In another arena, I’m in a discussion about policies of mandatory collection of DNA from arrested suspects.
There, the claim was made that this would allow calendestine collection of organ donation information and matching of unwilling donors to needy recipients.
Question: would ordinary DNA collection, by itself, be enough to determine organ matching?
You’ll have to define your DNA test a bit more specifically. The PCR or RFLP techniques that are used for ‘DNA profiling’ would normally not provide you with the sort of information needed to match a donor with a recipient.
However, if you are paranoid enough to believe that there is a conspiracy to match your organs to a desperately ill captain of industry somewhere, you will argue that any tissue sample can be diverted for nefarious purposes. Some lab tech shows up and draws three vials of your blood, and then gets capped by an agent of the Trilateral Commission and the blood ends up in a secret volcano lab somewhere.
HLA typing can also be done from a swab of cheek cells, and about 80% of the population secretes blood type antigens into their saliva. So in theory, yes, if you had the opportunity to get a cheek swab or blood draw, you could go a long way toward categorizing someone as a potential donor - but not via the normal law enforcement tests.
What do the folks in the other arena think will happen to the arrestees that have been tagged as potential donors? Assassination? And why aren’t the forces of evil already diverting blood samples from all the hospital labs across the nation (or ARE they?) It’s a much bigger pool of donors.
Well yes, you could determine organ matches through DNA samples, but the question is more of a “when”. Not today that I know of. Knowing the DNA doesn’t necessarily help you (not all DNA turns into proteins) because expression of certain proteins is dependent on both the person and the cell type, as well as many transcription factors (proteins that are required to turn the gene from DNA to RNA which makes proteins). So you would need to know all the transcription factors as well as the sequence that these transcription factors bind to. Are the transcription factors present? Are the binding sites for them present or mutated? What type of expression pattern is seen in the organ?
So yes, it is possible to tell if you’re a potential donor just based on DNA alone, but our ability to assess this is probably 50 years off. As brossa said, the techniques we use (PCR, RFLP, VNTR, Western Blot, ELISA, etc) are very specific and usually specific to a certain gene, as very few techniques we use today are random (RAPD analysis is the only one I can think of). Even knowing the gene doesn’t help all the time though, as it goes back to the transcription factors. But with current DNA Microarray technology (aka Gene Chips), finding a very good match with just your DNA or cDNA may be closer than ever.
You can probably get a good “guess” as to how close a match you have based on DNA and the techniques we have available, but from what I’ve heard (and this is from a patient, not a scientist, so I’ll call it anecdotal) from actual bone marrow donor recipients, a perfect match is actually less desirable, something about the variability improves the immune system…or something. I’m not 100% sure on that.