The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

The Genetic Structure of the Swedish Population

På svenska

Author

  • Keith Humphreys
  • Alexander Grankvist
  • Monica Leu
  • Per Hall
  • Jianjun Liu
  • Samuli Ripatti
  • Karola Rehnstroem
  • Leif Groop
  • Lars Klareskog
  • Bo Ding
  • Henrik Gronberg
  • Jianfeng Xu
  • Nancy L. Pedersen
  • Paul Lichtenstein
  • Morten Mattingsdal
  • Ole A. Andreassen
  • Colm O'Dushlaine
  • Shaun M. Purcell
  • Pamela Sklar
  • Patrick F. Sullivan
  • Christina M. Hultman
  • Juni Palmgren
  • Patrik K. E. Magnusson
Show all

Summary, in English

Patterns of genetic diversity have previously been shown to mirror geography on a global scale and within continents and individual countries. Using genome-wide SNP data on 5174 Swedes with extensive geographical coverage, we analyzed the genetic structure of the Swedish population. We observed strong differences between the far northern counties and the remaining counties. The population of Dalarna county, in north middle Sweden, which borders southern Norway, also appears to differ markedly from other counties, possibly due to this county having more individuals with remote Finnish or Norwegian ancestry than other counties. An analysis of genetic differentiation (based on pairwise F-st) indicated that the population of Sweden's southernmost counties are genetically closer to the HapMap CEU samples of Northern European ancestry than to the populations of Sweden's northernmost counties. In a comparison of extended homozygous segments, we detected a clear divide between southern and northern Sweden with small differences between the southern counties and considerably more segments in northern Sweden. Both the increased degree of homozygosity in the north and the large genetic differences between the south and the north may have arisen due to a small population in the north and the vast geographical distances between towns and villages in the north, in contrast to the more densely settled southern parts of Sweden. Our findings have implications for future genome-wide association studies (GWAS) with respect to the matching of cases and controls and the need for within-county matching. We have shown that genetic differences within a single country may be substantial, even when viewed on a European scale. Thus, population stratification needs to be accounted for, even within a country like Sweden, which is often perceived to be relatively homogenous and a favourable resource for genetic mapping, otherwise inferences based on genetic data may lead to false conclusions.

Publishing year

2011

Language

English

Publication/Series

PLoS ONE

Volume

6

Issue

8

Document type

Journal article

Publisher

Public Library of Science (PLoS)

Topic

  • Endocrinology and Diabetes

Status

Published

Research group

  • Genomics, Diabetes and Endocrinology

ISBN/ISSN/Other

  • ISSN: 1932-6203