By Julie Nixon
This week sees the US Supreme Court scheduled to hear an appeal against the previous decision in Association for Molecular Pathology v. Myriad Genetics, that isolated DNA which does not exist alone in nature can be patented. I previously blogged about how diagnostics in personalised medicine could be hindered by owners of gene patents holding a monopoly on sequences and discouraging the development of competing tests. But is the situation worse than we think? Do current US gene patents lay claim to a significant proportion of the human genome based on non-specificity of sequence uniqueness across the genome?
Recently a publication in Genome Medicine has claimed that based on recent court rulings that patents on very short fragments of DNA can give rise to intellectual property rights, these short fragments can match a section of 364 genes in the human genome. The longer the sequence of DNA patented, the more specific it becomes to an individual gene. Patent holders on very short stretches of DNA could lay claim to as much of 84% of the genes in the human genome. But could it be that the authors of this paper have come to their conclusion by misunderstanding the scope and construction of patent claims?
In a response to the article in Genome Medicine, Dr. Chris Holman, an associate professor of law at University of Missouri-Kansas City, found that most gene patent claims are based on the full length gene sequence. The Myriad gene patent litigation includes a patent claim directed to very short sections of the BRCA1 encoding sequence. Dr. Holman says claims of this sort are very rare and it is wrong to assume that the mention of a gene’s DNA sequence in a patent claim is equivalent to the patenting of the gene, which in turn leads to an assumption that any use of or research on any of these genes results in patent infringement. Reading through the patent claim of one of the patents used in the Genome Medicine study revealed the patented short stretch of nucleic acid is actually chemically modified compared to that found in nature. This patented synthetic nucleic acid doesn’t actually match the 84% of genes in the human genome as claimed. The patent claim is much narrower than that.
We should also bear in mind that the Myriad patents were filed in 1995, sometime before the technology that exists today allowed whole genomes to be sequenced cheaply and quickly. The Human Genome Project has shown that certain DNA sequences arise throughout the genome more often than was previously predicted. This does not mean that a patent can allow one short sequence to lay claim to every part of the genome it matches. Rather that such claims are invalid because much of the human genome is now prior art.
Of course innovation in diagnostic testing could still be threatened depending on how wide the courts interpret patent claims.
Meanwhile as we await the Myriad decision, even if the patents in question are ruled in valid, Myriad holds patents on methods of analysing BRCA genes for links to cancer that are outside the scope of the current case. So tests for mutations in the BRCA1 and BRCA2 genes may not become more widely available as hoped.