Finnish genetic diseases

The research I linked in my previous post brought to mind the question of Finns' excellent genetics. Now that even Wikipedia tells about the Finns' 4000-year-old genetic bottleneck and disease inheritance, I will link here texts about the birth history of this inheritance. When talking about the  history of genetic diseases for typical Finns, we talk about about 40 diseases, which are more common in Finns than in the rest of the world.

The texts  (link) and (link) describe that the origin of these 40 diseases dates back to the time of King Gustav Vasa of Sweden (link).  A small local population in southeastern Finland (a few hundred families, a link, text in Finnish), attracted by the free land promised by Vasa, dispersed over a wide area, establishing small village communities.  You can find more similar descriptions about this topic, but unfortunately only in Finnish.  Readers in Finland can use them.  Unfortunately the text behind the first link, despite of telling right about the age of Finnish disease inheritance, falls into a storytelling mode when describing the older Finnish ethnic history, leading to a contradiction whether the genetic bottle neck causing genetic diseases existed during the first or the latter occurrence.   This underlines how observant reader has to be when noticing incoherences in texts.  The latter text, written by a pioneer of the Finnish genetic research is more informative (remembering Reijo Norio's visionary work).

This southeastern Finnish population was formed during Sweden's third crusade (link) towards Finland, when Sweden and Novgorod divided the lands of the Karelians at the end of the 13th century. In the 16th century, in these new village communities of Gustav Vasa's time, certain alleles leading to disease inheritance were enriched. Although this description of one population of Southeast Finland in the 13th century does not quite tell the whole truth about the events, it describes well enough the course of events on a general level as the population rushed to the north, west and east in the hope of free farmland.

Finns have not lived here for 4000 years, hardly even 2000 years (link).  This is the idea you get today from archaelogists and linguists.  During the last twenty years there has been improvement in the research, yet it is difficult to find sources in English.  On the other hand stories offered on the internet tell about a handful of Finns who lived in Finland 4000 years ago (population size being 3000) is complete bullshit, which is served to an international readership in order to improve the story.  By a google search you can find  hundreds texts descripting the population age of Finns from the Ice Age.  Nothing beats a good story.  

Archaeological finds don't tell about spoken language, but most studies suggest that the migration representing most likely modern Finns came to the Southwestern Finland during the late Roman Iron Age.  This match well with the recent linguist evaluations of the Finnish and Estonian linguists (link).

In the text I linked first you find descriptions of "early settlements" and "late settlements". Late Settlements roughly describes this new settlement area from the time of Gustav Vasa, early settlements is an area that was mainly settled from 200AD to 1200AD by the southwestern Finnish root population. Although Finns have significantly mixed with each other during the 20th century due to economic changes, this phase of settlement history is still very clearly visible in all genetic test results, such as FST, IBD and PCA tests.

More about the topic, Link

More reading, in Finnish, link

Edit Mon 16. Sept. 10 pm.

Two pictures from Reijo Norio's book "Suomi neidon geenit".

In the first picture, CNF-disease carrier distribution over ages. Finnish type (CNF or NPHS1), is an autosomal recessive disease. The disease is most common in Finland, but many patients have been identified in other populations (although the mutation can be different).  I would see it as a genuine mutation that occurred in the Finnish root population. It is not clear if it was born in Finland or did it appear in the population before it arrived in Finland.

The second picture shows the main distribution of genetic diseases in Finland, with the east-west division assumed by the author. How the diseases were chosen for the picture is not clear to me, but I would assume that the distribution reflects the Iron Age, the black dots representing alleles distributed by Sámis and red ones by Finns.