title: Ancestry informative markers clarify the regional admixture variation in the Costa Rican population.
abstract: The genetic structure of Costa Rica's population is complex, both by region and by individual, due to the admixture process that started during the 15th century and historical events thereafter. Previous studies have been done mostly on Amerindian populations and the Central Valley inhabitants using various microsatellites and mitochondrial DNA markers. Here, we study for the first time a random sample from all regions of the country with ancestry informative markers (AIMs) to address the individual and regional admixture proportions. A sample of 160 male individuals was screened for 78 AIMs customized in a GoldenGate platform from Illumina. We observed that this small set of AIMs has the same power of hundreds of microsatellites and thousands of single-nucleotide polymorphisms to evaluate admixture, with the benefit of reducing genotyping costs. This type of investigation is necessary to explore new genetic markers useful for forensic and genetic investigation. Our data showed a mean admixture proportion of 49.2% European (EUR), 37.8% Native American (NAM), and 12.9% African (AFR), with a disproportionate admixture composition by region. In addition, when Chinese (CHB) was included as a fourth component, the proportions changed to 45.6% EUR, 33.5% NAM, 11.7% AFR, and 9.2% CHB. The admixture trend is consistent among all regions (EUR > NAM > AFR), and individual admixture estimates vary broadly in each region. Though we did not find stratification in Costa Rica's population, gene admixture should be evaluated in future genetic studies of Costa Rica, especially for the Caribbean region, as it contains the largest proportion of African ancestry (30.9%).
authors: Universidad de Costa Rica, Centro de Investigación en Biología Celular y Molecular, Universidad de Costa Rica, 2060 San José, Costa Rica.
authors: Rebeca
authors: R
authors: Cámpos-Sanchez
authors: Universidad de Costa Rica, Centro de Investigación en Biología Celular y Molecular, Universidad de Costa Rica, 2060 San José, Costa Rica. AND Universidad de Costa Rica, Escuela de Biología, Universidad de Costa Rica, 2060 San José, Costa Rica.
authors: Henriette
authors: H
authors: Raventós
authors: Universidad de Costa Rica, Escuela de Biología, Universidad de Costa Rica, 2060 San José, Costa Rica.
authors: Ramiro
authors: R
authors: Barrantes
mesh_terms: D044466:Asian People / Q000235:genetics; D044383:Black People / Q000235:genetics; D003364:Costa Rica / Q000453:epidemiology; D004272:DNA, Mitochondrial / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics*; D005838:Genotype; D005843:Geography; D006801:Humans; D007197:Indians, Central American / Q000235:genetics; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D010375:Pedigree; D044465:White People / Q000235:genetics
chemical_list: D004272:DNA, Mitochondrial; D005819:Genetic Markers