WASHINGTON (June 11, 2010)—The U.S. Food and Drug Administration is issuing regulatory letters to five genetic test makers, the first sign that the government is cracking down on companies that claim to use DNA samples to predict inheritable diseases.

The FDA letters notify each company that their tests are considered medical devices and therefore must be federally approved as safe and effective.

None of the companies has submitted their products for approval, according to the FDA.

The letters posted online deal with specific tests marketed by 23andMe Inc., deCODE Genetics, Illumina, Navigenics and Knome Inc.

FDA asks each of the companies to contact the agency to make arrangements for submitting tests for review.