The brief correctly asserts that merely isolating DNA does not change the DNA from being a “product of nature” and so unpatentable.
New and useful methods of identifying, isolating, extracting, or using genes and genetic information may be patented (subject to the prohibition against patenting abstract ideas), as may nearly any man-made transformation or manipulation of the raw materials of the genome, such as cDNAs. Thus, the patent laws embrace gene replacement therapies, engineered biologic drugs, methods of modifying the properties of plants or generating biofuels, and similar advanced applications of biotechnology. Crossing the threshold of section 101, however, requires something more than identifying and isolating what has always existed in nature, no matter how difficult or useful that discovery may be.
They do try to allow patenting of manipulated DNA, which is overall a valid goal. But I think that they err in claiming that all cDNA is such a manipulated DNA, and so patentable. My belief is that DNA sequences should be patentable only if the sequence itself has been manipulated: that there has been some change from the “wildtype” sequence that occurs in nature. Since cDNA is just a transcription of naturally occurring RNA sequences, it should not be patentable just because it has been transcribed. Otherwise we get into the silly situation where writing down a natural sequence makes a patentable object, because it is now in a different format.
Industrial and medical applications of DNA, RNA, and proteins should be patentable, even if the underlying sequence is a product of nature and not patentable. Inventions should be patentable, but discoveries should not be.
The friend-of-the-court brief does not go quite far enough in removing the ludicrous patentability of genes that is currently practiced by the Patent and Trademark Office. They continue to focus on the chemical nature of the gene and not its information content, thus missing the main point of DNA. One even suspects that they were bending over backwards to retain the patents for friends of theirs (this is the interpretation of their action as being corrupt, rather than simply stupid).