You can now go online and order a genetic test to find some mutations that increase breast and ovarian cancer risk as easily as you order a pizza delivery.

The Food and Drug Administration on Tuesday let the personal genetics company 23andMe become the first to market a test for three inherited BRCA gene mutations directly to consumers — no doctor's prescription needed.

The company — which was ordered to stop doing the same thing in 2013 because the test wasn't scientifically validated — called FDA approval "a major milestone in consumer health empowerment." The firm submitted data showing that the saliva-based DNA test was accurate for the mutations it detects and that consumers understood the results.

Genetic counselors and patient advocates expressed misgivings.

The test, to be offered as part of 23andMe's $199 "health plus ancestry" kit, looks for only the three BRCA mutations that are most common in people of Eastern European Jewish descent.  But BRCA1 and BRCA2 are huge genes, with more than 1,000 known mutations that dramatically increase the risk of breast and ovarian cancer.

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Lisa Schlager, vice president for community affairs at FORCE, an advocacy group dedicated to BRCA mutation carriers, said: "We did not know this was coming and are dismayed by its approval. We have significant concerns that consumers won't really understand the limitations."

Andrea Forman, a genetic counselor at Fox Chase Cancer Center in Philadelphia, echoed that worry. The three mutations are present in about 2 percent of Ashkenazi Jewish women, and account for 90 percent of the BRCA defects inherited by that ethnic group. But other ethnic populations very rarely have any of these so-called founder mutations.

"If you're Jewish, a negative result is reassuring," Forman said. "But 23andMe offered this testing several years ago and the FDA shut it down, partly because of the concern that people would be falsely reassured."

National guidelines recommend professional genetic counseling and BRCA testing for any woman with ovarian cancer, and for healthy women with family histories of breast and ovarian cancer.

But 23andMe CEO and cofounder Anne Wojcicki said the guidelines "limit who has access to BRCA testing."

"Many people do not know their family medical history or their ancestry," she wrote in a blog post Tuesday. "So, many people fall through the cracks in the current screening system, leaving them unaware of their risk."

The FDA stressed that the direct-to-consumer BRCA test comes "with a lot of caveats." Consumers and health-care providers should not use the results to decide on risk-reducing strategies such as intensive screening or preventive surgical removal of the breasts or ovaries. Nor should the test be used "without consulting a physician or genetic counselor," the FDA said in a statement.