Patient groups have a message for anyone thinking of taking 23andMe's new test

By the end of the month, 23andMe users will start to see some results among their other health and ancestry reports, including the results that tell you if you have an increased risk of Alzheimer's and Parkinson's disease.

The report will come with communications about what the test can and can't tell people. Still, members of a number of patient advocate groups have one piece of advice for those interested in seeing the results: talk to a genetic counselor, a professional who can explain the implications of what an increased risk for certain diseases means or your doctor.

On Thursday, the FDA identified 10 risk tests that 23andMe could include Parkinson's disease, late-onset Alzheimer's disease, Celiac disease, Gacher disease, as well as some other rare and blood disorders.

The Celiac Disease Foundation said they welcomed the news, but hopes that people will talk to their doctors if they test positive. Celiac disease is an autoimmune disorder in which the body can't process gluten, the protein found in wheat and other grains.

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An increased risk doesn't mean a person will necessarily get the disease — just that the chances are higher. For example, in a cancer-screening genetics test — which is not among the 10 that 23andMe is allowed to market — the risk of getting breast cancer increases to as high as 65% from 7% when a person has the BRCA1 or BRCA2 gene mutations. The FDA said in the release that this type of test counted functions as a diagnostic test, so it and others like it weren't included as part of the market authorization.

Some genetic tests can tell you a lot more definitively about what that risk means than others. For cystic fibrosis, if you have one of the variants associated with the disease, you will then have the inherited lung disorder. But when it comes to Parkinson's, Lehr explained, even if you genetics suggest you have an increased risk in the disease, the risk is still relatively low. The biggest risk factor is age, he said.

The same can be said for late-onset Alzheimer's. Keith Fargo, the Alzheimer's Association director of scientific programs and outreach, told Business Insider that there are three levels of genetic risk when it comes to Alzheimer's. The highest are the genes connected to early-onset Alzheimer's. In those cases, if you have the mutation, you will have the disease.

The second level is the APOE gene, which is the one 23andMe's test will screen for. In that case, if you have one copy of the mutation, you're at a three-times higher risk of one day getting Alzheimer's. If you have two copies, the risk goes up even more. Even so, it's not a done deal, Fargo said. People with multiple copies sometimes don't get the disease, and people with no copies can still get the disease. Then there are others that have been linked to an increased risk, but these are still mostly useful in the context of research.

The best place for APOE genetic testing, Fargo said, is in pinpointing the right Alzheimer's patients for certain clinical trials.

"It's extremely useful from a research perspective," he said. It's less useful for people who aren't experiencing symptoms. As with Parkinson's, age is a bigger risk factor. For people who live to be 85, they have a 33% chance of having Alzheimer's.

Getting the tests back on the map

Back in November 2013, the US Food and Drug Administration barred 23andMe from sending any of that data related to health to customers because of concerns that the company was misrepresenting genetic tests as medical advice.

When the test relaunched in 2015, 23andMe was able to provide health reports showing whether a person carried a variant for a genetic disease that could be passed down to his or her child, along with wellness reports providing information about caffeine consumption and lactose intolerance.

Now that the FDA has given 23andMe clearance, Hibbs said the company hopes to work with patient groups to make sure everyone's on the same page. During the FDA process, a lot had to be confidential, Hibbs said. Fargo said the Alzheimer's Association has been communicating for the past few years, and there are more discussions scheduled in the coming weeks to go over the announcement.