There are thousands of mutations that can occur in the BRCA1 or BRCA2 gene, some of which may increase a person's risk of cancer and some of which may not. This, Mother Jones writes, means "[i]nterpreting a BRCA mutation is an art."
Labs and clinicians rely on previous studies, modeling, and more to tease out a mutation's meaning and have built up databases with information on various mutations, it adds. As Mother Jones notes, Myriad Genetics has the most extensive one, as it held a patent on the BRCA genes for years, though that was struck down in 2013. It adds that while some labs have pledged to add their data — doing so slowly — to public databases like ClinVar, it says that Myriad has kept its data private, citing patient confidentiality.
According to Mother Jones, the American Civil Liberties Union has gotten patients to request their data from Myriad to add to the public repositories. The ACLU also filed a complaint in 2016 to try to get the company to release more complete data, it adds. Myriad tells Mother Jones, though, that it gets hundreds of requests a year and provides appropriate responses.
But Mother Jones adds that as the ACLU awaits a response, the size of databases like ClinVar have grown and may soon make the request unnecessary.