A high bar is likely to be set for companies seeking to sell genetic tests directly to consumers, according to top Food and Drug Administration officials.

The agency is convening a two-day public hearing starting Monday to discuss how it would regulate diagnostic tests, including direct-to-consumer tests.

In an interview, Jeffrey Shuren, head of FDA's medical-devices division, and Alberto Gutierrez, who oversees the FDA unit that regulates certain laboratory tests, said they considered direct-to-consumer genetic tests "high risk" and have already informed companies selling such tests through their websites that their tests appear to be medical devices requiring FDA approval.

Mr. Shuren suggested it could be difficult for direct-to-consumer tests to gain agency approval the way they are currently marketed. Mr. Shuren said he was concerned about cutting doctors out of the process of interpreting laboratory tests and afraid consumers could make risky medical decisions based on information that suggests they are at risk of developing cancer, diabetes or other diseases or could stop taking a needed medication.

The issue came to light in May after Pathway Genomics Corp., a closely held firm based in San Diego, announced plans to sell its Insight Saliva Collection Kit through Walgreen Co. and CVS Caremark Corp. Both retailers backed out of plans to sell the test after the FDA raised concerns.

The Insight Saliva and similar tests such as ones sold by other California firms, 23andMe Inc. and Navigenics Inc., are designed to predict a person's risk for developing certain diseases or how they might respond to certain drugs.

Pathway recently changed course and now requires its test to be ordered through a physician.

Direct-to-consumer tests are only one part of a broader category of diagnostic tests that haven't been FDA regulated.

The American Clinical Laboratory Association, which represents laboratories and makers of the tests, said it believes that current regulations do need to be updated, but said it was concerned that if current FDA medical-device regulations are applied to lab tests that it might impede the development of "cutting edge tests."

The FDA does regulate laboratory tests that are sold to hospitals and doctor's offices along with over-the-counter tests like blood glucose test strips, but it hasn't required approval for laboratory-developed tests that fall under a system regulated by the Centers for Medicare and Medicaid Services.

CMS certifies laboratories, but if a test is analyzed in the same lab, it traditionally hasn't required FDA approval because such tests were considered low-risk and easy to understand. But now that such laboratory-developed tests can predict a person's risk for cancer recurrence or the risk of developing other diseases, FDA officials say those should go through the FDA-approval process.

The move would affect several other companies including Quest Diagnostics and Laboratory Corporation of America, or LabCor, and Genomic Health Inc., which sells a test that's well regarded in the medical community for predicting the risk of breast-cancer recurrence.