Discerning the ancestry of European Americans in genetic association studies.

[Visigodo]

A new work posted by RR at Human Biodiversity Forum recently.

Background.

European Americans are often treated as a homogeneous group, but in fact form a structured population due to historical immigration of diverse source populations. Discerning the ancestry of European Americans genotyped in association studies is important in order to prevent false or negative associations due to population stratification and to identify genetic variants whose contibution to disease risk differs across European ancestries.

http://genetics.plosjournals.org/arc...030236.eor.pdf

[Menydh]

We note that Spain occupies an intermediate position between northwest and southeast Europe, while Poland lies close to Sweden and UK, supporting a recent suggestion that the northwest-southeast axis could alternatively be interpreted as a north-southeast axis.

No sh*t, Sherlock. They keep assuming that Northerners belong to a northwestern group, when in fact it is northeasten.

[Visigodo]

Originally Posted by Mynydd

No sh*t, Sherlock. They keep assuming that Northerners belong to a northwestern group, when in fact it is northeasten.

As we discuss before one interesting and surprising thing is that the spanish people studied are Andalusians!!!

And many of them cluster with Swedes, Poles and British, theoretically in the "Northern European" cluster!!!

I think there is still too much work to do with this genome wide SNP markers before to reach or to get a clear idea.

Just have a look at this:

[Menydh]

Originally Posted by Visigodo

As we discuss before one interesting and surprising thing is that the spanish people studied are Andalusians!!!

And many of them cluster with Swedes, Poles and British, theoretically in the "Northern European" cluster!!!

I noticed that the entire "Spanish" sample was said to be from "Southern Spain". But if the samples were taken from Americans who stated their ancestry, how can one even be sure that they are anything of what they claimed to be? One thing that I think that we've all learned through mingling with Americans on internet fora is that their claimed ancestry is the number one internet hoax.

I also noticed that the Italian sample was of about 124, out of which some 45 were from Southern Italy. Which again makes the results somehow odd.

Apart from that, to be sure I would have to see first one Swede bailando por soleares (dancing through soleares), dressed on a vestido de faralaes (a traditional Andalusian women's dress). It surely would be a more reliable test than these SNP tests.

I think there is still too much work to do with this genome wide SNP markers before to reach or to get a clear idea.

I'm not sure if I've quite understood these SNP markers tests. They are a mess.

From what I understood they are based with markers that are subject to environment mutation, and so they offer very different results to y-chromosome and mtdna tests. But this result points to something different, since the mutations occurred in two environment regions as far apart as Andalusia and Sweden should be much more noticeable.

I'm confused.