Genetic characterization of northeastern Italian population isolates in the context of broader European genetic diversity

• Published in: European journal of human genetics : EJHG Vol. 21; no. 6; pp. 659 - 665
• Main Authors: Esko, Tõnu, Mezzavilla, Massimo, Nelis, Mari, Borel, Christelle, Debniak, Tadeusz, Jakkula, Eveliina, Julia, Antonio, Karachanak, Sena, Khrunin, Andrey, Kisfali, Peter, Krulisova, Veronika, Aušrelé Kučinskiené, Zita, Rehnström, Karola, Traglia, Michela, Nikitina-Zake, Liene, Zimprich, Fritz, Antonarakis, Stylianos E, Estivill, Xavier, Glavač, Damjan, Gut, Ivo, Klovins, Janis, Krawczak, Michael, Kučinskas, Vaidutis, Lathrop, Mark, Macek, Milan, Marsal, Sara, Meitinger, Thomas, Melegh, Béla, Limborska, Svetlana, Lubinski, Jan, Paolotie, Aarno, Schreiber, Stefan, Toncheva, Draga, Toniolo, Daniela, Wichmann, H-Erich, Zimprich, Alexander, Metspalu, Mait, Gasparini, Paolo, Metspalu, Andres, D'Adamo, Pio
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01.06.2013
• Subjects: Biology; Cluster Analysis; Data processing; Discriminant analysis; Environmental health; Epidemiology; European Continental Ancestry Group - genetics; Genetic diversity; Genetic isolation; Genetic variance; Genetic Variation; Genetics; Genetics, Population; Genome, Human - genetics; Genomes; Geographical isolation; Geography; Homozygote; Hospitals; Human genetics; Humans; Italy; Life Sciences; Linkage disequilibrium; Linkage Disequilibrium - genetics; Mitochondrial DNA; Models, Genetic; Multiculturalism & pluralism; Polymorphism, Single Nucleotide - genetics; Population; Population genetics; Population studies; Single-nucleotide polymorphism; Territory; Towns; Italy; Germany; Finland; Estonia; Spain; population genetics; isolated population; genetic distance
• ISSN: 1018-4813; 1476-5438
• DOI: 10.1038/ejhg.2012.229

Population genetic studies on European populations have highlighted Italy as one of genetically most diverse regions. This is possibly due to the country's complex demographic history and large variability in terrain throughout the territory. This is the reason why Italy is enriched for population isolates, Sardinia being the best-known example. As the population isolates have a great potential in disease-causing genetic variants identification, we aimed to genetically characterize a region from northeastern Italy, which is known for isolated communities. Total of 1310 samples, collected from six geographically isolated villages, were genotyped at >145000 single-nucleotide polymorphism positions. Newly genotyped data were analyzed jointly with the available genome-wide data sets of individuals of European descent, including several population isolates. Despite the linguistic differences and geographical isolation the village populations still show the greatest genetic similarity to other Italian samples. The genetic isolation and small effective population size of the village populations is manifested by higher levels of genomic homozygosity and elevated linkage disequilibrium. These estimates become even more striking when the detected substructure is taken into account. The observed level of genetic isolation in Friuli-Venezia Giulia region is more extreme according to several measures of isolation compared with Sardinians, French Basques and northern Finns, thus proving the status of an isolate.