title: Nationwide Genomic Study in Denmark Reveals Remarkable Population Homogeneity.
abstract: Denmark has played a substantial role in the history of Northern Europe. Through a nationwide scientific outreach initiative, we collected genetic and anthropometrical data from ∼800 high school students and used them to elucidate the genetic makeup of the Danish population, as well as to assess polygenic predictions of phenotypic traits in adolescents. We observed remarkable homogeneity across different geographic regions, although we could still detect weak signals of genetic structure reflecting the history of the country. Denmark presented genomic affinity with primarily neighboring countries with overall resemblance of decreasing weight from Britain, Sweden, Norway, Germany, and France. A Polish admixture signal was detected in Zealand and Funen, and our date estimates coincided with historical evidence of Wend settlements in the south of Denmark. We also observed considerably diverse demographic histories among Scandinavian countries, with Denmark having the smallest current effective population size compared to Norway and Sweden. Finally, we found that polygenic prediction of self-reported adolescent height in the population was remarkably accurate (R2= 0.639 ± 0.015). The high homogeneity of the Danish population could render population structure a lesser concern for the upcoming large-scale gene-mapping studies in the country.
authors.affiliation: Bioinformatics Research Centre, Aarhus University, 8000, Denmark Centre for Biocultural History, Aarhus University, 8000, Denmark athanasiadis@birc.au.dk.
authors.forename: Georgios
authors.identifier: http://orcid.org/0000-0002-2927-4035
authors.initials: G
authors.lastname: Athanasiadis
authors.affiliation: Bioinformatics Research Centre, Aarhus University, 8000, Denmark.
authors.forename: Jade Y
authors.initials: JY
authors.lastname: Cheng
authors.affiliation: Bioinformatics Research Centre, Aarhus University, 8000, Denmark Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts 02115.
authors.forename: Bjarni J
authors.initials: BJ
authors.lastname: Vilhjálmsson
authors.affiliation: Tørring Gymnasium, 7160, Denmark.
authors.forename: Frank G
authors.initials: FG
authors.lastname: Jørgensen
authors.affiliation: Department of Biomedicine, Aarhus University, 8000, Denmark Initiative for Integrative Psychiatric Research, Aarhus University, 8000, Denmark Center for Integrative Sequencing, Aarhus University, 8000, Denmark.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Als
authors.affiliation: Dr. E. Martens Research Group of Biological Psychiatry, Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, 5021, Norway Norwegian Centre for Mental Disorders Research, K. G. Jebsen Centre for Psychosis Research, Department of Clinical Science, University of Bergen, 5021, Norway.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Le Hellard
authors.affiliation: Norwegian Centre for Mental Disorders Research, K. G. Jebsen Centre for Psychosis Research, Department of Psychology, University of Oslo, 0424, Norway Norwegian Centre for Mental Disorders Research, K. G. Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital, 0424, Norway.
authors.forename: Thomas
authors.initials: T
authors.lastname: Espeseth
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, 17177, Sweden Department of Genetics, University of North Carolina, Chapel Hill, North Carolina 27599-7264 Department of Psychiatry, University of North Carolina, Chapel Hill, North Carolina 27599-7264.
authors.forename: Patrick F
authors.initials: PF
authors.lastname: Sullivan
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, 17177, Sweden.
authors.forename: Christina M
authors.initials: CM
authors.lastname: Hultman
authors.affiliation: Centre for Biocultural History, Aarhus University, 8000, Denmark Department of Culture and Society, Aarhus University, 8000, Denmark.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Kjærgaard
authors.affiliation: Bioinformatics Research Centre, Aarhus University, 8000, Denmark Centre for Biocultural History, Aarhus University, 8000, Denmark Department of Bioscience, Aarhus University, 8000, Denmark.
authors.forename: Mikkel H
authors.initials: MH
authors.lastname: Schierup
authors.affiliation: Bioinformatics Research Centre, Aarhus University, 8000, Denmark Centre for Biocultural History, Aarhus University, 8000, Denmark.
authors.forename: Thomas
authors.initials: T
authors.lastname: Mailund
mesh_terms: D000293:Adolescent; D000886:Anthropometry; D003710:Demography; D003718:Denmark; D005260:Female; D005828:Genetics, Population; D015894:Genome, Human; D023281:Genomics; D006801:Humans; D008297:Male; D011156:Population Density
keywords: admixture; genetic prediction; human population genetics; polygenic risk score; population structure