“Knowledge of the population’s genetic structure is important for understanding where we come from and for identifying genes that underlie diseases,” says one of the leaders of the study, Professor Per Hall from the Department of Medical Epidemiology and Biostatistics at Karolinska Institutet.

The study showed that people from Northern and Southern Sweden are genetically different from each other. However, the genetic change from south to north is gradual, and no strong genetic borders exist within Sweden. In the study, the researchers used more than 350,000 genetic markers called single nucleotide polymorphisms (SNPs) that are distributed across the human genome. More than 1500 people of Swedish origin from different parts of the country were analyzed, and also compared to many neighboring populations.

“Despite close contacts within the Nordic region, the Swedes appeared genetically closer to Germans and British than to Finns”, says Professor Juha Kere from the Department of Biosciences and Nutrition at Karolinska Institutet.

The results also show that local genetic differences are small in Southern Sweden but larger in the North. These differences are a result of population history: in the north, the population has been smaller, which has led to pronounced local differences.

Karolinska Institutet is one of the world’s leading medical universities. It accounts for over 40 per cent of the medical academic research conducted in Sweden and offers the country’s broadest range of education in medicine and health sciences. Since 1901 the Nobel Assembly at Karolinska Institutet has selected the Nobel laureates in Physiology or Medicine.

Publication: ”Swedish population substructure revealed by genome-wide single nucleotide polymorphism data”, Elina Salmela, Tuuli Lappalainen, Jianjun Liu, Pertti Sistonen, Peter M. Andersen, Stefan Schreiber, Marja-Liisa Savontaus, Kamila Czene, Päivi Lahermo, Per Hall & Juha Kere, PLoS ONE 2011 6(2): e16747, doi:10.1371/journal.pone.0016747

Caption: Juha Kere, photo by Ulf Sirborn

For more information, please contact:
Juha Kere, Karolinska Institutet, +46 (0)73 421 3550, juha.kere@ki.se
Päivi Lahermo, University of Helsinki, +358 50 415 1182, paivi.lahermo@helsinki.fi,
Per Hall, Karolinska Institutet, +46 (0)73 396 0590, per.hall@ki.se