Last week, I told you about the US Supreme Court ruling that made it illegal to patent naturally occurring DNA. In that article, I talked briefly about the fact that the new ruling doesn't cover all DNA. It's still perfectly legal to patent synthetic DNA, and the court documents referred specifically to complementary DNA (aka cDNA).
This is where things get murky. Complementary DNA is a thing that can be both natural and synthetic. And, as a laboratory creation, it's an important step in a common method of replicating naturally occurring DNA. All of which leaves some holes in the idea that the Supreme Court ruling is a simple "win" for open-access science, patent activists, and patients. After all, if you can't patent a gene, but you can patent the laboratory copy of the gene, what's that mean? It's sort of like not being able to patent a novel, but being able to patent a copy of its contents that's had all the white space removed. It seems like everybody is a bit confused by this. So I wanted to take a moment to at least clarify what cDNA is and what some people, on different sides of the science/law/biotech divides, are thinking about it.
It starts with some stuff you learned back in junior high — how information from your DNA gets turned into actual working proteins.
DNA, you'll remember, is like a twisted ladder, a double helix. Split the ladder in half, add a few chemical changes, and you get RNA.* This molecule can do many things, but one of the big ones is moving genetic information from DNA to ribosomes, the cellular factories that build proteins. To do that, you need a special kind of RNA, messenger RNA (mRNA). This is basically just a condensed version of your genetic information — half a strand of DNA, but with all the bits that don't build proteins snipped out.
It's sort of like taking
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But scientists have another use for mRNA. If they want to make lots of copies of a specific gene, they can essentially put the mRNA in reverse, using it to create a whole strand of DNA. This lab-created DNA is nearly identical to the stuff that occurs naturally. The only difference is that, like the mRNA, it's lacking all the stuff that doesn't build proteins. And that is what counts as cDNA. Just to clarify, according to the ruling last week, you can't patent the DNA for
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That fact has left a lot of people with a lot of confusion about what this ruling will actually mean in the real world.
At The LA Times, Amina Kahn reported that Myriad Genetics — the company that had claimed a patent on two genes involved in breast cancer risk, and which ostensibly lost at the Supreme Court — actually saw their stock price go up in the wake of the ruling. That could be because a big, profit-affecting question (Can the company patent the genes?) got solved and, now, the company could turn around and patent cDNA versions of the genes. Sure, they lose some of their monopoly on the breast cancer industry, but they still have something special and aren't totally out of the game, financially. In fact, with a Supreme Court ruling in their pocket, Myriad's business model may now be more stable, since what they can and can't do is now more spelled out.
That seems to be a perspective shared by biotech consultant Susan Finston. The ruling, she writes, does open up the market to allow more companies to sell their own tests for breast cancer risk — but it's also not some kind of wide-scale smack down against the biotech industry.
All in all, the Myriad decision should not adversely affect the patentability of a broad swath of gene-based inventions. The ability of a patent applicant to avoid the law of nature exception, i.e, to “create or alter” DNA – whether via cDNA or through use of plasmids – limits the prospective impact of the case.
The opinion said in a footnote, however, that the Court was not actually ruling that cDNA is specifically entitled to a composition patent, and noted that the federal government had raised other objections under patent law to that phenomenon.
In fact, Justice Scalia's wrote a side note saying that he, himself, couldn't make any statements on the science beyond the simple fact that naturally occurring DNA is not something that a company creates, and thus, is not patentable. That's been interpreted by some people (including some of the commenters on the story last week) as an expression of some anti-science "I don't believe in DNA" position. But I'm not sure it is. Denniston, for instance, interprets it as something closer to Scalia saying that has absolutely no idea whether he believes DNA and cDNA should count as different things — he simply doesn't know enough about the science to say. And that's actually a pretty reasonable position to take. Especially when you consider the fact that cDNA can happen in nature, without the help of scientists. HIV, for example, can turn its own RNA into cDNA. That's how it makes copies of itself.
Taken all together, it's safe to assume that this is not the last time the Supreme Court will be talking about the patentability of cDNA. This is not a given yet.
The basic lesson that you should take away seems to be this: The Myriad Genetics ruling is really, really narrow. Yes, it prevents companies from patenting a gene that they just happened to find in the human body (or anyplace else). But it leaves plenty of room to patent genetic information — and it leaves plenty of room for future court battles over what genetic information can and cannot be patented. This is a big court case that only reduced uncertainty a tiny bit.
*Please note that I am simplifying the creation of RNA here. I've edited it to make it more clear that RNA is not simply DNA split in half. There's more to it than that. I hope this will not give people a clear and quick mental picture without being misleading.