CHICAGO (Reuters) - Genetic tests sold directly to consumers to help people trace their ancestry are imperfect and may lead some people to draw unfounded conclusions about their heritage, a report on the tests released on Thursday found.

More than 40 companies, including 23andMe Inc in Mountain View, California, in which Google has invested, and privately held Pathway Genomics Corp in San Diego, sell the tests to consumers.

They are not intended to provide insight into health information. Instead, the tests give a rough estimation of a person’s genetic ancestry.

But the growing popularity of the tests, which are not regulated, has raised some concerns among genetic experts who fear consumers are not fully aware of their limitations.

“A major issue regarding commercial ancestry testing is that there is no quality assurance guarantee,” according to a report led by researchers at Duke University on behalf of the American Society of Human Genetics and published in The American Journal of Human Genetics.

Joann Boughman, executive vice president of the American Society of Human Genetics, said genetic ancestry testing is very useful for understanding genetic differences in things like blood type or genetic diseases in large populations of people.

But they are less useful for individuals.

“If you swabbed your cheek and sent your DNA off to find out what your ancestral origins are, you would get a result back saying you are 5 percent African, 12 percent European and 70 percent Asian, or something like that,” Boughman said.

“The question we want people to think about is, what does that mean? Why would I want that information?”

The group is concerned that consumers who get the test results might read too much into them.

“Sometimes there are social and political and even economic implications,” Boughman said in a telephone interview. “In some states in the country, you have to prove you are a member of a specific Indian tribe to have access to either land or earnings from investments even in casinos.

“One of the ways you would supposedly be able to prove or disprove you were from that tribe is through this genetic ancestry testing,” she said.

A negative result could mean that those genes had been lost in an individual’s line because parents only pass along half of their genes to their children, she said.

Spokesmen for Pathway and 23andMe Inc could not be immediately reached for comment.

Boughman said genetic ancestry testing is different from direct-to-consumer genetic tests for health information, but the group has concerns about those too.

Walgreen Co this week planned to distribute genetic health tests from Pathway Genomics in its stores, but put those plans on hold after the U.S. Food and Drug Administration expressed concerns that the tests were not approved by the agency.