain cancer, Alzheimer's disease, diabetes and other illnesses, and get a referral from 23andMe to genetic counselors.