I ran across this Genome Medicine paper during the #SCOTUS and #BRCA gene patent discussions back in June, but it’s been sitting in my “to read” pile since. It’s a great resource if you’re curious about how much of the genome is covered by patents, because the answer is actually quite surprising.
Using bioinformatic methods, the authors look at the number of genes covered by patent claims. Many patents claim even very short segments of a gene, like the 15bp segments in the Myriad BRCA patents. But, as anyone who has tried to create nice specific PCR primers knows, most 15bp DNA sequences can be found in multiple places in the genome. How many different places? Drs. Rosenfeld and Mason are glad you asked.
The paper is open access so I recommend skimming through the whole thing. But here are a few interesting tidbits. The most broad claim in the BRCA patent (#5,747,282), the claim on any 15bp seqence from gene, actually also covers 689 (4%) other genes in the human genome. That is, 689 other genes share identical 15bp stretches with BRCA1, and so they are actually covered by the patent as well. How pervasive was this phenomenon of shared “15mers”?
- Every gene in the genome (they used the consensus CCDS) shares 15mers with another gene. The lowest number of matching genes for a 15mer was 5.
- As stated above, BRCA1 matched 689 other genes.
- TTN, granted a very big gene, matched 7,688 (42%) other genes!
- If one considers all sequence, not just coding sequence, then 99.999% of 15mers in the human genome are repeated at least twice.
- 58 current gene patents cover each at least 10% of the bases of human genes
- The “top” patent was US7795422, which alone claims sequences matching 91.5% of all human genes
- And, in a discovery that underscores the absurdity of gene patenting, a patent for improving bovine traits (i.e. a patent on a cow gene) claims sequences matching 84% of human genes.
The authors conclude: These results demonstrated that short patent sequences are extremely non-specific and that a 15mer patent claim from one gene will always ‘cross-match’ and patent a portion of another gene as well.
It’s a great article so have a look: http://genomemedicine.com/content/5/3/27
The plot below is titled: Total matches and average number of other genes patented plotted against k-mer size
