Dad, may I have your DNA?

January 26, 2008 10:45 PM

Would it be worthwhile to preserve a sample of my parents' DNA, with their permission, in case I ever need it for genetic testing of myself or my family?

My father may pass soon due to lung cancer. He smoked for many years before quitting 10 years ago. In anticipation of his passing, I'm thinking about all that stuff you would want to do with someone before they go.

I know that for certain kinds of genetic tests, it can be useful to compare someone's DNA against one or both of their parents to determine the heritance of some trait. As I understand it, this can be good to know both for my own health, and for that of any children I may have. I don't know much about exactly when this would be useful, and how often those situations would arise; that's part if what I'm out to find out here, from people who know more about genetic testing than I do.

Is this something that could be useful enough to justify the awkward conversation and the hassle involved? Do these situations arise often? Am I a monster for even thinking about this? Are there places that provide this service?

posted by anonymous to human relations (9 comments total)

You don't need to have an awkward conversation about it. Take a hair from his pillow.
I'm not a scientist, so I don't can't help you on that point. But why not get it just in case. It won't hurt anything. Getting his complete medical history might be even more valuable.
posted by HotPatatta at 11:14 PM on January 26, 2008

And I'm sorry to hear about your father's illness.
posted by HotPatatta at 11:15 PM on January 26, 2008

I don't see the point from a health standpoint. Either you've inherited a given form of a gene from a parent, or you haven't. If you need to know, you can test your own DNA and know for sure. Rather than testing your parents to identify a probablity.

It could be interesting from an intellectual standpont though, but only if you are into that sort of thing.
posted by Good Brain at 11:21 PM on January 26, 2008

To piggyback a bit on this, if one were to get a sample (let's say some hair) how would one preserve it so that it would still be useful in 100 years?

(Also, anonymous: I'm sorry to hear of your situation)
posted by tkolar at 11:25 PM on January 26, 2008

I should add that before DNA testing, knowing the history of illness in your family could helpn identify risk for vaious genetially linked diseases. Now, its less important, though I guess it might provide some insulation from an insurance company using your own generic tests against you.
posted by Good Brain at 11:28 PM on January 26, 2008

Is this something that could be useful enough to justify the awkward conversation and the hassle involved?

Would it really be awkward? I'm sure my parents would happily comply, especially since it's easy to give and could potentially help their child and grandchildren.

Do these situations arise often? Am I a monster for even thinking about this? Are there places that provide this service?

Why on earth would this make you a monster? Does tracing the history of cancer or heart disease in your family make you a monster? Of course not - it just means that you're using the best information available to you. Using genetic tests is just an advanced form of that.

Okay, now for the science. I am not a genetic counselor, and one of those would be able to answer your question much more completely. I do have some background in genetics, but I hope that someone with an even better understanding will come along and correct any errors or omissions in this post.

The screening I'm most familiar with is usually done when someone already is showing symptoms of genetic disease, like developmental problems or mental retardation. When you screen their DNA for copy number changes or SNPs, you will find that a great number of regions differ from the reference genome. Much of this is normal genetic variation within the human population, and trying to figure out which of these regions is the cause of the problem can be tough.

One way to quickly and easily narrow down the search is to run the same tests on the DNA of the parents, who are presumably phenotypically normal. Then, you can skip over all the DNA variants that you find in the normal parents, and focus in on those regions that are new mutations in the child. (this is slightly simplified, but you get the idea).

I presume that you don't have any obvious problems with your health at this point, so it may not be as useful to have your parent's DNA as you think, especially if you're into adulthood and past the age where most serious genetic disorders become apparent.

I'd urge you to get in touch with a genetic counselor or one of the companies that provides genetic testing. They'll likely answer your question even before charging you any money, especially if you say that you may be interested in having tests done in the future.

You might also want to try emailing one of the bloggers (many of whom are MDs) that write on this subject frequently. I'd start with the Gene Sherpa and look through some of the links in his sidebar as well. These people are on the front lines of this revolution in medicine, and as bloggers, are usually happy to educate the public on such matters.
posted by chrisamiller at 11:32 PM on January 26, 2008

Anon: Sorry to hear about you father.

Take a hair from his pillow.

Not real helpful, unless you luck out and get a hair with root attached (they don't fall out that way...) - hair is basically scales, not cells, and contains no useable nuclear DNA.

I wouldn't call you a monster; both my parents would understand / have understood such a request perfectly. As for worthwhile, a genetic screener or counsellor should be able to tell you if it's worthwhile / feasible / cost-effective to take a sample now and store it (the real tricky part) for some nebulous potential future benefit.
posted by Pinback at 12:35 AM on January 27, 2008

Unlikely to be useful. Search yourself for other reasons why you might do this.
posted by Ironmouth at 8:34 AM on January 27, 2008

I'm sorry to hear about your dad. My own father passed away when I was only 10 (gastric cancer) after a 2-year illness.

I happen to work in the life science research tools field after many years behind the research bench (in cancer, by the way), which means that I know a heck of a lot about DNA and how to purify/preserve it. Currently genome-wide association studies are revolutionizing medicine. To top it off there's a controversy over personal 'consumer genomics' such as 23andme and deCODEme offering whole-genome scans to the public, for as little as $998. (Navigenics is another entry in the field, but have not launched their service yet.)

Anyway, as it was previously noted unless you want to study an inherited trait is when having a 2-parent + affected sibling 'trio' is it worthwhile to have genetic samples taken from each, so there isn't much value (to be frank) in your father's genetic material for this purpose.

You could go ahead and collect a saliva sample for one of the above-mentioned services, you can check them out as they are very new. (Recent Wired story covered this very well.) While the jury's out on whether any of these services will be successful, I understand at least deCODEme will allow the downloading of the genotype scan so you would have the 'raw' data.

If you wanted to collect the DNA sample itself it would be as straightforward as using the saliva collection kit and having it purified via a contract laboratory, I don't know offhand who offers that kind of service, it is a lot easier than collecting a blood sample (and non-invasive to boot).

Getting back to my own father, I do not wish for me to have a sample of his DNA even if I had the opportunity to collect a sample back then. For $998 I could get a whole-genome scan of over 1 million HapMap-based SNPs on my own DNA and find out what the current science of genetics has to say on my relative risk for a number of cancers, including both my father's and my mother's haplotypes. And I expect in the future my children will have their own relative risk to measure, from my father through me to them.

I'd also add that although I work for a large commercial vendor of genetic and genomic analysis equipment and consumables, I have elected not to get my genome scanned, because I feel that there are too many privacy and social issues still unresolved. (I.e., will 23andMe keep my genotypes confidential? What if they get taken over?) In addition, the Genetic Information Nondiscrimination Act has been stalled in Congress, and I'd like to wait until the law (and society in general) has had a chance to catch up.
posted by scooterdog at 6:43 PM on January 27, 2008