title: Brazilian urban population genetic structure reveals a high degree of admixture.
abstract: Advances in genotyping technologies have contributed to a better understanding of human population genetic structure and improved the analysis of association studies. To analyze patterns of human genetic variation in Brazil, we used SNP data from 1129 individuals--138 from the urban population of Sao Paulo, Brazil, and 991 from 11 populations of the HapMap Project. Principal components analysis was performed on the SNPs common to these populations, to identify the composition and the number of SNPs needed to capture the genetic variation of them. Both admixture and local ancestry inference were performed in individuals of the Brazilian sample. Individuals from the Brazilian sample fell between Europeans, Mexicans, and Africans. Brazilians are suggested to have the highest internal genetic variation of sampled populations. Our results indicate, as expected, that the Brazilian sample analyzed descend from Amerindians, African, and/or European ancestors, but intermarriage between individuals of different ethnic origin had an important role in generating the broad genetic variation observed in the present-day population. The data support the notion that the Brazilian population, due to its high degree of admixture, can provide a valuable resource for strategies aiming at using admixture as a tool for mapping complex traits in humans.
authors.affiliation: Laboratory of Genetics and Molecular Cardiology, Heart Institute, Medical School of University of Sao Paulo, Sao Paulo, Brazil. alexandre.pereira@incor.usp.br
authors.forename: Suely R
authors.initials: SR
authors.lastname: Giolo
authors.forename: Júlia M P
authors.initials: JM
authors.lastname: Soler
authors.forename: Steven C
authors.initials: SC
authors.lastname: Greenway
authors.forename: Marcio A A
authors.initials: MA
authors.lastname: Almeida
authors.forename: Mariza
authors.initials: M
authors.lastname: de Andrade
authors.forename: J G
authors.initials: JG
authors.lastname: Seidman
authors.forename: Christine E
authors.initials: CE
authors.lastname: Seidman
authors.forename: José E
authors.initials: JE
authors.lastname: Krieger
authors.forename: Alexandre C
authors.initials: AC
authors.lastname: Pereira
mesh_terms: D044467:American Indian or Alaska Native / Q000235:genetics; D044383:Black People / Q000235:genetics; D001938:Brazil / Q000208:ethnology; D005006:Ethnicity / Q000235:genetics; D040342:Genetic Structures; D014644:Genetic Variation; D005828:Genetics, Population; D060148:HapMap Project; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D025341:Principal Component Analysis; D014505:Urban Population; D044465:White People / Q000235:genetics