Article

European Journal of Human Genetics (2016) 24, 1056–1062; doi:10.1038/ejhg.2015.233; published online 11 November 2015

The Italian genome reflects the history of Europe and the Mediterranean basin

Giovanni Fiorito1,2, Cornelia Di Gaetano1,2, Simonetta Guarrera1,2, Fabio Rosa2, Marcus W Feldman3, Alberto Piazza1,2 and Giuseppe Matullo1,2

  1. 1Department of Medical Sciences, University of Turin, Turin, Italy
  2. 2HuGeF Human Genetics Foundation, Turin, Italy
  3. 3Department of Biology, Stanford University, Stanford, CA, USA

Correspondence: Professor G Matullo, Department of Medical Sciences, University of Turin, Via Nizza 52, Turin 10026, Italy. Tel: +39 011 6709542; E-mail: giuseppe.matullo@unito.it

Received 27 January 2015; Revised 22 September 2015; Accepted 30 September 2015
Advance online publication 11 November 2015

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Abstract

Recent scientific literature has highlighted the relevance of population genetic studies both for disease association mapping in admixed populations and for understanding the history of human migrations. Deeper insight into the history of the Italian population is critical for understanding the peopling of Europe. Because of its crucial position at the centre of the Mediterranean basin, the Italian peninsula has experienced a complex history of colonization and migration whose genetic signatures are still present in contemporary Italians. In this study, we investigated genomic variation in the Italian population using 2.5 million single-nucleotide polymorphisms in a sample of more than 300 unrelated Italian subjects with well-defined geographical origins. We combined several analytical approaches to interpret genome-wide data on 1272 individuals from European, Middle Eastern, and North African populations. We detected three major ancestral components contributing different proportions across the Italian peninsula, and signatures of continuous gene flow within Italy, which have produced remarkable genetic variability among contemporary Italians. In addition, we have extracted novel details about the Italian population’s ancestry, identifying the genetic signatures of major historical events in Europe and the Mediterranean basin from the Neolithic (e.g., peopling of Sardinia) to recent times (e.g., ‘barbarian invasion’ of Northern and Central Italy). These results are valuable for further genetic, epidemiological and forensic studies in Italy and in Europe.