What to Know 23andMe is preventing third-party developers from accessing customers' raw genetic information

The company sent an email to its developer partners on Thursday

More than 5 million people have purchased 23andMe's at-home DNA test

23andMe, which provides DNA testing kits for consumers, is telling outside app developers that they'll no longer have access to the company's raw genomic data.

Developers of health apps, weight loss services and quantified self tests have been able to use 23andMe's anonymized data sets since 2012, when the company announced the opening of its application programming interface (API). The idea was to "allow authorized developers to build a broad range of new applications and tools for the 23andMe community," the company said at the time.

But on Thursday, 23andMe sent an email to developers, informing them that the API was being disabled in two weeks and that apps will only be able to use reports generated by the company and not the hard data.

"We're updating our API program to focus on apps that build on the interpretations and results we provide to our customers," 23andMe said in the email, which was viewed by CNBC.

23andMe is one of the largest makers of at-home DNA tests, which start at $199. More than five million people have sent in a spit sample in exchange for information about their ancestry, as well as some personalized health reports, like whether they're at greater risk of developing breast cancer.

The company works with pharmaceutical developers aiming to use genetic information to identify new drugs, and with academic researchers on genetics studies.

The API is currently being used by dozens of developers, said a person familiar with the matter, who asked not to be named because the information is confidential. It's caused controversy for 23andMe in the past. In 2015, Wired reported on an application that was using the API to block people from websites and apps based on personal characteristics like their gender and ancestry.

Developers will now be much more limited in how they access 23andMe's rich data and potentially in the services they can offer consumers. The company acknowledged changes to the program in an email to CNBC.

"Moving forward, we will only partner with developers building applications that leverage the data based on 23andMe reports," the company said. "Our hope is to bring added value to customers' overall experience. We're notifying existing developers and any impacted customers now in order to help them prepare for the changes to our program."

Raw data will still be available to research partners.

Privacy concerns

23andMe hasn't said if the move is designed to retain control over its data or in response to concerns about user privacy. The company had plans several years ago to launch an app store, according to two people familiar with the matter, but opted not to move forward with the project because of challenges with vetting third-party developers.

At-home DNA testing companies have been at the center of a privacy firestorm in recent months.

Earlier this year, police arrested a suspect in the decades-old Golden State Killer case based on genetic information, when investigators used an open-source service called GEDmatch to look for potential matches to DNA samples from the crime scene. The case involves 12 deaths and at least 50 rapes in California between 1974 and 1986.

23andMe customers can still choose to upload their genetic information to a service like GEDmatch and share it online or with a particular developer.

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