On June 13, 2013, the U.S. Supreme Court decided in Association for Molecular Pathology v. Myriad Genetics, Inc., No. 12-398, holding that a "naturally occurring DNA segment is a product of nature and not patent eligible merely because it has been isolated, but that cDNA [complementary DNA] is patent eligible because it is not naturally occurring." The Court was careful to note that "[t]his case…does not involve method claims, patents on new applications of knowledge about the [genes at issue], or the patentability of DNA in which the order of the naturally occurring nucleotides has been altered."

According to the Court, "Myriad discovered the precise location and sequence of what are now known as the BRCA1 and BRCA 2 genes. Mutations [i.e.,changes] in these genes can dramatically increase an individual's risk of developing breast and ovarian cancer…This knowledge allowed Myriad to determine the genes' typical nucleotide sequence [i.e., code], which, in turn, enabled it to develop medical tests useful for detecting mutations [i.e.,changes in the code] in these genes in a particular patient to assess the patient's cancer risk." Myriad accomplished this by extracting DNA from cells and isolating the genes in question. In addition, Myriad created "complementary DNA" (cDNA) based on an intermediate molecule in the process called messenger RNA (mRNA). While isolated genes (DNA) include periodic segments called exons that join together and encode protein, they also typically include segments between the exons, called introns, that do not encode protein and that are removed prior to making a protein by a process called "splicing." In this cellular process of making a protein encoded by the DNA, mRNA is produced, which includes joined exons but not the introns that existed in the DNA. Myriad used mRNA in a reverse-engineering process to generate cDNA.

Myriad obtained a number of patents on BRCA1 and BRCA2 genes. Some of its claims in the patents covered isolated DNA encoding BRCA1 and BRCA2 polypeptides, while other claims covered cDNA made from mRNA associated with BRCA1 and BRCA2. According to the Supreme Court, Myriad's patents would, if valid, give it the exclusive right to exclude others from isolating a person's BRCA1 and BRCA2 genes by breaking the covalent bonds that connect the DNA to the rest of the individual's genome.

The Association for Molecular Pathology sued Myriad, claiming that Myriad's patents are invalid under 35 U.S.C. § 101 because they cover products of nature. The District Court agreed with the association and held all of the asserted claims invalid. The Federal Circuit reversed, and held that both isolated DNA and cDNA were patentable under Section 101.

The Supreme Court affirmed in part and reversed in part. The Supreme Court disagreed with the Federal Circuit that isolated DNA was patentable. According to the Supreme Court, Myriad "found an important and useful gene, but separating that gene from its surrounding genetic material is not an act of invention." The Supreme Court distinguished its decision in Diamond v. Chakrabarty, 477 U.S. 303 (1980), on the ground that the patented bacterium in that case was created when scientists added four plasmids to a previously existing bacterium, thus creating a bacterium "with markedly different characteristics from any found in nature."

But the Supreme Court agreed with the Federal Circuit that cDNA presents a different situation, and is patentable under Section 101 because cDNA does not exist in nature. The Court stated that "cDNA retains the naturally occurring exons of DNA, but it is distinct from the DNA from which it was derived." The Court cautioned that its holding in this regard may not apply when a gene sequence has no introns that are removed in the production of mRNA.

Justice Thomas delivered the decision for a unanimous Court.

Link to opinion