The Core Rule: A naturally occurring DNA segment is a product of nature and is not patent-eligible merely because it has been isolated. Complementary DNA (cDNA), by contrast, is generally patent-eligible when it is not naturally occurring, subject to the limits explained by the Court.
1. Executive Summary
In Association for Molecular Pathology v. Myriad Genetics, Inc., the U.S. Supreme Court held that naturally occurring segments of DNA are not patent-eligible under 35 U.S.C. §101 simply because they have been isolated from the human genome. The Court reached a different conclusion for cDNA, which is created in the laboratory by removing introns from a messenger-RNA template and generally has a sequence not found in that form in nature.
The case concerned patents on BRCA1 and BRCA2 genes, variants of which are associated with increased risk of breast and ovarian cancer. Myriad’s discovery of the genes’ locations and mutations was scientifically important, but the Court distinguished discovery of a natural DNA sequence from creation of a non-naturally occurring DNA molecule.
WHY IT MATTERSMyriad draws a boundary between discovering and isolating a natural product and creating something with a materially different composition. It reshaped biotechnology patent strategy while leaving many questions about methods, applications, and other engineered biological materials to be assessed under their own claims.
2. Case at a Glance
- Court: Citation — Supreme Court of the United States: 569 U.S. 576 (2013)
- Court: Docket — Supreme Court of the United States: No. 12-398
- Court: Argued / decided — Supreme Court of the United States: April 15, 2013 / June 13, 2013
- Court: Opinion — Supreme Court of the United States: Justice Clarence Thomas
- Court: Vote — Supreme Court of the United States: Unanimous opinion; Justice Scalia concurred in part and in the judgment
- Court: Statute — Supreme Court of the United States: 35 U.S.C. §101 — patentable subject matter
- Court: Disposition — Supreme Court of the United States: Federal Circuit affirmed in part and reversed in part
3. Scientific Background: Genes, DNA, and BRCA1/BRCA2
DNA carries genetic information in a sequence of nucleotide bases: adenine (A), thymine (T), cytosine (C), and guanine (G). A gene is a DNA sequence associated with a functional product, often a protein or functional RNA. In many human genes, coding segments called exons are interspersed with noncoding segments called introns.
Why BRCA1 and BRCA2 mattered
Certain inherited variants in BRCA1 and BRCA2 are associated with substantially increased risks of breast and ovarian cancer.
Identifying the genes and their variants can help assess inherited cancer risk and inform clinical decisions.
Myriad researchers located the genes and identified mutations associated with increased risk. The dispute was about whether claims to isolated DNA molecules and related inventions were patentable.
The basic molecular pathway
- Genomic DNA: DNA in the chromosome includes exons and introns. — Transcription: A gene is transcribed into a primary RNA transcript. — RNA processing: Introns are removed and exons joined to form mature mRNA. — Protein (for protein-coding genes): The mRNA can be translated into a protein.
cDNA (complementary DNA) is made using mature mRNA as a template. Because the mature mRNA has had introns removed, cDNA ordinarily lacks the introns found in the corresponding genomic DNA. This difference drove the Court’s treatment of cDNA.
Visual Distinction: Genomic DNA: naturally occurring sequence, including introns in the relevant gene. | cDNA: laboratory-created DNA copy of processed mRNA, ordinarily lacking introns.
4. The Parties and the Challenged Patents
Myriad Genetics held patents related to BRCA1 and BRCA2, including claims to isolated DNA and cDNA, as well as claims concerning methods and screening technologies. The Association for Molecular Pathology, medical professionals, researchers, patients, and other plaintiffs challenged certain claims, arguing that they covered products of nature and abstract ideas.
What the challengers said
The genetic information in isolated BRCA DNA was the same information encoded in naturally occurring genes.
Removing a DNA segment from a chromosome did not make its nucleotide sequence a human invention.
Patents on the genes could affect clinical testing, scientific research, and the ability to study genetic variants.
Myriad’s position
Myriad argued that isolated DNA molecules were chemically distinct from DNA as it exists within chromosomes, and that identifying and isolating the genes required substantial scientific effort. The Supreme Court held that the discovery effort, however significant, did not make the naturally occurring genetic information patent-eligible as a product of nature.
5. Procedural History
District Court — Held the challenged claims invalid under §101, finding that the relevant DNA claims covered products of nature and that certain method claims were ineligible.
Federal Circuit — first decision — Reversed in part, treating isolated DNA as patent-eligible and reaching differing conclusions on method claims.
Supreme Court — first review — Vacated and remanded for reconsideration in light of Mayo Collaborative Services v. Prometheus Laboratories (2012).
Federal Circuit on remand — Again held isolated DNA claims eligible, reasoning that isolated DNA had a different chemical structure, while method-claim outcomes varied by claim.
