Suchergebnisse

Background: The geographical distribution of genes plays a key role in genetic epidemiology. The Chilean population has three major stem groups (Native American, European and African). Aim: To estimate the regional rate of American, European and African admixture of the Chilean population. Subjects and Methods: Forty single nucleotide polymorphisms (SNP ́s) which exhibit substantially different frequencies between Amerindian populations (ancestry-informative markers or AIM ́s), were genotyped in a sample of 923 Chilean participants to estimate individual genetic ancestry. Results: The American, European and African individual average admixture estimates for the 15 Chilean Regions were relatively homogeneous and not statistically different. However, higher American components were found in northern and southern Chile and higher European components were found in central Chile. A negative correlation between African admixture and latitude was observed. On the average, American and European genetic contributions were similar and significantly higher than the African contribution. Weighted mean American, European and African genetic contributions of 44.34% ± 3 9%, 51.85% ± 5.44% and 3.81% ± 0 .45%, were estimated. Fifty two percent of subjects harbor African genes. Individuals with Aymara and Mapuche surnames have an American admixture of 58.64% and 68.33%, respectively. Conclusions: Half of the Chilean population harbors African genes. Participants with Aymara and Mapuche surnames had a higher American genetic contribution than the general Chilean population. These results confirm the usefulness of surnames as a first approximation to determine genetic ancestry. ; Fil: Fuentes, Macarena. Universidad de Tarapacá; Chile ; Fil: Pulgar, Iván. Centro de investigaciones del Hombre en el desierto; Chile ; Fil: Gallo, Carla. Universidad de Chile; Chile ; Fil: BortolInI, María CátIra. Universidad Peruana Cayetano Heredia; Perú ; Fil: Quinteros, Samuel Canizales. Institutonacional de Ciencias Médicas y Nutrición "Salvador Zubirán"; México. Universidad Nacional Autónoma de México; México ; Fil: Bedoya, Gabriel. Universidad de Antioquia; Colombia ; Fil: Gonzalez Jose, Rolando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina ; Fil: RuIz LInares, Andrés. University College London; Estados Unidos ; Fil: Rothhammer, FrancIsco. Universidad de Tarapacá; Chile. Universidad de Chile; Chile

Background: The first large-scale genome-wide association study of gallbladder cancer (GBC) recently identified and validated three susceptibility variants in the ABCB1 and ABCB4 genes for individuals of Indian descent. We investigated whether these variants were also associated with GBC risk in Chileans, who show the highest incidence of GBC worldwide, and in Europeans with a low GBC incidence. Methods: This population-based study analysed genotype data from retrospective Chilean case-control (255 cases, 2042 controls) and prospective European cohort (108 cases, 181 controls) samples consistently with the original publication. Results: Our results confirmed the reported associations for Chileans with similar risk effects. Particularly strong associations (per-allele odds ratios close to 2) were observed for Chileans with high Native American (=Mapuche) ancestry. No associations were noticed for Europeans, but the statistical power was low. Conclusion: Taking full advantage of genetic and ethnic differences in GBC risk may improve the efficiency of current prevention programs. ; Federal Ministry of Education & Research (BMBF) 01DN15021 European Union (FP7 Research infrastructures) within the initiative "Biobanking and Biomolecular Research Infrastructure -Large Prospective Cohorts" (Collaborative study "Identification of biomarkers for gallbladder cancer risk prediction Towards personali Germany's Excellence Initiative of Heidelberg University within the program "Mobilitaetsmassnahmen im Rahmen internationaler Forschungskooperationen 2015-16" support program "Stiftungen und Preise" of the Ruprecht-Karls-Universitaet Heidelberg German Research Foundation (DFG) LO 2061/1 Biobank of University of Chile