title: Heterogeneity in genetic admixture across different regions of Argentina.
abstract: The population of Argentina is the result of the intermixing between several groups, including Indigenous American, European and African populations. Despite the commonly held idea that the population of Argentina is of mostly European origin, multiple studies have shown that this process of admixture had an impact in the entire Argentine population. In the present study we characterized the distribution of Indigenous American, European and African ancestry among individuals from different regions of Argentina and evaluated the level of discrepancy between self-reported grandparental origin and genetic ancestry estimates. A set of 99 autosomal ancestry informative markers (AIMs) was genotyped in a sample of 441 Argentine individuals to estimate genetic ancestry. We used non-parametric tests to evaluate statistical significance. The average ancestry for the Argentine sample overall was 65% European (95%CI: 63-68%), 31% Indigenous American (28-33%) and 4% African (3-4%). We observed statistically significant differences in European ancestry across Argentine regions [Buenos Aires province (BA) 76%, 95%CI: 73-79%; Northeast (NEA) 54%, 95%CI: 49-58%; Northwest (NWA) 33%, 95%CI: 21-41%; South 54%, 95%CI: 49-59%; p<0.0001] as well as between the capital and immediate suburbs of Buenos Aires city compared to more distant suburbs [80% (95%CI: 75-86%) versus 68% (95%CI: 58-77%), p = 0.01]. European ancestry among individuals that declared all grandparents born in Europe was 91% (95%CI: 88-94%) compared to 54% (95%CI: 51-57%) among those with no European grandparents (p<0.001). Our results demonstrate the range of variation in genetic ancestry among Argentine individuals from different regions in the country, highlighting the importance of taking this variation into account in genetic association and admixture mapping studies in this population.
authors.affiliation: Departamento de Antropología, University of Buenos Aires, Buenos Aires, Argentina.
authors.forename: Sergio
authors.initials: S
authors.lastname: Avena
authors.forename: Marc
authors.initials: M
authors.lastname: Via
authors.forename: Elad
authors.initials: E
authors.lastname: Ziv
authors.forename: Eliseo J
authors.initials: EJ
authors.lastname: Pérez-Stable
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Gignoux
authors.forename: Cristina
authors.initials: C
authors.lastname: Dejean
authors.forename: Scott
authors.initials: S
authors.lastname: Huntsman
authors.forename: Gabriela
authors.initials: G
authors.lastname: Torres-Mejía
authors.forename: Julie
authors.initials: J
authors.lastname: Dutil
authors.forename: Jaime L
authors.initials: JL
authors.lastname: Matta
authors.forename: Kenneth
authors.initials: K
authors.lastname: Beckman
authors.forename: Esteban González
authors.initials: EG
authors.lastname: Burchard
authors.forename: María Laura
authors.initials: ML
authors.lastname: Parolin
authors.forename: Alicia
authors.initials: A
authors.lastname: Goicoechea
authors.forename: Noemí
authors.initials: N
authors.lastname: Acreche
authors.forename: Mariel
authors.initials: M
authors.lastname: Boquet
authors.forename: María Del Carmen
authors.initials: Mdel C
authors.lastname: Ríos Part
authors.forename: Vanesa
authors.initials: V
authors.lastname: Fernández
authors.forename: Jorge
authors.initials: J
authors.lastname: Rey
authors.forename: Mariana C
authors.initials: MC
authors.lastname: Stern
authors.forename: Raúl F
authors.initials: RF
authors.lastname: Carnese
authors.forename: Laura
authors.initials: L
authors.lastname: Fejerman
mesh_terms: D001118:Argentina; D002874:Chromosome Mapping / Q000379:methods; D005006:Ethnicity / Q000235:genetics*; D005260:Female; D014644:Genetic Variation; D005828:Genetics, Population / Q000379:methods; D005838:Genotype; D006801:Humans; D008297:Male; D044469:Racial Groups / Q000235:genetics*