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The Supreme Court Speaks: No Patent Protection For Isolated Naturally Occurring DNA

A recent Supreme Court opinion clarifies the patentability of genetic material. In the case of Association for Molecular Pathology et al. v. Myriad Genetics, Inc., et al., the Supreme Court unanimously held, on June 13, 2013, that a naturally occurring DNA segment is a product of nature and not patent eligible merely because it has been isolated. However, man-made complementary DNA (“cDNA”), having only the exon portions of a native DNA strand, is patent eligible because it is not naturally occurring. This article provides a summary of the Myriad case, followed by a brief tutorial on DNA for those interested in the science behind the case.

For developers of DNA-based technologies, Myriad offers a few important tips. Patent claims to naturally occurring nucleic acids are not patent eligible simply because the nucleic acids have been isolated. Patent eligible claims should be directed to non-naturally occurring nucleic acids, such as cDNA or man-made variant sequences. Alternatively, the invention should be protected as a method of performing a task using the DNA sequence, rather than seeking to protect the sequence itself. As early stage research on newly discovered DNA sequences cannot be patented, companies - and perhaps universities - may wish to use greater secrecy with potentially valuable DNA-based inventions until they have been distilled into practical (and protectable) methods. However, this cuts against the recent adoption of a “first-to-file” patent system in the United States, which encourages early patent filing. While Myriad provides a new bright line test with respect to patent eligibility, the best way to adapt to this guidance will depend upon the developer’s specific needs and the development stage of the DNA-based technology.

Explanation of the Case

Myriad Genetics, Inc. (“Myriad”) discovered the precise location and sequence of two human genes, BRCA1 and BRCA2. Mutations in these genes are linked to a substantial increase in risk of breast and ovarian cancer. Myriad used this information to develop medical tests that are useful in detecting mutations in a patient’s BRCA1 and BRCA2 genes, and thereby determining whether the patient has an increased risk of cancer.

Myriad obtained several patents directed to the BRCA1 and BRCA2 genes. Only claims directed to “isolated DNA,” that is, DNA separated from the rest of an organism’s genetic material, are at issue in the recent Supreme Court case. Several of the isolated DNA claims are directed to the DNA sequences of BRCA1 and BRCA2 as they exist in the human body. Other isolated DNA claims are directed to cDNA sequences corresponding to the proteins produced from the BRCA1 and BRCA2 genes.

Several entities offered genetic testing for BRCA mutation, which necessarily required isolation of the BRCA sequences, or portions thereof, from human patients. Myriad repeatedly asserted its patents against these entities, causing them to cease offering testing services.

A physician interested in offering BRCA genetic testing, along with patients, advocacy groups, and others, filed suit seeking a declaration that Myriad’s patents are invalid for being directed to patent-ineligible subject matter. U.S. patent law, specifically 35 U.S.C. § 101, states that a patent may be obtained for “any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof.” Courts have long recognized three judicially-created exceptions to these broad categories of patent-eligible subject matter, namely, “laws of nature, natural phenomena, and abstract ideas.”

The district court initially hearing the case granted summary judgment to the petitioners on the isolated DNA claims at issue based on its conclusion that both isolated DNA and isolated cDNA are patent-ineligible products of nature. On appeal, the Court of Appeals for the Federal Circuit reversed, holding both to be patent-eligible. The Supreme Court granted a petition for certiorari, vacated the judgment, and remanded the case for further consideration in light of another recent Supreme Court decision, Mayo Collaborative Services v. Prometheus Laboratories, Inc. Upon remand, Federal Circuit maintained its position that both isolated DNA and isolated cDNA are patent-eligible subject matter. The case then returned to the Supreme Court a second time.

Here, the Supreme Court held that an isolated naturally occurring DNA segment is a product of nature and not patent eligible merely because it has been isolated. When Myriad explained the extensive effort and difficulty required to identify the roughly 5,500 (BRCA1) and 10,200 (BRCA1) bases in the exons for each gene, as compared to the roughly 3 billion bases in the entire human genome, the Court noted that “groundbreaking, innovative, or even brilliant discovery does not by itself satisfy” the patent eligibility requirement. The Court also noted that Myriad did not create or alter the genetic information coded in the BRCA genes. The Court further determined that the Patent Office’s practice of issuing patents directed to isolated DNA was not a sufficient reason to hold that isolated DNA is patent eligible. In contrast, the Supreme Court acknowledged that cDNA is not naturally occurring and therefore should be considered patent-eligible subject matter.