Supreme Court — 2013 — Held naturally occurring DNA segments ineligible even when isolated, but held cDNA generally eligible because it is not naturally occurring in the same form. It did not decide the eligibility of every method or application claim that might involve BRCA genes.
6. The Legal Question and Holding
Can a naturally occurring segment of DNA become patent-eligible merely because it has been isolated from the human genome? And does laboratory-created cDNA receive the same treatment?
Holding: No for naturally occurring DNA segments: isolation alone does not make them patentable. Generally yes for cDNA: it is not naturally occurring in the same form, although very short DNA sequences may present special cases where no introns are present to remove.
7. Section 101 and the Product-of-Nature Exception
Section 101 broadly identifies patentable subject matter, but the Supreme Court has recognized exceptions for laws of nature, natural phenomena, and products of nature. These exceptions prevent patents from removing basic tools of science from public use.
The key question was not whether Myriad had discovered something valuable. It was whether the claimed composition was something the inventors had created or instead a naturally occurring genetic sequence that they had located and isolated.
Discovery versus invention
- Concept: Discovery — Illustration: Finding where BRCA1 or BRCA2 occurs in the genome. — Myriad analysis: Scientifically important, but discovery alone does not create a patent-eligible natural DNA segment.
- Concept: Isolation — Illustration: Removing a DNA segment from surrounding chromosomal material. — Myriad analysis: Isolation alone does not change the natural genetic information in a way sufficient for eligibility.
- Concept: Creation / modification — Illustration: Producing a DNA molecule whose relevant structure is not naturally occurring in that form. — Myriad analysis: May support eligibility, as with cDNA, depending on the claimed molecule and the facts.
8. Why Isolated Genomic DNA Was Ineligible
The relevant information exists in nature — The nucleotide sequence that identifies the BRCA gene is encoded in the human genome.
Locating the gene was not the same as creating it — Myriad’s work identified the location and sequence, but the Court distinguished that discovery from invention of the sequence itself.
Isolation did not overcome the product-of-nature rule — The Court rejected the argument that the chemical severing of DNA from the chromosome alone made the claimed genetic information patent-eligible.
The Court focused on the nature of the claimed composition — The analysis was directed to the claims before it, not a declaration that every isolated biological material is unpatentable.
PRECISE SCOPEThe decision addresses naturally occurring DNA segments claimed as isolated DNA. It should not be read as deciding that all biotechnology inventions, all engineered DNA, or every diagnostic method involving genes is ineligible.
9. Why cDNA Was Treated Differently
The Court explained that cDNA is created by using mature messenger RNA as a template to make a DNA copy. Since mature mRNA has had introns removed, cDNA generally omits introns and therefore is not the same DNA molecule as the naturally occurring genomic segment.
The exon sequence in cDNA corresponds to the coding portions of the gene.
The introns present in genomic DNA are absent from ordinary cDNA made from processed mRNA.
That structural difference meant cDNA was not a naturally occurring product in the same form and was generally patent-eligible under the product-of-nature analysis.
QUALIFICATIONThe Court noted that a short stretch of DNA may not be patent-eligible as cDNA if it contains no introns to remove and therefore is not meaningfully different from the naturally occurring sequence.
10. What the Court Did Not Decide
It did not decide the patent eligibility of every method claim involving BRCA genes.
It did not decide all claims directed to new applications of knowledge about BRCA1 or BRCA2.
It did not hold that all cDNA claims are automatically valid under every patentability requirement.
It did not decide that a naturally occurring DNA sequence becomes eligible merely by being described, detected, or associated with a medical use.
It did not decide that all engineered DNA molecules or other modified biological compositions are ineligible.
Patent eligibility under §101 is only one requirement. A claim must also satisfy applicable novelty, non-obviousness, disclosure, enablement, and definiteness rules.
11. Relationship to Mayo and Other Cases
- Case: Diamond v. Chakrabarty (1980) — Central principle: A genetically engineered bacterium with markedly different characteristics was patent-eligible. — Connection: Contrasts a human-created composition with a naturally occurring DNA segment.
- Case: Diamond v. Diehr (1981) — Central principle: A specific industrial process using a mathematical relationship may be eligible when considered as a whole. — Connection: Shows that use of a scientific principle within a concrete process differs from claiming a natural product itself.
- Case: Mayo v. Prometheus (2012) — Central principle: Routine steps added to a natural correlation may not create an eligible application. — Connection: Myriad cited the same concern about monopolizing basic tools of science, but dealt with naturally occurring DNA compositions.
- Case: Association for Molecular Pathology v. Myriad (2013) — Central principle: Isolated naturally occurring DNA is ineligible; cDNA generally differs because it is lab-created. — Connection: The case’s central distinction.
