U.S. Supreme Court Holds That Isolated Human Genes Cannot Be Patented, but cDNA Can

On June 13, 2013, in Association for Molecular Pathology v. Myriad Genetics Inc., the Supreme Court of the United States ruled on whether Myriad Genetics’ patents for the human BRCA1 and BRCA2 genes (i.e., naturally occurring DNA segments) are directed to patentable subject matter. In a unanimous decision, the Court held that a "naturally occurring DNA segment is a product of nature and not patent eligible merely because it has been isolated, but cDNA [complementary DNA] is patent eligible because it is not naturally occurring."

This decision reverses the decades-long practice of the U.S. Patent and Trademark Office (USPTO) of granting patents on naturally occurring DNA sequences as long as they are "isolated" from nature.


Myriad’s patents relate to the exact location and sequence of two genes: BRCA1 and BRCA2. Mutations in these genes can dramatically increase an individual’s risk of developing breast and ovarian cancer. Information on the typical sequence of these two genes enabled Myriad to develop medical tests for assessing whether a patient’s DNA sample has mutations in these genes and, therefore, an increased risk of cancer.

Section 101 of U.S. patent law provides that new and useful compositions of matter and new and useful improvements to compositions of matter are patentable subject matter. However, the courts have long held that this provision contains an implicit exception against patenting the laws of nature.

The U.S. Supreme Court’s Decision

The U.S. Supreme Court found that the principal contribution of Myriad was uncovering the precise location of the BRCA1 and BRCA2 genes within their chromosomes. Myriad did not create or alter any of the genetic information in the BRCA1 or BRCA2 genes; this information existed in nature before Myriad discovered it. The Court stated that although these are important and useful genes, separating a gene from its surrounding genetic material, regardless of how research-intensive this may be, is insufficient to satisfy the requirement under §101 that a composition of matter not be a product of nature.

The Court did, however, find that cDNA may be patentable. cDNA contains only the portions of naturally occurring DNA that code for proteins (i.e., the non-coding portions of naturally occurring DNA are removed), making the cDNA distinct from the DNA from which it was derived. cDNAs are not products of nature – they are synthetic DNA molecules that are created in a laboratory. Although the Court held that cDNAs as a class are patent eligible, it cautioned that not all cDNAs will be patentable subject matter. If a short cDNA sequence is derived from naturally occurring DNA but cannot be distinguished from the naturally occurring DNA, it will not be patentable.

The U.S. Supreme Court indicated that its decision does not implicate the patent eligibility of any type of method claims, and expressly noted that Myriad could have sought to patent any "innovative method of manipulating genes" that it invented while searching for the BRCA1 and BRCA2 genes. The Court also stated that this case "does not involve patents on new applications of knowledge about the BRCA1 and BRCA2 genes". In addition, the Court said that it was not deciding on "the patentability of DNA in which the order of the naturally occurring nucleotides has been altered," because these endeavours involve a different inquiry.


Shortly after the decision was released, a memorandum was sent to patent examiners at the USPTO directing them to reject product claims "drawn solely to naturally occurring nucleic acids or fragments thereof, whether isolated or not." The memorandum also states that the USPTO will review the decision and will issue more comprehensive guidance on patent eligible subject matter.

As a consequence of this decision, issued U.S. patents and patent applications claiming isolated DNA or short DNA sequences may be attacked for lack of patentable subject matter. Patent owners and applicants may wish to review their patent portfolios to determine if their patents or applications are vulnerable to such attacks. However, it is still possible to obtain patents on new genetic discoveries, including "innovative methods of manipulating genes" and "new applications of knowledge" obtained from these genes. This decision also provides positive news for companies that rely on cDNA information to make therapeutic proteins.

There is no doubt that courts and patent authorities in other jurisdictions will be looking at the decision of the U.S. Supreme Court, at least for the purpose of considering the reasoning it articulated. However, it remains to be seen how this decision will affect gene patents in Canada and around the world.

To discuss these issues, please contact the author(s).

This publication is a general discussion of certain legal and related developments and should not be relied upon as legal advice. If you require legal advice, we would be pleased to discuss the issues in this publication with you, in the context of your particular circumstances.

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