The Physics Police

The Physics Police

Friday, June 14, 2013

Supreme Court on DNA

Steven Salzberg has expressed some criticism regarding the recent, mixed ruling of the Supreme Court on the issue of patenting DNA.

He claims that the Syllabus contains numerous factual errors, for example:
The nucleotides that code for amino acids are exons, and those that do not are introns.
Saltzberg says that, on the contrary:
The nucleotides that code for amino acids are contained within the exons, but they are not the same thing.
But, according to the NIH, an exon is:
Coding sequence of DNA present in mature messenger RNA.
I fail to see any difference in these three descriptions. In common parlance, the term exon refers to both the DNA sequence that is excluded from mature RNA, and the RNA that is transcribed but later cut out. The Supreme Court's description seems fine to me.

Saltzberg also takes issue with this quotation from the Syllabus:
...synthetically create exons-only strands of nucleotides known as composite DNA (cDNA). cDNA contains only the exons that occur in DNA, omitting the intervening introns.
He says that this definition is wrong, because:
cDNA stands for complementary DNA, because the DNA produced is the complement of the original strand.
He's got a point. Since 1973, cDNA has been short for complementary DNA, where you start reading from the 3" instead of the 5" end.

But in this court case, we have a NEW term, called "composite DNA". The document defines this term, and uses parenthesis to define a shorthand. It's confusing, but fair!

Of course, I suspect that "composite DNA" is a bullshit term cooked up by Myriad's lawyers to confuse the issue and sound credible.

I think this is the part of the Syllabus that scared people:
cDNA is patent eligible because it is not naturally occurring.
As it happens, you won't find their "composite DNA" in in nature. If such a molecule has application in the medical field (I can't think of any), then a process to manufacture such a molecule is deserving of patent protection.

On the Human Genome Project website, genetic tests are described like this:
... researchers design short pieces of DNA called probes, whose sequences are complementary to the mutated sequences. These probes will seek their complement among the three billion base pairs of an individual's genome. If the mutated sequence is present in the patient's genome, the probe will bind to it and flag the mutation.
This goofy "composite DNA" stuff wouldn't make a good probe, because the patched together sequence of exons won't match the patient's DNA, and so won't bind to it.

But neither Myriad nor any company holds any patent for this (presumably) useless stuff. No test for breast cancer requires licensing of this hypothetical stuff.

This isn't really a mixed verdict at all. Gene patenting is now a thing of the past!

What does this mean for the average person? The cost of genetic tests, like the one for breast cancer, will cost less.

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