The Evolving Law on Written Description of Nucleotide Sequences

The "written description" requirement of U.S. patent law, set forth in 35 USC § 112, requires the patent specification to describe the invention in sufficient detail to demonstrate that the inventors had possession of the subject matter of the claims when the specification was filed. In the field of biotechnology, a number of factors may affect whether a disclosure adequately describes claims drawn to nucleotide sequences, such as the degeneracy of the genetic code, the correlation between a nucleotide sequence and the amino acid sequence it encodes, and homology between genes in the same or different species. The U.S. Court of Appeals for the Federal Circuit has issued several decisions, summarized below, that explain how the written description requirement applies to nucleotide sequence claims. As shown by a recent decision from the Court¹ and a decision from the U.S. Patent Office Board of Patent Appeals and Interferences, ² both discussed below, this area of U.S. patent law is