Characterization Of Danube Swabian Population Samples On A High-Resolution Genome-Wide Basis

Abstract

Background: German-derived ethnicities are one of the largest ethnic groups in Hungary, dating back to the formation of the Kingdom of Hungary, which took place at the beginning of the 11th century. Germans came to Hungary in many waves. The most significant immigration wave took place following the collapse of the Ottoman Empire in East-Central Europe which closed the 150-year long Ottoman occupation. To date, there are no comprehensive genome-wide studies investigating the genetic makeup of the Danube Swabians. Here we analyzed 47 Danube Swabian samples collected from elderly Danube Swabian individuals living in the Dunaszekcső-Bár area, Danube side villages in Southwest Hungary. Based on self-declaration they did not admix with other ethnic groups for 3-6 succeeding generations. Using Illumina Infinium 720K Beadchip genotype data, we applied allele frequency-based and haplotype-based genome-wide marker data analyses to investigate the ancestry and genetic composition of the collected Danube Swabian samples.Results: Haplotype-based analyses like identity by descent and homozygosity by descent analyses show that the investigated Danube Swabians remained isolated from other ethnic groups which was supported by the D-statistics results. According to our results, the investigated Danube Swabian individuals do not possess detectable recent admixture, and our results suggest that their main source of ancestry can be traced back to the region of Germany. Conclusions: This is the first analysis of Danube Swabian population samples based on genome-wide autosomal data. Our results establish the basis for conducting further comprehensive research on Danube Swabians and on other German ethnicities of the Carpathian basin, which can help reconstruct their origin, and identify their major archaic genomic patterns.