title: Genetic demography of Antioquia (Colombia) and the Central Valley of Costa Rica.
abstract: We report a comparative genetic characterization of two population isolates with parallel demographic histories: the Central Valley of Costa Rica (CVCR) and Antioquia (in northwest Colombia). The analysis of mtDNA, Y-chromosome and autosomal polymorphisms shows that Antioquia and the CVCR are genetically very similar, indicating that closely related parental populations founded these two isolates. In both populations, the male ancestry is predominantly European, whereas the female ancestry is mostly Amerind. In agreement with their isolation, the Amerindian mtDNA diversity of Antioquia and the CVCR is typical of ethnically-defined native populations and is markedly lower than in other Latin American populations. A comparison of linkage disequilibrium (LD) at 18 marker pairs in Antioquia and the CVCR shows that markers in LD in both populations are located at short genetic distances (<approximately 1 cM), whereas markers separated by greater distances are in LD only in the CVCR. This difference probably reflects stochastic variation of LD at the limited number of genome regions compared. The genetic similarity of the populations from Antioquia and the CVCR together with differences in LD between them should be exploitable for the identification and fine mapping of shared disease-related gene variants.
authors.affiliation: The Galton Laboratory, Department of Biology (Wolfson House), University College London, UK.
authors.forename: Luis G
authors.initials: LG
authors.lastname: Carvajal-Carmona
authors.forename: Roel
authors.initials: R
authors.lastname: Ophoff
authors.forename: Susan
authors.initials: S
authors.lastname: Service
authors.forename: Jaana
authors.initials: J
authors.lastname: Hartiala
authors.forename: Julio
authors.initials: J
authors.lastname: Molina
authors.forename: Pedro
authors.initials: P
authors.lastname: Leon
authors.forename: Jorge
authors.initials: J
authors.lastname: Ospina
authors.forename: Gabriel
authors.initials: G
authors.lastname: Bedoya
authors.forename: Nelson
authors.initials: N
authors.lastname: Freimer
authors.forename: Andrés
authors.initials: A
authors.lastname: Ruiz-Linares
mesh_terms: D003105:Colombia; D003364:Costa Rica; D003710:Demography; D005260:Female; D014644:Genetic Variation; D005828:Genetics, Population; D006801:Humans; D007198:Indians, North American / Q000235:genetics; D015810:Linkage Disequilibrium; D008297:Male