In a landmark case centering on gene patenting, the U.S. Supreme Court on Thursday ruled unanimously that patents can be held on synthetically produced genetic material but not on naturally occurring human genes. This will profoundly affect breast cancer screenings because it opens the field of diagnostic breast cancer testing services to all competitors, as the court ruled that isolated DNA sequences, natural to the human body, are not eligible to be patented.

The case was brought by the ACLU against Myriad Genetics, which had patented two genes linked to breast and ovarian cancer. In 1994, Myriad, along with its partners, isolated the sequence of the breast cancer gene named BRCA1. They patented the gene. In 1995, they isolated  the sequence of the BRCA2 gene, and patented that. In 1996, Myriad introduced the BRACAnalysis product, which detects certain mutations in the BRCA1 and BRCA2 genes that can prove women to be at high risk for breast cancer and ovarian cancer.

Because Myriad owned the patents, there was no competitive market for lowering the cost of breast cancer screening, but now there will be an open field for diagnostic services.

But Myriad was content with the ruling because the Court allowed patent protections on forms of DNA produced by scientists in laboratories, called cDNA.  The processes used to carry out diagnostic tests are also eligible for patents. If the Court had ruled all genetic material, synthetic and natural was unpatentable, millions of dollar in investment would have been lost.

In the Court’s opinion, written by Justice Clarence Thomas, he wrote, “A naturally occurring DNA segment is a product of nature and not patent eligible merely because it has been isolated, but cDNA is patent eligible because it is not naturally occurring.”