Genetic testing for racial mix

General Questions
#1

Quick question. I have a friend who is interested in finding out what “race” (I know, I know) she is.

She looks well, like anything…from Native American to Middle Eastern and everything in-between depending on how you look at her and how much sun she’s had.

Grew up in foster care, no parents, no family and being “human”, isn’t enough…

She’s interested in trying DNA TESTING, is the science any good? A waste of time?

Opinions welcomed, on the science only please, I can’t speak for her moviations…

as always, thanks.

#2

I work at a place that does genetic testing for parentage, so I asked the doctor if the DNA testing could tell what race someone is, and he says “not for sure”. Hope that’s helpful.

#3

There are a number of genetic characteristics that have a high correlation to various ethnic groups (and a very few characteristics that are nearly exclusive to a few ethnic groups). This means that some genes (alleles) will establish a greater or lesser probability of one’s membership in some group or another.

If your friend was a male descended from pre-Columbian Americans, there would be about a 50% chance (iirc) that there was a specific C-T switch on the Y chromosome which would guarantee that there was some Indian ancestry.
Similarly, if one’s mtDNA matches one of the various “daughters of Eve” that have been catalogued by region, one might be able to associate one’s ancestry with a particular region. (This can be tricky, however, the is a family in Bristol, England who can trace their lineage back before the Crusades who carries an mtDNA marker that is associated with Africa. Speculation is that the marker came into Britain with the Romans.)

The labs probably (I hope) make a good faith effort to match up haplotypes or something from commonly recognized pools, but I would have to wonder how much energy (and money) they invest in keeping their databases as up to date as possible and how much effort and time they invest in the analysis. DNA testing is still laborious and expensive. Anyone who is doing this sort of testing for dozens, or even hundreds, of dollars is probably not doing exhaustive quality control.

#4

Hmmm. I work in a clinical genetics lab, just FYI. I’ve never heard of these people, and, while their site doesn’t scream “SCAM!” at me, there are one or two things that kind of make me wonder. Firstly, nowhere on their site that I saw did they say exactly what kind of test they’re doing - is it sequencing? PCR? Southern blotting? I only skimmed a few of their pages, so if it’s there, I’m wrong.

Secondly, there’s an occasional misspelling and the mouseovers don’t work very well, which could just be the fault of their web guy. But I tend to be wary of companies with poorly-put-together websites.

Finally, they claim to test all 23 pairs of chromosomes, but they only charge $219, which is ridiculously low, in my experience. We charge at least that much in our lab for our cheapest one-mutation tests. Usually more. If we were going to look at at least 23 loci at once, our price would easily be in the thousands.

So, though I’m not saying definitely don’t do it, I’d do some more research into this company before giving them any of my money.

#5

Unfortunately, she’s a she…

If a person is racially mixed, you want to look at both the maternal lines (thru mtDNA, which you get excusively from your mother) and paternal lines (thru the Y chromosome, which you get exclusively from your father). She might want to ask her father or brother (if she has one) to furnish the Y chromosome part.