The Supreme Court noted that its purview in Myriad did not include any method claims or any new applications of knowledge about the BRCA genes. The Court also did not consider the patentability of claims directed to DNA in which the order of the naturally occurring bases has been altered. In its earlier consideration of the case, the Federal Circuit found that method claims directed to “comparing” or “analyzing” DNA sequences were patent-ineligible, while method claims directed to screening potential cancer therapeutics via changes in growth rates were patent-eligible. Protecting DNA-based technology via method claims is a viable alternative to protecting cDNA or other non-naturally occurring nucleotide sequences, however, there is no bright line clearly dividing patent-eligible and non-patent eligible method claims.

An interesting point to ponder is that the Supreme Court explicitly expressed no opinion on whether cDNA satisfies the statutory requirements of novelty and non-obviousness for patentability. As explained below, a cDNA sequence can be predicted from a known mRNA sequence, or from a DNA sequence if the introns are known. We expect that claims directed to cDNA sequences based on known genes will likely face significant difficulty in satisfying the non-obviousness requirement.

Explanation of the Science

Deoxyribonucleic acid (“DNA”) is the molecule of heredity in all living organisms. Two long strands of DNA wrap around each other in the now well-known double helix configuration. Thinking of the double helix as a twisted ladder, the “rungs” of the ladder are nitrogenous bases. The strands are held together by bonds between the bases. There are four types of bases, adenine, thymine, guanine, and cytosine, abbreviated as A, C, G, and T, wherein A always pairs with T and C always pairs with G. Hence, one strand of DNA is the complement of the other.  



DNA Strand 1

DNA Strand 2

Genetic information is coded in the precise order of bases in the strand. A gene is a sequence of bases that is read (indirectly, as will be explained later) as a template to produce proteins. A mutation is an error in the genetic sequence, such as an erroneous pairing between an A and a C, or the addition or deletion of a base from one strand but not the other. Production of a protein from a mutated sequence may result in a non-functioning or malfunctioning protein.  

Unregulated cell growth, that is, cancer, can result from a variety of different genetic mutations. Both the BRCA1 and BRCA2 genes code for proteins that repair DNA. Patients with mutated BRCA1 or BRCA2 genes that produce non-functional proteins lack a vital repair mechanism and accumulate additional genetic mutations over time. If any of these additional mutations result in a non-functioning protein designed to restrain cell growth or a malfunctioning protein designed to encourage cell growth trapped in an “always active” state, cancer will result. Therefore, detection of mutations in BRCA1 or BRCA2 indicate an increased risk of cancer.


Creation of proteins from DNA involves two mains steps, known as transcription and translation. In transcription, the bonds between DNA strands separate and the helix partially unwinds into two separate strands. One strand is used as a template to create a complementary ribonucleic acid (“RNA”) strand. Bases in the DNA strand pair with their counterparts with the exception that RNA uses U instead of T. Transcription results in a single strand RNA molecule, known as pre-RNA.


DNA Strand 1


Eukaryotes, that is, all organisms apart from bacteria, often have discontinuous genes. Sequences of bases that code for a particular protein, referred to as exons (for expressed regions), are interspersed with introns (for intervening sequences). Pre-RNA is spliced in a complex operation to remove the introns, resulting in messenger RNA (mRNA). mRNA includes bases corresponding only to the exons in the original DNA strand. In translation, bases in the mRNA are read as instructions for assembling amino acids to form proteins.




exon   intron   exon


Scientists can extract DNA and RNA from organisms and isolate specific sequences using well known laboratory methods. Using the natural bonding between bases, a strand of mRNA can be used as a template to create a new synthetic DNA strand through a process referred to as “reverse transcription.” The resulting cDNA strand is the complement of the mRNA strand, and is identical to the original DNA strand with one significant exception: introns have been removed due to splicing. Therefore, a cDNA strand corresponds to the exon-only portions of the original DNA strand.



DNA Strand 1



If you have any questions regarding these or other patent matters, please contact Dr. Brian Chellgren or another patent attorney at Bingham Greenebaum Doll LLP.   [link to:]


To learn more about Brian W. Chellgren and his practice, visit his profile. [link to:]



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