Quest Diagnostics Inc, the world's largest provider of diagnostic testing services, is working with France's national health agency to build an expanded database for BRCA1 and BRCA2 gene mutations to better determine patient hereditary risks of breast and ovarian cancer.

Other medical testing companies and public laboratories can participate in the project, called BRCA Share, for which Quest will charge an annual fee in return for access to the curated database, Madison, New Jersey-based Quest said on Tuesday.

Laboratory Corporation of America, Quest's biggest U.S. competitor in medical diagnostics testing, has also agreed to participate.

Genetic information gathered from DNA testing is not always shared by diagnostics laboratories, which can make it difficult for those with smaller databases to analyze gene mutations. This can result in uncertainty for patients about their cancer risk and appropriate preventative care.

The French National Institute of Health and Medical Research collects all BRCA1 and BRCA2 genetic testing information in France through 16 labs that are part of the Unicancer Genetic Group and maintains a database that is the foundation of the project.

While other databases exist to share genetic information, differences in terminology and format as well as duplications can make them difficult to use, said Charles Strom, Quest's vice president for genetics and genomics.

With the broader pool, Quest will also be able to conduct research studies, he said.

Fees for access to the database will run from the tens of thousands of dollars to hundreds of thousands of dollars for private laboratories.

The number of tests for BRCA1 and BRCA2 mutations has jumped since Angelina Jolie revealed 18 months ago that she had the mutation associated with breast and ovarian cancer.

There are some mutations in the BRCA1 and BRCA2 genes that are well recognized as raising the risk of breast and ovarian cancer, but there are thousands of other possible mutations in the genes whose significance remains unknown.

In the United States, Myriad Genetics Inc has the longest history of BRCA testing as well as the highest volume of tests. It holds over 90 percent of the market for hereditary cancer testing and has cited its database as a competitive advantage.

Myriad had held a patent on BRCA1 and BRCA2 testing, but after the U.S. Supreme Court ruled it invalid, other laboratories entered the market in 2013.

In addition to Quest and LabCorp, Invitae Corp, privately held Ambry Genetics and the University of Washington in Seattle offer BRCA1 and BRCA2 testing.