Dan MacArthur has a very good post, New York Times adopts medical establishment line on personal genomics:
The NY Times has an article entitled "Buyer beware of home DNA tests" that adopts the paternalistic party line of the medical establishment: taking DNA tests without a doctor's advice is hazardous to your health.
Remarkably, the article acknowledges that qualified genetic counsellors are few and far between and that "most practicing physicians lack the knowledge and training in genetics to interpret [DNA tests] properly", and yet still suggests that customers should "take the findings to a qualified expert".
Begging the question: which qualified expert should customers be taking their test results to? The over-worked genetic counsellor who has enough on their plate dealing with serious genetic conditions without having to worry about a patient with a type 2 diabetes relative risk of 1.17? Or the general practitioner who understands less about modern genetics than the typical DTC genetics customer?
Doctors are bad at using Bayes' Rule. There is no shame in that, it seems a human cognitive bias, but if you're a professional being paid a lot of money it's a different issue altogether.
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This seems as good a place as any to ask: what's your verdict on commercial genealogical DNA test kits? Legitimate or crackpot?
for entertainment purposes only ;-) there are particular cases where it seems useful. e.g., even though Y and mtDNA tests are tracking only one lineage, they seem to offer concrete psychological utils to black americans. i can think of other cases. some have told me i should see if i have the genghis khan haplotype, or, as is much more likely my family just picked up the name as an honorific.
most white americans will simply find out what they already know though.
also, the crackpot part is in the framing and interpretation.
Speaking personally on the geneological side, the autosomal tests are crap unless you're doing 23andMe and even then you need to know what you're doing to get any use out of it. Mitochondrial tests are mostly not very useful (though I did figure out, as mildly suspected, that one of my ancestresses was Norwegian Sami).
Y chromosome is more useful, and actually it's most genealogically useful for white americans of colonial ancestry, because the population expansion means that there's a higher chance of useful blind matches (my father has two blind matches related to him within the past 400 years that we didn't previously know were related). I managed to identify my father's immigrant ancestor despite a 150 year gap in paper trail. We also discovered that an individual who should match us based on his paper trail is actually descended from a different immigrant ancestor - now he gets to figure out where the paper trail went wrong.
Maybe it's ridiculous of me to take offense, but as a GP I certainly can understand and parse out useful information from tests, advise on the difference between relative risk and absolute risk, make sense of a load of numbers, and help people make decisions based on the available information.
I would have thought that's pretty much my job description, so why would you say I (or my colleagues) are not capable of it?
More to the point, I get loads of elderly people (known colloquially as "snowbirds") who winter in your fair country, get sold a load of pseudo-medical "screening" such as full-body CT scans, for which there is absolutely no evidence of benefit and wacks of evidence for harm... who come to me afterwards with a load of nonsense written on a piece of paper for me to interpret. My interpretation is usually, you wasted your money. So selling them "DNA testing"... in your country where they understand science so well they acquitted OJ.
Oh excellent. Gag me.
as is much more likely my family just picked up the name as an honorific.
A Pakistani friend of mine apparently regards a Khan patronym as a marker of direct or indirect Pathan (Pashtoun) ethnicity. I almost bought it (lots of anecdotal evidence) until now.