- Case: Alice Corp. v. CLS Bank (2014) — Central principle: Claims directed to abstract ideas require an inventive concept beyond routine implementation. — Connection: Later application of the two-step framework associated with Mayo, in a different judicial-exception context.
12. Worked Claim Concepts
Concept A — isolated naturally occurring BRCA gene
ILLUSTRATIVE CLAIM IDEAAn isolated DNA molecule comprising a naturally occurring BRCA1 nucleotide sequence, merely because the sequence has been separated from the chromosome.
Why vulnerable under Myriad: the claim is directed to the naturally occurring genetic sequence, and isolation alone does not make that sequence patent-eligible.
Concept B — cDNA molecule
ILLUSTRATIVE CLAIM IDEAA cDNA molecule corresponding to a gene’s mature mRNA, with introns absent because the DNA copy is made from processed RNA.
Why it may be eligible under Myriad: cDNA is generally not naturally occurring in the same form. This does not guarantee validity; novelty, non-obviousness, enablement, written description, and other requirements still apply.
Concept C — method using a gene sequence
ILLUSTRATIVE CLAIM IDEAA defined laboratory method that uses a gene sequence as one element of a specific technical procedure.
Why the answer is not automatic: Myriad did not resolve every method claim. The claim must be analyzed based on its actual steps and subject matter, including any relevant Mayo-type concerns if it relies on a natural relationship.
These are teaching examples, not actual claims from the litigation and not legal advice.
13. Practical Lessons for Biotechnology and Patent Drafting
Do not rely on isolation alone. — Explain what human-created structure or technical feature makes the claimed molecule different from its natural counterpart.
Define the claimed molecule precisely. — Distinguish genomic DNA, cDNA, short sequences, modified sequences, vectors, and other constructs in the claim language and specification.
Separate discovery from implementation. — A discovery of a gene or natural sequence is different from a specifically engineered construct, assay, or process using that knowledge.
Do not overread Myriad. — The decision was about particular DNA composition claims; method claims and new applications require claim-specific analysis.
Support the technical contribution in the specification. — Describe how engineered elements are made and what structural or functional properties distinguish them.
Analyze every patentability requirement. — Section 101 eligibility does not substitute for novelty, non-obviousness, written description, enablement, or definiteness.
14. Ratio Decidendi
RATIOA naturally occurring DNA segment is a product of nature and does not become patent-eligible merely because it has been isolated from surrounding genetic material. cDNA is generally eligible because its intron-free structure is created in the laboratory and is not naturally occurring in the same form, subject to the Court’s qualification for sequences that do not differ meaningfully from nature.
15. Key Terms
- Term: Genomic DNA — Meaning: DNA as organized in chromosomes, including introns where present.
- Term: Gene — Meaning: A DNA sequence associated with a functional product, often a protein or RNA.
- Term: BRCA1 / BRCA2 — Meaning: Genes in which certain inherited variants are associated with elevated breast and ovarian cancer risk.
- Term: Exon — Meaning: A segment retained in mature RNA after intron removal; exons may include coding and noncoding portions.
- Term: Intron — Meaning: A sequence removed from a primary RNA transcript during RNA processing.
- Term: mRNA — Meaning: Messenger RNA that carries information used in protein synthesis.
- Term: cDNA — Meaning: Complementary DNA made from an RNA template; cDNA from mature mRNA generally lacks introns.
- Term: Product-of-nature exception — Meaning: The rule that a naturally occurring product is not patent-eligible merely because it has been discovered or isolated.
- Term: Patent eligibility — Meaning: The §101 threshold inquiry into patentable subject matter and judicial exceptions.
16. Primary Sources and Further Reading
Official U.S. Reports case record — GovInfo https://www.govinfo.gov/app/details/USREPORTS-569/USREPORTS-569-576
Official U.S. Reports PDF — Supreme Court opinion https://www.govinfo.gov/content/pkg/USREPORTS-569/pdf/USREPORTS-569-576.pdf
Cornell Legal Information Institute — full opinion https://www.law.cornell.edu/supremecourt/text/12-398
Supreme Court docket — No. 12-398 https://www.supremecourt.gov/search.aspx?filename=/docketfiles/12-398.htm
35 U.S.C. §101 — Patentable subject matter https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title35-section101&num=0&edition=prelim
17. Final Takeaway
Remember This: Myriad separates a naturally occurring genetic sequence from a DNA molecule created in a non-natural form. Finding and isolating a gene does not, by itself, make the gene patentable; laboratory-created cDNA is generally treated differently because its structure is not naturally occurring in the same form.
Educational case summary only. For a particular patent claim, review the exact claim language, specification, prosecution history, and controlling law.
Related patent research
Mayo v. Prometheus (2012): Diagnostics and laws of nature
Diamond v. Chakrabarty (1980): Patenting engineered organisms
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