title: Characterization of the biological processes shaping the genetic structure of the Italian population.
abstract: BACKGROUND
  The genetic structure of human populations is the outcome of the combined action of different processes such as demographic dynamics and natural selection. Several efforts toward the characterization of population genetic architectures and the identification of adaptation signatures were recently made. In this study, we provide a genome-wide depiction of the Italian population structure and the analysis of the major determinants of the current existing genetic variation.
  
  
  RESULTS
  We defined and characterized 210 genomic loci associated with the first Principal Component calculated on the Italian genotypic data and correlated to the North-south genetic gradient. Using a gene-enrichment approach we identified the immune function as primarily involved in the Italian population differentiation and we described a locus on chromosome 13 showing combined evidence of North-south diversification in allele frequencies and signs of recent positive selection. In this region our bioinformatics analysis pinpointed an uncharacterized long intergenic non-coding (lincRNA), whose expression appeared specific for immune-related tissues suggesting its relevance for the immune function.
  
  
  CONCLUSIONS
  Our study, combining population genetic analyses with biological insights provides a description of the Italian genetic structure that in future could contribute to the evaluation of complex diseases risk in the population context.
authors.affiliation: Computational Biology Unit, Institute of Molecular Genetics-National Research Council, Pavia, Italy. parolo@igm.cnr.it.
authors.forename: Silvia
authors.initials: S
authors.lastname: Parolo
authors.affiliation: Computational Biology Unit, Institute of Molecular Genetics-National Research Council, Pavia, Italy. lisa@igm.cnr.it.
authors.forename: Antonella
authors.initials: A
authors.lastname: Lisa
authors.affiliation: Molecular Biology Laboratory, Istituto Auxologico Italiano, Milan, Italy. gentilini.davide@gmail.com.
authors.forename: Davide
authors.initials: D
authors.lastname: Gentilini
authors.affiliation: Molecular Biology Laboratory, Istituto Auxologico Italiano, Milan, Italy. a.diblasio@auxologico.it.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Di Blasio
authors.affiliation: Department of Cardiovascular Research, IRCCS Mario Negri Institute for Pharmacological Research, Milan, Italy. simona.barlera@marionegri.it.
authors.forename: Simona
authors.initials: S
authors.lastname: Barlera
authors.affiliation: Department of Cardiovascular Research, IRCCS Mario Negri Institute for Pharmacological Research, Milan, Italy. enrico.nicolis@marionegri.it.
authors.forename: Enrico B
authors.initials: EB
authors.lastname: Nicolis
authors.affiliation: Department of Cerebrovascular Diseases, IRCCS Istituto Neurologico Carlo Besta, Milan, Italy. giorgio.boncoraglio@istituto-besta.it.
authors.forename: Giorgio B
authors.initials: GB
authors.lastname: Boncoraglio
authors.affiliation: Department of Cerebrovascular Diseases, IRCCS Istituto Neurologico Carlo Besta, Milan, Italy. eugenio.parati@istituto-besta.it.
authors.forename: Eugenio A
authors.initials: EA
authors.lastname: Parati
authors.affiliation: Computational Biology Unit, Institute of Molecular Genetics-National Research Council, Pavia, Italy. bione@igm.cnr.it.
authors.forename: Silvia
authors.initials: S
authors.lastname: Bione
mesh_terms: D001686:Biological Phenomena; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics; D063990:Gene Ontology; D056426:Genetic Loci; D005828:Genetics, Population; D015894:Genome, Human; D006801:Humans; D007558:Italy; D025341:Principal Component Analysis; D012641:Selection, Genetic