Meanwhile, genetic carrier tests are more accurate because scientists know more about single gene disorders, such as Huntington's disease and sickle cell anemia, Faucett said.

CNN: Walgreens postpones plans to sell personal genetic tests

Most genetic tests have not been approved by the FDA, said W. Andrew Faucett, director of the genomics and public health program at the Emory University School of Medicine.

CNN: Walgreens postpones plans to sell personal genetic tests

"You can get different risks based on this test versus a similar test done by one of their competitors because they're looking at different risk markers and using different risk algorithms, " Faucett said.

CNN: Walgreens postpones plans to sell personal genetic tests