“One Package Fits All” DNA Testing

by Dr. Hsien-Hsien Lei
Posted January 4, 2008 in DNA Testing, Polls About DNA

Mixing genealogy/ancestry genetic testing with medical genetic testing has always seemed tricky to me. My feeling is that most people who are interested in learning more about their family tree tend to be wary of using their DNA to understand their medical history. The target market for the two sides of consumer genetic testing may overlap, but not completely. So, difficulty arises when unexpected results surface from what were supposed to be purely genealogy-based DNA tests.

Last summer, the DYS464 Y-DNA marker was found to be associated with spermatogenic failure and consequently, male infertility. The frequency of the specific AZFc deletion in the DYS464 marker could be as rare as 1 in every 8000 markers and as common as 1 in 1000. According to The Genetic Genealogist, at least six genealogy DNA testing companies offer testing for the DYS464 marker. Customers who have this specific deletion may be shocked to find that they are not the biological father of their children and those who have not become fathers yet, may find that they will never have biological children of their own. How many genetic testing companies disclose the possibility of this unexpected finding from genealogy DNA testing? How many customers even have a clue that they might be in for more than just a link to some distant relative by participating in genealogy DNA testing?

Customers of next-gen personal genomics companies should be aware that they are not only signing up for genealogy DNA testing, but also genetic testing that will give them information on disease risk and propensity for certain physical and physiological characteristics. These next-gen genetic tests are being offered as one package that cannot be bought in parts although deCODEme allows customers to disable disease risk analysis for their account. (Disabling the disease risk analysis doesn’t mean you get a discount on their $985 service, however.)

This week, US News & World Report highlights GeneTree, 23andMe, deCODEme, AfricanDNA, and the Personal Genome Project. The article makes no distinction between genetic testing for genealogy purposes vs medical purposes and misleads the reader into thinking that the focus is on genetic genealogy with the title – A High-Tech Family Tree: New services use DNA to connect relatives and track down ancestors. But it’s hard to blame the reporter for getting confused when companies like 23andMe and deCODEme offer both genealogy DNA testing and what is essentially medical genetic testing (calculating risk of diseases and correlations between genetic markers and disease/physical and physiological characteristics) and yet maintain the stance that the data and analyses customers receive are not to be used for making health care decisions.

The information provided by deCODEme should be used within this informational context, realizing that there are many other factors besides genetics that contribute to disease development of the complex diseases included in deCODEme’s information services. The goal of deCODEme is to empower you by helping you to get to know your genome. If the information provided raises questions or concerns about your health, we recommend you see your doctor and discuss other options of testing or implementation of approved preventive measures.

It’s starting to seem that the many uses of DNA are getting muddled up in people’s minds. Is it possible or desirable to keep different types of results segregated? For example, a customer may not be ready to know if he’s at increased risk of such and such disease, but he might be willing to dip his toes in the water for some fun stuff like seeing if he shares genetic markers with some political despot. Keeping the various types of genetic testing separate is possible but difficult. After all, all genetic testing examines the only set of DNA each of us has and the same stretch of DNA can tell more than one story.

The genetic testing market is still in its infancy. As it develops, it is sure to split off into services catering to each type of customer and the various information levels that are desired. deCODEme is on the right track by allowing their customers to turn off the disease risk prediction function but it would be even better when we’re able to create customized genetic testing packages to suit our individual needs. We may be as unique as our DNA but right now, genetic testing is still one package fits all.

What type of DNA test are you interested in? Take the poll below the fold.

Tags: genetics, genes, dna, genetic testing, genetic genealogy, dna tests, decodeme, 23andme, africandna, genetree

(5 comments)

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5 Comments

Comment by Steven Murphy MD

2008-01-05 00:31:06

a

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Comment by Steven Murphy MD

2008-01-05 00:37:34

Hsien,
Sorry about that. This is precisely why I have been advocating caution here. The same thing has been going on with nutrigenomic SNP testing. There are medically validated SNPs out there that are being used to “customize” vitamins for you. This is running a similar risk. The problem I see is the blurring of this testing with the validated, respected field of medical genetics. I am a physician. I went to medical school for a reason (No I didn’t want 280k in USD debt the hard way) and I have to speak with physicians every day. I would rather they not think that I do genealogic testing. No offense to Blaine. But I would not like these two to be blurred lest I lose the position of being a MEDICAL provider.

-Steve
http://www.thegenesherpa.blogspot.com
http://www.helixhealth.org

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Comment by Hsien-Hsien Lei, PhD

2008-01-07 23:30:31

Steve, If physicians are truly confusing medical genetic testing with genealogy DNA testing, I fear for my health and safety!

(I’ll take the “a” comment to mean that you’ve given this post an A.)

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Comment by Barry Starr

2008-01-07 16:16:49

Great post. I think I like the idea of having a test like deCODE done and just looking at my genealogy for now. As science progresses, I may become more interested in the medical side and will take a peek then. Given how expensive individual genetic tests are, this seems pretty cost effective in the long run. Do these companies let you narrow your results so that you can just see the results for a single condition?

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Comment by Hsien-Hsien Lei, PhD

2008-01-07 23:32:51

Hi Barry, Since I’m not a customer of any of these services, I’m not sure how much tweaking you can do once you’re viewing your data. I think early adopters will want to see it all but later ones might prefer to digest it piecemeal. Also, I think it is currently much more cost effective and informative to take a single or set of genetic tests specific to a condition rather than signing up for a genome scan.

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