Today, in Association for Molecular Pathology v. Myriad Genetics, Inc., the U.S. Supreme Court unanimously ruled that isolated human genes are not patentable, but held that cDNA is patentable, thus affirming in part and reversing in part an earlier Federal Circuit decision (see August Client Alert) which had held both to be patent eligible under 35 U.S.C. §101.

Myriad’s patents included claims directed to isolated nucleotide sequences covering two human genes, BRCA1 and BRCA2, which when mutated are associated with increased risk for developing breast or ovarian cancer. The claims at issue covered the native DNA sequences in isolated form, segments of the native sequences, and cDNA synthesized in the laboratory from the native sequences.

In the decision written by Justice Thomas, the Court ruled that the genes and gene segments isolated by Myriad were naturally occurring DNA and, as a product of nature, were not patent eligible merely because they were isolated. However, the Court ruled that cDNA encoding these genes was patent eligible because it is not naturally occurring. The Court was also careful to mention that methods of obtaining or using naturally occurring sequences may be subject to patent protection and particularly expressed no opinion on whether sequences that have been scientifically altered would be patentable.

The decision is likely to have far-reaching implications for the many gene patents already issued over the past 25 years. It is estimated that around 20 percent of all human genes are patented.